1250 Amp 3 Pole 600v Mccb Circuit Breaker

A 1250 amp 3 pole 600v mccb circuit breaker mainly consists of three basic parts, which is the contact system, the arc extinguishing system, and trip units. These trip units provide different protection functions, including over current protection, under voltage protection, thermal protection, and shunt tripping. A 1250 amp 3 pole 600v mccb circuit breaker is closed either manually or by a motorized driver. Once the contacts are closed, they are held in position by a trip free mechanism. When a fault occurs, the corresponding trip unit activates the mechanism, releasing the latch and causing the 1250 amp 3 pole 600v mccb circuit breaker to trip automatically, thereby protecting the circuit.

1. Shunt trip unit

The shunt trip is used for remote control operation. It allows the circuit to be opened through a 1250 amp 3 pole 600v mccb circuit breaker from a distance.

2. Over current trip unit

This unit provides protection against short circuits and over current. When the current exceeds the preset value, the electromagnetic force generated by the trip unit releases the latch. The moving contact then separates rapidly under spring force, interrupting the circuit.

3. Under voltage trip unit

This unit provides protection against voltage loss. Its coil is directly connected to the power supply and remains energized under normal conditions, which allows the 1250 amp 3 pole 600v mccb circuit breaker to stay closed. When the supply is lost or the voltage drops significantly, the magnetic force weakens and becomes lower than the spring force. The spring then drives the moving core, releasing the latch and causing the 1250 amp 3 pole 600v mccb circuit breaker to trip.

4. Thermal trip unit

When an overload current flows through the 1250 amp 3 pole 600v mccb circuit breaker, the bimetal strip inside the thermal trip unit heats up due to the current. Because the two metals have different coefficients of expansion, they bend at different rates when heated. This deformation pushes the tripping mechanism, causing the 1250 amp 3 pole MCCB molded case circuit breaker to open and interrupt the circuit.

1250 amp 3 pole 600v mccb circuit breaker parameter: