Ganged circuit breakers

Discussion in 'Electrical and Wiring' started by Outbacker, Jun 2, 2006.

  1. Jun 2, 2006 #1

    Outbacker

    Outbacker

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    In my electrical panel, there are 2-15 amp breakers that have been ganged together and they were for used for supplying power to a large baseboard heater. I have removed the heater and will not be replacing it. I would rather run the wiring out to my shop for more power. Anyway, do the ganged 15 amp's equal 30 amps? If I run the power out to the shop, will I have theoretically 30 amps to the plug? It seems logical to me, but I would rather ask. Thanks.
     
  2. Jun 2, 2006 #2

    Square Eye

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    No.

    The tandem breakers = 15 amps @ 120 volts x 2 breakers = 15 amps @240 volts.

    Tandem breakers draw power from each leg of the 240 volt power source. Each leg is 120 volts. The breaker on each leg is 15 amps.
     
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  3. Jun 2, 2006 #3

    Outbacker

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    Thanks. What is the advantage of having ganged breakers? I know this seems like a silly question, but if I am still getting 15 amps, what does the 240 volts provide? Thanks again.
     
  4. Jun 2, 2006 #4

    Square Eye

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    Amps x volts = watts

    Flow x pressure = power

    120 volts is plenty good for most household devices and accessories. To run a heating element large enough to heat a home or an A/C compressor, 240 volts handles the power much more efficiently. More voltage and less amperage runs cooler. More amperage generates more heat which is energy being dissapated into the air. A 120 volt motor running at the required amperage to match a 240 volt motor's output power, runs much less efficiently, is much larger, and will run much hotter and will not last as long as the 240 volt motor.

    A tandem breaker, when overloaded, kicks both sides of the 240 volt hot wires. Each leg is 120 volts, if only one side had a problem in it's circuit, the tandem breaker will kick and shut power down to both sides. This protects the equipment from running underpowered or from damaging anything around it.

    The powerlines out on your street are commonly 14,400 or 7,200 volts before it's reduced in the transformer in front of your home. Higher voltage is easier to deal with than higher amperage. If the power companies had to produce 120 volt at the required amperage, the wire would be as big around as you are tall. I think of voltage as pressure, amperage as flow, and watts are the resulting power.
     
  5. Jun 2, 2006 #5

    inspectorD

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    I could not have explained that better.. that is exactly how I tell my students how it works.
    I liken it to plumbing which everyone understands.
    Nice job Square Eye...ever teach?:D
     
  6. Jun 14, 2006 #6

    Gord Kurtenbach

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    Hi. I'm renovating my kitchen and just moving the receptacles a bit. I found this thread and thought it might answer as question I have.

    In our breaker box there are 2 15 amp breakers that are ganged together so they act as one switch. These are wired to single 14/3 cable with the black carrying the hot from one of the breakers and the red carrying the hot from the other breaker. The neutral is just the one white wire. This is then wired to 2 receptacles so that each receptacle is has its own breaker but share the neutral.

    Seems this is just way of avoiding having to run two cables.

    My question is: Is this a safe/accepted practice?

    thanks,
    Gord
     
  7. Jun 15, 2006 #7

    petey_racer

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    From what I know this is a very typical way of wiring kitchen receptacles in Canada.
     
  8. Jun 15, 2006 #8

    Square Eye

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    Code in the USA requires 12-2 w/g and 20 amp breakers.

    Tandem breakers and shared neuterals are acceptable to some inspectors, not to others. I have no idea what Canada electrical code is. Check your local electrical supply house. The guys who work in these places often have experience and can help with this sort of question.
     
  9. Jun 15, 2006 #9

    petey_racer

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    In the US, under the NEC, tandem breakers (in a panel that accepts them legally) and multi-wire circuits (shared neutrals) ARE legal.

    Also, the NEC does not "require" 12/2. It simply requires 20 amp circuits for kitchen receptacles. If I want to run 12/3 an split wire the receptacles Canada style that is my choice, but it is still quite legal.
     
  10. Jun 16, 2006 #10

    Square Eye

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    You wouldn't get away with it in Russelville, Ky. Mr. Whitehead didn't like it so it wasn't allowed.

    The code is subject to the interpretation of the inspector.

    I said 12-2, sorry, yes you'd have to run 12-3 to share a neutral.

    What is your problem with me Petey?
     
  11. Jun 16, 2006 #11

    petey_racer

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    Then I would have to ask Mr. Whitehead to show me in verse what he finds not to code.
    Inspectors are NOT God and do not make the rules. They can also NOT simply interpret the rules to suit their own ideas and agendas. Or simply because "They don't like it". That one amazes me.
    More folks need to question some of the misinterpretations of certain inspectors.


    No problem with you personally.
    When I see something that is not actually code accurate, yet is written as if it were fact, I feel the need to state what the actual code is. I try to mention that what I write is according to the NEC, so if an area has not adopted it yet they can adjust the facts to what their area follows. An example is Canadian code. I try not to reply with code information since I do not know what is code accurate in Canada.

    I see so many people on boards like this, most of whom are not even in the trade, who reply with erroneous information. I don't go to framing message boards and give advice on what size header to use over a garage door, nor do I go to plumbing boards and give advice on what size vent stack to use.
     
  12. Jun 16, 2006 #12

    Square Eye

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    I served my time as a master electrician, now I'm doing other things. You are NOT the only electrician on the forum.
     
  13. Jun 17, 2006 #13

    petey_racer

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    When did I ever say I was?


    That's cool. How long were you in the trade?
    I hope you are keeping up on current codes. It's a great career to fall back on if you need it.
     
  14. Jan 27, 2014 #14

    Lectrowiz

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    You guys are screwing this guy up. You are not talking about "Tandem" breakers. Tandem breakers take up only one space, thus only one hot leg. They are two slim breakers that are half the size of regular breakers that take up the space of one single pole breaker. They are not "double pole" breakers like what you are describing to this gentleman.
     
  15. Jan 28, 2014 #15

    JoeD

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    The OP was not asking about tandem breakers. He asked a double pole breaker that was supplying a heater.
     
  16. Jan 28, 2014 #16

    nealtw

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    Eight years later I am sure he has this sovled.
    Lectrowiz; Welcome to the site.
     
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