Interlocks
30
NXAIR /
≤ 40 kA
110-0134.9 / 14
7.2
Mechanical interlocks in panel versions with switching-device trucks
Action
Internal preconditions
Inserting the switching-device truck in the panel
Switching-device truck available
Pulling the switching-device truck out of the panel
None
Racking the switching-device truck to service
position
Switching-device truck inserted and interlocked
Low-voltage connector plugged
High-voltage door closed
Circuit-breaker in OPEN position /
contactor in OPEN position
Feeder earthing switch in OPEN position
Plugging on the low-voltage connector
Consistent coding between connector and
switching-device truck fulfilled
1)
Racking the switching-device truck to test position
Circuit-breaker in OPEN position /
contactor in OPEN position
Closing the circuit-breaker
Switching-device truck in interlocked end position
(test position or service position)
Closing the circuit-breaker / closing the contactor
Undervoltage release not electrically operated
Closing the contactor
HV HRC fuse-links not tripped
Opening the circuit-breaker / opening the contactor
None
Operating the feeder earthing switch
Switching-device truck in test position
Operating the busbar earthing switch
None (see note below)
Opening the high-voltage door
Switching-device truck in test position
Closing the high-voltage door
Low-voltage connector plugged on
1)
Not feasible with contactor panel with panel width 435 mm
7.3
Mechanical interlocks in panel versions with switch-fuse combination
Action
Internal preconditions
Operating the switch-fuse combination
Feeder earthing switch in OPEN position and high-
voltage door closed
Operating the feeder earthing switch
Switch-fuse combination in OPEN position and
high-voltage door closed
Opening the high-voltage door
Switch-fuse combination in OPEN position