AIC rating

[Gategator37]

Can someone give me a quick rundown on how to figure the AIC rating of a panel? I believe there is a shorthand way to do it, I know it won't be dead on, but close

 

[zog]

Can someone give me a quick rundown on how to figure the AIC rating of a panel? I believe there is a shorthand way to do it, I know it won't be dead on, but close

AIC rating is determined by testing doen by the manufacture, it is not something you calculate.

 

[ControlFreak]

Doesn't the panel AIC become the lowest AIC of any component within the panel?

 

[Gategator37]

The AIC is also shown on the drawings, isn't this a calculation done by an engineer? They have to know the available fault current.

 

[zog]

The AIC is also shown on the drawings, isn't this a calculation done by an engineer? They have to know the available fault current.

The available fault current is a calulation doen by the engineer, not the same as AIC, which is an equipment rating. The calulated available fault current cannot exceed the AIC of the equipment.

 

[Jraef]

Are you referring to the requirement in 110.9 that all equipment, including panelboards, to be rated for the available fault current?

Read this thread to get a better overall understanding of the issues and then come back with more specific questions relating to your problem at hand. Otherwise we will all go on and on ASS-U-Me-ing what you might mean.

 

[Gategator37]

Thanks guys for clearing this up, it makes perfect sense to me now! Well, the difference between AIC and available fault current

 

[mbeatty]

Doesn't the panel AIC become the lowest AIC of any component within the panel?

The Short Circuit Current Rating (SCCR) of a control panel is based on the lowest rated applicable component in the panel. The feeder circuit to the panel must provide protection so that the available fault current that the control panel can see is limited to no higher than the SCCR of the control panel.
Regards,
Mark

 

[jrohe]

The calulated available fault current cannot exceed the AIC of the equipment.

Unless you series rate, but since that's not part of the OP's question, let's not get into that.