Home > Knowledge > Content

11kv up to 36kv Medium Voltage Sf6 Switchgear

Jul 22, 2017

Basic Info

  • Voltage Level: Medium Voltage

  • Structure: Cabinet

  • Specification: IEC, GB

  • HS Code: 8535210000

  • Certification: ISO9001

  • Installation: Fixed

  • Current: AC

  • Origin: China

Product Description
SF6 insulated Ring Main Unit
Gas Insulated Ring Main Unit
is a SF6 insulated ring main unit for the secondary distribution network. It can be supplied in 10 different configurations suitable for most switching applications in 12/24/36 kV distribution networks. As an option, it can be delivered as extendable ring main unit.Together, SF6 insulated Ring Main Unit represent a complete solution for 12/24/36 kV secondary distribution networks.

C - Cable switch moduleF - Cable switch moduleV - Cable switch module
D - Direct cable connection moduleDe - Direct cable connection module with earthing switchM - Metering module

Modularity and external busbar
All modules except the metering module and circuit-breaker module are only 325 mm wide.

Transformer protection
SF6 insulated Ring Main Unit offers a choice between a switch fuse combination and circuit breaker with relay for transformer protection. The switch fuse combination offers optimal protection against short-circuits, while the circuit breaker with relay option offers better protection against low overcurrents. Circuit breaker with relay is always recommended for larger transformers.

Normal operation conditions
The rated characteristics of the switchgear are valid under the following ambient conditions:
minimum ambient temperature: - 25 °C
maximum ambient temperature: + 40 °C

Tested according to following
IEC 62271-1/IEC 62271-100/IEC 62271-102/IEC 62271-103/IEC 62271-105/IEC 62271-200/IEC 60529:
SF6 insulated Ring Main Unit 

Outer assembly

outer assembly
Upper front cover
1. Manometer
2. Nameplate module
3. Short circuit indicator
4. Capacitive voltage indication
5. Load break / earthing switch position indicator
6. Push buttons close/open operation
7. Charged spring indicator
8. Self-powered protection relay
9. Vacuum circuit-breaker position
10. Operation shaft
11. Padlock device
Lower front cover
12. Nameplate switchgear
13. Fuse blown indicator
14. Disconnector / earthing switch position indicator
15. Capacitive voltage indication
Cable compartment cover
16. Cable compartment cover standard
17. Cable compartment cover with inspection window
18. Support bar (removable)
Side cover
19. Lifting lug
20. Operating handle (standard on right hand side)


Inner assembly

1. Mechanism compartment
2. SF6 gas tank
3. Cable compartment
4. Pressure relief area

Technical data

SF6 insulated Ring Main


Switch disconnectorEarthing switchSwitch-fuse disconnectorDownstream earthing switchVacuum circuit-breakerEarthing switch/ disconnector
Rated voltageKv12/17,5/2412/17,5/2412/17,5/2412/17,5/2412/17,5/2412/17,5/24
Rated frequency 5)Hz50/50/5050/50/5050/50/5050/50/5050/50/5050/50/50
Power frequency withstand voltagekV28/38/5028/38/5028/38/5028/38/5028/38/5028/38/50
Lightning impulse withstand voltagekV95/95/12595/95/12595/95/12595/95/12595/95/12595/95/125
Rated normal currentA630/630/630 2001) 200/200/200 
Breaking capacities:       
active loadA630/630/630     
closed loopA650/650/650     
off load cable chargingA140/140/140     
off load transformerA  20/20/20   
earth-fault cable chargingA117/91/91     
short-circuit breaking currentkV  see2) 16/16/16 
Making capacitykV52,5/40/4052,5/40/40see2)12,5/12,5/12,540/40/4040/40/40
Short time current 3 sec. 3)kV21/16/1621/16/16  16/16/1616/16/16