Panelboard AIC rating

[codequestion]

I have panel 240/120V installed in 208/120V service. No 240V loads. Panel rated AIC rating at 240V is 10ka. What would be the AIC rating at 208V?

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[augie47]

10ka ?? Seems exceptionally low.
As is often the case with your questions, the devil is in the details.
Provide us with manufacturer and catalog number and I'm sure some of the panelboard experts here can provide an answer.

 

[don_resqcapt19]

I don't think I have ever seen the AIC specified at a voltage less than 240. In my opinion, it is still 10,000 amps at 208.

 

[infinity]

Wouldn't the AIC rating be the same as when the panel was still in the box it came in?

 

[electrofelon]

We have to be more precise here. A Panelboard doesn't have an AIC rating - the breakers do. I have seen larger frame breakers give AIC at 208 vs 240, but I don't recall seeing this for miniature circuit breakers.

 

[texie]

We have to be more precise here. A Panelboard doesn't have an AIC rating - the breakers do. I have seen larger frame breakers give AIC at 208 vs 240, but I don't recall seeing this for miniature circuit breakers.

I would agree. If you have a panel with a SCCA of 10K, even you had 22K AIC breakers it is still limited to 10K.

 

[electrofelon]

I would agree. If you have a panel with a SCCA of 10K, even you had 22K AIC breakers it is still limited to 10K.

I would think (but can't say for sure) that Panelboards have a sccr no lower than the highest AIC breaker that fits. I think this would be 22k for resi panelboards /loadcenters.

 

[publicgood]

Good question. Generally, I think it should list at 208V to be certain of the listing. Technically probably 15% lower than then 240V kAIC rating.

 

[electrofelon]

Good question. Generally, I think it should list at 208V to be certain of the listing. Technically probably 15% lower than then 240V kAIC rating.

Usually the AIC goes up as the voltage goes down.

 

[mopowr steve]

AIC is the highest level of current (A) the breaker is listed to withstand and open/clear durring a bolted fault. This value is not given in Volt-Amps (VA) otherwise the value would be different in relation to the voltage the breaker is connected to.

SCCR is the highest level current an enclosure is listed to endure/contain should a bolted fault occurs with-in.

Hence why we should know what the max available fault current is that’s supplied by utility so equipment is matched up so not to disintegrate.

 

[Jraef]

To answer the specific question though, when equipment listed for an AIC (or SCCR) level at 240V, it does not change for 208V, it's the same.

 

[electrofelon]

To answer the specific question though, when equipment listed for an AIC (or SCCR) level at 240V, it does not change for 208V, it's the same.

Yeah i was mistaken. I could have sworn I have seen different values at 240 and 208, but I looked at a bunch of larger framed 600v breakers and that was not the case.