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Faults and troubleshooting methods for KYN switchgears

May 15, 2017

 


Faults and troubleshooting methods for KYN movable high voltage switchgears


No.

Fault

Causes

Troubleshooting  

1

CB cannot be   closed

The CB trolley   is not at the right position.

Make sure if   the CB trolley is at test position or working position.

The wiring for   secondary control circuit is loosed.

Use screw   drawer to connect the loosed connector.

Closing voltage   is low.

Check if the   voltage at the two side of closing winding is low and regulate power supply voltage  

The block   winding or closing winding is broken or burned.  

Exchange block   winding or closing winding; check voltage at the two side of closing winding   is high or not and mechanical circuit is jammed or not.

2

CB cannot be   opened

The wiring for   secondary control circuit is loosed.

Use screw   drawer to connect the loosed connector.

Opening  voltage is low.

Check if the   voltage at the two side of opening winding is low and regulate power supply voltage  

Opening  winding is broken or burned.  

Check opening winding;   check voltage at the two side of opening winding is high or not, regulate   power supply voltage and mechanical circuit is jammed or not. Exchange opening   winding

3

CB trolley   cannot be rotated in when at test position

CB cannot move   when at closing position due to interlock mechanism; when CB is at open   status, CB trolley can move from test position to working position.

Make sure the   CB is opened.

CB trolley   cannot be moved when grounding switch is closed due to interlock mechanism.

Make sure   grounding switch is opened.

If grounding   switch is opened, but CB trolley cannot be rotated in, check if the operation   tongue piece at the grounding switch operation hole is at the right position.  

If operation   tongue piece is not reset, regulate grounding switch operation mechanism.

The working of   CB shutters is abnormal.

Check door   lifting mechanism  is deformed, jammed   or not and check if the working of CB chamber shutter is normal.

4

CB trolley   cannot be rotated out when at working position

CB cannot move   when at closing position due to interlock mechanism; when CB is at open   status, CB trolley can move from working position to test position. If CB is opened,   CB trolley still cannot be rotated out, the bottom plate is jammed normally.  

Make sure CB   is opened, then operate to check bottom plate mechanism.

5

Grounding   switch cannot be operated

Operation tongue   piece cannot be pressed down because cable side is electrified. ( interlock   requirement)

Analyze the   causes of electrifying.



Block magnetic   iron of grounding switch is not acted, operation tongue piece cannot be   pressed down.

Check block   power supply is normal , block magnetic iron is electrified. If the power   supply is normal but the block magnetic iron is not electrified, change block   magnetic iron.



There is   interlock between grounding switch and cable chamber due to FIVE PREVENTIONS;   if the door of cable chamber is not closed, grounding switch cannot be   closed.

Make sure the   cable chamber door is closed.



There is  fault on driving mechanism.

Check the   driving part