Technical description
Use of MV type Rotoblok
Modern, indoor medium voltage ROTOBLOK type switchgear cubicles. They are designed for the distribution of three-phase electricity with 50 Hz rated frequency, and rated voltage up to 25 kV in industrial distribution networks. Switchgears are configured from single typical modules with diverse accessories. Information and technical data included in this catalogue allow the designer to build a switchgear from typical modules.
If different modules or dimensions are needed to configure and design the switchgear, please contact the manufacturer.
Characteristics
The ROTOBLOK type switchgear cubicle is an indoor, two-compartment switchgear, in a galvanized steel sheet housing (which assures potential equalization), with a single primary busbar system. The switchgear is equipped with an advanced air insulated switchgear apparatus. The cubicle has separated primary busbars and cable compartments, while the arc-proof design ensures a high level of operator safety.
Rotoblok distribution bays have the following properties:
- small dimensions compared to rated voltage, defined insulation level, primary busbars rated current and fault currents,
- two-compartment bays construction allowing the primary busbars to be divided from the power cable connections compartment,
- high operation reliability,
- long operation without the need for service and maintenance operations,
- high corrosion resistance: the switchgear cubicle structure is made from sheets covered with a layer of zinc-aluminum alloy,
- universality in designing different switchgear configurations with any number of bays,
- advanced and reliable switchgear apparatus including the disconnectors and GTR type disconnectors (ZPUE), VB-4S circuit breakers (ZPUE) or circuit breakers from other manufacturers,
- adapted for installation of modern equipment security-control,
- the possibility to mount the switchgear cubicle on the wall helps to save space in the distribution room, which is important during modernization and expansion of existing switchgears,
- quick and easy access to monitor and maintain the switchgear units,
- simple operation.
Safety and interlock system
The safety interlock system prevents incorrect switching procedures and opening the distribution bay door before switching off the power supply and closing the grounding switch. Opening of the grounding switch is possible only when the bay door is closed (or after purposeful release of the interlock using a special key provided with the switchgear – for example in order to test the voltage of a cable). Every feeder and circuit breaker bay is normally equipped with capacitive voltage dividers on each phase, and a voltage indicator. This facilitates checking for lack of voltage on a cable and safe phase detection.
At the request of the client it is possible to equip the switchgear with bay capacitive voltage dividers, which are not available in standard equipment.
High operation safety is achieved through:
- arc-proof design - resistance to internal arcing effects,
- specially reinforced bay structure (enclosures, locks, hinges),
- mechanical interlocks, which prevent incorrect switching procedures and touching the live apparatus,
- access to control gear and control circuits is possible when primary circuits are out of the operator’s reach,
- application of monitoring, signaling, and mechanical circuits, electric position indicators, and inspection windows,
- visual indicator of disconnector contacts, switch-disconnector and grounding switch condition, and installing inspection windows in order to control these units,
- possibility to disconnect the switch-disconnector without an operating lever (optional – GTR 2, GTR 2V),
- application of disconnectors and switch-disconnectors, which create visible double separation,
- maintaining the order of the 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 – Part 1: Common specifications”,
- PN-EN 62271-200 - “High Voltage Switchgear and Controlgear – Part 200: Altering current 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: Alternating current circuit breakers”,
- PN-EN 62271-102 - “High Voltage Switchgear and Controlgear – Part 102: High voltage altering current disconnectors and grounding switches”,
- PN-EN 62271-103 - “High Voltage Switchgear and Controlgear – Part 103: Disconnectors with rated voltages above 1 kV and up to and including 52 kV”,
- PN-EN 62271-105 - “High Voltage Switchgear and Controlgear – Part 105: Alternating current switch-fuse combinations”.
Certified by the Electrotechnical Institute.
