Medium voltage switchgears

Types of bays

The switchgear may be composed of various functional units:

• feeder bays with a circuit breaker and with optional voltage measurement,
• transverse bus coupler bay,
• longitudinal, double cubicle bus coupler bay with a circuit breaker and sectionalizer,
• metering bay,
• feeder bay with switch disconnector.

The withdrawable module of the switchgear may be equipped with a circuit breaker, contactor, sectionalizer, set of fused voltage transformers. It may be placed in the positions of: service, test/disconnection and separation.

Characteristics and advantages

Main advantages

• visual inspection of the state of switches - disconnectors, circuit breaker and earthing switch
• doors in the rear of the switchgear - excellent access to cables and instrument transformers
• removable inspection plates - easy access to disconnectors
• advanced gas blow-out system - specially designed pressure relief duct discharges pressure from inside the bay
• optional gas exhausting duct - discharges gases outside of the switching room
• remote control - optional electrical drives for all switches
• possibility of equipping with current and voltage sensors
• bay with a fused switch disconnector - auxiliary transformer feeder

Characteristic features

• air insulated,
• frame-less, self-supporting design constructed with zinc-coated riveted steel sheets,
• double busbar system,
• IAC AFLR internal arc classification,
• interlocks and protections against performing incorrect switching operations,
• free-standing with access to cable connections from the rear of the cabinet,
• ease of operation,
• versions with manual drives or electrical drives of main switches and withdrawable module are available, depending on requirements and configuration of switchgear bays,
• high operational safety.

The switchgear is designed in a manner that ensures that normal operation, inspections and maintenance operations may be performed in a safe manner.

High operational safety is achieved through:

• internal arc resistance of the switchgear enclosure,
• interlocks between switching operations and opening of doors,
• racking the withdrawable module with doors closed,
• controlling the switches remotely or locally,
• the use of internal compartments and partitions,
• the possibility of visual control of switching operations through inspection windows,
• bay voltage indication system.

Basic technical data

Compliance with standards:

The RELF 2S type switchgear meets the requirements of the following standards:

• (PN-EN) IEC 62271-1 - “High-voltage switchgear and controlgear. Common specifications”,
• (PN-EN) IEC 62271-200 - “High-voltage switchgear and controlgear. AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV”,

The switchgear is certified by appropriate accredited bodies.

Design

The RELF 2S switchgear bay is designed as a cubicle with separate functional compartments:

Functional compartments of a feeder bay with circuit breaker:

1. busbar compartment of system I
2. busbar compartment of system II
3. disconnector compartment of system I
4. disconnector compartment of system II
5. internal pressure relief and blow-out duct
6. auxiliary circuits LV compartment
7. main device compartment
8. cable compartment
9. gas exhausting duct (optional)

Other types of bays on arrangement with the manufacturer.
Bay equipment may be adapted to special requirements on arrangement with the manufacturer.

Characteristics

The Rotoblok type switchgear is a two compartment, indoors switchgear in metal enclosure made of zinc-coated metal sheet (which ensures equipotential bonding), with a single primary busbars system. The switchgear is equipped with state-of-the-art, air insulated switching devices. It has separate primary busbars and cable compartments, and the arc-proof design ensures high level of operational safety.

The distribution bays have the following properties:

• small external dimensions compared to rated voltage, defined insulation levels, primary busbar rated currents and short-circuit currents,
• two-compartment bay ensuring the separation of the primary busbar circuit from the section used to connect power supply cables,
• high reliability of operation,
• long operating period without the need for troublesome maintenance operations,
• high corrosion resistance, the switchgear design uses metal sheet which has been zinc-coated for corrosion protection,
• universality in designing different switchgear configurations with any number of bays,
• use of state of the art, reliable switching devices, such as GTR type disconnectors and switch disconnectors (ZPUE), or circuit breakers by other manufacturers,
• adapted for the installation of state of the art protection and control devices,
• the possibility of wall-mounting of the switchgear, saving space in the switching room, which is particularly important during retrofits and expansions of existing switching stations,
• easy and quick access to switchgear devices for supervision and maintenance,
• simple operation.

System of interlocks and protections

A system of interlocks prevents incorrect switching operations and opening of the distribution bay doors before voltage is disconnected and the earthing switch is closed. Opening of the earthing switch is possible only when the bay doors are closed (or after the interlock is purposefully released with a special key provided with the switchgear - for example in order to perform a voltage test of a cable). Each feeder bay and circuit breaker bay is equipped as standard with capacitive voltage dividers on each phase and a voltage indicator. Such a solution facilitates checking the cable for lack of voltage and safe phase testing with a phase comparator.

At the customer's request it is possible to provide capacitive voltage dividers in bays which do not have them as standard.

High safety of operation, achieved by:

• arc-proof design - resistance to internal arcing effects,
• specially reinforced bay design (enclosures, locks, hinges),
• mechanical interlocks, which prevent incorrect switching operations and touching live devices,
• access to controlgear and control circuits is possible while the primary circuits parts cannot be touched by the operator,
• the use of monitoring and signalling systems, and mechanical and electrical position indicators, and inspection windows,
• visual indicator of disconnector contacts, switch-disconnector and earthing switch state, and installing of inspection windows to control them,
• possibility of disconnecting the switch disconnector without an operating lever (optional - GTR 2, GTR 2V),
• the use of visible double gap disconnectors and switch disconnectors,
• forcing the sequence of switching operations.

Basic technical data

Compliance with standards:

The Rotoblok type switchgear meets the requirements of the following standards:

• PN-EN62271-1 - “High-voltage switchgear and controlgear. Common specifications”,
• PN-EN 62271-200 - “High-voltage switchgear and controlgear. AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV”,
• PN-EN 62271-100 - “High-voltage switchgear and controlgear. Alternating-current circuit-breakers”,
• PN-EN 62271-102 - “High-voltage switchgear and controlgear. Alternating current disconnectors and earthing switches”,
• PN-EN 62271-103 - “High-voltage switchgear and controlgear. Switches for rated voltages above 1 kV up to and including 52 kV”,
• PN-EN 62271-105 - “High-voltage switchgear and controlgear. Alternating current switch-fuse combinations”.

The switchgear is certified by the Electrotechnical Institute.

In case of transformers with higher powers please contact the switchgear manufacturer.
In Rotoblok type switchgear typical fuse links are used acc. to the IEC 282-1, DIN 43625 standard, with thermal protection.

Construction of switchgear type Rotoblok

The design of each bay includes elements constructed with zinc-coated metal sheet, and bolted or riveted together. The construction of each bay ensures the possibility of easy assembly in any switchgear unit, and also rapid disassembly (e.g. in order to carry single bays into the station) and custom reconfiguration. Each bay may be constructed wider than its standard dimension. This solution is used when replacing older large size switchgears (e.g. Rue, M20) with a Rotoblok switchgear, when problems may occur with shifting the old cables to a new attachment point.

Each bay has two compartments, that is, the frame and the main disconnector shaft form a mechanical and electrical partition between the lower part of the switchgear and the primary busbar circuit. After opening the bay doors touching the primary busbar circuit is impossible. Each bay is equipped with a lower earthing switch (in a transformer bay it is installed under the fuse bases).

Each bay has a system of mechanical interlocks, which fulfils two primary tasks:

• prevents opening the door of any compartment before its power supply is switched off and the earthing switch is closed; therefore it prevents electric shock,
• forces the proper sequence of the switching operations.

Capacitive voltage dividers used in the bays allow checking for lack of voltage, and safe phase testing from the front side of the bay, in a safe manner, using a LV bipolar indicator without needing to open the bay doors. Additionally, inspection windows installed in the doors allow the observation of each element in the bay, for example: open circuits, condition of transformers, chambers, connections, etc.

An auxiliary circuits compartment is located at the top of the circuit breaker bay, used to install such elements as: terminal strips, relays, batteries, additional (or primary) protection modules, etc.

Switching devices

Switching devices

The main devices used in the aforementioned bays include:

• GTR1, GTR 2, GTR 2V type switch disconnectors (ZPUE)
• GTR 4, GTR 4W type disconnectors (ZPUE)
• circuit breakers by leading manufacturers

View of the GTR 1 switch disconnector in the “on” position

1 - galvanized steel frame
2,3 - resin insulators
4 - fixed contacts
5 - primary isolating shaft
6 - mobile contacts
7 - arc-quenching contact
8 - lower grounding switch
9 - grounding switch contact
10 - switch disconnector socket
11 - grounding switch socket
12 - switch disconnector position indicator
13 - voltage indicator
14 - grounding switch position indicator
15 - door interlock leaver

View of the GTR 2V switch disconnector in the “on” position

1 - zinc-coated steel frame
2,3 - resin insulators
4 - fixed contacts
5 - main insulating shaft
6 - moving contacts
7 - arcing moving contact
8 - lower earthing switch
9 - earthing switch contact
10 - charging socket and charging indicator
11 - “on”/“off” switch
12 - earthing switch socket
13 - switch disconnector position indicator
14 - voltage indicator
15 - earthing switch position indicator
16 - door interlock lever
17 - fuse link position indicator
18 - fuse base
19 - fuse link
20 - post insulator or capacitive voltage divider

Line feederwith manual drive

Line feederwith manual drive

Electrical diagram

Front view

Inside front view

Inside side view

* Rotoblok 17,5 kV switchgear depth

 

Standard equipment
	Device name	Type	Amount
1.	Switch disconnector with a lower earthing switch	GTR 1 or GTR 2	1
2.	Busbar circuit	P 40x5 / P 40x10	3
3.	Capacitive voltage divider		3
4.	Cable clamp	UKZ	3
5.	Cable termination		3
6.	Cable		3
7.	Neon voltage indicator operating with the capacitive voltage divider		1
8.	Switch disconnector socket (for GTR 1)		1
9.	Charging socket and indicator (for GTR 2)		1
10.	“On”/“off” switch (for GTR 2)		1
11.	Earthing switch socket		1
12.	Inspection window		1
13.	Window which allows the use of a torch to check the position of contacts in case of a lighting failure		3
14.	Warning plate		1
15.	Door handle		1

 

Additional equipment at the customer's request
a	Short-circuit current indicator attached by cable	1
b	Short-circuit current indicator attached by busbar	3

