Racking; Disconnect Through Connect; Connect Through Disconnect - ABB VM1 Installation And Service Instructions Manual

5.4. Racking

VM1/A/P circuit-breakers are designed with two positive
racking positions: Disconnect, Connect. In the Disconnect
position the shutters are closed. Electrical closing from the
front panel is allowed for up to 60 seconds without control
power (if the capacitors are fully charged) and manual opening
is allowed. Electrical operation of the circuit-breaker is allowed
with control power supplied through the secondary contacts
with the shutters closed. As the circuit-breaker approaches
the Connect position, an increase in racking force is required
to lift the shutters and to engage the primary contacts. In the
Connect position, the primary disconnects are fully engaged
and the shutters are open. Electrical operation of the circuit-
breaker through the secondary contacts remains enabled.
Close door racking is mandatory between all positions
1. Engage the racking handle (item 1 Figure 8) with the
racking screw collar (item 2 Figure 8).
a. CLOCKWISE (cw) rotation inserts the circuit-breaker
towards the primary contacts.
b. COUNTER-CLOCKWISE (ccw) rotation withdraws the
circuit-breaker away from the primary contacts.
Circuit-breaker rack-ing-in/-out must be carried out gradually
to avoid shocks which may deform the mechanical interlocks
and the end-of-runs.The torque normally required to carry out
rack-ing-in and racking-out is <25 Nm.This value must not be
exceeded. If operations are prevented or difficult, do not force
them and check that the operating sequence is correct.
fig. 8
16
Racking-in
Max. 25 Nm

5.5. Disconnect through connect

1. Perform a visual inspection of the circuit-breaker:
a. Verify Close/Open Indicator shows OPEN.
b. Verify "READY" indicator lamp turns on (may take
approximately two minutes).
2. Racking-in operation:
a. Verify switchgear door is CLOSED
b. Begin racking by rotating the racking handle to the
CLOCKWISE direction.
c. Twenty (20) revolutions (200mm) will move the circuit-
breaker between the Test and Connect positions.
• The Connect position is indicated by a positive lock,
preventing further racking shaft rotation.
• Closing of the circuit-breaker is prevented between Test and
Connect positions.

5.6. Connect through disconnect

1. Perform a visual inspection of the circuit-breaker:
a. Verify Close/Open Indicator shows OPEN.
b. Verify switchgear door is CLOSED.
2. Racking-out operations:
a. Begin racking by rotating the racking handle in the
COUNTER-CLOCKWISE direction.
b. Twenty (20) revolutions (200mm) will move the circuit-
breaker between the Connect and Disconnect positions.
• Closing of the circuit-breaker is prevented between Connect
and Disconnect positions
Racking-out
2
1