Components of Circuit Breaker

Auxiliary contacts: mechanically linked contacts with the circuit breaker main circuit splitting and closing mechanism, mainly for the display of the circuit breaker splitting and closing status, connected to the control circuit of the circuit breaker through the splitting and closing of the circuit breaker, the implementation of control or interlocking of its related appliances. For example, to signal lights, relays and other output signals. Case circuit breaker shell grade rated current 100A for a single breakpoint conversion contact, 225A and above for the bridge contact structure, the agreed heating current of 3A; shell grade rated current 400A and above can be installed two normally open, two normally closed, the agreed heating current of 6 A. The number of operating performance and the total number of operating performance of the circuit breaker is the same.

Alarm contact: used for circuit breaker accident alarm contact, and this contact only when the circuit breaker off the breakout action, mainly for the circuit breaker load overload short circuit or under-voltage and other faults when the free debonding, alarm contact from the original normally open position converted to closed position, connected to the auxiliary line in the indicator or bell, buzzer, etc., display or remind the circuit breaker fault debonding state. As the circuit breaker occurs due to load failure and the chance of free decoupling is not too much, thus the life of the alarm contact is 1/10 of the life of the circuit breaker. alarm contact operating current generally does not exceed 1A.

Divided-excitation decoupler: Divided-excitation decoupler is a decoupler excited by a voltage source, its voltage is not related to the main circuit voltage. Shunt excitation decoupler is an accessory for remote manipulation of the break. When the supply voltage is equal to any voltage between 70% and 110% of the rated control supply voltage, it can reliably break the circuit breaker. Shunt-excited decoupler is a short-time working system, the coil energization time generally can not exceed 1S, otherwise the line will be burned. Plastic case circuit breaker to prevent coil burnout, in series with a micro switch in the sub-excitation release coil, when the sub-excitation release through the armature suction, micro switch from the normally closed state converted to normally open, due to the sub-excitation release power control line is cut off, even if artificially press the button, the sub-excitation coil will always be re-energized this avoids the coil burnout situation. When the circuit breaker is closed again, the micro switch is in the normally closed position again.

Undervoltage detriggers: undervoltage detriggers are a type of detriggers in which the terminal voltage drops to a specified range, so that the circuit breaker has a delay or no delay in disconnection, when the supply voltage drops (even slowly) to a range of 70% to 35% of the rated operating voltage, undervoltage detriggers should operate, undervoltage detriggers in the supply voltage is equal to 35% of the rated operating voltage of the detriggers, undervoltage detriggers should be able to prevent the circuit breaker from closing; when the supply voltage is equal to or greater than 85% of the rated operating voltage of the undervoltage release, the breaker should be able to ensure reliable closure under thermal conditions. Therefore, when a certain voltage drop occurs in the supply voltage in the protected circuit, the circuit breaker can be automatically disconnected to cut off the power supply, so that the breaker below the load appliance or electrical equipment from under-voltage damage. When used, the undervoltage detrigger coil is connected to the power side of the circuit breaker, the undervoltage detrigger is energized before the circuit breaker can close.

External accessories

Electric operating mechanism: This is an accessory for remote automatic breaking and closing of circuit breakers, electric operating mechanism has two kinds of motor operating mechanism and solenoid operating mechanism, motor operating mechanism for molded case circuit breaker case frame level rated current 400A and above circuit breakers, solenoid operating mechanism for molded case circuit breaker case frame level rated current 225A and below circuit breakers, either solenoid or electric motor, their suction and rotation direction are the same, only by the position of the cam inside the electric operating mechanism to reach the closure and division, the circuit breaker when operated with the electric mechanism, at any voltage between 85% and 110% of the rated control voltage, should be able to ensure reliable closure of the circuit breaker.

Rotating operating handle: applicable to plastic case circuit breakers, the cover of the circuit breaker is equipped with a mechanism for rotating the operating handle, the shaft of the handle is installed in its institutional fit hole, the other end of the shaft passes through the door hole of the drawer cabinet, the handle of the rotating handle is installed in the head of the rotating shaft exposed above the door of the set, the round or square seat of the handle is fixed on the door with screws, such installation enables the operator outside the door through the handle of the handle Clockwise or counterclockwise rotation of the handle to ensure the closing or breaking of the circuit breaker. At the same time, turning the handle ensures that the door cannot be opened when the circuit breaker is closed; only when the handle is turned in the break or re-break, the door of the switchboard can be opened. In an emergency, when the breaker is “closed” and the door needs to be opened, press the red release button on the side of the rotating handle.

Extension handle: is an external extension handle, directly mounted on the handle of the circuit breaker, generally used for 600A and above high-capacity circuit breakers, manual breaking and closing operations.

Handle latching device: is installed in the handle frame with a card, the handle is punched and then locked with a padlock. Mainly used for circuit breakers in the closed.

Working state, do not allow other people to switch and cause a power outage accident, or circuit breaker load side circuit needs to be repaired or not allowed to energize, to prevent the breaker from being closed by mistake.

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