Technical data: | ||
Rotoblok 17,5kV
|
Rotoblok 24
|
|
Nominal grid voltage |
15 kV
|
20 kV
|
Highest apparatus voltage |
17,5 kV
|
25 kV
|
Rated frequency / number of phases |
50 Hz / 3
|
|
Rated power frequency withstand voltage |
55 kV / 63 kV
|
50 kV / 60 kV
|
Rated lightning impulse withstand voltage 1,2/50 µs |
95 kV / 110 kV
|
125 kV / 145 kV
|
Rated continuous current |
630 A
|
630 A - 1250*1) A
|
Rated short-time withstand current |
up to 16 kA (1s)
|
up to 20 kA (1s)
|
Rated peak current strength |
up to 40 kA
|
up to 50 kA
|
Internal arcing class (IAC) |
AF up to 16 kA (1s)
|
|
Degree of protection |
IP4X
|
Service conditions: | |
Ambient temperature | |
- short-time maximum
|
+ 40°C
|
- maximum daily average
|
+ 35°C
|
- maximum yearly average
|
+ 20°C
|
- lowest prolonged
|
+ 25°C1)
|
Relative humidity | |
- maximum daily average
|
95%
|
- maximum monthly average
|
90%
|
- maximum daily average of vapour pressure
|
2,2 kPa
|
- maximum monthly average of vapour pressure
|
1,8 kPa
|
Atmosphere in installation location | no significant salt, steam, dust, smoke, flammable or corrosive gases pollution, and no icing, frost and dew |
Installation altitude | up to 1000 meters above sea level2) |
Vibrations | vibrations caused by external causes or earthquakes are not taken into account |
Notice:
*1) Unless the control-metering and protection unit manufacturer have stated otherwise.
*2) If the mounting altitude of the switchgear cubicle is higher than 1000 meters above sea level, the level of the switchgear insulation should be adjusted using an indicator compliant to 2.2.1 paragraph regulations of the PN-EN 62271-1 standard.
Transformer rated power that can be connected and disconnected using GTR 2V disconnector depending on medium voltage: | ||
Nominal grid voltage | Rated current | Maximum transformer rated power |
6 kV | 60,6 A | 630 kVA |
10 kV | 57,7 A | 1000 kVA |
15 kV | 48,1 A | 1250 kVA |
20 kV | 46,2 A | 1600 kVA |
Regarding transformers with higher power, please contact the manufacturer.
In the Rotoblok type switchgear typical fuse links there are used according to IEC 282-1, DIN 43625 standard, with thermal protection.
Construction of cubicles type Rotoblok
Each bay construction is composed of elements made from galvanized steel sheets and bolted or riveted. Each bay design allows easy integration into any switchgear set, as well as quick dismantling (for example, in order to install a single cell) and custom reconfiguration. Bays can be made broader than their standard dimensions. This is a very useful solution, for example, while replacing old, large-size switchgears (for example, RUe, M20) with the Rotoblok switchgear, which can result in some difficulties with the arrangement of old cables.
Each bay has two compartments, i.e. a frame and the main disconnector shaft, which form a mechanical and electrical partition between the lower part of the switchgear and the primary busbar. After opening the bay door, it is impossible to touch the primary busbar. Each bay is equipped with a bottom grounding switch (in the transformer bay it is situated under the fuse bases).
Each bay has a mechanical interlock system, which fulfils two primary tasks:
- prevents opening the door of any compartment before switching off the power supply and closing the grounding switch; as a result it prevents electric shock,
- maintaining the order of the switching operations.
Capacitive voltage dividers allow the voltage to be checked, and for safe “chamfering” from the front side of the bay, i.e. by a low voltage bipolar indicator without the need to open the door. In addition, inspection windows installed in the door allow the observation of each element in the bay, for example, the compartment, open circuits, condition of fuse links, interrupters, links, etc.
An auxiliary circuits compartment is located at the top of the circuit breaker bay. Here, auxiliary bay elements are installed, such as: clamping slats, relays, batteries, additional (or primary) interlock modules, etc.
