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5.1. Interlocks
5.1.1. interference blocking
A mechanical plug interference blocking in the circuit-breaker
compartment prevents under rated circuit-breakers from
being inserted into higher rated compartments. The code
plate rating includes continuous current, interrupting current,
close and latch capability, and maximum voltage.
interlocks / protection against malfunction (for
withdrawable circuit-breakers for abb switchgear)
The Vmax/w circuit-breaker contains a number of interlocks.
MODIFICATION TO INTERLOCkS CAN
RESuLT IN SERIOuS bODILy INjuRy OR
DEATH. DO NOT OVERRIDE, by-PASS OR
ADjuST INTERLOCkS.
DANGER
These interlocks are provided to prevent incorrect operations
and/or malfunctions. The interlocks are the following:
• the withdrawable truck can only be moved from the test/
isolated position to the service position (and vice versa) if
the circuit-breaker is open (this means that first of all the
circuit-breaker must be opened).
• the circuit-breaker can be closed if the withdrawable truck
is exactly in the defined disconnected position or in the
connected position (electric interlock).
• the circuit-breaker can be opened manually in the service or
test position when it is not powered.
• the switchgear is provided with devices which only allow
connection and disconnection of the plug connector (3)
(fig.2A) in the test/ isolation position.
5.1.2. interlocks in the case where abb
withdrawable trucks are used
1) The Vmax/w circuit-breaker can only be closed when the
withdrawable truck is in the test or service position.
2) A mechanical interlock positioned on the withdrawable
truck prevents a closed circuit-breaker from being moved
from the test position to the service position.
3) Vmax/w circuit-breaker can only be racked-in/ isolated if
the locking electromagnet in the truck is supplied (as well
as being open) if available in the truck.
Positive position for removal
The handle release pin prevents withdrawing the circuit-
breaker from the compartment by blocking withdrawal of
the locking tabs. The handle release pin blocks the handles
unless the circuit-breaker is in the Disconnect position.
5. Operation, installation and maintenance