Line feeder with motor drive

Line feeder with motor drive

Electrical diagram

Front view

Inside front view

Inside side view

* Rotoblok 17,5 kV switchgear depth

Standard equipment
	Device name	Type	Amount
1.	Switch disconnector with a lower earthing switch and motor drive adapted for remote control via cables or via radio	GTR 1M or GTR 2M	1
2.	Busbar circuit	P 40x5 / P 40x10	3
3.	Capacitive voltage divider		3
4.	Cable clamp	UKZ	3
5.	Cable termination		3
6.	Cable		3
7.	Neon voltage indicator operating with the capacitive voltage divider		1
8.	Switch disconnector socket (for GTR 1M)		1
9.	Charging socket and indicator (for GTR 2M)		1
10.	“On”/“off” switch (for GTR 2M)		1
11.	Earthing switch socket		1
12.	Inspection window		1
13.	Window which allows the use of a torch to check the position of contacts in case of a lighting failure		3
14.	Warning plate		1
15.	Door handle		1
16.	Control panel for motor drive		1
17.	“Close” button		1
18.	“Open” button		1
19.	Operation mode selection switch		1
20.	Auxiliary circuits compartment		1

Additional equipment at the customer's request
a	Short-circuit current indicator attached by cable	1
b	Short-circuit current indicator attached by busbar	3

Transformer feeder design

Transformer feeder design

Electrical diagram

Front view

Inside front view

Inside side view

* Rotoblok 17,5 kV switchgear depth

Standard equipment
	Device name	Type	Amount
1.	Fuse switch disconnector with earthing switch	GTR 2V	1
2.	Busbar circuit	P 40x5 / P 40x10	3
3.	Post insulator		3
4.	Cable clamp	UKZ	3
5.	Cable termination		3
6.	Cable		3
7.	Charging socket and indicator		1
8.	“On”/“off” switch		1
9.	Earthing switch socket		1
10.	Inspection window		1
11.	Window which allows the use of a torch to check the position of contacts in case of a lighting failure		3
12.	Warning plate		1
13.	Door handle		1
14.	Fuse base which forms an integral part of the switch disconnector		1
15.	Fuse link		1

Additional equipment at the customer's request
a	Fuse switch disconnector with earthing switch and motor drive	GTR 2VM	1
b	Capacitive voltage divider		3
c	Neon voltage indicator operating with the capacitive voltage divider		1
d	Tripping coil		1
e	Gland for cable entry with the use of a tripping coil		1
Note! The earthing switch in the switch disconnector earths the lower part of the fuse link.

Tripping coil operation in a transformer bay with gas-flow protection or thermal protection of the transformer

Tripping coil operation in a transformer bay with gas-flow protection or thermal protection of the transformer

Note!
Cable cross-section and protection currents should be selected according to the tripping coil supply voltage.

Bus coupler unit design

Bus coupler unit design

Electrical diagram

Front view

Inside front view

Inside side view

* Rotoblok 17,5 kV switchgear depth

Standard equipment
	Device name	Type	Amount
1.	Disconnector with a lower earthing switch	GTR 4	1
2.	Busbar circuit	P 40x5 / P 40x10	3
3.	Post insulator or capacitive voltage divider		3
4.	Neon voltage indicator operating with the capacitive voltage divider		1
5.	Disconnector socket		1
6.	Earthing switch socket		1
7.	Inspection window		1
8.	Window which allows the use of a torch to check the position of contacts in case of a lighting failure		3
9.	Warning plate		1
10.	Door handle		1

Additional equipment at the customer's request
a	Switch disconnector with a lower earthing switch	GTR 2	1
b	Switch disconnector with a lower earthing switch and motor drive	GTR 1M or GTR 2M	1
Note! The construction of a bus coupler bay without a lower earthing switch is possible

Desing of transformer feeder type RWT

Desing of transformer feeder type RWT

Electrical diagram

Front view

Inside front view

Inside side view

Standard equipment
	Device name	Type	Amount
1.	Circuit breaker		1
2.	Disconnector with a lower earthing switch	GTR 4	1
3.	Busbar circuit	P 40x5 / P 40x10	3
4.	Capacitive voltage divider		3
5.	Cable clamp	UKZ	3
6.	Cable termination		3
7.	Cable		3
8.	Current transformer operating with the protection system	IP 24 / PP-20W / PP-15W	3
9.	Protection system	Mupasz / REF MiCOM	1
10.	Neon voltage indicator operating with the capacitive voltage divider		1
11.	Disconnector socket		1
12.	Earthing switch socket		1
13.	Inspection window		1
14.	Window which allows the use of a torch to check the position of contacts in case of a lighting failure		1
15.	Warning plate		1
16.	Door handle		1
17.	Auxiliary circuits compartment		1
18.	Charging socket		1
19.	“ON” button		1
20.	“OFF” button		1
21.	Charging indication		1
23.	Control switches and lamps		1
24.	Cable tray		1
25.	Load-bearing frame		1

Desing of bus cupler unit type RWS

Desing of bus cupler unit type RWS

Electrical diagram

Front view

Inside front view

Inside side view

Standard equipment
	Unit	Type	Amount
1.	Circuit breaker		1
2.	Disconnector with a lower earthing switch	GTR 4	1
3.	Busbar circuit	P 40x5 / P 40x10	3
4.	Capacitive voltage divider		3
8.	Current transformer operating with the protection system	IP 24 / PP-20W / PP-15W	3
9.	Protection system	Mupasz / REF MiCOM	1
10.	Neon voltage indicator operating with the capacitive voltage divider		1
11.	Disconnector socket		1
12.	Earthing switch socket		1
13.	Inspection window		1
14.	Window which allows the use of a torch to check the position of contacts in case of a lighting failure		1
15.	Warning plate		1
16.	Door handle		1
17.	Auxiliary circuits compartment		1
18.	Charging socket		1
19.	„ON” button		1
20.	„OFF” button		1
21.	Charging indication		1
23.	Control switches and lamps		1
24.	Cable tray		1
25.	Load-bearing frame		1
26.	Insulating bushing		1

Control circuits panel: “auxiliary circuits compartment”

Control circuits panel: “auxiliary circuits compartment”

The auxiliary circuits compartment (17) contains control strips, protection units, control & metering devices and buttons. Based on documentation provided by the customer, the manufacturer determines the position of the auxiliary circuit devices in the switchgear. Auxiliary circuit leads and cables are placed in the compartment in cable trays, and exit the compartment through glands. The auxiliary circuits in the remaining compartments run in protection tubes. The bypass circuits between adjacent bays run in trays. It is recommended that auxiliary circuit cables are run from individual distribution bays to the control room in a cable duct or on cable ladders installed on the walls.

Construction method for a cable duct under the Rotoblok type MV switchgears

Construction method for a cable duct under the Rotoblok type MV switchgears

Figures 1, 2, 3 present a cable duct construction proposal. The cable bending radius (which depends on its outside diameter, according to PBUE) should taken into account when establishing the dry and oil cables duct depth. It is possible to avoid or reduce the depth of the cable duct by using a raised base or a raised floor.

Fig. 1 Top view - version with a common duct along the Rotoblok switchgear

 
 

Note!: Minimum distance from the wall 30 mm
1) Example bays with a width of 700, 700, 900 mm (respectively, from the left)
2) Duct under the switchgear.

Fig. 2 Top view - version with separate outgoing feeders and cable entries at the rear of the Rotoblok switchgear

* - Rotoblok 17,5 kV switchgear depth

Note!: Minimum distance from the wall 30 mm
1) Example bays with a width of 1000, 900 mm (respectively, from the left)
2) Duct under the switchgear.

Fig. 3 Side view

Dry single-core cable

Cable cross-section (mm2)	Bending radius (mm)	Duct depth K (mm)
50	370	400
70	400	430
95	440	470
120	470	500
150	500	550
185	540	600
240	590	700

Rotoblok switchgear cable connections

Rotoblok switchgear cable connections

Switch disconnector and circuit breaker feeder bays
Cable type	Cable termination
	Manufacturer	Type		Cable cross-section [mm2]
Single core, with plastic insulation e.g. YHAKXs, YHKX, XUHAKXs, XRUHKs, ...	CELLPACK	CHE-I 24kV		25-150
				70-240
		CAE-I 24kV		35-120
				70-240
		CAESK-I 24kV		70-150
				120-240
	Nexans (EUROMOLD)	ITK224 (stretch sleeve)		25-240
		AIP20 (slip-on)		25-120
		AIS20 (slip-on)		70-300
		AIN20 (slip-on)		25-1200
		24MONOi1 (shrink sleeve)		25-240
	TYCO ELECTRONIC	Rated voltage	Typ (stretch sleeve)
		6/10	POLT-12xxx	25-1200
		8,7/15 i 12/20	POLT-24xxx	25-800
		18/30	POLT-42xxx	35-800

^*) Note: The manufacturer should be consulted regarding the manner of connection of cables and used terminations

Transformer bays
Single core, with plastic insulation e.g. YHAKXs, YHKX, XUHAKXs, XRUHKs, ...	As in feeder bays
Tri-core oil-filled with paper insulation saturated with non-running saturant and common coating, e.g.: HAKnFta, KnY, KnFTA, ...	The manufacturer should be consulted regarding the manner of connection of cables and used terminations

Note:
In all cases a cable duct is required under the switchgears. As an option, the switchgear may be placed on a raised base or on a raised floor. In case other type of terminations is used, please contact the manufacturer.

Various types of Rotoblok switchgear units

Side view of a circuit breaker or switch disconnector bay

Side view of an MV circuit breaker bay

Side view of a switchgear with a busbar bridge combining two sections placed on opposite sides of a corridor - example solution

* - Rotoblok switchgear 17,5 kV depth

Note:
Figures shown on subsequent pages are only an example of bay equipment. It is possible to adapt the bay configuration to specific requirements of the end user. In this case manufacturer should be asked to provide drawings.

RL1 (line feeder)

RL1 (line feeder)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RL4 (line feeder with metering)

RL4 (line feeder with metering)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RT1 (transformer feeder)

RT1 (transformer feeder)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RS1L¹⁾ (bus coupler unit with disconnector or switch disconnector on the left side)

RS1L¹⁾ (bus coupler unit with disconnector or switch disconnector on the left side)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RS4 (bus coupler unit with disconnector or switch disconnector on the left side)

RS4 (bus coupler unit with disconnector or switch disconnector on the left side)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RP1 (metering unit)

RP1 (metering unit)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RO1 (lightning arrester unit)

RO1 (lightning arrester unit)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram.
1) It is possible to design the unit in mirrored version
2) It is possible to design the bus coupler unit without a lower earthing switch

RŁ2 (Incoming cable-connection feeder)

RŁ2 (Incoming cable-connection feeder)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

Rtpwł4 (auxiliary transformer unit)

Rtpwł4 (auxiliary transformer unit)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

RTpwł 25kVA + RT1 (auxiliary transformer unit - max. power 25 kVA)

RTpwł 25kVA + RT1 (auxiliary transformer unit - max. power 25 kVA)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

RWT (circuit breaker transformer bay)

RWT (circuit breaker transformer bay)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

RWT3 (circuit breaker transformer feeder)

RWT3 (circuit breaker transformer feeder)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

RWTp14 (circuit breaker transformer feeder with voltage measurement)

RWTp14 (circuit breaker transformer feeder with voltage measurement)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

RWS (bus coupler unit with with disconnectors and circuit breaker)

RWS (bus coupler unit with with disconnectors and circuit breaker)

Electrical diagram

Cross-section Front view

Note:
Optional equipment was marked with red on the electrical diagram

Characteristics

The Rotoblok SF type switchgear is a two compartment, indoors air insulated switchgear (AIS) in a mental enclosure made of zinccoated metal sheet (which ensures equipotential bonding), with a single primary busbars system. The switchgear is equipped with state-of-the-art, three-position disconnectors and switch disconnectors in SF₆ insulation.

