63a 3p Molded Case Circuit Breaker

Operating Principles of 63a 3p molded case circuit breakers

(1) Current sensing and interruption

Inside the 63a 3p molded case circuit breaker, a sensing element monitors the current flowing through the circuit. When the current rises above a preset level, it generates a magnetic force that actuates the tripping mechanism. It causes the contacts to open quickly and break the circuit, based on the principle of electromagnetic action.

(2) Thermal protection

Under overload conditions, the thermal element of a 63a 3p molded case circuit breaker heats up. A bimetal strip bends as the temperature increases, which in turn releases the trip mechanism and disconnects the main circuit. This prevents overheating and reduces the risk of fire caused by prolonged over current.

(3) Under voltage and shunt tripping

When the supply voltage drops below a certain level, the armature in the under voltage release drops out, triggering the trip mechanism and opening the circuit. In addition, when the shunt trip device is energized, its armature pulls in and also activates the same tripping mechanism, disconnecting the main circuit.

Main Functions of 63a 3p molded case circuit breakers

(1) Short circuit protection

In the event of a short circuit, the current rises sharply to a very high value. The 63a 3p molded case circuit breaker responds almost instantaneously, which opens the circuit to protect equipment from severe electrical stress.

(2) Overload protection

If the load current exceeds the rated value for a period of time, the 63a 3p molded case circuit breaker will trip automatically. It helps prevent overheating and damage to wiring and connected equipment.

(3) Automatic disconnection

Whenever a fault occurs, the 63a 3p molded case circuit breaker can cut off the power supply without manual intervention. More over, The function plays a important role in safeguarding both equipment and personnel within the electrical system.

63a 3p molded case circuit breaker Parameter:

The difference between a 63a 3p molded case circuit breaker and miniature circuit breakers

1. Short-circuit breaking capacity:

There is a clear difference in fault interruption capability. 63a 3p molded case circuit breakers typically offer an ultimate breaking capacity of about 36kA to 120kA at 400V, whereas 63a 3p miniature circuit breakers are usually rated in the range of 6kA to 10kA.

2. Adjustability of protection characteristics:

With a 63a 3p MCCB, overload and short circuit protection can be set independently, and the trip values can be adjusted manually. Electronic trip units can even provide multistage protection. In contrast, a 63a 3p MCB has fixed protection characteristics, which use a combined thermal magnetic mechanism with standard B, C, or D curves that cannot be adjusted.

3. Installation and mechanical strength:

63a 3p molded case circuit breakers are generally mounted using bolts to ensure a more secure connection. It makes them suitable for higher current applications and environments with vibration. 63a 3p MCBs, on the other hand, are designed for quick installation on standard 35mm DIN rails, which is convenient but offers less mechanical robustness.

4. Typical applications:

63a 3p MCCBs are widely used in industrial power distribution systems, motor protection, and feeder circuits at secondary or tertiary levels. However, 63A 3P MCBs are mainly intended for final distribution circuits, such as lighting and socket outlets in residential or commercial installations.