Switching units
The primary switching units in the abovementioned bays are:
- switch disconnector type GTR1, GTR 2, GTR 2V (ZPUE)
- disconnectors type GTR 4, GTR 4W (ZPUE)
- circuit breakers type VB-4S (ZPUE), or from other manufacturers

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

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 - rearming socket and armed position indication
11 - activate/deactivate - switch
12 - grounding switch socket
13 - switch disconnector position indicator
14 - voltage indicator
15 - grounding switch position indicator
16 - door interlock leaver
17 - fuse-link position indicator
18 - fuse-folder frame
19 - fuse-link
20 - support insulator or capacitive voltage divider

1 - circuit breaker poles with vacuum interrupters
2 - medium voltage connections
3 - turn off button
4 - turn on button
5 - manual drive lever
6 - circuit breaker indicator
7 - indication of the drive arming
8 - operation meter
Feeder bay with manual drive
Standard equipment | |||
No. | Unit | Type | Amount |
1. | Switch-disconnector with grounding switch | GTR 1 lub GTR 2 | 1 |
2. | Primary busbar system | P 40x5 / P 40x10 | 3 |
3. | Capacitive voltage divider | DCL 20 | 3 |
4. | Cable clamp | UKZ | 3 |
5. | Cable duct | 3 | |
6. | Cable | 3 | |
7. | Neon voltage indicator, which cooperates with the capacitive voltage divider | 1 | |
8. | Switch disconnector contact (for GTR 1) | 1 | |
9. | Arming contact and indicator (for GTR 2) | 1 | |
10. | “activate” –“ deactivate” switch (for GTR 2) | 1 | |
11. | Grounding switch contact | 1 | |
12. | Inspection window | 1 | |
13. | Inspection glass allowing use of torch in case of light fault | 3 | |
14. | Warning plate | 1 | |
15. | Door handle | 1 |
Additional equipment at the request of the client: | ||
a | Current flow, short circuit indicator joined to the cable | 1 |
b | Current flow, short circuit indicator joined to the busbar | 3 |
Feeder bay with engine drive
Standard equipment | |||
No. | Unit |
Type | Amount |
1. | Switch-disconnector with lower grounding switch and engine drive adapted for remote control via cables or radio signal | GTR 1M lub GTR 2M | 1 |
2. | Primary busbar system | P 40x5 / P40x10 | 3 |
3. | Capacitive voltage divider | DCL 20 | 3 |
4. | Cable clamp | UKZ | 3 |
5. | Cable duct | 3 | |
6. | Cable | 3 | |
7. | Neon voltage indicator, which cooperates with the capacitive voltage divider | 1 | |
8. | Switch disconnector contact (for GTR 1M) | 1 | |
9. | Arming contact and indicator (for GTR 2M) | 1 | |
10. | “activate” –“ deactivate” switch (for GTR 2M) | 1 | |
11. | Grounding switch contact | 1 | |
12. | Inspection window | 1 | |
13. | Inspection glass allowing use of torch in case of light fault | 3 | |
14. | Warning plate | 1 | |
15. | Door handle | 1 | |
16. | Control panel of the engine drive | 1 | |
17. | “Close” button | 1 | |
18. | “Open” button | 1 | |
19. | Operation switch | 1 | |
20. | Auxiliary circuits compartment | 1 |
Additional equipment at the request of the client: | ||
a | Current flow, short circuit indicator joined to the cable | 1 |
b | Current flow, short circuit indicator joined to the busbar | 3 |
Transformer bay design
Standard equipment | |||
No. | Unit |
Type | Amount |
1. | Switch-disconnector with grounding switch | GTR 2V | 1 |
2. | Primary busbar system | P 40x5 / P 40x10 | 3 |
3. | Support insulator | IPA | 3 |
4. | Cable clamp | UKZ | 3 |
5. | Cable duct | 3 | |
6. | Cable | 3 | |
7. | Arming contact and indicator | 1 | |
8. | “activate” –“ deactivate” switch | 1 | |
9. | Grounding switch contact | 1 | |
10. | Inspection glass | 1 | |
11. | Inspection glass allowing use of torch in case of light fault | 3 | |
12. | Warning plate | 1 | |
13. | Door handle | 1 | |
14. | Fuse base, which is an integral part of the switch disconnector | 1 | |
15. | Fuse link | 1 |
Additional equipment at the request of the client: | |||
a | Fuse switch disconnector with grounding switch and engine drive | GTR 2VM | 1 |
b | Capacitive voltage divider | 3 | |
c | Neon voltage indicator, which cooperates with capacitive voltage divider | 1 | |
d | Disengaging coil | 1 | |
e | Choke to lead the cables using disengaging coil | 1 | |
Notice! The grounding switch in switch disconnector grounds the lower part of the fuse link. |
Disengaging coil cooperation in the transformer bay with gas-flowing or thermal protection of the transformer
Notice!
Cable cross-sections and protective currents should be selected according to disengaging coil supply voltage.
