NK(XGN-12/24/35kV/38kV) series fixed type indoor AC metal clad switchgear (SF6 RMU Abbreviation). one of minimized switchgear with the character of excellence reliability and maintenance free ,is a new product self –developed by R&D of  group based on the years experience in R&D and fabrication on products and on the advance technology of ABB SF6 LBS &ABB Uniswitch Safe-Ring\Safe-Plus.

The product is suitable for AC 3 to 24 / 35KV 38kVpower distribution system with configuration either ring

or radiant.. Its all live part including LBS,CB, ES and primary busbar are sealed in the tank made of

stainless steel and the elbow –shape cable connectors and adopted for the incoming or out-going, that

leds it is suitable for use in the bad ambient condition and relatively restricted space ,just like in

pre-fabricated substation, underground substation, industrial and mining enterprises or in high humidity

and heavy pollution area.

         The series of RMU is compliance with the following standards and its service life is mord than 20 years under normal ambient condition.

 

 27.5kV Fully insulated sealed inflatable cabinet breaker C-GIS zero gauge SF6

Special for High Speed railway (CRH)  Electric System

 

 

GB/T1022-1999 <<Common specifications for high-voltage switchgear and controlgear standars>>

IEC 694:1996 Common specifications for high-voltage switchgear and controlgear standards EQV

 

GB3804-2004 <<Alternating current high voltage load-breaker>>

(IEC 60265-1/FDIS: 1997 high voltage switchgear part 1:Swiches for rated voltage above 1KV and less than 52KV .MOD

 

 

GB/T1984-2003 <<Alternating current high –voltage circuit-breaker>>

(IEC 62271-100: 2001 high –voltage switchgear and controlgear part 100: high-voltage alternating-current circuit-breakers .MOD)

 

GB/T1984-2004<<High-voltage alternating-current disconnectors and earthing Switches>>

(IEC 62271-100: 2002 high –voltage  alternating-current disconnectors and earthing switches .MOD)

 

DL/T404-1997<<Indoor AC high voltage switchgear>>

(IEC298:1990 A.C metal-enclosed switchgear and controlgear for rated voltages above 1KV and up to including 52KV .EQV)

 

DL/.T791-2001<<Specifications of A.C. HV gas-filled switchgear panel >>

 (IEC420:1990   high-voltage alternating current switch-fuse combination and IEC 517-1990

Gas-insulated metal-enclosed switchgear for rated voltage of 72.5KV and above :MOD)

 

 

                                        

                   Product code of manufacturer

                   NK(XGN-12/24/35)

                   NK 

                          X  Cubicle Type

                             G  Fixde Type

                                 N  Indoor

                                   Design Series

                                        12/24/35/38/40.5 kV Rated Voltage

                                               (V、F、C、D)  

                                                      Combination Scheme

                                                      V:  

                                                      V: VCB unit

                                                       F:  

                                                       F : LBS-Fuse combination unit

                                                       C:  

                                                       C: LBS unit

                                                       D:  

                                                       D: in & Out Directly unit

                   

 

 

 

The outline and base structure of cubicle

1 Connecting bushing(for extending)

2 Fuse chamber

3 Cable chamber

4 Operating mechanism

5 Unit gas filled

6 Support frame

 

 

 

 

Features in configuration

The RMU consists of 5 portions :Gas filled chamber, Operation mechanism, Supporting frame,Cable chamber, Fuse chamber and Secondary circuit(LV) chamber

1 One tank design: Multi-circuit in one gas filled tank with agile combination to performance difference power distribution functions

2 With SF6 gas as insulated medium to reduce the volume greatly

3 Shield cable terminals with touchable surface and reliable safety character are suitable for abominable ambient condition

4 Using SF6 as the arc extinguishing medium ,the LBS which adopting gas-pressed are extinguishing principle is able to break the transfer current up to 2200A

5 The circuit breaker is vacuum type with high breaking capacity and no pollution to SF6 gas

6 There is a perfect mechanical interlock between LBS and ES.

7 The state of contacts can be chock in difference angles by eye easy from some viewing windows of tank filled

8 The cubicle is equipped with the living indicator, pressure gage and the over pressure releaser to ensure the safety of service

9 The tank filled with gas and made from stainless steel is earthing reliably to increase the electric safety

10 The fuse is barreled in insulated cylinder to prevent the pollution in which the fuse body is easy to replace

11 If need to extend to fit a bushing on the top of cubicle for extending is available

12 The multi-branch cable plugs and arresters can be fitted in bottom support chamber with vast space

 

  

 

 

   Product code of manufacturer

  

 

  

 

 

Operating mechanism

   Operating mechanism of LBS: Manual or motor,

Spring energy storing for performing fast C & fast O operation.

 

 

   Operating mechanism of ES:

Manual operating; The main earthing blade is provided with the capacity of making short circult current due its fast closing design.

There is a rellable mechanical interlock between the LBS and the ES,when the LBS is in close position the ES cannot be closed;when,contrarily,the ES is closed the LBS can not be closed.

 

 

 

 

The mechanism of LBS-Fuse combination unit:

   Manual or motor energize the O & C springs synchronously, The indicator of “ Spring energized “will appear after spring energized.

 

When closing ,the C spring release the energy stored quickly to close the LBS, the O spring keeps in energized estate, if the fuse is melted due to the fault current, then the  firing-pin of fuse strikes the releaser of LBS to open quickly.

 

When opening, the O spring will release the stored energy to perform the “ast open” by the opposition-operation of manual or motor (or by the shunt releaser or by the strike action of the firing-pin of fuse)

 

 

 

 

 

 

Operating mechanism of CB

Spring mechanism drives the close or open energy to CB by seal bellows driver

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas filled chamber

NK(XGN-12/24/35/38/40.5kV)series SF6 RMU is a kind of GIS ,its all HV living part are sealed in a stainless

Steel tank which filled with SF6 gas at 0.03Mpa in as insulation and arc extinguishing medium.

   There is a special absorbent inside ,to absorb the trace moisture of SF6 gas and the decompositions of SF6 by the function of arc and other impurity/.

  Each gas-filled tank of cubicle is equipped with a pressure gauge, and with a pressure releaser and the pressure relief channel. If the gas pressure in the tank rises up to abnormal value due to the arc or high temperature ,then the releaser is broken firstly by pressure to release the pressure therefore to ensure the

Safety of operator and the equipment.

 

 

  

 

 

 

 

 

LBS

The LBS adopts the princlple of straight move to compress gas to extinguish the arc.The current carrying part is apart from the arc-extinguishing prat,during the opening, the gas compressed by the piston

and cylinder with opposite movement blows to the arc quickly via a nozzle,then the arc is being stretched

and cooled off till quenched

 

 

 

 

 

 

 

 

LBS-Fuse combination unit

The fuse is barreled in insulated cylinder in which the fuse body is easy to replace from the

Front side of cubicle. The insulated cylinder is inserted in gas filled tank and with sealed well from

Tank ,so the gas in the tank can not leak and the fuse has a reliable contact with the living part in side.

If the fuse in any phase is melted due to the fault current, then LBS to be opened quickly.