The tank of each of these devices is constructed with stainless steel, which ensures maintaining a perfect technological condition of the switchgear over its entire operation period. It has separate primary busbars and cable compartments, and the arc-proof design ensures high level of operational safety.

The distribution bays have the following properties:

• reduced dimensions compared to air insulated switchgear while maintaining high electrical parameters such as insulation level, rated currents and short-circuit current resistance,
• two-compartment bay ensuring the separation of the primary busbar circuit from the section used to connect power supply cables,
• high reliability of operation,
• long operating period without the need for troublesome maintenance operations,
• high corrosion resistance, the switchgear design uses zinc-coated metal sheet,
• universality in designing different switchgear configurations with any number of bays,
• use of state of the art, reliable switching devices, such as GTR SF type disconnectors and switch disconnectors (ZPUE), and VCB GIS type circuit breakers (ZPUE) or by other leading manufacturers,
• adapted for the installation of state of the art protection and control devices,
• the possibility of wall-mounting of the switchgear, saving space in the switching room, which is particularly important during retrofits and expansions of existing switching stations,
• easy and quick access to switchgear devices for supervision and maintenance,
• simple operation.

System of interlocks and protections

• arc-proof design - resistance to internal arcing effects,
• specially reinforced bay design (enclosures, locks, hinges),
• mechanical interlocks, which prevent incorrect switching operations and touching live devices,
• access to controlgear and control circuits is possible while the primary circuits parts cannot be touched by the operator,
• the use of monitoring and signalling systems, and mechanical and electrical position indicators, and inspection windows,
• use of three-position “on - off - earth” disconnectors and switch disconnectors with mechanical position indicators,
• the use of fast earthing switch with an impulse drive,
• the use of fast earthing switch with an impulse drive guarantee safety in case of an incorrect switch to a short-circuit.

Basic technical data

Compliance with standards:

The Rotoblok type switchgear meets the requirements of the following standards:

• (PN-EN) IEC 62271-1 - “High-voltage switchgear and controlgear. Common specifications”,
• (PN-EN) IEC 62271-200 - “High-voltage switchgear and controlgear. AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV standard,”
• (PN-EN) IEC 62271-100 - “High-voltage switchgear and controlgear. Alternating-current circuit-breakers”,
• (PN-EN) IEC 62271-102 - “High-voltage switchgear and controlgear. Alternating current disconnectors and earthing switches”,
• (PN-EN) IEC 62271-103 - “High-voltage switchgear and controlgear. Switches for rated voltages above 1 kV up to and including 52 kV”,
• (PN-EN) IEC 62271-105 - “High-voltage switchgear and controlgear. Alternating current switch-fuse combinations”.

Certified by the Electrotechnical Institute.

Method of cable duct construction under Rotoblok SF and rotoblok SF type MV switchgears

The Rotoblok SF type switchgear is a two compartment, indoors air insulated switchgear (AIS) in a mental enclosure made of zinccoated metal sheet (which ensures equipotential bonding), with a single primary busbars system. The switchgear is equipped with state-of-the-art, three-position disconnectors and switch disconnectors in SF₆ insulation. The tank of each of these devices is constructed with stainless steel, which ensures maintaining a perfect technological condition of the switchgear over its entire operation period. It has separate primary busbars and cable compartments, and the arc-proof design ensures high level of operational safety.

Fig. 1 Cable duct proposal, to be constructed under Rotoblok SF switchgear

Note!: Minimum distance from the wall 30 mm

1. Example bays with a width of 1000, 500, 500 mm (respectively, from the left),
2. Cable duct under the switchgear.

Fig. 3 - Proposed depth of the cable duct under the Rotoblok SF switchgear

Dry single-core cable

Cable cross-section (mm2)	Bending radius (mm)	Tray depth k (mm)
50	370	400
70	400	430
95	440	470
120	470	500
150	500	550
185	540	600
240	590	700

Rotoblok SF switchgear cable connections

Construction of switchgear type Rotoblok SF

Side view and dimensions

Side view and dimensions

1. - Stainless steel tank filled with SF₆ gas with switching devices
2. - Drive mechanism compartment
3. - Insulating bushings
4. - Safety valve

Note!
Figures shown on subsequent pages are only an example of bay equipment. It is possible to adapt the bay configuration to specific requirements of the end user. In this case manufacturer should be asked to provide drawings.

SL1 (line feeder)

SL1 (line feeder)

Electrical diagram

Front view

mass = 175 kg

Note!
Optional equipment is marked with red.

SL2 (line feeder)

SL2 (line feeder)

Electrical diagram

Front view

mass = 190 kg

Note!
Optional equipment is marked with red.

ST2 (transformer feeder)

ST2 (transformer feeder)

Electrical diagram

Front view

mass = 210 kg

Note!
Optional equipment is marked with red.

SP1 (metering unit)

SP1 (metering unit)

Electrical diagram

Front view

mass = 390 kg

Note!
Optional equipment is marked with red.

SS1L(P.^*)) (bus coupler unit with disconnector or switch disconnector on the left side)

SS1L(P.^*)) (bus coupler unit with disconnector or switch disconnector on the left side)

Electrical diagram

Front view

mass = 265 kg

Note!
Optional equipment is marked with red. *) When post type current transformers are used instead of bushing type

SS2L(P.^*)) (bus coupler unit with disconnector or switch disconnector on the left side)

SS2L(P.^*)) (bus coupler unit with disconnector or switch disconnector on the left side)

Electrical diagram

Front view

mass = 465 kg

Note!
Optional equipment is marked with red. *) When post type current transformers are used instead of bushing type

SO1 (lightning arrester unit)

SO1 (lightning arrester unit)

Electrical diagram

Front view

mass = 100 kg

Note!
Optional equipment is marked with red.

SŁ2 (Incoming cable-connection feeder)

SŁ2 (Incoming cable-connection feeder)

Electrical diagram

Front view

mass = 100 kg

STpwł4 (auxiliary transformer unit)

STpwł4 (auxiliary transformer unit)

Electrical diagram

Front view

Note!
Optional equipment is marked with red.

STpwł 25kVA + ST1 (bay with an auxiliary transformer with a max. power of 25 kVA)

STpwł 25kVA + ST1 (bay with an auxiliary transformer with a max. power of 25 kVA)

Electrical diagram

Front view

Note!
Optional equipment is marked with red.

SWG1 (circuit breaker feeder)

SWG1 (circuit breaker feeder)

Electrical diagram

Front view

Note!
Optional equipment is marked with red.

SWTp(5^*)) (circuit breaker transformer feeder)

SWTp(5^*)) (circuit breaker transformer feeder)

Electrical diagram

Front view

Note!
Optional equipment is marked with red. *) It is possible to design the unit in a mirror variant

SWTp(5^*)) (circuit breaker transformer feeder with voltage measurement))

SWTp(5^*)) (circuit breaker transformer feeder with voltage measurement))

Electrical diagram

Front view

Note!
Optional equipment is marked with red. *) It is possible to design the unit in a mirror variant

SWS1 (bus coupler unit with with disconnectors and circuit breaker)

SWS1 (bus coupler unit with with disconnectors and circuit breaker)

Electrical diagram

Front view

Note!
Optional equipment is marked with red.

Characteristics

Characteristics

• miniature switchgear dimensions while maintaining high technical parameters,
• very high safety level, including arc protection - confirmed by appropriate certificates,
• possibility to configure the switchgear from a range of different purpose bays: feeder, transformer, circuit breaker, metering, cable bays,
• the possibility of configuring the switchgear with the use of a wide range of bays: feeder, transformer, circuit-breaker, bus coupler, metering,
• possibility of easily expanding the switchgear with additional assemblies (which should be taken into account when placing the order) each assembly may be manufactured as expandable,
• the possibility of adapting the switchgear to work with remote control and metering systems, e.g. to work in Smart Grid networks,
• fast earthing switch, which earths the fuse link on both sides in the transformer bay,
• the main SF₆ gas tank is made of stainless, acid-resistant steel, with welded connections, which ensure environmental and 6 personal safety, and remain sealed over the entire period of switchgear operation,
• the manufacturer is able to recycle the waste switchgear and safely remove the SF₆ gas from their tanks.

Possible markings/naming scheme

Safety

• robust construction of TPM type switchgear ensures high reliability,
• the tank is constructed of stainless, acid-resistant steel, ensuring resistance to environmental conditions,
• use of shielded terminations guarantees safety, e.g. during servicing operations with the front panel removed and live supply cables,
• gas pressure indicator - pressure meter which shows the correct pressure of insulating gas inside the tank,
• resistance to internal arc of 20 kA as a standard and 22 kA in custom design,
• pressure increase caused by internal arcing is eliminated by opening the safety valve installed in the lower part of the switchgear's tank. The gases are discharged to the cable duct, eliminating the hazard to personnel,
• each switchgear unit is equipped with voltage indicators, which enable the personnel to make sure that the insulating bushing terminals are not live,
• legible system display which improves intuitiveness of operation and facilitates reading the state of devices,
• a set of mechanical interlocks enables opening the front panels of the cable compartment only after the earthing switch is closed,
• a set of mechanical interlocks between the devices, which prevents performing incorrect switching operations,
• optional use of electromagnetic interlocks, which prevent the closing of the earthing switch with live supply cables,
• a set of auxiliary contacts with device state output, guaranteeing safety of remote operation,
• the use of pressure control at all times for the motor drive option guarantees safety of remote operation.

Basic technical data

Compliance with standards:

The TPM type switchgear meets the requirements of the following standards:

• PN-EN 62271-1 - „High-voltage switchgear and controlgear - Part 1: Common specifications”,
• PN-EN 62271-200 - „High-voltage switchgear and controlgear - Part 200: AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV”,
• PN-EN 62271-100 - „High-voltage switchgear and controlgear - Part 100: High-voltage alternating-current circuit-breakers”,
• PN-EN 62271-102 - „High-voltage switchgear and controlgear - Part 102: High-voltage alternating current disconnectors and earthing switches”,
• PN-EN 62271-103 - „High-voltage switchgear and controlgear - Part 103: Switches for rated voltages above 1 kV up to and including 52 kV”,
• PN-EN 62271-105 - „High-voltage switchgear and controlgear - Part 105: Alternating current switch-fuse combinations”.

