Results 1 to 15 of 15
  1. #1
    Andy Jarchow's Avatar
    Andy Jarchow Guest

    Default 60 amp service but 100amp main???

    What are the issues with this or is it ok? A 100 amp main breaker, #4copper main wire, 125 amp main panel but a round meter socket which would indicate a 60 amp service.

    Thank you



    Similar Threads:
    Inspection Referral

  2. #2
    Roger Frazee's Avatar
    Roger Frazee Guest

    Default Re: 60 amp service but 100amp main???

    Hi Mike

    Hmmm I'm not sure why you are saying a round meter socket means 60 amp service ?

    Anyway #4 copper is allowed for 100 amps for a dwelling service entrance. If however you actually can verify that the service is 60 amps from the utility then this would not be correct.

    The issue is that if the utility ran 60 amp wire to a 60 amp meter socket it would be over protected by the 100 amp breaker in the service equipment.

    Does it look like someone has recently replaced or upgraded the service equipment and service entrance conductors?


  3. #3
    Join Date
    Feb 2009
    Location
    Southern Vancouver Island
    Posts
    4,607

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Roger Frazee View Post
    Hi Mike

    Hmmm I'm not sure why you are saying a round meter socket means 60 amp service ?
    That is info from Carson Dunlop training maybe. They should have said round bases are often found on older 60 Amp services.
    I see them upgraded to 100 Amp fairly often. I'm no expert, but I think if the larger service wires can be fed thru without over bending, the authorities allow it?

    John Kogel, RHI, BC HI Lic #47455
    www.allsafehome.ca

  4. #4
    Join Date
    Aug 2008
    Location
    Maryland
    Posts
    1,970

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Roger Frazee View Post
    Anyway #4 copper is allowed for 100 amps for a dwelling service entrance. If however you actually can verify that the service is 60 amps from the utility then this would not be correct.

    The issue is that if the utility ran 60 amp wire to a 60 amp meter socket it would be over protected by the 100 amp breaker in the service equipment.
    Roger, the utilty wires would stop at the weatherhead and are sized differently than the service entrance conductors.

    Also 60 amp wiring protected by 100 amp OCP would be under protected, not over.


  5. #5
    Andy Jarchow's Avatar
    Andy Jarchow Guest

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Roger Frazee View Post
    Hi Mike

    Hmmm I'm not sure why you are saying a round meter socket means 60 amp service ?

    Anyway #4 copper is allowed for 100 amps for a dwelling service entrance. If however you actually can verify that the service is 60 amps from the utility then this would not be correct.

    The issue is that if the utility ran 60 amp wire to a 60 amp meter socket it would be over protected by the 100 amp breaker in the service equipment.

    Does it look like someone has recently replaced or upgraded the service equipment and service entrance conductors?
    Yes it does look like the service (panel) was updated but it still has the old style meter. Back when the round meter socets were used they were all 60 amp. When the services were updated to 100 amp the meter socet were also updated to a square meter socet.

    Doesn't the utility control how many amps are going to the house?


  6. #6
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,042

    Default Re: 60 amp service but 100 amp main???

    Quote Originally Posted by Roger Frazee View Post
    The issue is that if the utility ran 60 amp wire to a 60 amp meter socket it would be over protected by the 100 amp breaker in the service equipment.
    Quote Originally Posted by Jim Port View Post
    Also 60 amp wiring protected by 100 amp OCP would be under protected, not over.
    The 60 amp conductors would be under-rated, the protection would be over-rated, or over-protected, meaning the protection rating is over that of the rating of the conductors. Under-protected is fine as you could protect 60 amp conductors with a 30 amp breaker and be fine (with regards to protection of the conductors, not necessarily fine with regards to loads and usage of the system).

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  7. #7
    Roger Frazee's Avatar
    Roger Frazee Guest

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Jim Port View Post
    Roger, the utilty wires would stop at the weatherhead and are sized differently than the service entrance conductors.

    Also 60 amp wiring protected by 100 amp OCP would be under protected, not over.
    The utility uses the NESC and yes if this is an overhead drop then the NEC takes over at the connection to the drip loop just before the weatherhead.. So if overhead likely #4 cu from the connection point all the way to the service equipment.

    I really don't think there will be an issue with the utility wire size and the 100 amp breaker but the possibility does exist even if that isn't a concern of the electrician.. However it is the electricians responsibility to make sure the meter socket in this case is rated at least 100 amps.

    100 amp breaker protecting 60 amp wire is under protecting ? I'm not following....

    EDIT:

    I see Jerry has replied with a explanation that likely clears up what my meaning was for over protected.


  8. #8
    Roger Frazee's Avatar
    Roger Frazee Guest

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Mike Krueger View Post
    Yes it does look like the service (panel) was updated but it still has the old style meter. Back when the round meter socets were used they were all 60 amp. When the services were updated to 100 amp the meter socet were also updated to a square meter socket.

    Doesn't the utility control how many amps are going to the house?
    Nope, what they do is hang a transformer or pad mount one that will provide enough amps for the services to dwellings connected to that transformer. The main breaker or fuses at the dwellings service equipment controls the maximum amps needed from the transformer for that one dwelling.

    You will have to verify that the meter socket is rated only 60 amp... if so then it will need to be upgraded to match the service equipment and 100 amp rating.