Coupler bay design
Standard equipment | |||
No. | Unit |
Type | Amount |
1. | Disconnector with lower grounding switch | GTR 4 | 1 |
2. | Primary busbar system | P 40x5 / P 40x10 | 3 |
3. | Capacitive voltage divider or support insulator | DCL 20 or IPA | 3 |
4. | Neon voltage indicator, which cooperates with the capacitive voltage divider | 1 | |
5. | Disconnector contact | 1 | |
6. | Grounding switch contact | 1 | |
7. | Inspection glass | 1 | |
8. | Inspection glass allowing use of torch in case of light fault | 3 | |
9. | Warning plate | 1 | |
10. | Door handle | 1 |
Additional equipment at the request of the client: | |||
a | Switch disconnector with lower grounding switch | GTR 2 | 1 |
b | Switch disconnector with lower grounding switch and engine drive | GTR 1M or GTR 2M | 1 |
Notice! It is possible to design the coupler bay without a lower grounding switch. |
RWT bay design
Standard equipment | |||
No. | Unit |
Type | Amount |
1. | Circuit breaker | VB-4S | 1 |
2. | Switch-disconnector with grounding switch | GTR 4 | 1 |
3. | Primary busbar system | P 40x5 / P 40x10 | 3 |
4. | Capacitive voltage divider | DCL 20 | 3 |
5. | Cable clamp | UKZ | 3 |
6. | Cable duct | 3 | |
7. | Cable | 3 | |
8. | Current switch, which cooperates with the protection unit | IP 24 / PP-20W / PP-15W | 3 |
9. | Protection unit | Mupasz / REF MiCOM | 1 |
10. | Neon voltage indicator, which cooperates with the capacitive voltage divider | 1 | |
11. | Disconnector contact | 1 | |
12. | Grounding switch contact | 1 | |
13. | Inspection glass | 1 | |
14. | Inspection glass allowing use of torch in case of light fault | 1 | |
15. | Warning plate | 1 | |
16. | Door handle | 1 | |
17. | Auxiliary circuits compartment | 1 | |
18. | Arming contact | 1 | |
19. | “activate” switch | 1 | |
20. | “deactivae” switch | 1 | |
21. | Arming indicator | 1 | |
23. | Control switches and lamps | 1 | |
24. | Cable tray | 1 | |
25. | Support frame | 1 |
RWS bay design
Standard equipment | |||
No. | Unit |
Type | Amount |
1. | Circuit breaker | VB-4S | 1 |
2. | Switch-disconnector with lower grounding switch | GTR 4 | 1 |
3. | Primary busbar system | P 40x5 / P 40x10 | 3 |
4. | Capacitive voltage divider | DCL 20 | 3 |
8. | Current switch, which cooperates with the protection unit | IP 24 / PP-20W / PP-15W | 3 |
9. | Protection unit | Mupasz / REF MiCOM | 1 |
10. | Neon voltage indicator, which cooperates with the capacitive voltage divider | 1 | |
11. | Disconnector contact | 1 | |
12. | Grounding switch contact | 1 | |
13. | Inspection glass | 1 | |
14. | Inspection glass allowing use of torch in case of light fault | 1 | |
15. | Warning plate | 1 | |
16. | Door handle | 1 | |
17. | Auxiliary circuits compartment | 1 | |
18. | Arming contact | 1 | |
19. | “activate” switch | 1 | |
20. | “deactivate” switch | 1 | |
21. | Arming indicator | 1 | |
23. | Control switches and lamps | 1 | |
24. | Cable tray | 1 | |
25. | Support frame | 1 | |
26. | Isolator bushing | 1 |
Control cable chart: “auxiliary circuits compartment”
Mounted in an auxiliary circuits compartment (17) are control bars, protection units, a control-metering unit, and switches. Based on the client-provided documentation, the manufacturer determines the position of the auxiliary circuit units in the switchgear. Cables and auxiliary circuits are led through the cable trays inside the compartment, and next through chokes outside the compartment. The auxiliary circuits in the remaining compartments are in protection tubes. The circular circuits between adjacent bays are in trays. It is recommended that auxiliary circuit cables be led from respective distribution bays to installation rooms through the cable channel or on cable ladders installed on the walls.
Cable tray under Rotoblok type MV switchgears
Below figures present optional cable tray performance. The tray depth for dry and oil-filled cables should be made in order to accommodate the radius of the cable, depending on its outside diameter, which determines the degree to which it can be bent, according to PBUE. It is possible to avoid the use of a cable tray, or reduce its depth, by using a high base or elevated floor.
