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Thread: Couple of questions about 220 volt

  1. #1
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    Question Couple of questions about 220 volt

    My first question is , my shaper is 3hp , my jointer is 3hp. I plan on running off the same plug not at the same time. Is there any issues with changing the 220 plug on end of shaper to one like on end of jointer? I would use the same amperage plug , 30 amps. I think the jointer is a Nema 6-20 Plug. The round 4 prong with a bit of twist when I insert into wall outlet.

    Another 220 question if I turn a single 220 receptacle into a double 220.
    Do I u just use jumper wires to get down to the lower receptacle if i'm hot wired to the top?


    THANKS

  2. #2
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    If your circuit is protected by a 30 amp breaker, then you should be using NEMA 6-30 plug and receptacles. If the circuit is protected by a 20 amp breaker, you should be using 6-15 or 6-20 receptacles. Receptacle amperage ratings must match the breaker rating per NEC. There is an exception that allows 20 amp branch circuits to use 15 amp duplex receptacles. Other than that, receptacle rating = breaker rating.

    With 3 HP machines, a 20 amp circuit is quite satisfactory and 15 or 20 amp duplex receptacles will fill your need. I'm not sure what you mean by "single 220 receptacle into a double 220". If the receptacle is a 15/20 amp duplex, then you shouldn't need to do anything "special" to get power to both halves of the receptacle. If you're talking about two separate 30 amp receptacles, simply wire them in parallel.
    Tom Veatch
    Wichita, KS
    USA

  3. #3
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    Quote Originally Posted by Tom Veatch View Post
    If your circuit is protected by a 30 amp breaker, then you should be using NEMA 6-30 plug and receptacles. If the circuit is protected by a 20 amp breaker, you should be using 6-15 or 6-20 receptacles. Receptacle amperage ratings must match the breaker rating per NEC. There is an exception that allows 20 amp branch circuits to use 15 amp duplex receptacles. Other than that, receptacle rating = breaker rating.

    With 3 HP machines, a 20 amp circuit is quite satisfactory and 15 or 20 amp duplex receptacles will fill your need. I'm not sure what you mean by "single 220 receptacle into a double 220". If the receptacle is a 15/20 amp duplex, then you shouldn't need to do anything "special" to get power to both halves of the receptacle. If you're talking about two separate 30 amp receptacles, simply wire them in parallel.
    What I meant by a double 220 was I wanted two outlets connected to the same breaker but only be using one at a time. So I dont have to reach behind DC to unplug and plug in again heater or Planer etc.

  4. #4
    Quote Originally Posted by Craig D Peltier View Post
    What I meant by a double 220 was I wanted two outlets connected to the same breaker but only be using one at a time. So I dont have to reach behind DC to unplug and plug in again heater or Planer etc.
    Yes, that can be done. You can either use two separate receptacles in separate boxes or a duplex receptacle, which is essentially two outlets in one box. I don't know how NEMA feels about two separate boxes on a single 220v breaker, but I know it can be done. I've done that for a few of my 'one at a time' tools.

  5. #5
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    Quote Originally Posted by Don Eddard View Post
    ... I don't know how NEMA feels about two separate boxes on a single 220v breaker, but I know it can be done. ...
    I've seen/heard rumblings that some jurisdictions limit 240v circuits to a single outlet. But that position is technically indefensible and the NEC doesn't, to my understanding, put any different restrictions on the number of outlets on a 240v branch circuit than it does on a 120v branch.

    So, wire two receptacles into a 240v circuit using the same techniques that you'd use for a 120v circuit. In fact, it's actually a little simpler with 240v since you don't have to be concerned with which wire (other than the grounding conductor) you connect to which terminal.
    Tom Veatch
    Wichita, KS
    USA

  6. #6
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    "But that position is technically indefensible and the NEC doesn't, to my understanding, put any different restrictions on the number of outlets on a 240v branch circuit than it does on a 120v branch."
    Note that the National Electrical Code (NEC) limits the number of outlets for any type of circuit. The idea is to limit the possible amount of current that all connected devices will use at once, not what you intend to use. You can certainly do what you're suggesting, but it won't be code.

  7. #7
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    Are dual 220 outlets always pre wired so that you can have to connect to two poles an not use a jump wire to the poles below or above?
    Thanks

  8. Quote Originally Posted by David Keller NC View Post
    Note that the National Electrical Code (NEC) limits the number of outlets for any type of circuit. The idea is to limit the possible amount of current that all connected devices will use at once, not what you intend to use. You can certainly do what you're suggesting, but it won't be code.
    No, the NEC does not limit the number of outlets per circuit in a residential installation. You are permitted to install as many as you wish.

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