The switchgear is certified by the Electrotechnical Institute.

Notice:
Rated currents of the fuse links to protect primary transformer circuits (recommended by leading manufacturers), with rated voltage 6 kV, 10 kV, 15 kV and 20 kV, should be selected in accordance with IEC 282-1, DIN 43625 thermal protection.

Field equipment

L - line feeder equipment

L - line feeder equipment

Parameters
Ur	= 25 kV
Fr	= 50/60 Hz
Ud	= 50/60 kV
Up	= 125/145 kV
Ir	= 630 A
Ik	= do 20 kA
Ip	= do 50 kA
IA	= do 22 kA
	switch disconnector class M2, E3
	earthing switch class M0, E2

Electrical data of line functional unit (L)
Continuous rated current	Ir	630 A
Rated short-circuit making current	Ima	50 kA
Rated low inductance circuit breaking current	Iload	630 A
Rated ring network circuit breaking current	Iloop	630 A
Rated buried cable charging breaking current	Iicc2	60 A
Rated overhead line charging breaking current	Iicc1	20 A
Rated earth fault breaking current	Ief1	180 A
Rated buried cable and overhead line charging breaking current in earth fault conditions	Ief2	104 A
Switch disconnector class		M2, E3
Earthing switch class		M0, E2

Standard

• meets the requirements of the PN-EN 62271-103 Switches for rated voltages above 1 kV up to and including 52 kV standard,
• the L unit as a single module with option of expanding, in almost any configuration up to four units in a common tank,
• disconnector-earthing switch unit, the construction of which is based on common moving contacts and separated fixed contacts of the earthing switch and switch disconnector,
• switch disconnector with a switching operations arc quenching system,
• manual double spring drive which ensures intuitive and easy operation and snap-action closing and opening of the switching devices,
• system display representing the state of devices and entire primary circuits,
• type C insulating bushings with M16 thread, equipped with capacitive voltage dividers intended for operation with voltage indicators in the LRM system and to operate with electromagnetic interlocks,
• cable voltage indicator in the LRM system,
• pressure meter - gas pressure indicator with a scale with two zones, indicating the rated absolute pressure of the SF₆ gas - 125 kPa (0.125 MPa) at a temperature of 20°C (one per one 6 tank),
• a system of mechanical interlocks between the devices and front panels of the cable compartment preventing incorrect switching operations - removing the front panel only after closing the earthing switch,
• safety valve (one per one tank), which is opened by pressure increase caused by arcing inside the tank, directing the gases downwards, to the cable duct, eliminating the hazard to personnel,
• cable clamps.

Option

• 24 V DC motor drive (other supply voltage on request), possibility of easy expansion at the facility,
• pressure control - for operating with motor drive, telemetry,
• SEM SC 11 field controller plus local control panel, Modbus communication or binary communication
• auxiliary contacts as representation of state of devices for telemetry systems,
• voltage sensors - low power transformers,
• current transformers, Rogowski coils,
• earth fault transformers,
• short-circuit current indicators,
• auxiliary circuits cubicle/operation with telemetry,
• “ON”, “OFF” signalling in the form of signalling lamps,
• anti-condensation heaters,
• possibility of expanding on the left and right side,
• key interlock of the switch disconnector or earthing switch socket,
• electromagnetic interlock of the earthing switch socket,
• overvoltage limiters.

T - tansformer feeder equipment

T - tansformer feeder equipment

Parameters
Ur	= 25 kV
Fr	= 50/60 Hz
Ud	= 50/60 kV
Up	= 125/145 kV
Ir	= 250 A (125 A fuse link)
Ik	= 20 kA (1s)
Ip	= 50 kA
IA	= do 22 kA
Itransf	= 720 A
	switch disconnector class M2, E3

Electrical data of the fused transformer functional unit (T)
Continuous rated current	Ir	250 A
Maximum thermally protected fuse link current		125 A
Through-current	Itransfer	720 A
Switch disconnector electrical class		M2, E3
Maximum transformer power		6 kV	800 kVA
		10 kV	1000 kVA
		15 kV	1600 kVA
		20 kV	2000 kVA

Standard

• meets the requirements of the PN-EN 62271-105 Alternating current switch-fuse combinations standard
• the T unit as a single module with option of expanding, in almost any configuration up to four units in a common tank,
• disconnector-earthing switch unit, the construction of which is based on common moving contacts and separated fixed contacts of the earthing switch and switch disconnector,
• lower earthing switch, ensuring earthing on both sides of the fuse links,
• switch disconnector with a switching operations arc quenching system,
• manual double spring drive which ensures intuitive and easy operation and snap-action closing and opening of the switching devices,
• system display representing the state of devices and entire primary circuits,
• stored energy release mechanism function, which allows the switch disconnector contacts to be opened when MV fuse links with thermal protection (striker) or a tripping coil is used,
• blown fuse link indicator,
• type A insulating bushings with plug-in socket, equipped with capacitive voltage dividers intended for operation with voltage indicators in the LRM system and to operate with electromagnetic interlocks,
• cable voltage indicator in the LRM system,
• a system of mechanical interlocks between the devices and front panels of the cable connection compartment preventing incorrect switching operations - removing the front panel only after the earthing switch is closed,
• safety valve (one per one tank), which is opened by pressure increase caused by arcing inside the tank, directing the gases downwards, to the cable duct,
• cable clamps.

Option

• 24 V DC motor drive (other supply voltage on request), possibility of easy expansion at the site,
• pressure control - for operating with motor drive, telemetry,
• SEM SC 11 field controller plus local control panel, binary or Modbus communication,
• auxiliary contacts as representation of state of devices for telemetry systems,
• fuse links with integrated temperature limiter (thermal trip), acc. to the IEC 60282-1, DIN 43625 standard, e.g. by SIBA
• voltage sensors - low power transformers,
• current transformers, Rogowski coils,
• “ON”, “OFF” signalling in the form of signalling lamps,
• anti-condensation heaters,
• possibility of expanding on both sides,
• key interlock of the disconnector or earthing switch socket,
• electromagnetic interlock of the earthing switch socket, option dedicated for renewable energy system,
• shunt trip - DWN 24 V DC coil, 230V AC/DC (other voltages on request).

W - circuit breaker feeder

W - circuit breaker feeder

Parameters
Ur	= 25 kV
Fr	= 50/60 Hz
Ud	= 50/60 kV
Up	= 125/145 kV
Ir	= 630 A
Ik	= do 20 kA (1s)
Isc	= do 50 kA
Icc1	= 10 A
Icc2	= 31,5 A
	circuit braker class M2, E2
	operating sequence duty cycle (O-0, 3s-CO-3min-CO)

Electrical data of circuit breaker feeder (W)
Continuous rated current	Ir	630 A
Short-circuit making current	Ima	40 kA / 50 kA / 52,5 kA *1)
Short-circuit breaking current	Isc	16 kA / 20 kA / 21 kA *1)
Rated low inductance circuit breaking current		630 A
Cable line current with no load - Icc1 / Icc2	Icc1 / Icc2	10 A / 31,5 A
Circuit breaker class		M2, E2
Operating sequence duty cycle		0-0, 3s-CO-3min-CO

Custom design:
¹⁾ For 12 kV voltage.

Standard

• meets the requirements of the PN-EN 62271-100 Alternating current circuit-breakers standard,
• meets the requirements of the PN-EN 62271-102 Alternating current disconnectors and earthing switches standard,
• the W bay as a single module with option of expanding, in almost any configuration up to four bays in a common tank,
• circuit breaker unit, the construction of which is based on the use of vacuum chambers with a breaking current of 16 kA or 20 kA, enclosed in an SF₆ gas filled tank,
• disconnector-earthing switch unit, the construction of which is based on common moving contacts and separated fixed contacts of the earthing switch and disconnector. The function of the disconnector is to ensure a safe gap in the circuit,
• manual spring drive of the circuit breaker, which ensures intuitive and easy operation and snapaction closing and opening of the switching devices, the drive has a charging system which allows a rapid breaker on-off cycle,
• manual spring-less drive of the disconnector and earthing switch, which ensures intuitive and easy operation of the switching devices,
• system display representing the state of devices and entire primary circuits,
• circuit breaker charging indication,
• independent protection, preferably AZZ-4 (by ITR) or WIC 1 (by Woodward) with dedicated current transformers,
• type C insulating bushings with M16 thread, equipped with capacitive voltage dividers intended for operation with voltage indicators in the LRM system and to operate with electromagnetic interlocks,
• cable voltage indicator in the LRM system,
• pressure meter - gas density indicator with a scale with two zones, indicating the rated absolute pressure of the SF₆ gas - 125 kPa (0.125 MPa) at a temperature of 20°C (one per one tank),
• a system of mechanical interlocks between the devices and front panels of the cable compartment preventing incorrect switching operations - removing the front panel only after closing the earthing switch,
• safety valve (one per one tank), which is opened by pressure increase caused by arcing inside the tank, directing the gases downwards, to the cable duct, eliminating the hazard to personnel,
• cable voltage indicator,
• cable clamps.

Option

• 24V DC motor drive for the circuit breaker and for the disconnector and earthing switch (other supply voltage on request),
• pressure control - for operating with motor drive, telemetry,
• auxiliary contacts as representation of state of devices for telemetry systems,
• protections other than preferred independent, unit controllers, ATS automation,
• voltage sensors - low power transformers,
• current transformers, Rogowski coils,
• earth fault transformers,
• auxiliary circuits cubicle/operation with telemetry,
• “ON”, “OFF” signalling in the form of signalling lamps,
• anti-condensation heaters,
• possibility of expanding on both sides,
• overvoltage limiters.

S - bus sectionalizer panel

S - bus sectionalizer panel

Parameters
Ur	= 25 kV
Fr	= 50/60 Hz
Ud	= 50/60 kV
Up	= 125/145 kV
Ir	= 630 A
Ik	= do 20 kA (1s)
Ip	= 50 kA
IA	= do 22 kA
	switch disconnector class M2, E3
	earthing switch class M0, E2

Standard

• meets the requirements of the PN-EN 62271-103 Switches for rated voltages above 1 kV up to and including 52 kV standard,
• the S unit as a single module expandable both to the right and to the left,
• disconnector, the construction of which is based on common moving contacts and on fixed contacts,
• switching operations arc quenching system,
• manual single or double spring drive (depending on the use of an earthing switch), which ensures intuitive and easy operation and snap-action closing and opening of the switching device,
• system display representing the state of devices and entire primary circuits,
• pressure meter - gas density indicator with a scale with two zones, indicating the rated absolute pressure of the SF₆ gas - 125 kPa (0.125 MPa) at a temperature of 20°C (one per one tank),
• safety valve (one per one tank), which is opened by pressure increase caused by arcing inside the tank, directing the gases downwards, to the cable duct, eliminating the hazard to personnel.

