ABB VM1-T Manual page 17

M E D I U M V O LTA G E P R O D U C T S
• 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 module:
- Replacement of the circuit breaker control
module may only be performed by ABB after-
sales service personnel or by specially trained
specialists. This is because the internal
sequence times are set by jumpers on each
individual control unit.
2. Withdrawable assembly:
(Figures 9/8, 9/9, 9/26 and 9/27)
• Disconnect plug connector 37.
• For motorized withdrawable assemblies, remove
the two socket head bolts which are accessible
from below the assembly.
• 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 with-
drawable assembly and slide blocker 41.2 must
be 0.1 + 0.4 mm. If a correction is necessary, the
screws 41.3 are to be released and the slide
blocker 41.2 is to be adjusted by a feeler gauge.
Thereafter the screws must be fixed again.
7.5 Test on withdrawable parts
with VM1-T type circuit
breakers
The following conditions are to be checked to test
the function of the withdrawable part.
7.5.1 Motor-driven withdrawable parts
(non-standard)
Inspection of motor-driven withdrawable parts
should be performed as for manually operated
withdrawable parts in accordance with Section
7.5.2:
• Turn off the supply voltage (m.c.b.), since the
motor could otherwise be braked electrically.
• Turn hand crank 38 in the required direction (see
Figure 9/25).
Note:
When the withdrawable part moves, the motor
turns. The motor functions in such a case like a
generator, i.e. it can lead to reverse voltages in the
terminals.
7.5.2 Checking the auxiliary switch settings
on withdrawable parts
(Figures 9/14 and 9/25)
Compliance with the interlock conditions in the
test/disconnected and service position areas is
ensured by position signalling switches -BT2 and
located in the withdrawable assembly and factory-
set.
In test operations, the withdrawable part must be
moved by hand with the crank fitted with the motor
power switched off.
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.
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