AIC Ratings for Utilization Equipment

[rme]

A Return comment from a plan review that included 2 large pieces of refrigeration equipment required we provide the Fault Current rating of the rfrigeration utilization equipment siting NEC section 110.10. Our calculated FC is 22KAIC at the point of termination to the equipment. We have provide main and feeder OC devices fully rated for available fault current for each feeder. The equipment manufacturer says their UL listing requirements do not include withstand rating testing so they do not rate their equipment for fault current. The AHJ says that we must assume 5kAIC. Since we cannot prove a series rating to 22K with any overcurrent protection (fused or molded case circuit breaker) the AJH says the refer equipment must be fully rated. We beleive our service and feeder OC meets the requrements of 110.10. Is the AHJ accurate that this section is to be applied to the refrigeration utilization equipment that is covered under UL. If this is the case, they why are not switches, contactors, motor starters and the like required to be provided with an interupting rating? We have other equipment in the building like hydrolic elevator machines, HVAC equipment that they could also apply this to and note of this equipment is rated, but all is UL listed. This is the first time we have been asked to prove the withstand rating of equipment like this.

Please comment and help if you can.

RME

 

[templdl]

Re: AIC Ratings for Utilization Equipment

Is the equipment in question motor control? If so the manufacturer should have a listing for a combination rating such as with a fused disconnect, contactor and OLR. Should the OEM have purchased then separately as components and the component manufactured has not extended a UL listing to the OEM which is not very likely,the 5kaic applies. Remember that the kaic rating is with those components assembled in an enclosure which addresses the extent of damage should those components be subjected to a given fault, such as keeping the from blowing off and all of the pieces of the components from exiting the enclosure.