Frequently Asked Questions
Reliability And Maintenance-Fuses and Circuit Breakers
Electrical system reliability in modern commercial and industrial environments is not a luxury, it is a requirement. And overcurrent protective devices play a major role in the reliability of these systems.
Fuses
Modern current-limiting fuses operate by very simple, reliable principles. Fuses do not have to be maintained. By their inherent design, fuses do not have elements or mechanisms to calibrate, adjust or lubricate. If and when fuses are called upon to open on an overcurrent, installing the same type and amp rated fuses provide the circuit with new factory-calibrated protection. The original design integrity can be maintained throughout the life of the electrical system. One last point on fuse systems; the terminations, clips and disconnects should be maintained according to manufacturers recommendations.
Circuit Breakers
In contrast, circuit breakers are mechanical devices (even those with electronic sensing) and circuit breakers require periodic maintenance, testing and, if necessary, reconditioning or replacement. This is required per the circuit breaker manufacturers' instructions, NFPA 70B Recommended Practice for Electrical Equipment Maintenance, and NEMA AB4. If circuit breakers are not properly maintained, the interrupting rating, circuit component protection, coordination and electrical safety may be compromised.
