What is the size of my electrical service (pics)

Discussion in 'Electrical Forum discussion & Blog' started by teddynono, Feb 2, 2011.

  1. teddynono

    teddynono New Member

    Messages:
    6
    Location:
    DC
    Hey Gang,

    I have 240v service coming in from outside. There are three wires--two hot and one neutral. I am not sure what gauge the service wire is.

    It comes into the panel and is connected to a 60 amp main breaker. But the wire going into the 60 amp main breaker looks narrower than the wire coming in from the street.

    Does that mean that each of the hot wires are 120 V and 30 amps (for 240 V and 60 amps total?).

    Or is it calculated some other way? Is the main breaker always sized to the maximum current that the service wires can carry?

    By the way, this is a Square D QO breaker box.

    Thank you!

    [​IMG]

    [​IMG]
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,570
    Location:
    North Carolina
    That is a split bus panel of either 150 or 200 amps.
  3. Jim Port

    Jim Port Electrical Contractor

    Messages:
    156
    Location:
    Maryland
    The 60 amp breaker is only to shut off power to the lower part of the panel. It is not a main to shut off the whole panel. You can have up to 6 breakers to shut down the power to the panel. The incoming lugs will still be hot.

    You can see some labeling in the larger insulated wires going to the topmost terminals in the panel. Tell the size and then someone can tell you what size service you have.
  4. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    1,015
    Location:
    NY State, USA
    I was going to say 100 or 150A. :p
  5. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Seems to me he simply walks to the meter panel that feeds this and reads the breaker rating.

    Those wires arent coming off the transformer.

    Whats the mystery?
  6. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    Very interesting...never saw one of those. Is there a main breaker after the meter and before the panel? If there is not than the only way to shut off power to the panel is to pull the meter........
    Last edited: Feb 3, 2011
  7. Jim Port

    Jim Port Electrical Contractor

    Messages:
    156
    Location:
    Maryland
    If this is a split buss panel, like several suspect, there is no breaker ahead of this panel.
  8. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    1,015
    Location:
    NY State, USA
    A) Very few places have a main outside by the meter.

    B) You obviously have never seen a split-buss panel.
  9. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    1,015
    Location:
    NY State, USA
    No, the way to shut off power is to throw the (typically) four or six mains.
  10. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    Answering the last 2 posts......My house is a 2 family. 1 service, 2 meters. Panle number 1 is just inside from the meter panel outside. Main breaker is inside in the panel.......Panel number 2 is on the other side of the house some 35 feet away. Main breaker for panel number 2 is in a weatherproof enclosure just below the meter pan.......So an outside breaker is not all that rare to me anyway and I believe it was done properly when installed in 1978.And as far as turning the breakers off to de-energize the panel in the split buss panel....yes I am aware of what opening the breakers will do.......I was thinking about being able to de-energize the panel completely.
  11. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    Deleted by jwelectric duplicate post
    Last edited by a moderator: Feb 3, 2011
  12. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    Deleted by jwelectric duplicate post
    Last edited by a moderator: Feb 3, 2011
  13. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    Website seems to ignore my attempts to remove multiple posts.....I tried to delete them...
  14. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    1,015
    Location:
    NY State, USA
    I was referring to requiring an outside disconnect as mandatory. What you have is standard anywhere in the country if the panel is that far into the structure.
  15. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Hereabouts, every house and mobile home I ever saw feeds a subpanel in the house from a remote drop or underground line that has a meter and disconnect on the pole or post. And usually a space for a few breakers for the well.

    You guys are suggesting that the feed to this panel comes from a remote meter without a breaker on the feed wire?

    Never saw one without it here. You would run unprotected wires 50 or 200 feet from the meter to a subpanel???
    Last edited: Feb 4, 2011
  16. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    1,015
    Location:
    NY State, USA
    This has always been required for mobile homes.

    Absolutely.



    Yup, absolutely, if underground or outside. And not to a "sub-panel", to the main panel(s).
    Once the wire enters the house there must be a disconnect near the point of entry. This is an NEC code. Your local southwest codes are more stringent.
  17. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Sounds foolish to me. Hate to hit that direct connection to the transformer with the backhoe!

    The only underground cables around here are PO CO owned, 6' deep in a sand bed, from the the transformer,
    paid for [ and installed or paid to be installed] by the homeowner, and going to a meter with a breaker for any destination beyond.
  18. Bobelectric

    Bobelectric Electrical Contractor

    Messages:
    39
    Location:
    Eighty Four,Pa. 15330
    100 amp sub panel.
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