Option

• 24 V DC motor drive (other supply voltage on request), possibility of easy expansion at the facility,
• earthing switch of the primary circuit of the right section,
• primary circuits (before and after the disconnector) voltage indicator,
• pressure control - for operating with motor drive, telemetry,
• SEM SC 11 field controller plus local control panel, binary or Modbus communication,
• auxiliary contacts as representation of state of devices for telemetry systems,
• anti-condensation heaters,
• possibility of expanding on both sides,
• key interlock of the disconnector or earthing switch socket.

M - metering panel equipment

M - metering panel equipment

Parameters
Ur	= 25 kV
Fr	= 50/60 Hz
Ud	= 50/60 kV
Up	= 125/145 kV
Ir	= 630 A
Ik	= do 20 kA (1s)
Ip	= do 50 kA

Standard

• meets the requirements of the PN-EN 62271-200 AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV standard,
• the M unit as a single module expandable both to the right and to the left,
• a system of primary busbars enclosed in a stainless steel tank,
• a set of current transformers and voltage transformers,
• primary circuits voltage indicator,
• system display representing the state primary circuits,
• pressure meter - gas density indicator with a scale with two zones, indicating the rated absolute pressure of the SF₆ gas - 125 kPa (0.125 MPa) at a temperature of 20°C (one per one tank),
• safety valve (one per one tank), which is opened by pressure increase caused by arcing inside the tank, directing the gases downwards, to the cable duct, eliminating the hazard to personnel.

Option

• pressure control - for operating with motor drive, telemetry,
• anti-condensation heaters,
• option of connecting with side connectors or cable terminations.

TPM type MV switchgear compartment

Switching device compartment

The switching device compartment is placed in a tank made from stainless steel sheet, with SF₆ gas is used as insulation, with very high dielectric strength and very good arc quenching ability. The following components were installed in the tank: primary busbars, switches and bushings. The switching device is an integrated disconnector and earthing switch, which is also opened and closed by snap-action. Each tank has a safety valve which can be opened to relieve the pressure increase caused by internal arcing. In TPM and TPM Kompact switchgear system, the valve is installed at the bottom of the tank in the cable connection compartment of one of the feeder units. Isolator bushings are equipped with capacitive voltage dividers, connected to voltage indicators located on the front panel of the switchgear cabinet. The switch disconnector itself and its drive mechanisms are exceptionally durable and reliable devices. Their design allows for 5000 operating cycles without any adjustment, maintenance, or component replacement.

Fuses compartment

Fuse links with integrated temperature limiter are installed in the switchgear fuses compartment (in special insulating tubes), in accordance with the DIN 43625 standard. The design of the fuses compartment prevents its opening before the earthing switch has been closed. Closing the switch disconnector in the transformer feeder is possible only after the fuse compartment door is closed. In the event the fuse link is blown, the striker mounted on the link trips the circuit breaker in the transformer feeder. The switch disconnector can be re-closed after replacement of the fuse links.

Drive mechanism compartment

The drive mechanism compartment contains the integrated, direct manual (motor driven) operating mechanism for switch disconnector and earthing switch or vacuum circuit breaker and disconnector with an earthing switch. The transformer feeder is moreover equipped with a stored energy release mechanism, which allows the switch disconnector to be opened after the activation of the fuse link striker, or in case a tripping coil is used. A blown fuse link is indicated on the front panel of the drive. In the switchgear cabinet operating mechanism compartment, there is a pressure gauge (calibrated to take into account state depending on temperature), which indicates the correct SF₆gas pressure inside the tank. Cable voltage indicators are installed In the front side of the switchgear cabinet.

Cable compartment

In the cable compartment, cable terminations are used to connect cables from the power grid to the switchgear. Individual feeders of the cable compartments have metal partitions which separate one feeder from another.
Each cable compartment is equipped with:

• type C insulating bushings for incoming, outgoing and transformer feeders equipped with a power circuit breaker,
• type A insulating bushings for transformer feeders equipped with MV fuses,
• cable clamps,
• earthing terminals for return cables.

Moreover each bay allows the installation of the following equipment:

• current transformers, Rogowski coils,
• voltage sensors,
• overvoltage limiters,
• combined systems with the use of deep front panels, e.g.: two terminations per phase, termination + voltage sensor, termination + overvoltage limiter, two terminations per phase + voltage sensor, two terminations per phase + overvoltage limiter, termination + overvoltage limiter + voltage sensor.

The TPM type switchgear is designed for the installation of cables with a cross-section up to 630 m², such as:

• in plastic insulation, e.g.: YHAKXS, YHKX, XUHAKXS, XRUHKS.

Construction method for a cable duct under the TPM type MV switchgears

Figures 1–3 present a cable duct construction proposal. The cable bending radius (which depends on its outside diameter, according to PBUE) should be taken into account when establishing the dry cables duct depth. Figure 1 shows the suggested cable duct depth. It is possible to avoid or reduce the depth of the cable duct by using a raised base or a raised floor.

TPM switchgear cable connections

Approximate dimensions / TPM switchgear connection options

Insulating bushing type C

Main termination

Coupling termination

Overvoltage limiter

Voltage sensor (low power transformer)

Expandable units connection method

The TPM switchgear can be expanded with additional assemblies (on the condition that this was discussed at the pricing and ordering stage). The examples of connection methods were presented on figures below. Detailed information is provided in the Switchgear Operation & Maintenance Manual.

Example 1. TLL⁺ + LLL⁺ switchgear top connection

Electrical diagram

Front view

Example 2. TLL⁺ (l, p) system

Electrical diagram

Front view

Top view

Example 3. TLL⁺(p) + LLL⁺(l) switchgears side connection

Electrical diagram

Front view

TPM switchgear side views and dimensions

TPM - typical configurations

TL / LT configuration (transformer feeder, line feeder)

TL / LT configuration (transformer feeder, line feeder)

Optional equipment was marked with red on the electrical diagram.

TLL / LLT configuration (transformer feeder, 2 line feeders)

TLL / LLT configuration (transformer feeder, 2 line feeders)

Optional equipment was marked with red on the electrical diagram.

TLLL / LLLT configuration (transformer feeder, 3 line feeders)

TLLL / LLLT configuration (transformer feeder, 3 line feeders)

Optional equipment was marked with red on the electrical diagram.

TLLT configuration (2 transformer feeders, 2 line feeders)

TLLT configuration (2 transformer feeders, 2 line feeders)

Optional equipment was marked with red on the electrical diagram.

TT configuration (2 transformer feeders)

TT configuration (2 transformer feeders)

Optional equipment was marked with red on the electrical diagram.

LL configuration (2 line feeders)

LL configuration (2 line feeders)

Optional equipment was marked with red on the electrical diagram.

LLL configuration (3 line feeders)

LLL configuration (3 line feeders)

Optional equipment was marked with red on the electrical diagram.

LLLL configuration (4 line feeders)

LLLL configuration (4 line feeders)

Optional equipment was marked with red on the electrical diagram.

WL / LW configuration (circuit breaker feeder, line feeder)

WL / LW configuration (circuit breaker feeder, line feeder)

Optional equipment was marked with red on the electrical diagram.

WLL / LLW configuration (circuit breaker feeder, 2 line feeders)

WLL / LLW configuration (circuit breaker feeder, 2 line feeders)

Optional equipment was marked with red on the electrical diagram.

WLLL / LLLW configuration (circuit breaker feeder, 3 line feeders)

WLLL / LLLW configuration (circuit breaker feeder, 3 line feeders)

Optional equipment was marked with red on the electrical diagram.

WLLW configuration (2 circuit breaker feeders, 2 line feeders)

WLLW configuration (2 circuit breaker feeders, 2 line feeders)

Optional equipment was marked with red on the electrical diagram.

WW configuration (2 circuit breaker feeders)

WW configuration (2 circuit breaker feeders)

Optional equipment was marked with red on the electrical diagram.

WWW configuration (3 circuit breaker feeders)

WWW configuration (3 circuit breaker feeders)

Optional equipment was marked with red on the electrical diagram.

WWWW configuration (4 circuit breaker feeders)

WWWW configuration (4 circuit breaker feeders)

Optional equipment was marked with red on the electrical diagram.

LWWW configuration (line feeder, 3 circuit breaker feeders)

LWWW configuration (line feeder, 3 circuit breaker feeders)

Optional equipment was marked with red on the electrical diagram.

TPM - typical configurations - single units

L⁺ (p,l) configuration (line feeder)

L⁺ (p,l) configuration (line feeder)

Optional equipment was marked with red on the electrical diagram.

T⁺ (p,l) configuration (transformer feeder)

T⁺ (p,l) configuration (transformer feeder)

Optional equipment was marked with red on the electrical diagram.

W⁺ (p,l) configuration (circuit breaker feeder)

W⁺ (p,l) configuration (circuit breaker feeder)

Optional equipment was marked with red on the electrical diagram.

S configuration (bus coupler unit)

S configuration (bus coupler unit)

Optional equipment was marked with red on the electrical diagram.

M840 metering unit

Electrical diagram

Dimensions

Optional equipment was marked with red on the electrical diagram.

TPM KOMPAKT - typical configurations

LTL configuration (transformer feeder and 2 line feeders)

LTL configuration (transformer feeder and 2 line feeders)

Optional equipment was marked with red on the electrical diagram.

LLTL configuration (transformer feeder and 3 line feeders)

LLTL configuration (transformer feeder and 3 line feeders)

Optional equipment was marked with red on the electrical diagram.

Characteristics and advantages

The Rotoblok VCB type switchgear is a two compartment, indoors switchgear in metal enclosure made of zinc-coated metal sheet, with a single primary busbars system. The switchgear is an air insulated switchgear (AIS) with compact dimensions, ensured by the use of an innovative three function medium voltage isolator switch which replaces three devices used previously: circuit breaker, disconnector and earthing switch. For the quenching of electric arc vacuum chambers built into resin insulators are used, which in turn are installed on a common rotating shaft, which can be used as a disconnector. A system of mechanical interlocks prevents incorrect switching operations, and opening of the distribution bay doors before voltage is disconnected and the earthing switch is closed. Custom design and used materials guarantee high durability and reliability, but mainly very high safety.