  9. #9
    Andy Jarchow's Avatar
    Andy Jarchow Guest

    Default Re: 60 amp service but 100amp main???

    Thank you all for your help!!

    When I check a service to decide what amp service I’m dealing with I look at several things (in my report I have a section that asks for the amperage of the service). I check the main wire, main breaker, main panel max amp ratting, and style of meter. For liability reasons I will note that the service is a 60 amp in this case. If I said it was a 100 and my client found out after it was only a 60 I may be paying for a 100 amp service.

    If the meter socket/wires were rated for 60 amps max who would pay for this my client or the utility?

    Thanks again
    Have a great day!
    mk


  10. #10
    Join Date
    Aug 2008
    Location
    Maryland
    Posts
    1,970

    Default Re: 60 amp service but 100amp main???

    I doubt that you will get the utility to pay to upgrade something that is not installed by them and is the responsibility of the homeowner.

    A minimum 100 amp service has been common for quite awhile.

    When I said under protected I meant that the breaker was not providing the level of protection it should have, similar to someone underperforming a task, ie unacceptable. Having 60 amp conductors protected by a 100 amp OCPD leaves them under protected as they could overheat before the breaker would open.

    I would consider over protected having a 30 amp rated conductor having a lesser size breaker installed than required, like a 15.

    Last edited by Jim Port; 04-08-2010 at 06:03 AM.

  11. #11
    Join Date
    Aug 2008
    Location
    Maryland
    Posts
    1,970

    Default Re: 60 amp service but 100amp main???

    Would you consider someone wearing suspenders and a belt as over or under protected?


  12. #12
    Roger Frazee's Avatar
    Roger Frazee Guest

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Jim Port View Post
    Would you consider someone wearing suspenders and a belt as over or under protected?
    I would say "properly protected" due to the circumstances......

    Jim

    I actually believe I understood what you meant by under protected but It is just hard for me to think that way in terms of an OCPD. It would be interesting to hear others opinions as how one would look at a 100 amp breaker protecting 60 amp rated wiring. I may be in the minority....


  13. #13
    Roger Frazee's Avatar
    Roger Frazee Guest

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Mike Krueger View Post
    Thank you all for your help!!

    When I check a service to decide what amp service I’m dealing with I look at several things (in my report I have a section that asks for the amperage of the service). I check the main wire, main breaker, main panel max amp ratting, and style of meter. For liability reasons I will note that the service is a 60 amp in this case. If I said it was a 100 and my client found out after it was only a 60 I may be paying for a 100 amp service.

    If the meter socket/wires were rated for 60 amps max who would pay for this my client or the utility?

    Thanks again
    Have a great day!
    mk
    Hi Mike

    If you actually have a 60 amp service and 60 amp meter socket, the utility would have to verify that the existing service drop they ran is adequate for the new service equipment, they are not responsible for the meter socket.

    IMO if in fact 100 amp service equipment was installed when a 60 amp meter socket existed at the time ... the liability lies with the owner of the property who would then contact the installer to see what gives with the oversite of the meter socket being under rated. It would not be the responsibility of the buyer.

    The utility is only responsible up to the weather head at the connection point to the drip loop. The weather head, mast, and meter socket and wiring from the connection point at the drip loop to the service equipment is the responsibility of the owner of the property.

    The utility owns the meter that plugs into the meter socket.


  14. #14
    Andy Jarchow's Avatar
    Andy Jarchow Guest

    Default Re: 60 amp service but 100amp main???

    That makes sense. Thank you all for your help!
    mk


  15. #15
    dana1028's Avatar
    dana1028 Guest

    Default Re: 60 amp service but 100amp main???

    Quote Originally Posted by Roger Frazee View Post
    Hi Mike

    If you actually have a 60 amp service and 60 amp meter socket, the utility would have to verify that the existing service drop they ran is adequate for the new service equipment, they are not responsible for the meter socket.

    IMO if in fact 100 amp service equipment was installed when a 60 amp meter socket existed at the time ... the liability lies with the owner of the property who would then contact the installer to see what gives with the oversite of the meter socket being under rated. It would not be the responsibility of the buyer.

    The utility is only responsible up to the weather head at the connection point to the drip loop. The weather head, mast, and meter socket and wiring from the connection point at the drip loop to the service equipment is the responsibility of the owner of the property.
    I think a lot of what you are saying is local utility practice. In my area the utility is responsible for the meter - even though the electrician installs the mast, service conductors and meter socket, the utility verfies the installed equipment and are responsible for the meter.

    Re: Sizing the service drop.

    I just replaced a 30A, 240v service with a 100A, 240v service [mast, service conductors, meter socket] - the utiliy did not change the service drop conductors - reason: the load didn't change.

    A typical 2000 sq. ft. home using gas appliances calculates out at ~50A, 240v of electrical load - the utilities know this and provide a drop accordingly.

    I just had a 30-day energy audit done - my service was metered for peak usage....never exceeded 25A at any one time during the month.

    Also - utility companies use different service drop conductors that used by us - different tables are used for ampacity - if you look at Table 310.17 NEC you will see a #8 THW conductor has a 70A value...more than enough for the typical home....utilities won't spend the money for full sized conductors when they know they aren't necessary.....the worst that can happen? The wire burns out and they come out and replace it.


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •