Standards

IEC 62271-100 high voltage alternating current circuit breakers

IEC 62271-105: alternating current switch-fuse Combination

IEC 62271-102: alternating current disconnectors and earthing switches

IEC 62271-200 A.C. metal enclosed switchgear and controlgear for rated voltage above 1 kV and up to and including 52 kV

IEC 62271-103 high voltage switches for rated voltage above 1 kV and less than 52 kV

IEC 60694: Common specifications for high-voltage switchgear and controlgear standards

IEC 60265-1 Switches for rated voltages above 1 kV and less than 52 kV

IEC 60529: Degrees of protection provided by enclosures (IP Code)

Service environment:
a) Air temperature:Maximum temperature: +40ºC; Minimum temperature:-25ºC

b) Humidity:Monthly average humidity 95%; Daily average humidity 90% .

c) Altitude above sea level:Maximum installation altitude: 3000m

d) Ambient air not apparently polluted by corrosive and flammable gas, vapor etc.

e) No frequent violent shake

Technical data

1) Depending on the current rating of the fuse-link    2) Limited by high voltage fuse-links

^GRM gas insulated ring main unit is for the secondary distribution network 11/17.5/24/36 kV. It  is a completely sealed system with a stainless steel tank containing all live parts and switching functions. A sealed steel tank with constant atmospheric conditions ensures a high level of reliability as well as personnel safety and a virtually maintenance-free system.
It offers a choice of either switch-fuse combination or circuit-breaker with relay for protection of the transformer. SafeRing can be supplied with an integrated remote control and monitoring unit

Switch Module:
The switch Module is a three position switchdisconnector and earthing switch using SF6 gas as an arc quenching medium.
The switch position is close - open - earthed. In the open position the switch satisfies the disconnector requirements. 

F Module:
The switch-fuse module has a three position switch disconnector and earthing switch identical to the switch module.
By means of the fuse tripping device it operates as a switchfuse combination. There is a double earthing switch which in earthed position connects earth to both sides of the fuse-links simultaneously.
Both earthing switches are operated in one operation. The switch-fuse and earthing switch is mechanically interlocked to prevent hazardous access to the fuse-links.
The lower cover which gives access to the fuse-links is also mechanically interlocked with the earthing switch.

V Module:
The vacuum circuit-breaker module has vacuum bottles as interrupters of the current.
In series with the circuit-breaker main circuit is connected a three-position disconnector / earthing switch.
The operation between vacuum circuit-breaker and disconnector/ earthing switch is mechanically interlocked.