The distribution bays have the following properties:

• the use of a state-of-the-art TGI type device (manufactured by ZPUE S.A.) which combines three functions: circuit breaker, disconnector and earthing switch,
• miniaturisation of bay dimensions, and therefore switchgear dimensions while maintaining high electrical and utility parameters (the main width of Rotoblok VCB bay is only 500 mm),
• the interlock system is limited to a single device,
• the device may be controlled locally or remotely (e.g. by radio),
• high safety of operation is ensured by forcing of correct witching operations,
• two visible, full insulation air gaps ensure the highest level of safety,
• the device in off and open position provides by itself a mechanical and isolating partition between the primary busbar compartment and the cable connections part
• improvement of reliability by elimination of multiple mechanical and electrical interlocks,
• simplification and improvement of reliability of construction through elimination of many busbar connections,
• long operating period without the need for troublesome maintenance operations,
• the main apparatus shaft (circuit breaker + switch disconnector) can be replaced quickly and simply during service operations,
• high corrosion resistance, the switchgear design uses metal sheet which has been zinc-coated for corrosion protection,
• adapted for the installation of state of the art protection and control devices by various manufacturers,
• the possibility of wall-mounting of the switchgear, saving space in the switching room is particularly important during retrofits and expansions of existing switching stations,
• easy and quick access to switchgear devices for supervision and maintenance,
• simple operation.

Basic technical data

View of the switch

Device operating positions

Rotoblok VCB switchgear bay variants

VCB 1

VCB 1

Electrical diagram

Front view

Note:
These pictures present exemplary bay equipment. It is possible to configure the bays to the customer’s needs. In such cases, please contact the manufacturer to request pictures.
Optional equipment is marked with red.

1. Using 24 kV supportive current transformers instead of bushing transformers.
2. Using a fuse base above the voltage transformers.
3. Using voltage transformers.
4. A TGI 24 apparatus with current transformers can be located on the right side of the bay.
5. When the Rotoblok VCB bays are connected with Rotoblok 17,5 kV and Rotoblok SF bays, the height of the switchgear bay is 1950mm, and the depth is 950 mm. When the Rotoblok VCB bays are connected with Rotoblok 24 bays, the height of the switchgear bay is 1950 mm, and depth 1150 mm.

VCB 2(3¹⁾)

VCB 2(3¹⁾)

Electrical diagram

Front view

Note:
These pictures present exemplary bay equipment. It is possible to configure the bays to the customer’s needs. In such cases, please contact the manufacturer to request pictures.
Optional equipment is marked with red.

1. Using 24 kV supportive current transformers instead of bushing transformers.
2. Using a fuse base above the voltage transformers.
3. Using voltage transformers.
4. A TGI 24 apparatus with current transformers can be located on the right side of the bay.
5. When the Rotoblok VCB bays are connected with Rotoblok 17,5 kV and Rotoblok SF bays, the height of the switchgear bay is 1950mm, and the depth is 950 mm. When the Rotoblok VCB bays are connected with Rotoblok 24 bays, the height of the switchgear bay is 1950 mm, and depth 1150 mm.

VCB 5(6^*2))

VCB 5(6^*2))

Electrical diagram

Front view

Note:
These pictures present exemplary bay equipment. It is possible to configure the bays to the customer’s needs. In such cases, please contact the manufacturer to request pictures.
Optional equipment is marked with red.

1. Using 24 kV supportive current transformers instead of bushing transformers.
2. Using a fuse base above the voltage transformers.
3. Using voltage transformers.
4. A TGI 24 apparatus with current transformers can be located on the right side of the bay.
5. When the Rotoblok VCB bays are connected with Rotoblok 17,5 kV and Rotoblok SF bays, the height of the switchgear bay is 1950mm, and the depth is 950 mm. When the Rotoblok VCB bays are connected with Rotoblok 24 bays, the height of the switchgear bay is 1950 mm, and depth 1150 mm.

VCB O5

VCB O5

Electrical diagram

Front view

Notice:
These pictures present exemplary bay equipment. It is possible to configure the bays to the customer’s needs. In such cases, please contact the manufacturer to request pictures.
Optional equipment is marked with red.

1. Using 24 kV supportive current transformers instead of bushing transformers.
2. Using a fuse base above the voltage transformers.
3. Using voltage transformers.
4. A TGI 24 apparatus with current transformers can be located on the right side of the bay.
5. When the Rotoblok VCB bays are connected with Rotoblok 17,5 kV and Rotoblok SF bays, the height of the switchgear bay is 1950mm, and the depth is 950 mm. When the Rotoblok VCB bays are connected with Rotoblok 24 bays, the height of the switchgear bay is 1950 mm, and depth 1150 mm.

VCB S1L(P⁴⁾)

VCB S1L(P⁴⁾)

Electrical diagram

Front view

Note:
These pictures present exemplary bay equipment. It is possible to configure the bays to the customer’s needs. In such cases, please contact the manufacturer to request pictures.
Optional equipment is marked with red.

1. Using 24 kV supportive current transformers instead of bushing transformers.
2. Using a fuse base above the voltage transformers.
3. Using voltage transformers.
4. A TGI 24 apparatus with current transformers can be located on the right side of the bay.
5. When the Rotoblok VCB bays are connected with Rotoblok 17,5 kV and Rotoblok SF bays, the height of the switchgear bay is 1950mm, and the depth is 950 mm. When the Rotoblok VCB bays are connected with Rotoblok 24 bays, the height of the switchgear bay is 1950 mm, and depth 1150 mm.

VCB S3L(P⁴⁾)

VCB S3L(P⁴⁾)

Electrical diagram

Front view

Note:
These pictures present exemplary bay equipment. It is possible to configure the bays to the customer’s needs. In such cases, please contact the manufacturer to request pictures.
Optional equipment is marked with red.

1. Using 24 kV supportive current transformers instead of bushing transformers.
2. Using a fuse base above the voltage transformers.
3. Using voltage transformers.
4. A TGI 24 apparatus with current transformers can be located on the right side of the bay.
5. When the Rotoblok VCB bays are connected with Rotoblok 17,5 kV and Rotoblok SF bays, the height of the switchgear bay is 1950mm, and the depth is 950 mm. When the Rotoblok VCB bays are connected with Rotoblok 24 bays, the height of the switchgear bay is 1950 mm, and depth 1150 mm.

Examples of the switchgear Rotoblok VCB in combination with the Rotoblok switchgear and Rotoblok SF

Electrical diagram

Front view

Electrical diagram

Front view

Characteristics of the switchgear

• The switchgear is designed to operate in distribution transformer stations in industrial sites which generate, distribute and consume electricity.
• The switchgear complies with the requirements of (PN-EN) IEC 62271-200, (PN-EN) IEC 62271-1 and GOST, provides IP4X degree of protection. It is designed to work in normal conditions defined by the (PN-EN) IEC 62271-1 standard.
• The switchgear is designed to assure safety during normal operation, inspection and handling.
• The switchgear cubicle is of a frameless construction, made of galvanized steel sheets and fixed with rivets. It is in the form of a multicompartment cabinet, with walls and partitions that form a self-supporting structure.
• There are four compartments in the switchgear bay: cable connections, busbars, withdrawable main device and LV auxiliary circuits compartment.
• The cabinet's door and side shields of the outermost bays (back shields for wall mounted cubicles) are powder coated.

Types of bays

The switchgear may be composed of various functional units.
These are:

• incoming/outgoing feeder bays,
• bus coupler bays,
• bus riser bays,
• metering bays with the possibility of busbars earthing,
• switch disconnector bay,
• others - acc. to arrangements.

The withdrawable module of the switchgear may be equipped with a circuit breaker, contactor, sectionalizer or a set of fused voltage transformers. The withdrawable module may be placed in the positions of: service, test/disconnection and separation.

Characteristic and advantages

• air insulated,
• optional electrical drives for all switches - fully automated switchgear,
• Loss of Service Continuity category - LSC2B (three MV compartments),
• possibility of equipping with current and voltage sensors - environmentally friendly solution,
• IAC AFLR internal arc classification,
• interlocks and protections against performing incorrect switching operations,
• wall-standing or free-standing options,
• optional thermal imaging measurements of cable connections or temperature monitoring system,
• possibility of expanding the switchgear with additional bays,
• possibility of bay replacement without the need to draw aside the adjacent bays,
• ease of operation.

The switchgear ensures high safety of operation through:

• internal arc resistance of the switchgear enclosure,
• improper switching operations interlocks and door locks and interlocks,
• racking the withdrawable module with doors closed,
• the use of compartments with PM class partitions,
• the possibility of visual control of switching operations through inspection windows,
• the use of blow-out flaps which limit the pressure increase in case of an internal arcing fault,
• optional gas exhausting duct - discharges gases outside of the switching station room,
• bay voltage indication system.

Basic technical data

Compliance with standards

The RELF type switchgear meets the requirements of the following standards:

• (PN-EN) IEC 62271-1 - „High-voltage switchgear and controlgear. Common specifications”,
• (PN-EN) IEC 62271-200 - „High-voltage switchgear and controlgear. AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV”.

The switchgear is certified by appropriate accredited bodies.

Note:

1. - bay height may differ due to construction and height of the LV compartment. Details should be arranged with the manufacturer,
2. - if the switchgear installation altitude is higher than 1000 m. a.s.l. the switchgear insulation level should be corrected in accordance with the standard.

Switchgear design

Design

Design

The RELF switchgear bay is designed as a cabinet divided into four separate functional compartments:

1. busbars compartment (medium voltage circuits),
2. main device compartment (medium voltage circuits),
3. cable compartment (medium voltage circuits),
4. auxiliary circuits LV compartment (low voltage circuits).

RELF version I

RELF version II

RELF 36

RELF ex

The switchgear cubicle is constructed of bent steel sheets, riveted together, without welding. Walls and partitions create a selfsupporting structure. A corrosion-resistant zinc-coated sheet is used for the construction of cabinets.

High-strength round-head steel rivets were used to connect structural elements. Functional compartments are limited by internal vertical and horizontal partitions. The internal partitions are attached to side walls, reinforcing and stabilising the entire enclosure. Additionally, two-part side covers made of painted sheet are bolted to the external walls of the outer bays of the switchgear.

The switchgear may be constructed as free-standing or wall-standing. The front belt between the doors of the main device compartment and the doors to the cable connection compartment and the horizontal partition between these compartments are removable (does not apply to the RELF 36 version), which significantly facilitates maintenance and installations.

Internal partitions allow safe access to main device compartment and cable connection compartment, even when the primary busbars are live.

In accordance with the LSC (Loss of Service Continuity) category, the switchgear meets the criteria of LSC2B. This condition is met by switchgear with three MV compartments and the withdrawable module placed in the test/disconnection position.

The MV circuits compartment doors are made of powder coated sheet. Doors use hinges and bolts which can stand up to explosiontype loads. The hinges allow opening the doors by approximately 135º (170º in case of RELF 36). Upper and lower edges of the doors were reinforced by appropriately shaped and welded reinforcing profiles.

Doors to the main device compartment are equipped with an inspection window used for visual control of the position of the withdrawable module and switching operations.

The design of the doors allows the mechanical opening of the circuit breaker in operating position with the doors closed.

Blow-out flaps

All MV compartments have blow-out duct openings in their top zone, closed with flaps. Their task is to discharge any pressure created inside the compartment as a result of an internal arc fault.

