- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
A submittal from an elevator vendor included information about a circuit breaker that was internal to their control panel. It had an AIC rating of 5000 amps. Our calculation shows an available fault current at that location of 9000 amps. Does their breaker need to be replaced with one that has an AIC rating of 10kA or higher? My boss thinks so, and I don?t think it would be a bad idea. But is it required? The vendor is asking for a large increase in price to change out the breaker.
Looking at it from the vendor?s perspective, my take would be that the elevator equipment is UL listed as an entity, and the NEC therefore has no jurisdiction.
Looking at it from the perspective of ?what could go wrong,? the only fault that the breaker would see is one that is internal to the elevator equipment. If that fault were as high as 9000 amps, then their internal breaker might not be able to trip. Rather, it might have its contacts welded together, thus allowing the fault to continue unabated. The event would be terminated by the fused disconnect upstream of the elevator controller. In the meantime, the fault would destroy the controller, so why should we care that the breaker is also destroyed?
Comments? Opinions? Is this actually covered in the NEC?
Looking at it from the vendor?s perspective, my take would be that the elevator equipment is UL listed as an entity, and the NEC therefore has no jurisdiction.
Looking at it from the perspective of ?what could go wrong,? the only fault that the breaker would see is one that is internal to the elevator equipment. If that fault were as high as 9000 amps, then their internal breaker might not be able to trip. Rather, it might have its contacts welded together, thus allowing the fault to continue unabated. The event would be terminated by the fused disconnect upstream of the elevator controller. In the meantime, the fault would destroy the controller, so why should we care that the breaker is also destroyed?
Comments? Opinions? Is this actually covered in the NEC?