Interlocks/Protection Against Malfunction - ABB VM1 Installation And Service Instructions Manual

5.3. Interlocks/protection against
malfunction
A series of interlocks is 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
circuitbreaker must be opened).
• the circuit-breaker can be closed if the withdrawable truck is
exactly in the defined test position or in the service position
(electric interlock).
• the circuit-breaker can be opened manually in the service
or test position when it is not powered, but it cannot be
closed.
• the switchgear is provided with devices which only allow
connection and disconnection of the plug connector
(Secondary disconnects Fig. 4) (Fig. 7) in the test/ isolation
position.
Any detailed information regarding additional interlocks,
e.g. in connection with the earthing switch operating
mechanism, is given in the specific order documentation.
fig. 7a
2
fig. 7b
interlocks
The VM1/A/P circuit-breaker contains a number of interlocks.
A description of each interlock follows as encountered during
racking of the circuit-breaker into the compartment.
Modification to interlocks may result in serious bodily
injury or death.
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
1
current, interrupting current, close and latch capability, and
maximum voltage.
2
1
3
dangeR
ModifiCation to inteRloCkS Can ReSult in
hazaRdouS ConditionS to PeRSonnel and
equiPMent. do not oveRRide, by PaSS oR
adjuSt inteRloCkS.
15