Replacement Of Components; Tests On Withdrawable Parts With Vm1; Type Circuit Breakers; Checking The Auxiliary Switch Settings On Withdrawable Parts - ABB VM1 Manual

VM1 - INSTRUCTION MANUAL BA 504/05 E
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7. Maintenance
7.4.2
• Only remove and reassemble circuit breaker parts
and accessories when the breaker has been
switched off and the working area is to be isolated
and secured against reclosing.
• All supply voltage sources must be disconnected
and secured to prevent reconnection during the
removal and installation work.
• The storage capacitor is to be discharged in
accordance with the instructions in section 7.1.
1. Circuit breaker control unit:
• Replacement of the circuit breaker control unit
may only be performed by ABB after-sales service
staff or specially trained skilled personnel. Reason:
the internal sequence times for the control unit are
set by jumpers on each control unit.
2. Withdrawable assembly:
(Figures 9/8, 9/10, 9/27 and 9/28)
• Disconnect plug connector 37.
• Unbolt the circuit breaker from the withdrawable
assembly (4 x M12 bolts).
• Mount the circuit breaker on a new withdrawable
assembly in the reverse order.
• Check the settings of the slide blocker 41.2:
- The circuit breaker is in the ON position.
- The distance between pawl 35.5 on the
withdrawable assembly and slide blocker 41.2
must be 0.1+ 0.4 mm.
If a correction is necessary, the screw 41.5 has
to be released and the slide blocker 41.2 has to
be adjusted by a feeler gauge. Thereafter the
screw must be fixed again.

Replacement of components

7.5 Tests on withdrawable parts
with VM1 type circuit breakers
The following conditions are to be checked to test
the function of the withdrawable part.
7.5.1 Checking the auxiliary switch settings on
withdrawable parts
(Figures 9/10 and 9/21)
Compliance with the interlock conditions in the
test/disconnected and service position areas is
ensured by position signalling switches -BT2 and
-BT1 located in the withdrawable assembly and
factory-set.
In test operations, the withdrawable part must be
moved by hand with the crank.
1. Settings in the area of the test/disconnected
position:
• Move the withdrawable part out of the test/
disconnected position towards the service
position with a few turns of the crank.
• Slowly move the withdrawable part back to the
stop.
- Auxiliary switch -BT2 must then switch over just
before the stop is reached.
• Slowly insert the withdrawable part from the test/
disconnected position towards the service
position until auxiliary switch -BT2 just operates
(approx. 30° rotation of the crank).
- It is no longer possible to switch the circuit
breaker on in this position.
- When the hand crank is turned further, the
position of the circuit breaker is polled by pawl
35.5 after a total angle of turn of approx. 90°. If
the circuit breaker is closed, the withdrawable
part cannot be moved any further.
• For this test, the function of the blocking magnet
-RL2 (if fitted) must be disabled manually.
2. Settings in the area of the service position:
• Move the withdrawable part out of the limit
position towards the test/disconnected position
with a few turns of the crank.
• Slowly move the withdrawable part forwards again
to the stop:
- Auxiliary switch -BT1 must then switch over just
before the stop is reached.
• Slowly move the withdrawable part out of the
service position towards the test/disconnected
position until auxiliary switch -BT1 just responds
(approx. 30° rotation of the crank).
- When the hand crank is turned further, the
position of the circuit breaker is polled by pawl
35.5 after a total angle of turn of approx. 90°. If
the circuit breaker is closed, the withdrawable
part cannot be moved any further.