Replies

1. 
   BillHartmann | May 23, 2005 12:04am | #1

   "The main breaker in the panel says 100 amps; does that necessarily mean that I have 100 amp service? Could I have 60 amps and just have that breaker in place? Could I call the utility company and ask them? Do I need to buy an expensive tester?"

   Yes, it is possible.

   My friend bought a 50 year old house with a 100 amp main panel. Which would have been fine, except she was adding electric range and drier.

   However, came to find out that the panel had been replaced sometime in the past and the meter and drop cable where only 60 amp. And that cable was in bad shape and started arcing as it was moved aside to make room for the replacement.

   The utility company should be able to tell you.

   But also look at the meter, it will have some kind of model number on it that will often tell the size.

2. 
   Stuart | May 23, 2005 12:22am | #2

   I suppose it's possible that the previous owner did a handyman special and installed a 100 amp panel on a 60 amp service, but if it was installed correctly it most likely is a 100 amp service (there should be a sticker on the door where the local inspector signed off on it when it was installed.)  The main breaker can be the same ampacity as the service, or it can be smaller, but it can't be larger. 

   The wires coming in from the utility should be at least #4 or #3 gauge (depending on how they do it in your area) for a 100 amp service, you may be able to see the wire gauge stamped on the wire insulation where they come in the top of the panel.  You could call the utility company if you want to be 100% sure.

   Edited to add:  I just read Bill's reply, and I agree with what he said about taking a look at the meter - it will probably say on it somewhere if it's for 60, 100 or whatever.

   
   

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   Edited 5/22/2005 5:27 pm ET by Stuart

1. 
   BillHartmann | May 23, 2005 12:43am | #3

   In my friends case the tri-plex was at rated for at least 100 amps and maybe more.But I suspect that it had been replaced during an ice storm that we had a couple of years ago.I know cable and telco have been ripped out a couple of times since them and are temporary being supported by heavy telco ground wire lashed to the new steel mask that was put in when she upgraded the service to 200 amps.Now that the weather is nice I am going to have to take out so siding and build a solid mounting block to tie them to.

3. 
   rjw | May 23, 2005 02:30am | #4

   Ultimately, it is the size of the wires between the connection at the weatherhead (I'm assuming overhead service) and the meter and the meter and the main disconnect.)

   Generally they have to be #4 CU or #2 AL (depending on the temp rating.)

   If the wires from the pole get bigger at the splice just before the weatherhead - it's _probably_ upgraded to 100A.

   If the meter base is round, it's _probably_ 60 Amp, unless it was installed between WWII and the late 50's early 60's, when (at least in my area) they were also using the round meter base for 100 A services, in which case it could be either.

   Side note:

   You say you are going to be doing a lot of electrical work in the house.

   I hope you are planning to learn about what you are doing (such as learning about wire sizes) before putting yourself, your family, your neighbors, any future owners and the firefighters at risk.

   As a home inspector, the two scariest things I see in houses are (i) crappy, dangerous wiring done by amateurs and (ii) crappy, dangerous gas appliances.

   Amateurish electrical workmanship often rates classification as a "major point of concern" in my reports.

   Even if I don't see anything obviously dangerous, amateurish workmanship raises concerns about the areas which are not inspected as part of a standard home inspection.

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   Sojourners: Christians for Justice and Peace

1. 
   Gunner | May 23, 2005 05:09am | #6

   What Bob said. It's not a place to try and save money.

    

    

   Shout out to Andy C. Namaste my friend.

   http://www.hay98.com/

2. 
   musashi | May 24, 2005 01:36am | #7

   First, I want to thank you (and everyone else who responded) for your ideas and suggestions. You wrote:"I hope you are planning to learn about what you are doing (such as learning about wire sizes) before putting yourself, your family, your neighbors, any future owners and the firefighters at risk.
   As a home inspector, the two scariest things I see in houses are (i) crappy, dangerous wiring done by amateurs and (ii) crappy, dangerous gas appliances."I am reading books, wandering around the electrical aisles at Home Depot and Lowe's to learn about materials, carefully planning the load on my panel and on the individual circuits, learning about wire sizes, and looking at the NEC. I also have 10 years experience renovating apartments in New York City (the carpentry side of things). The last thing I want to do is a "handyman special", which, actually, is what this place is at the moment. I will move slowly and carefully, with some electrician friends looking over my shoulder.Thanks again for your help and your concern.AlexOutside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
   -Groucho MarxEdited 5/23/2005 6:37 pm ET by Pelon1

   Edited 5/23/2005 6:37 pm ET by Pelon1

1. 
   JohnSprung | May 24, 2005 03:58am | #8

   > wandering around the electrical aisles at Home Depot and Lowe's to learn about materials,

   Kinda like wandering around at McDonald's to try to learn how to be a fine chef. 

   The boxes carry mainly the cheapest, lowest quality stuff.  You'll find Square-D's Homelite line there, but not the QO, etc..... 

    

   -- J.S.

    

1. 
   decornut | May 24, 2005 05:41am | #9

   All the Home Depots in my area (about 100 miles N of NYC) have QO panels and breakers.  And those QO breakers and panels are listed in Home Depot's "Probook", so theoretically, any HD that doesn't have them in stock can order them and get a quick delivery from a HD warehouse.

4. 
   DanH | May 23, 2005 02:54am | #5

   Double check that there isn't another breaker outside, near the meter. If not, then either the service is 100A, or it's illegally configured.