what are check points to be checked while charging
switchyard?(CT,PT,BREAKER,POWER TRANSFORMER)
Answer Posted / arun 9865576777
Transformer Commissioning Work
Preliminary Test
1. HT Switchgear End
 HT BKR IR Value
Open Condition Closed
Condition
R-RI= R-Y=
R-E=
Y-YI= Y-B=
Y-E=
B-BI= B-R=
B-E=
2. Transformer end
 TRF IR Value
Note: - Neutral earth should be open
LV line PT fuse& earth link open
15sec 60sec 600sec PI
HV-E
LV-E
HV-LV
After the above tests put back neutral earth line pt fuse&
earth link Connection properly.
3. LV Panel End
 LT BKR IR Value
Open Condition
Closed Condition
R-RI= R-Y=
R-E=
Y-YI= Y-B=
Y-E=
B-BI= B-R=
B-E=
Preliminary Checks
1. HT Switchgear End
 Check Relay Setting
 Check Tightness Of CT TB
 HT Cable Connection
 Interlock Trial
 Stability Check
 BKR Trial In Test Mode
 Check Fuse
 Check MTR Operation
 Reset The All Relay
 Check Control Supply
 Reset Max Value On Relay
2. Transformer End
 TRF Body Earth
 TRF Neutral Earth
 HT Cable Connection
 Check Tightness Of CT TB
 Check WTI,OTI (or) Door Inter Lock Trial
 Check OTI,WTI Setting
 LV Side Flexible Tightness
 Check Marshalling Box Control Supply
3. LV Panel End
 Check Relay Setting
 Check Tightness Of CT TB
 LV Side Flexible Tightness
 Check Line PT Fuse
 BKR Trial In Test Mode
 Check Control Fuse
 Check MTR Operation
 Check U/V Trip Throw Line PT
 Reset The All Relay
 Check Control Supply
Before Charging
 Line PT should be in service
 LV BKR should be open condition
After TRF Charging
 Note Down Electrical Parameter In HT Side & LT Side
 Phase Sequence In LT Side
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