Single phase 230v 60hz 5kw in US with two 120v legs

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Old 06-14-12, 07:26 PM
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Single phase 230v 60hz 5kw in US with two 120v legs

This question is surely answered somewheres around here, but dang if I can find it, so I am asking for some help from the esteemed and highly qualified panel:

The appliance is a 1Ph, 230v, 60hz, 5kw load, GSHP with g,N,L. There is a snippet of the wiring diagram below...I want to connect it to my electric power in the US: single phase, 60hz, two 120v legs. One way is: connect one 120v leg to L, the other 120v leg to N, white to ground. Is that good enough?
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Old 06-14-12, 07:33 PM
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No. You have two hots, 240 volts between them.

Connect one hot to "N", one hot to "L", and a ground wire (green or bare) to the ground. White can not be used as a ground. You will need a 30 amp circuit for this appliance and #10 wire.
 
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Old 06-15-12, 10:43 AM
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'Bout the Line and Load, Hot, Neutral and Ground: this connection as you described was not what I might have done. I would have messed up the neutral and ground, So, load ground will go to line ground.

I got it! Thanks!
 
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Old 06-20-12, 11:31 AM
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A followup: What would you do about the neutral wire. Would you just not run it to the appliance.

Pardon my ignorance: I am not sure what the difference is in using the neutral vs the ground since both are bonded in the distribution panel (in this case)
 
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Old 06-20-12, 12:19 PM
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What would you do about the neutral wire. Would you just not run it to the appliance.
If it is 240 not 120/240 you don't run a neutral. If you already have cap at both ends. In some cases such as stoves and dryers you would run it for future use but cap it.

Pardon my ignorance: I am not sure what the difference is in using the neutral vs the ground since both are bonded in the distribution panel (in this case)
The neutral is there to carry current. The ground provides a low impedance path for fault currents back to the breaker. Outside of the first OCPD panel they should never be connected or used interchangeably because if neutral and ground are connected outside the panel dangerous currents could be imposed on the ground. Example: Hand on metal sink and touch a refrigerators metal shell that is grounded but also carrying a neutral current because of an improper connection and zap, you just bought the farm.
 
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Old 06-20-12, 12:29 PM
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What would you do about the neutral wire. Would you just not run it to the appliance.
That's correct. A neutral is used to complete a 120V circuit using one of the split legs of the single-phase 240V power supplied by the POCO. Single-phase 240 does not use the neutral.

I am not sure what the difference is in using the neutral vs the ground since both are bonded in the distribution panel (in this case)
The neutral ultimately returns to the center point of the transformer. It is a current-carrying conductor, and always carries current when a 120V load is in use. It can be thought of as equivalent to a drain pipe in a plumbing system.

The ground is not a current-carrying conductor. It exists to carry power safely to ground if something malfunctions. It can be thought of as equivalent to an emergency overflow pipe that dumps out directly onto (into) the ground, in a plumbing system.

Neutral and ground are never connected together on the load side of the service entrance.
 
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Old 06-26-12, 12:24 AM
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I had best rewire that submersible pump...
 
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