AIR CIRCUIT BREAKERS - Electrical and Electronics Division

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Note : �or ordering information, refer pages 2/45 - 2/55
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ACCESSORIES
INTERNAL
SHUNT RELEASE
The shunt release provides remote tripping of the circuit breaker. The coil of
shunt release is designed for short time as well as continuous operation (‘DX’
range).
The operation voltage is :
85% to 110% of the rated voltage in AC
75% to 125% of the rated voltage in DC
Shunt release coil is short time rated, micro-switch is provided in the release to
cut off the supply. Once the MCCB trips, this prevents burning of coil even if the
supply to shunt coil is continuously fed.
UNDER VOLTAGE RELEASE
The under voltage release is used for protecting the installation against low voltage
situation. The under voltage release is designed to operate when the voltage
drops below a tripping threshold. This can also be used for remote tripping &
electrical interlocking purpose.
The tripping threshold is :
35% to 70% of rated in AC
35% to 70% of rated in DC
Circuit breaker closing is possible only if the voltage exceeds 85% of the rated
voltage.
AUXILIARY CONTACT BLOCK
The auxiliary contact block is used for remote signaling and control purposes.
This consists of one or more than one potential free change-over contacts. It
indicates the circuit breaker status- whether open or closed.
TRIP ALARM CONTACT
The trip alarm contact gives tripping indication once the MCCB trips. The potential
free change- over contacts can be used for indication or for control circuit.