630a 3p Thermal Magnetic Molded Case Circuit Breaker

A 630a 3p thermal magnetic molded case circuit breaker is an essential and important protective device used in low voltage power distribution system. It adopts a fully enclosed insulating housing, of which the MCCB integrates essential components including the contact system, arc extinguishing unit, and tripping mechanism into a compact structure.

Because of designed as a sealed unit, A 630a 3p thermal magnetic molded case circuit breaker is generally not intended for disassembly or repair. It is widely applied in industrial and commercial installations to offer protections in medium and small capacity circuits, typically serving as branch or end of line protection devices.

Within the category of circuit breaker, molded case circuit breakers are positioned between Air Circuit Breakers of which typically is used as main incomers in distribution systems, and Miniature Circuit Breakers, of which is commonly used in residential and light duty applications

Typical applying cases of a 630a 3p thermal magnetic molded case circuit breakerinclude motor protection circuits, distribution boards, and power supply lines for medium sized equipment.

630a 3p thermal magnetic molded case circuit breaker parameter:

630a 3p thermal magnetic molded case circuit breaker Functional Characteristics

1. Overload Protection:

In a 630a 3p thermal magnetic molded case circuit breaker, the overload protection is also called long time protection. The overload protection is based on the thermal deformation of a bimetal strip. The tripping time follows an inverse time characteristic: higher current results in faster tripping. This protects conductors and equipment from overheating under sustained overload conditions.

2. Short Circuit Protection

Commonly speaking, short circuit protection is implemented using instantaneous protection in a 630a 3p thermal magnetic molded case circuit breaker. The magnetic trip unit provides instantaneous protection. When current reaches approximately 8 to 12 times the rated value, the thermal magnetic molded case circuit breaker trips within half a power frequency cycle, which is around 10 ms. This ensures interruption occurs before the short circuit current reaches its peak.

3. Undervoltage Protection

With an undervoltage release installed, tripping occurs if voltage drops below 70% of rated value for more than 1 second. Instant tripping occurs if voltage falls below 35% of rated value. This function helps prevent damage to motors caused by low voltage operation.

4. Earth Leakage Protection

630a 3p thermal magnetic molded case circuit breakers with integrated electronic protection modules can detect residual current via a zero sequence current transformer.  Tripping occurs if the leakage module detected over 30 mA for personal protection and 300 mA for fire protection. Tripping time is generally within 0.1 seconds.