Min A.I.C. per Panel Schedule

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Aledrell

Senior Member
E-1 page of print on panel schedule says MIN A.I.C 22/10k Service Rated
and another one MIN A.I.C 42/10k Service rated, the other two panel schedules simply say MIN A.I.C 10,000.

Now I thought I understood series rating but some commericial inspector decided to confuse the crap out of me on a job not to long ago, and my supplier confuses the opposite dirrection. Now when an electrical engineer writes MIN A.I.C. 42/10k Service rated does it mean 42 k upstream (in this case SES 200amp fused pullouts as panels are MLO) or does it mean that the panel enclosure needs to be rated as such with only 10k breakers. I would do my own calculations but the print is messed up not providing any utility information.
 

ron

Senior Member
I've not seen that type of nomenclature, but I would guess that 42K/10kAIC means that the panel needs to be series rated at 42kAIC with a minimum value of 10kAIC for any of the devices on its own.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Ron is correct. This is the method Square D uses with their loadcenters when describing their series ratings. A 22/10kAIC panel is series rated for 22kAIC when using 10kAIC branch breakers.
 
I have seen panels with main disconnecting/CBer means having this designation.

The main breaker is rated for 22K and the secondary CBers are rated for 10K


It has been my understanding that the CBer/bus/enclosure are given the final rating by the "weakest link in the chain" within the enclosure of discussion.


With that said, I am correct or is the evaluation performed in a different manner?
 

ron

Senior Member
Pierre,
If there was no tested combination between the main and branches, then the overall rating would be the weakest link, 10kA.
If the panel was labeled per 110.22, then it would get the series rating of the combined tested assembly.
 

Aledrell

Senior Member
No Main Breaker

No Main Breaker

No Main breaker specked on these, fused SES JJNL fuses only. Supplier says I see these all the time use 10k loadcenter CH. Last week on another residential 600amp service had to get a sticker for combination rating with enigineer calc. It is a 12000 sf custom 600amp ses four pull outs 200/200/200/100 obviously the 42/10k is closest approx 10ft and so on distance wise. If I didn't have people telling me different things maybe this wouldn't be such a difficult concept to understand. My main concern is that I have to install fully rated load centers, which can be very expensive.
 

Aledrell

Senior Member
Thanks Ron

Thanks Ron

Thanks Ron appriciate the info, I will make sure loadcenters have series rating stickers.
 
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