TOPIC: Determining Electrical Service

Hey guys I was curious to find out how to determine service amperage if you have multiple smaller main disconnects?  I was looking at my panel the other day and noticed it has 4 main disconnects (all are 50 amp or less ratings).  It states on the panel that you must turn all four off in order to fully shut power off the house. 

I understand how to find service size for a house; you look for the lowest rated item in the chain.  But looking at a panel with the highest rated breaker being 50 Amps that would be misleading.

Would I then look at the meter box and service entrance wire size to determine the amperage? 
Would I total up the breaker amp ratings (I think this one could get you into trouble)?

John

If you get a chance post a picture of your panel.

I would say to determine the service amperage size you would use the size of your service entrance cables as you say it does not feed directly into a main breaker.

Also the size of the exterior meter could also determine the size. There has been a lot of discussion on service meters and size.

For example my house has an updated 100 amp panel but still has the 60 amp meter base. Both the city and electrician approved the installation. Now some may argue that my service is 60 amps due to the meter base.

I am not an expert on electrical but I am also looking to learn and I can speek freely here and not be worried about being bashed by a bunch of guts who think they are inspection Gods.

Yes I will get some pics up here soon.  In your case I would call your service 60 Amps.  You look for the smallest rated item in the chain of items which for you would be 60 Amp meter base.  Thus 60 Amp service.

If I was inspecting my house I would call this a 100 amp service even though it has a 60 amp meter base.

I do not have the memory or knowledge to explain all the information and topics of discussion on meter bases. I have spoken to electricians, LJH, inspectors on this topic. One of my inspector friends who is a licensed electrican actually made a picture an was explaining the meter base. I have it around somewhere.

I only call out the 60 amp meters if they are in poor condition. (Like the cable, drops, service point.

These are my notes from NACHI.


Determining Available Home Service

The correct way to determine the available amperage is to determine the ampacity of the lowest rated of the following components

Service supply
Electric meter & socket
Service entrance conductors
Service disconnect
Distribution panel

Here are a couple of examples:
A 200 amp service lateral, a 200 amp meter and base, a 175 amp rated SEC, a 150 amp rated panel, and a 125 amp service disconnect. = A 125 amp reportable service supply.
A 150 amp service drop, a 60 amp meter and base, a 150 amp SEC, a 100 amp rated panel, and a 100 amp service disconnect. = A 60 amp reportable service supply.


Anyway, I'm headin out to go get some pics of the panel.

Here are some pics I took.  This is the first time I have looked at my panel.  So don't judge me!  LOL