AIC Rating VS Short Circuit Rating...

[831]

I have the following comment in front of me:

Provide short circuit rating of MCC in accordance w/ 430.98 of the 2005 NEC (not to be confused w/ AIC rating).

430.98 is a marking requirement, but are AIC and a short circuit rating any different?

Why then am I confused when the note is telling not do be confused???

 

[davidr43229]

There is a huge difference between AIC (Ampere Inturrupting capacity) or AIR (Ampere Inturrupting Rating) and SCCR Rating. Call the MFG'r of the MCC to get an SCCR rating to be properly applied within your Electrical Distribution System, based upon Available Fault Current.
Just my $.02

 

[winnie]

SCCR is based upon the ability of the device to survive the short circuit current.

AIR is based upon the ability of the device to survive the short circuit current while trying to open the circuit.

Opening a circuit against a short is often a much more difficult job then simply carrying the current for a short period of time until something else opens the circuit.

-Jon