A sudden increase of pressure inside the switchgear compartment breaks the plastic bolts and opens the flaps, which may activate limit switches installed at the roof of the switchgear. Limit switches activated by the flaps being opened send an impulse which trips the main circuit breaker. This allows limiting the effects of an arc fault generated inside the cubicle compartment.

Withdrawable module

The withdrawable module is a unit composed of a racking system, and depending on the bay function: circuit breaker, contactor, set of fused voltage transformers, or a sectionalizer. The racking system performs the physical connection of the withdrawable module with the switchgear bay. It's stationary part is connected with the bay by interlocking on both sides in guide rail cut-outs.

The moving part of the racking system is shifted between the service position and the test/disconnection position using a drive screw operated manually with a crank, or with an electric drive, while the doors are closed. The service and test/disconnection position is signalled by position indicators, after the module reaches an appropriate position.

The shutters in the main device compartment are discussed in the main device compartment description.

Cubicle compartments

The busbars compartment is inaccessible during normal operation. For maintenance purposes access to busbars is possible from the top of the cabinet, after removing the blow-out flaps (or from the main device compartment side after removing the partition - for RELF 36). It is closed on both sides with gland plates made of non-magnetic steel sheet or insulating material. These plates prevent damage from spreading to adjacent bays in case of an electric arc in the busbars compartment.

Gland plates and bushings insulators are elements which support the busbars. Outgoing busbars branch off from the main busbars and enter the spouts which separate the busbar compartment from the main device compartment.

The main device compartment is available after its doors are open in an interlock-controlled mode. The main device compartment contains the withdrawable module and all the elements necessary for its operation with the cubicle bay, such as: withdrawable module guide rails, shutters, spouts with fixed contacts, door interlock and earthing switch interlock elements and auxiliary circuits socket/plug.

The spouts are installed in the partition separating the main device compartment from the cable connection compartment and busbars compartment. Fixed contacts and outgoing busbars are set in the spouts.

The shutters with an unlocking mechanism are installed in the main device compartment. Their task is to separate the compartment space from fixed contacts, which may be live when the withdrawable module is in the test/disconnection or separation position. A safe insulation space remains between the contacts and the closed shutters.

Racking in the withdrawable module from the test/disconnection position to the operating position causes the shutters to slide apart and the fixed contacts to be exposed, allowing the circuit breaker tulip contacts to connect.

Mechanical indicators of the circuit breaker position and drive charging state are visible through the inspection window.

The cable connection compartment is designed to connect cables or busbars and is accessible after opening only the front doors (wall-standing version) or front and rear doors (free-standing version) in an interlock-controlled mode1). This compartment contains current transformers, an earthing switch, and depending on operational requirements, optionally: voltage transformers2), earth fault transformers and surge arresters.

Voltage transformers are installed in the front part of the connection compartment (not in RELF 36kV).

The earthing switch is equipped with a manual drive, or a manual and motor drive. Its status is indicated by the position indicator.

The compartment bottom is closed by a split floor cover, which also acts as a cable gland plate. Openings in the plate are covered with rubber cable glands. Cable clamps installed on supports are used to fasten the cables.

The auxiliary circuits LV compartment is constructed in the form of a control cubicle and is completely separated from the high voltage zone of the switchgear. The cubicle has its own sheet metal enclosure and is prefabricated independently of the high power part of the switchgear. It may be equipped with devices on a separate station, and then attached to the switchgear cabinet.

The cubicle is intended for the installation of: protection relays and IEDs, instrumentation & control devices and automation system elements.

It is installed on the roof of the switchgear, above the switching device compartment. In its bottom, top and side walls a series of openings are made for lead and cable glands and cable trays. These openings are covered by plates, in which holes can be made according to design needs. An assembly plate fixed to the rear wall of the LV cubicle was designed for the installation of devices. The devices may be also fixed on the side walls. On arrangement with the manufacturer, the cubicle design may be adapted to individual needs of the customer and of the design.

Main busbars

A single, three-phase busbar system is used in the switchgear. The busbars are installed in a separate compartment.

The main busbars are supported by distribution busbars which come out of the spouts and on insulating bushings installed in the side partitions.

Busbar cross-sections are selected in accordance with the rated current of the switchgear.

Insulating elements

The switchgear uses epoxy resin insulators. In the connection compartment the busbars are supported by post insulators.

For supporting the main busbars and passing them through switchgear bays, bushings are used, set in the gland plates of the bay side walls.

The passages through the partition between the switching device compartment and the busbars compartment and the connection compartment are provided by spouts.

Protective earthing

An earthing conductor is placed in every cabinet, in the form of a copper busbar with a cross-section of 40x10 mm, placed at the bottom of the cabinet. These busbars are bridged between the cabinets, creating an earthing conduit. The conduit is terminated by terminals on the left and right side of the switchgear, used to connect it to the facility's earthing system.

Cable connections

The connection compartments are designed for entry of single- or multi-core MV cables.

¹⁾ in the RELF 36 version the connection compartment is accessible after opening the cabinet doors and removing the partition on the side of the switching device compartment.
²⁾ does not apply to the RELF 36 version.

System of interlocks and protections

System of interlocks and protections

The switchgear may be equipped with a range of standard and additional mechanical and electrical interlocks, intended to improve operational safety:

Mechanical interlocks:

1. prevent racking the withdrawable module in or out of the operating position when the circuit breaker is closed,
2. allow the closing and opening of the circuit breaker only in the operating and test/disconnection positions,
3. allow the closing of the earthing switch only in the test/disconnection or separation position of the withdrawable module,
4. prevent racking in the withdrawable module from the test/disconnection position to the operating position if the earthing switch is closed,
5. prevent opening the switching device compartment door if the withdrawable module is in the operating or intermediate position,
6. prevent opening the cable compartment door (or bay door in the RELF 36 version) if the earthing switch is open,
7. allow changing the position of withdrawable module only when it is locked in a bay,
8. prevent racking in the withdrawable module from the test/disconnection position to the operating position if the compartment door is open (optional),
9. prevent racking in the withdrawable module from the test/disconnection position to the operating position until the circuit breaker control circuits supply plug is connected to the circuit breaker (option - contact the manufacturer),
10. prevent racking in the withdrawable module from the test/disconnection position to the separation position until the circuit breaker control circuits supply plug is set to the separation position (option - contact the manufacturer),
11. a servicing truck for the transporting of withdrawable modules may be equipped with a secure bay coupling mechanism, which prevents changing the position of the racking truck even when its wheels are unlocked (optional),
12. a servicing truck for the transporting of withdrawable modules may be constructed in a way that allows moving the withdrawable module from the truck to the bay only after mechanical coupling of the truck with the bay (optional),
13. a servicing truck for the transporting of withdrawable modules may be constructed in a way that allows uncoupling the truck from the bay only after the withdrawable module is locked in the bay or in the truck,
14. allow locking the drive of shutters which cover the fixed contacts in the switching device compartment (optional),
15. allow locking access to the earthing switch operating mechanism latch.

The cable connection compartment door lock is constructed to allow closing and locking the door after it has been opened and the earthing switch has been set to the OPEN (de-earthed) position with the doors open. Afterwards, the interlock prevents opening the door again until the next earthing operation.

On arrangement with the manufacturer it is possible to use additional key and padlock interlocks.

 

Electrical interlocks:

1. prevent closing the circuit breaker if its auxiliary circuits are not powered; only mechanical opening of the circuit breaker is possible (optional),
2. prevent racking the withdrawable module to the operating position without power supply to the control circuits (optional),
3. prevent access to the earthing switch drive when closing of the earthing switch requires additional conditions (for example, main busbar earthing switch can be closed only when the withdrawable modules in the particular section are in the test/disconnection position),
4. prevent access to the withdrawable module drive when racking the module requires additional conditions.

Interlocks are always designed to fit to a particular project.

On arrangement with the switchgear's manufacturer, it is possible to install additional interlocks, which operate based on limiting switches and electromagnetic locks.

The door design allows them to be unlocked in an emergency and the compartment to be accessed when needed.

Switchgear equipment

Switchgear equipment

Switching devices

The switchgear may be equipped as standard with VB-4 (ZPUE), SION (Siemens), VD4 (ABB), HVX (Schneider Electric) vacuum circuit breakers; HD4 (АВВ) gas insulated circuit breakers; 3TM (Siemens), ConVac (ABB) contactors. Other devices may be used on arrangement with the switchgear manufacturer. A fast earthing switch type US1 (ZPUE) or EK6 (ABB) is used to provide the highest level of safety. As standard, NAL/NALF (ABB) type devices are used as switch disconnectors.

Metering instrumentation

Transformers by different manufacturers are used for metering purposes. Bay voltage indication utilizes capacitive insulators or transformers with voltage dividers and a voltage indicator.

Protection devices

The switchgear can be equipped with low voltage devices by any manufacturer, according to the individual needs of the customer. It is also possible to install any digital protection relay, or IED.

An internal arc protection system can be installed in the switchgear. The systems sense the internal arc by detecting the flash and an additional voltage or current criteria inside the protected switchgear. When these two events occur simultaneously, the system is activated and a circuit breaker tripping impulse is sent.

Diagrams of primary and auxiliary circuits, switchgear automation

Diagrams of primary and auxiliary circuits, switchgear automation

Primary circuits

Structural diagrams of primary circuit examples are shown on Figure 2. The connection compartment's equipment varies depending on the bay type. Alternative solutions to the ones presented can be implemented on arrangement with the manufacturer.

Auxiliary circuits

LV auxiliary circuits consist of: protection relays, metering, control, automation and signalling systems. An auxiliary circuits compartment located at the front, top part of the switchgear cabinet is intended for the devices of these circuits.

The dimensions of the compartment and example arrangement of devices are presented on figures 3 and 4.

Diagrams of example internal and assembly connections for primary and auxiliary devices for a typical switchgear equipment can be obtained by contacting the switchgear manufacturer.

Switchgear automation

The switchgear is designed to operate in SCADA systems. With this goal in mind it is equipped with digital protection relays (with possible digital communication) and automation systems. The switchgear can then operate in master control systems and automated control systems.

Switchgear packaging, transport and installation

Switchgear packaging, transport and installation

Packaging

Three packaging methods are used for RELF type switchgears:

1. standard packaging - the switchgear cubicle is placed on a pallet and wrapped with shrink wrap,
2. in boxes - switchgear cubicles are packaged as described above and put into boxes,
3. maritime transport packaging - switchgear cubicles with inserted moisture absorbing material are placed in barrier plastic sheet bags, which are evacuated. The switchgears protected in this manner are transported on pallets or in boxes.

Transport

Switchgears are transported as single cubicles. Transport in the room and to the room in which the switchgear is to be installed can be done with a crane, forklift, or on rollers.

