10
Anti-trip plate
With upper/lower main terminals earthed (breaker
CONNECTED) and the circuit breaker closed the anti-trip plate
prevents the breaker tripping. To fit the anti-trip plate, first
remove the breaker facia as described above. Slide anti-trip
plate as shown (Figs 41 & 42) and re-fit facia.
Fig. 41
Fig. 42
To fit mechanical trip alarm
Remove the ACB fasia. Using a suitable nut runner, remove
the lower right hand M-PRO fixing. Fit mechanical trip alarm
as shown (Fig. 43). Ensure that the actuator arm of the micro
switch is not behind the protruding pin.
Fig. 43
Connect the wires via. the spade connectors to the respective
locations of the secondary isolating contacts B7 and B8 (Fig.
44) and tie wrap them to the side of M-PRO. Replace facia.
Fig. 44
Mechanical Operations Counter
The optional pack contains an operations counter with fixing
screws. The unit is fitted to the inside of the circuit breaker
facia.
Mounting instructions:-
•
Remove facia from the circuit breaker.
•
Position the operations counter (Fig. 45) over the two holes
provided inside the cover, ensuring that the indicator face is
aligned to show through the window provided in the cover .
•
Fix in position using the screws provided.
When replacing the facia, the operating arm on the counter
should engage with a small lever protruding from the circuit
breaker mechanism.
Note: The operations counter cannot be reset.
Fig. 45
Breaker mis-insertion stop
This ‘pin and gate’ device prevents insertion of a circuit
breaker into a cassette if the nominal rating of the breaker is
incompatible with that of the cassette and its ancillary
equipment.
Fig. 46 shows a pin block assembly mounted on the circuit
breaker. It is fixed by replacing the corresponding hex. bolt
with M6 x 150mm long for frame size two breakers & M6 x
115mm long for frame one (tighten to 11 Nm). Fig 47 shows
the corresponding restrainer assembly mounted on the
cassette by one M4 nut and lock washer. There are two of
these assemblies, the other is fitted to the opposite side of the
cassette.
Fig. 46
Pin block assembly
Fig. 47
Recommended configurations are provided with the mis-
insertion device for the entire M-PACT range.
