Installing 'M-Pact' Circuit Breakers; Operating 'M-Pact' Circuit Breakers; Secondary Circuit Isolation; Withdrawal Of 'M-Pact' Circuit Breaker - GE M-PACT Operating And Installation Instructions

Installing 'M-PACT' Circuit Breakers

Drawout type
Normally, drawout type circuit breakers will be delivered
already mounted in cassettes.
Remove the breaker from its cassette using procedures
described in the section 'Withdrawal of M-PACT Circuit
Breaker'.
Position the cassette as required in the switchboard.
Note: The cassette may be lifted by hand but, if a handling
truck or other lifting gear is employed, all four of the lifting
holes provided at front and rear of the cassette should be
used.
Position cassette in place and connect incomming and
outgoing cables/busbars. When connecting busbars ensure
there is minimal deflection/stress to the back of the cassette.
Fix the cassette using 4 off M8 bolts to 25Nm at front and rear
fixing points. Note, the cassette base before and after fixing
must be flat and the frame square. Check that the safety
shutters move freely after the fixing bolts have been fully
tightened.
An earthing point is provided on the right hand side of each
cassette (viewed from front).
Fixed type
Fasten the circuit breaker into position on a suitable support
structure using 4 off M8 bolts to 25Nm.
Adequate clearance should be provided above the circuit
breaker to permit removal of arc chutes and inspection of
arcing contacts.
A clearly marked earthing point is provided on either side of
the circuit breaker.

Operating 'M-PACT' Circuit Breakers

Closing procedure
Pull the orange charging handle out and down to charge the
closing springs (requires approximately 7 movements of the
handle to fully charge).
If a motorised spring charging unit is fitted, the springs will be
automatically charged as soon as the motor is energised.
Pressing the ON pushbutton or energising the closing coil (if
fitted) will close the circuit breaker.
Closing cannot occur if:
• The OFF button is in a depressed position.
• The breaker is positioned anywhere between CONNECTED,
TEST and DISCONNECTED positions.
• The M-PRO protection unit is at 'Manual Reset' and the reset
button is protruding from the front facia. (Press the reset button
to clear the breaker for closing).
• An undervoltage release is fitted but not energised.
• The breaker is in the TEST or CONNECTED position with the
racking handle inserted.
• A key interlock (e.g. Castell etc.) or direct inter-breaker
mechanical interlock is operating on the breaker.
Opening procedure
Pressing the OFF pushbutton or energising the shunt trip coil
(if fitted) will open the breaker.
Tripping under fault conditions will be automatic depending on
the protective device installed and its settings.

Secondary Circuit Isolation

A set of 32 self-aligning secondary circuit isolating contacts are
provided in two blocks, B and C, each clearly numbered 1 – 16
(note, for certain protection configurations, an additional A
block is fitted). These are easily accessible at the top of the
circuit breaker and ensure isolation of secondary circuits when
'M-PACT' is in the DISCONNECTED position.
Fig 1
Wiring terminals have a dual connecting facility to allow
termination of secondary wiring by screw or spade connectors.
The numbered terminals on blocks B and C relate to
connection details shown on wiring diagrams in Section 3.
Withdrawal of 'M-PACT' Circuit
Breaker
Ensure that the circuit breaker has been tripped, indicating
OFF, and that the closing springs are fully discharged (If a
motorised spring charging unit is fitted, rack the breaker to the
ISOLATED position then close and trip the breaker to
discharge closing springs).
Remove any padlocks from the racking panel.
Remove the racking handle from its stowage (Fig. 2).
Fig. 2
Remove the torque bar from inside the handle (Fig. 3)
Fig 3
Torque bar hole
3
Torque bar Securing screw