Originally Posted By: berby This post was automatically imported from our archived forum.
I’m confused guys.How do you come up with the panel rating. I thought you measure the service wire coming into the panel box. If two wires both measure 4, I thought the panel rating would be 200. But i read in the IQ that you count the # of breakers to come up with the panel rating. So if i have two wires that measure 4 each and i count 12 breakers. Is my panel rating 200 or 60 amp. if the question is 60 do i tell the buyer they will need to upgrade their panel box, if they are plaining to use modern electric appliances
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
The branch circuit breakers won’t really tell you much. The first indication of the service size is the disconnect size. Then you should really look at the size of the service entrance conductors, conductor material and the labelling on the panel.
From what I have seen here, you may still need an electrician if everything does not agree because there are a lot of folks slamming mismatched equipment together. The real <safe> rating is the smallest link in the chain.
Originally Posted By: jmyers This post was automatically imported from our archived forum.
Barron,
I believe it would be a good idea for you to take a basic electrical course which would certainly help you understand what you are inspecting.
That said,
The panel rating would be on the panel itself. What you are looking for is the rating of three components. Of those three components, the service rating would be the lesser of the three.
For example, if you have a 4/0 aluminum service wire, a 200 amp main breaker and a 200 amp panel, the maximum rating on that service would be 200 amps.
If you have service wire rated for 150 amps, with a 200 amp main breaker and a 200 amp panel that maximum rating for that service is 150 amps.
Dude, if you don't know what you are inspecting, you should not be inspecting it, or at least asking someone that does to help you or inspect it for you. You are playing Russian roulette with other peoples lives.
Originally Posted By: cbuell This post was automatically imported from our archived forum.
It may be time for one of the resident sparkys to chime in here. It is my understanding that the “service rating” is based on the size of the mains coming into the Main Panel period. This can be difficult to determine but nonetheless is the true “service rating”. The point being that you don’t want to have service equipment that is oversized for the size of the service wires coming in. A panel with a 200amp rating and a 200 amp disconnect on service wires with a 60 amp rating would not be a good idea. This is why it is important to identify “service rating”, “panel rating” and “main disconnect” rating (or multiple disconnect if that applies). Only one of the three doesn’t provide a very clear picture of the overall “service”. In a perfect world all three would have the same rating-----but that is why we have jobs!
Originally Posted By: tallen This post was automatically imported from our archived forum.
cbuell wrote:
It may be time for one of the resident sparkys to chime in here. It is my understanding that the "service rating" is based on the size of the mains coming into the Main Panel period. This can be difficult to determine but nonetheless is the true "service rating". The point being that you don't want to have service equipment that is oversized for the size of the service wires coming in. A panel with a 200amp rating and a 200 amp disconnect on service wires with a 60 amp rating would not be a good idea. This is why it is important to identify "service rating", "panel rating" and "main disconnect" rating (or multiple disconnect if that applies). Only one of the three doesn't provide a very clear picture of the overall "service". In a perfect world all three would have the same rating-----but that is why we have jobs!
Sorry, that is not the case, for many reasons, but I wont get into that.
The service is rated at it's lowest rated component period!!
You are speaking of the potential service rating, BIG difference.
-- I have put the past behind me,
where , however, it now sits, making rude remarks.
Originally Posted By: bbadger This post was automatically imported from our archived forum.
Greg Fretwell wrote:
. The real <safe> rating is the smallest link in the chain.
I had missed this thread but as one of the 'resident sparkys'  I agree that in general Greg is correct.
I only say in general because there are a lot of exceptions to that can be used.
I think I will go back and look at each post.
-- Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
Originally Posted By: bbadger This post was automatically imported from our archived forum.
berby wrote:
I thought you measure the service wire coming into the panel box. If two wires both measure 4, I thought the panel rating would be 200.
Not sure what you mean by measure.
If the service conductors are 4 AWG, those conductors would be rated 65 amp max.
You may have meant 4/0 AWG, those conductors would be rated 200 amp max.
By the way that assumes aluminum conductors, copper would be rated 100 and 250 respectively.
berby wrote:
But i read in the IQ that you count the # of breakers to come up with the panel rating.
Normally that is false, the only time that holds true is if you have 2 to 6 service disconnect breakers, than the combined rating of them could be the service size.
-- Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
Originally Posted By: bbadger This post was automatically imported from our archived forum.
jmyers wrote:
Barron,
I believe it would be a good idea for you to take a basic electrical course which would certainly help you understand what you are inspecting.
That said,
The panel rating would be on the panel itself. What you are looking for is the rating of three components. Of those three components, the service rating would be the lesser of the three.
For example, if you have a 4/0 aluminum service wire, a 200 amp main breaker and a 200 amp panel, the maximum rating on that service would be 200 amps.
For what it is worth I agree with what I left of Joe's post. 
-- Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
Originally Posted By: bbadger This post was automatically imported from our archived forum.
tallen wrote:
If you have a 200 amp meter and feeders rated at 100 amps and a 150 amp main breaker  Refer it to a sparkey.
Yes that would be a problem.
-- Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
Originally Posted By: bbadger This post was automatically imported from our archived forum.
cbuell wrote:
It is my understanding that the "service rating" is based on the size of the mains coming into the Main Panel period. This can be difficult to determine but nonetheless is the true "service rating". The point being that you don't want to have service equipment that is oversized for the size of the service wires coming in. A panel with a 200amp rating and a 200 amp disconnect on service wires with a 60 amp rating would not be a good idea.
Charles your on the right track but the service is only as 'strong' as its weakest link.
So while I might use some 200 amp conductors because I had them on hand if I install a 100 amp 'anything' onto them, meter socket, panel, main breaker it is only a 100 amp service.
-- Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
RR