aic rating and panel reconnection

mjmike

Senior Member
We have a project that will combine several older electrical services into a single new service entrance panel. There will also be several remote panels that will be removed from a service that remains and reconnected to the new service. The panels are very old and the panel tag does not have a listed AIC rating. There is also not a main breaker as they are MLO (at least for the remote panels). How is this typically handled to make sure the panel can safely be connected to the new system?
 

templdl

Senior Member
Location
Wisconsin
We have a project that will combine several older electrical services into a single new service entrance panel. There will also be several remote panels that will be removed from a service that remains and reconnected to the new service. The panels are very old and the panel tag does not have a listed AIC rating. There is also not a main breaker as they are MLO (at least for the remote panels). How is this typically handled to make sure the panel can safely be connected to the new system?
I have addressed many requests for the kaic ratings for vintage breakers for this very issue. I have gone back into the archives ofolder catalog data and provided my customers with a PDF for each breaker that included the kaic.
Then, the next issue for the contractor is how to address any kaic rating issues that are most likely to exist. But at least the contractor will have some documentation for the existing breakers.
 

mjmike

Senior Member
From a design standpoint though with no panel tag or main breaker, are all breakers looked at and the AIC would be the lowest? What if there is no indication on the breaker make or any data on the breakers?
 
If the breakers are older without any technical documentation, reconnection might not be a good idea...
without documentation I would recommend to the client replacement of the unknown panels with new...
what are some of the existing panel names?
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Engineer
From a design standpoint though with no panel tag or main breaker, are all breakers looked at and the AIC would be the lowest? What if there is no indication on the breaker make or any data on the breakers?
Back in the 50-60's the minimum rating of breakers (Federal Spec, E-frame size) was 7.5kAIC@120/240V. However, the more general purpose breakers, like Square D's QO were only rated 5kAIC.
Somewhere in the early 70's, breaker testing was changed and 10kAIC became more common.

It appears UL did not have its current labeling procedures until the mid 80's, so it is possible older equipment does not have legible information.

A prudent course of action maybe to assume all 'unmarked' devices are only 5kAIC.
 

templdl

Senior Member
Location
Wisconsin
From a design standpoint though with no panel tag or main breaker, are all breakers looked at and the AIC would be the lowest? What if there is no indication on the breaker make or any data on the breakers?
Please refer to my recommendation to get some published catalog data from the manufacturer which I had provided countless times.
 

templdl

Senior Member
Location
Wisconsin
If the breakers are older without any technical documentation, reconnection might not be a good idea...
without documentation I would recommend to the client replacement of the unknown panels with new...
what are some of the existing panel names?
Have you checked to see if it is available or it is being assumed that it is not?
 

mjmike

Senior Member
Don't know the panel makes so no research was done. We will be pulling covers in the future to see if any info is present. Interesting on the history of the older panels and the low ratings. Assuming no date is present is the only course of action to replace the panel if over 5K AIC?
 

templdl

Senior Member
Location
Wisconsin
Don't know the panel makes so no research was done. We will be pulling covers in the future to see if any info is present. Interesting on the history of the older panels and the low ratings. Assuming no date is present is the only course of action to replace the panel if over 5K AIC?
The common thing that is done is to make a call to the beaker manufacturer and advise them of the beaker type. If they maintain old catalog data and if that data included kaic ratings. If so could they Email you a PDF of that page which could be used to support your information.which I have provided countless times when requested. I fail to see what the issue is except if contractor wants to make it difficult for themselves. There have been occasions where the product is vintage enough that I was not able to identify suitable documentation to provide ratings at which point the contractor must proceed knowing that the rating of the device is unknown. I agree that 5kaic is a default rating if all else is unknown.
All that I know is when I prove a contractor with a picture of the original catalog 'cut sheet' that includes the information that they were looking for they were elated.
 
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