Motor Protection Circuit Breakers in SouthAfrica

Motor Protection Circuit Breaker

Introduction : 3RV circuit-breakers are compact, current-limiting circuit-breakers designed for fuseless motor feeders of the 21st century. The circuit-breakers are therefore referred to as “Motor Protection Circuit Breai‹ers” (MPCB).

The circuit-breaker fulfils the isolation conditions as per IEC 947-3 and the additional test conditions for circuit breakers with isolation characteristics as per IEC 947-2. The MPCBs can be deployed as mains and emergency stop circuit breakers with appropriate accessories.

Features :

• MPCB / contactor combination for fuseless motor feeder (type-2 coordinated).
• Rotary operating mechanism.
• MPCB with "relay function”. A totally new concept.
• Suitable for service temperatures up to 70°C
• Current limiting type. Tripping time 5 msec.
• Wide range of site fittable accessories, common for complete range.
• Trip free mechanism.

Advantages :

• Short circuit proof for faults upto 50 KA - high system uptime.
• Visual On / Off / Trip indication, reset function, padlock feature.
• "Relay function™ — results in longer life of the system because the contactor interrupts overload faults, instead of the MPCB.
• Reliability of protection is ensured.
• Faster fault clearing for enhanced life of installations.
• Flexibility in designing the system with minimum inventory.
• Positive opening in the event of faults.