Notice!: Minimum distance from wall – 30 mm
1) Exemplary bay with 700, 700, 900 mm width (from the left side)
2) Tray under the switchgear.
* - Rotoblok 17,5 kV switchgear depth
Notice!: Minimum distance from wall – 30 mm
1) Exemplary bay with 1000, 900 mm width (from the left side)
2) Tray under the switchgear.
Cable cross-section (mm2) | Bend 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 switchgear cable links
Switch disconnector and circuit breaker feeder bays | ||||
Cable type | Cable termination | |||
Manufacturer | Type | Cable cross-section [mm2] | ||
Cable type: single core with plastic sleeve, for example, YHAKXs, YHKX, XUHAKXs, XRUHKs, ... |
Tyco Electronics (Raychem) | POLT-24D/1XI | 70-240 | |
Barnier | 01100-EUIC | 50-240 | ||
01300-EUEP | 50-240 | |||
NKT (F&G) | EAVI 20 | 35-240 | ||
TI - 24 | 35-240 | |||
ABB | SEI (Um ≤ 24 kV) | 50-240 | ||
SEHDI 20.2 | 25-35 and 300-630 | |||
3M | QT II | |||
Set number | Set number | |||
93-EB62-1PL | 5641 | 25-95 | ||
93-EB63-1PL | 5642 | 95-240 | ||
93-EB64-1PL | 5643 | 250-500 | ||
Nexans (EUROMOLD) | ITK-224 | 25-240 | ||
CELLPACK | Unit number | Type | ||
266438 | CHE-I 24kV 25-150 | 25-150 | ||
266439 | CHE-I 24kV 70-240 | 70-240 | ||
Tri-core oil-filled cable with paper insulation saturated with non-running agent and common lining, for example: HAKnFta, KnY, KnFTA, ... *) |
Tyco Electronics (Raychem) | EPKT-24 B3MIH2-CEE01 | 25-50 | |
EPKT-24 C3MIH2-CEE01 | 70-185 | |||
EPKT-24 D3MIH2-CEE01 | 240-300 | |||
3M | QT II - Pb-W | |||
Set number | Set number to phase extension with 20 cm |
|||
93-FB615-3 | 93-P615-3 | 25-70 | ||
93-FB625-3 | 93-P625-3 | 70-185 | ||
93-FB635-3 | 93-P635-3 | 185-300 | ||
CELLPACK | Unit number | Type | ||
197532 | CHEP(H)-3I 24kV 25-150 | 25-150 | ||
197533 | CHEP(H)-3I 24kV 70-240 | 70-240 |
*) Notice: The manufacturer should be consulted regarding the manner of the cable and terminations connection.
Transformer bays | |
Cable type: single core with plastic sleeve, for example, YHAKXs, YHKX, XUHAKXs, XRUHKs, … |
As in feeder bays |
Tri-core oil-filled cable with paper insulation saturated with non-running agent and common lining, for example: HAKnFta, KnY, KnFTA, ... |
The manufacturer should be consulted regarding the manner of the cable and terminations connection |
Notice:
A cable tray is required under switchgears of any kind. Alternatively, the switchgear can be installed on a high base or elevated floor. If other cable terminations are used, please contact the manufacturer.
Various types of Rotoblok switchgear bays
* - Rotoblok switchgear 17,5 kV depth
Notice:
The pictures shown on the next pages 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 the pictures.
RL1 (feeder bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RL4 (feeder bay with meter)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RT1 (transformer bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RS1L1) (coupler bay with switch disconnector or disconnector on the left)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RS4 (coupler bay with switch disconnector Or disconnector on the left)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RP1 (metering bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RO1 (lightning arrester bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
1) It is possible to design the bay in mirror variant
2) It is possible to design the coupler bay without a lower grounding switch
RŁ2 (Coupler bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
Rtpwł4 (bay with auxiliary transformer)
Notice:
Optional equipment on the electrical diagram is marked in red.
RTpwł 25kVA + RT1 (bay with auxiliary transformer with maximum rated power 25kVA)
Notice:
Optional equipment on the electrical diagram is marked in red.
RWT (circuit breaker transformer bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
RWT3 (transformer bay)
Notice:
Optional equipment on the electrical diagram is marked in red.
RWTp14 (circuit breaker transformer bay)
Notice:
Optional equipment on the electrical diagram is marked in red.