Specifications

A.22
Technical overview
A
GE Power Controls
M-PACT Accessories
A wide range of optional accessories have been
developed that are compatible with all M-PACT air
circuit breakers, regardless of nominal rating or
frame size. Each one incorporates ‘easy-fit’ design
features for quick installation, either in the factory or
by the user on site.
Motorised spring charging unit
The unique motor/gearbox unit is specially designed
to operate with the full range of M-PACT breakers.
It is easily fitted with just two bolts.
In the event of circuit breaker closure, this unit will
automatically recharge the spring in readiness for
instant reclosure should the need arise.
High speed recharging ensures that the springs are
fully charged within approximately three seconds
following a release.
As an optional feature, a “springs charged” contact
is available for the motor unit.
Circuit breaker closing coil
The closing coil is an easy-to-fit, clip-on unit, with
simple plug-in connectors. This permits either local
or remote release of the spring charged closing
mechanism by electrical operation.
An additional anti-pumping safety feature also ensures
that the electrical closing signal must be released
before further closure is attempted, and a cut-off is
instigated should a closing signal be maintained.
Because each coil operates within a wide voltage
range, the number of individually rated coils
required is drastically reduced.
Shunt trip
Energisation, locally or remote, will instantaneously
activate the circuit breaker mechanism, ensuring
rapid disconnection of the main contacts.
In addition, a series connected auxiliary switch
ensures automatic isolation whenever the circuit
breaker is open.
Shunt trip releases also have a wide operational
voltage range, and they include the same easy-fit,
clip-on/plug-in connectors as the closing coil above.
Undervoltage release
Instantaneously releases the circuit breaker trip
mechanism should the supply voltage dip below the
pre-set value. Simple to install, these devices have
the same easy-fit features as previously described.
Note: This is a ‘no-volt/no-close device. The
circuit breaker cannot be closed (manually or
electrically) unless the undervoltage release coil
is energised.
Time delay undervoltage release
Similar to the above, but this electronic device prevents
nuisance tripping of the circuit breaker if circuit
interruption is not desirable when supply voltage
drop is only transient. Fixed time delay 3 sec ±1sec.
Auxiliary trip combination
The M-PACT circuit breaker can be equipped with
the following auxiliary trips or releases
1 x Shunt trip + 1 x Closing coil +
1 x Undervoltage release or 1 time delay
Undervoltage release