Operation & Maintenance Manual
20
COMMISSIONING
ELECTRICAL SWITCHING SEQUENCE FOR GIS INCOMING/ OUTGOING FEEDER PANEL
Q0 Circuit Breaker Q1 Busbar disconnecting switch Q2 Earthing Switch
(Q1 & Q2 incorporated in one 3 position switch)
INITIAL STATUS
Q1 - OFF
Q0 - OFF
Q2 - OFF
CONNECTING FEEDER
TO MAIN BUSBAR
Q1 - OFF to ON
Q0 - OFF
Q1 - ON
Q0 - OFF to ON
Q2 - OFF
Q2 - OFF
DISCONNECTING FEEDER
FROM MAIN BUSBAR
Q1 - ON to OFF
Q0 - OFF
Q2 - OFF
Q2 - OFF
Q1 - ON
Q0 - ON to OFF
SWITCHING SEQUENCE
STEP - 0
BUS
Q0
Q1
Q2
STEP - 1
BUS
Q0
Q1
Q2
STEP - 2
BUS
Q0
Q1
Q2
STEP - 3
BUS
Q0
Q1
Q2
STEP - 4
BUS
Q0
Q1
Q2
1) SWITCHING VCB
INITIAL STATUS
Q1 - OFF
Q0 - OFF
Q2 - OFF
CONNECTING CABLE
TO EARTH BUS
Q1 - OFF
Q0 - OFF
Q1 - OFF
Q0 - OFF to ON
Q2 - OFF to ON
Q2 - ON
DISCONNECTING CABLE
FROM EARTH BUS
Q1 - OFF
Q0 - OFF
Q2 - ON
Q2 - ON to OFF
Q1 - OFF
Q0 - ON to OFF
SWITCHING SEQUENCE
STEP - 0
BUS
Q0
Q1
Q2
STEP - 1
BUS
Q0
Q1
Q2
STEP - 2
BUS
Q0
Q1
Q2
STEP - 3
BUS
Q0
Q1
Q2
STEP - 4
BUS
Q0
Q1
Q2
2) CABLE EARTHING:
*BEFORE OPERATION, ENSURE FEEDER IS DEAD.
DURING ELECTRICAL OPERATION DO NOT INSERT OPERATING HANDLE
Note: The below operating sequence is standard operating sequence. If any key interlocks / key exchange are provided please refer
key interlock arrangement provided by Design.
