Determining Existing Service Panel Size

Jimsolar

I have a Crouse Hinds residential service panel from 1990. Unfortunately, the label on the inside of the swing up door is missing. I have been the sole owner of the house since it was built, and never removed it, so maybe 20 years of heat from the sun delaminated it. At any rate, I am trying to determine if it is a 200 or 225 amp rated panel. The only label inside is a UL listing # that is 692083, but that may be related to the testing procedure and not the panel. This question ties into my recent thread about my service panel being too small-- actually I very well could already have a 225 amp panel. Does anyone know how to determine the size of a panel if the label is missing? Thanks!

niel

Re: Determining Existing Service Panel Size

do you have breakers in the panel? i am assuming you are currently using the panel and the main breaker from the service lead-in is a big give-away as to the service rating. ie 100a breaker = 100a service rating.

icarus

Re: Determining Existing Service Panel Size

Neil,

That is not entirely true however.
One could,, for a variety of reasons have a panel that was built an approved for one amperage,,, but carries a smaller main breaker. So far example, a 200 amp rated panel,, might have been wired with a 100 amp main in the beginning because the original owner didn't need the 200 amp capacity,,, and didn't want the expense.

Now it is also possible that the service conductors for the 200 amp RATED panel are sized for the 100 amp main breaker,,, so switching out the breakers is not always possible to up grade the panel. On would have to check with the utility to make sure that the service conductors, and the transformer and transformer fusing is acceptable for the upgraded service.

This of course doesn't get the OP any closer to solving the issue of his current panel situation.

Tony

niel

Re: Determining Existing Service Panel Size

icuras,
i guess i must give a disclaimer as i am assuming that nobody else had modified the panel in any way and i must say that most people do not go buy a lower sized main breaker for the heck of it. yes, we 're' nut cases do that sort of thing, but the majority of people don't even know what size service they have let alone know that the breaker can be changed. in most cases it is safe to say that the main breaker is a dead give-away of the panel rating for they would supply a 200a main breaker with a 200a service panel.

mike95490

Re: Determining Existing Service Panel Size

Edison, in So. Calif, has a record of the service panel. When I bought my house '82, it had 60A service (2, 30A fuses) and was marked such on my bill. Might help

(one circuit for overhead lights, one for outlets. 1940 construction)

dwh

Re: Determining Existing Service Panel Size

niel wrote: »

icuras,
i guess i must give a disclaimer as i am assuming that nobody else had modified the panel in any way and i must say that most people do not go buy a lower sized main breaker for the heck of it

As I stated on the other thread, some manufacturers build differently rated panels using the same basic components.

It is quite possible that there could be a service installed with a 200a main breaker, but everything else in the can is rated at 225a.

It's common to install residential service panels of 100/200/400 amps. It's not at all common to install a 225a service on a residence - not because of the panel rating, but because the service entance (pipe, wire, etc.) has to be sized up - and if you are going to do that, you might as well install a larger panel while you are at it.


So, the question in the OP is, "How to determine the existing panel's ampacity rating?"

Well...that's might be a tough one.

First of all, I'd call up Crouse-Hinds and ask them. They might have a very easy way to tell exactly what that panel is...like maybe something stamped into it somewhere that can't fall off like a decal.

They might also have some old-timer there who could ID that panel from a picture in about a second.

Or maybe that UL number will be enough for them to look it up and tell you what you have.


If they can't help, you could measure the buss bars and then compare them to a chart...like this:

http://www.stormcopper.com/design/Ampacity-Quick-Chart.htm

If you can prove the buss bars are rated high enough, and there is enough space in the can, you might get the inspector to sign off on it.


You might check to see if there is a 225a breaker available for that panel - Crouse-Hinds might not have made one for that panel...if they did it might be because the panel is rated for it..

niel

Re: Determining Existing Service Panel Size

most panels have busses rated higher than the panel itself comes as, but it still is considered xxx ampere panel even though the components are rated xxx times 120% (i believe it is). now nitpicking my statement doesn't make me wrong as in most cases what i said is correct
now he can call the manufacturer, but i'd lay money down that it is a panel of what the main breaker's rating is not considering the overrating that is standard in all panels.

icarus

Re: Determining Existing Service Panel Size

Just to further pick nits,,,,

Often times main panels come Sans breakers,, including the main.,, so in some cases there is an incentive ($$) to use a smaller main.

Tony

lorelec

Re: Determining Existing Service Panel Size

dwh wrote: »

It is quite possible that there could be a service installed with a 200a main breaker, but everything else in the can is rated at 225a.

This may be so. The last Siemens panel I bought has a 125A rating stamped on the label, but came with a 100A main breaker.

I hate to sound like a broken record, but I would suggest (Jimsolar) that, if you haven't already done so, you go in for a face-to-face talk with someone from the agency that has jurisdiction over your installation. Explain exactly what it is you need to accomplish and how you'd like to do it, and then ask them for their suggestions. If you're not happy with the answers you get, you can always ask them to explain how their decisions relate to code, or you can make an appointment with someone in a higher position, as they often have the authority to make exceptions on a case-by-case basis. Be nice and act poor. Also wouldn't hurt to have a copy of the pertinent NEC sections or local code with you so that you can refer to them.

Marc

Jimsolar

Re: Determining Existing Service Panel Size

Thanks for your great suggestions. I called Crouse-Hinds, and they gave me a number for Siemans, and after pleading with them to help a non-distributor residential homeowner, they hooked me up with someone who was familiar with their old panels and is trying to make a determination from some pictures of the panel I sent them. So, maybe, just maybe it is a 225 amp panel after all. I'll let you all know. Again, many thanks!