Rotoblok SF

Construction of MV type Rotoblok SF allows for flexible putting together boxes of each type of the family. The simple yet robust design ensures operational reliability, safety and arc-proof.

General description

Medium Voltage switchgear - Rotoblok SF

The subject of this document is a Rotoblok SF type state-of-the-art, indoor medium voltage switchgear intended for distribution of three-phase alternating current with a frequency of 50 Hz, at a rated voltage up to 25 kV, in industrial and commercial power sector distribution grids. The switchgears are configured from standard single modules with varied equipment. The information and technical data specified herein enable the designer to assemble a switchgear from typical modules. In case modules with equipment not specified herein or with changed dimensions are needed, the scope of equipment should be arranged with the manufacturer.

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.

Basic electrical data:
  Rotoblok SF
Rated network voltage 20 kV
Highest device voltage 25 kV
Rated frequency / number of phases 50 Hz / 3
Rated short-time network frequency withstand voltage 50 kV / 60 kV
Rated withstand lightning surge voltage 1.2/50 μs 125 kV / 145 kV
Continuous rated current 630 A
Rated short-time withstand current 20 kA (1s)
Rated peak withstand current 50 kA
Resistance to internal arc effects 16 kA (1s)
IP protection rating IP4X
Service conditions:
Ambient temperature  
- peak short-time
+ 40°C
- highest day average
+ 35°C
- highest annual average
+ 20°C
- lowest long-term
+ 25°C1)
Relative humidity of air  
- highest day average
95%
- highest month average
90%
- highest day average vapour pressure
2,2 kPa
- highest month average vapour pressure
1,8 kPa
Atmosphere at the place of installation no significant contamination with salt, vapour,
dust, smoke, flammable or corrosive
gasses and lack of icing,
frosting and dewing
Installation altitude up to 1000 m asl2)
Vibrations vibrations caused by external
factors or earthquakes negligible

Note:
*1) Unless the manufacturer of instrumentation & control and protection devices has specified otherwise.
*2) If the switchgear installation altitude is higher than 1000 m ASL the switchgear insulation level should corrected by an indicator in accordance with the guidelines of item 2.2.1 of the PN-EN 62271-1 standard.

Rated power of transformers that can be connected and disconnected using GTR SF 2V, GTR SF 2VM switch disconnectors, depending on voltages on the MV side:
Rated network voltage Rated current Max. transformer power
6 kV 77 A 800 kVA
10 kV 57,7 A 1000 kVA
15 kV 61,6 A 1600 kVA
20 kV 57,7 A 2000 kVA

In Rotoblok SF type switchgear typical fuse links are used acc. to the IEC 282-1, DIN 43625 standard, with thermal protection.

Switching devices
  • GTR SF 1 - switch disconnector with earthing switch,
  • GTR SF 1M - switch disconnector with earthing switch and motor drive,
  • GTR SF 2V - fused switch disconnector with earthing switch,
  • GTR SF 2VM - fused switch disconnector with earthing switch and motor drive,
  • GTR SF 4 - disconnector with earthing switch,
  • VCB GIS circuit breaker with disconnector and earthing switch.

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

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

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

Feeder bay

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 Type (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

Construction of switchgear type Rotoblok SF

Side view and dimensions

Rotoblok SF - 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)

Electrical diagram

Electrical diagram Rotoblok SF - feeder bay

Front view

Front view Rotoblok SF - feeder bay

mass = 175 kg

Note!
Optional equipment is marked with red.

SL2 (line feeder)

Electrical diagram

Electrical diagram Rotoblok SF - feeder bay

Front view

Front view Rotoblok SF - feeder bay

mass = 190 kg

Note!
Optional equipment is marked with red.

ST2 (transformer feeder)

Electrical diagram

Electrical diagram Rotoblok SF - transformer bay

Front view

Front view Rotoblok SF - transformer bay

mass = 210 kg

Note!
Optional equipment is marked with red.

SP1 (metering unit)

Electrical diagram

Electrical diagram Rotoblok SF - metering bay

Front view

Front view Rotoblok SF - metering bay

mass = 390 kg

Note!
Optional equipment is marked with red.

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

Electrical diagram

Electrical diagram Rotoblok SF - bus coupler bay with disconnector or switch
disconnector on the left side

Front view

Front view Rotoblok SF - bus coupler bay with disconnector or switch
disconnector on the left side

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)

Electrical diagram

Electrical diagram Rotoblok SF - bus coupler bay with disconnector or switch disconnector on the left side

Front view

Front view Rotoblok SF - bus coupler bay with disconnector or switch disconnector on the left side

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)

Electrical diagram

Electrical diagram Rotoblok SF - lightning arrester bay

Front view

Front view Rotoblok SF - lightning arrester bay

mass = 100 kg

Note!
Optional equipment is marked with red.

SŁ2 (Incoming cable-connection feeder)

Electrical diagram

Electrical diagram Rotoblok SF - switch bay

Front view

Front view Rotoblok SF - switch bay

mass = 100 kg

STpwł4 (auxiliary transformer unit)

Electrical diagram

Electrical diagram Rotoblok SF - auxiliary transformer bay

Front view

Front view Rotoblok SF - auxiliary transformer bay

Note!
Optional equipment is marked with red.

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

Electrical diagram

Electrical diagram Rotoblok SF - bay with an auxiliary transformer with a max. power of 25 kVA

Front view

Front view Rotoblok SF - bay with an auxiliary transformer with a max. power of 25 kVA

Note!
Optional equipment is marked with red.

SWG1 (circuit breaker feeder)

Electrical diagram

Electrical diagram Rotoblok SF - transformer bay

Front view

Front view Rotoblok SF - transformer bay

Note!
Optional equipment is marked with red.

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

Electrical diagram

Electrical diagram Rotoblok SF - transformer bay

Front view

Front view Rotoblok SF - transformer bay

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))

Electrical diagram

Electrical diagram Rotoblok SF - transformer bay with voltage measurement)

Front view

Front view Rotoblok SF - transformer bay with voltage measurement)

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)

Electrical diagram

Electrical diagram Rotoblok SF - bus coupler bay

Front view

Front view Rotoblok SF - bus coupler bay

Note!
Optional equipment is marked with red.

MV switchgear (medium voltage)

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