For crane transport, the cubicle is equipped with transport lugs. The angle of lifting ropes should not exceed 120°. Attaching the lifting ropes directly to the cabinet structure is prohibited. To enable lifting the switchgear with a forklift, the cubicle is placed on a transport pallet.

During the transport and installation of the switchgear cubicle, special care should be taken to not to damage the paintwork and steel sheet enclosures.

Main devices, such as circuit breakers, contactors, withdrawable modules, and LV devices sensitive to vibrations, are transported separately in the manufacturers' original packages.

Switchgear installation

The manner of switchgear placement and external cable and busbar connections depend on the design of the facility where it will be installed. These connections should be performed according to the instructions established during arrangements with the switchgear manufacturer. The switchgears can be placed directly on concrete floor, on foundation frame attached to the floor, or on a steel or concrete structure of the facility.

Regardless of the type of foundation, switchgears must be placed exactly horizontally and attached to the foundation.

The placement of the switchgear in a room is presented on figures 5a,b,c. The X dimension depends on the manner in which the switchgear is placed:

• for a wall-mounted placement the recommended distance is at least 100 mm,
• for free-standing placement, full opening of the rear doors requires an X not less than the width of the widest bay of the switchgear.

Recommended minimum distance from closed safety flaps on the switchgear roof to the room ceiling: 600 mm.

Due to the switchgear installation technology it is recommended that the Y dimension of the room be at least 1000 mm higher than the total length of the switchgear.

The recommended minimum room doors height A for the switchgear should be higher by at least 350 mm than the height of the switchgear.

On figure 6a,b,c example dimensions for holes to be made in the floor for cable entries are shown. They should be treated as demonstrations, and their exact location agreed upon when ordering the switchgear.

On figure 7a,b the load bearing/installation frame of the RELF and RELFex switchgear is shown, with holes for attaching the switchgears to the foundation, on figure 8 - methods for attaching the switchgears to the foundation.

Standard equipment delivered with the switchgear

Standard equipment delivered with the switchgear

Standard equipment delivered with the switchgear

Each switchgear is equipped with:

• fasteners for connecting all the units together,
• withdrawable module racking crank,
• earthing switch drive crank,
• withdrawable module transport cart (with the exception of RELF 36),
• cabinet key doors.

Documents delivered with the switchgear:

• declaration of conformity,
• switchgear manual,
• operation and maintenance manuals and warranty cards for the used devices,
• as-built documentation for the switchgear,
• warranty card.

Drawings

Drawings

List of figures

• Figure 1a - RELF bay equipment - version I
• Figure 1b - RELF bay equipment - version II
• Figure 1c - RELF 36 bay equipment
• Figure 1d - RELF ex bay equipment
• Figure 2a - Structural diagrams of RELF and RELF ex primary circuits
• Figure 2b - Structural diagrams of RELF 36 primary circuits
• Figure 3a - RELF bay auxiliary circuits compartment - version I
• Figure 3b - RELF bay auxiliary circuits compartment - version II
• Figure 3c - RELF 36 bay auxiliary circuits compartment
• Figure 3d - RELF ex bay auxiliary circuits compartment
• Figure 4a - Examples of device layout in the RELF bays auxiliary circuits compartment
• Figure 4b - Examples of device layout in the RELF ex bays auxiliary circuits compartment
• Figure 5a - Placement of the RELF switchgear
• Figure 5b - Placement of the RELF 36 switchgear
• Figure 5c - Placement of the RELF ex switchgear
• Figure 6a - Example dimensions of the cubicle bases and floor holes for RELF bays
• Figure 6b - Example dimensions of the cubicle bases and floor holes for RELF 36 bays
• Figure 6c - Example dimensions of the cubicle bases and floor holes for RELF ex bays
• Figure 7a - RELF switchgear support frame
• Figure 8 - Mounting the switchgear on the floor

Figure 1a - RELF bay equipment - version I

Figure 1a - RELF bay equipment - version I

1. main device: circuit breaker, contactor
2. current transformers
3. earthing switch
4. voltage transformers
5. spouts
6. bushings
7. capacitive post insulators
8. main busbars
9. outgoing busbars
10. earth fault transformer
11. earthing busbar
12. shutters
13. cable tray (optional)
14. safety flaps

Figure 1b - RELF bay equipment - version II

Figure 1b - RELF bay equipment - version II

1. main device: circuit breaker, contactor
2. current transformers
3. earthing switch
4. voltage transformers
5. spouts
6. bushings
7. capacitive post insulators
8. main busbars
9. outgoing busbars
10. earth fault transformer
11. earthing busbar
12. shutters
13. cable tray (optional)
14. safety flaps

Figure 1c - RELF 36 kv bay equipment

Figure 1c - RELF 36 kv bay equipment

1. main device: circuit breaker
2. current transformers
3. earthing switch
4. surge arresters
5. spouts
6. bushings
7. main busbars
8. outgoing busbars
9. earthing busbar
10. shutters mechanism
11. safety flaps
12. protective relay

Figure 1d - RELF ex bay equipment

Figure 1d - RELF ex bay equipment

1. withdrawable circuit breakers
2. earthing switch
3. current transformers
4. voltage transformers (option)
5. protection relay
6. outgoing busbars
7. bushings
8. spouts
9. safety flaps
10. LV compartment
11. earth fault transformer
12. surge arresters

Figure 2a - Structural diagrams of RELF and RELF ex primary circuits

Figure 2a - Structural diagrams of RELF and RELF ex primary circuits

Figure 2b - Structural diagrams of RELF 36 kV primary circuits

Figure 2b - Structural diagrams of RELF 36 kV primary circuits

Figure 3a - RELF bay auxiliary circuits compartment - version I

Figure 3a - RELF bay auxiliary circuits compartment - version I

Figure 3b - RELF bay auxiliary circuits compartment - version II

Figure 3b - RELF bay auxiliary circuits compartment - version II

Dimensions [mm]
H	600	600	600	400	400	400
S	995	795	645	995	795	645
H1	500	500	500	350	350	350
S1	900	700	550	900	700	550

Figure 3c - RELF 36 kV bay auxiliary circuits compartment

Figure 3c - RELF 36 kV bay auxiliary circuits compartment

Figure 3d - RELF ex auxiliary circuits compartment

Figure 3d - RELF ex auxiliary circuits compartment

Figure 4a - Examples of device layout in the RELF bays auxiliary circuits compartment

Figure 4a - Examples of device layout in the RELF bays auxiliary circuits compartment

Figure 4b - Examples of device layout in the RELF ex bays auxiliary circuits compartment

Figure 4b - Examples of device layout in the RELF ex bays auxiliary circuits compartment

Figure 5a - Placement of the RELF switchgear

Figure 5a - Placement of the RELF switchgear

Notice:
In case of specific requirements that affect the switchgear cubicle dimensions, please contact the switchgear manufacturer.

Figure 5b - Placement of the RELF 36 kV switchgear

Figure 5b - Placement of the RELF 36 kV switchgear

Notice:
In case of specific requirements that affect the switchgear cubicle dimensions, please contact the switchgear manufacturer.

Figure 5c - Placement of the RELF ex switchgear

Figure 5c - Placement of the RELF ex switchgear

Notice:
In case of specific requirements that affect the switchgear cubicle dimensions, please contact the switchgear manufacturer.

Figure 6a - Example dimensions of the cubicle bases and floor holes for RELF bays

Figure 6a - Example dimensions of the cubicle bases and floor holes for RELF bays

Floor hole layout for cubicles with a width of 1000 mm

Floor hole layout for cubicles with a width of 650 mm

Floor hole layout for the range of cubicles with a depth of 1250 mm

Dimensions [mm]
S	600	750	950

Note:
The presented solutions are examples. Solutions for specific projects available after contacting the manufacturer.

Figure 6b - Example dimensions of the cubicle bases and floor holes for RELF 36 kV bays

Figure 6b - Example dimensions of the cubicle bases and floor holes for RELF 36 kV bays

Note:
The presented solutions are examples. Solutions for specific projects available after contacting the manufacturer.

Figure 6c - Example dimensions of the cubicle bases and floor holes for RELF ex bays

Figure 6c - Example dimensions of the cubicle bases and floor holes for RELF ex bays

Dimensions [mm]
H	650	800	1000
G1	310 mm - for 2 cable / phase 560 mm - for 4 cable / phase

Note:
The presented solutions are examples. Solutions for specific projects available after contacting the manufacturer.

Figure 7a - RELF switchgear support frame

Figure 7a - RELF switchgear support frame

Dimensions [mm]
G	1180	1180	1180
S	600	750	950
S1	350	500	700

Dimensions [mm]
G	1500		1550	1563		1600		1650
S	650	800	650	800	1000	800	1000	1000
S1	400	500	400	500	700	500	700	700

Figure 7b - RELF ex switchgear support frame

Figure 7b - RELF ex switchgear support frame

Dimensions [mm]
S	400	550	750
G1	650	800	1000

Figure 8 - Mounting the switchgear on the floor

Figure 8 - Mounting the switchgear on the floor

RELF 12 kV and 17.5 kV with a cabinet depth of 1250 mm

RELF 12 kV i 17,5 kV / RELFex

RELF 24 kV

RELF 36 kV

Data sheet examples

Characteristics of the switchgear

Characteristics

The RXD type switchgear is designed to operate in substations of generation, distribution and industry companies.

It meets the requirements of the (PN-EN) IEC 62271-200 and (PN-EN) IEC 62271-1 standards, provides an IP4X protection degree acc. to (PN-EN) IEC 60529. It is intended for operation in normal conditions, as specified by the (PN-EN) IEC 62271-1 standard.

The switchgear is designed in a manner that ensures that normal operation, inspections and maintenance operations may be performed in a safe manner.

In order to protect against corrosion it uses a frame-less design made of zinc-coated steel sheet, and the doors and side covers of outer bays are powder painted.

Types of Bays

The switchgear may be composed of various functional units:

• incoming/outgoing bays,
• coupler bays,
• metering bays with the possibility of earthing of the main busbars,
• switch disconnector bay,
• transformer bay,
• reactive power compensation bay.

The withdrawable module of the switchgear may be equipped with a circuit breaker, contactor, sectionalizer or a set of fused voltage transformers.

It may be placed in the positions of: service, test/disconnection and separation.

Advantages

• air insulated,
• design constructed with zinc-coated, riveted steel sheets, without welding,
• loss of service continuity - LSC2 for 12 kV and LSC1 for 36 kV,
• version with main busbars in a separate compartment with PM class partitions - for 12 kV,
• high operational safety,
• IAC AFLR internal arc classification,
• interlocks and protections against performing incorrect switching operations,
• wall-standing or free-standing versions, access from the front of the cubicle,
• wide range of devices and bays types,
• possibility of expanding the switchgear with additional bays,
• ease of operation.