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10-30-2010, 04:00 PM   #1
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## why no neutral?

I understand that a water heater does not use a white neutral, only an equipment ground. (I could have saved money and bought 6/2 wire instead of the 6/3).

What I don't get is why ???

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I'm gonna hurl myself against the wall
because I'd rather feel bad than not feel anything at all
Warren Zevon

10-30-2010, 04:49 PM   #2
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The highest wattage a residential water heater can be is 5500 watts=30 amps@240=#10 awg! Normally they are 4500 watts.

 10-30-2010, 04:53 PM #3 You talking to me?     Join Date: Dec 2007 Location: sw mi Posts: 7,551 Rewards Points: 6,290 because it isn't needed. your house system provides 2 voltages: 120 and 240. The 120 is sourced by a hot and a neutral and the 240 from two hots on opposing legs. While there are some appliances that require 120 and 240 (120/240 volt circuit), there are also appliances that need only one or the other. In those 120/240 circuits, you would have the two hots plus the neutral. a dryer as an example typically requires a 120/240 circuit. That indicates both 120 and 240 volt sources are needed. The heating element uses the 240 and the controls typically use the 120. most residential water heaters are pretty low tech with mechanical thermostats and overloads so they do not need the 120 volts typically used in control circuits such as with the dryer. the reason the 240 volts is used is as simple as: it allows a lower (amperage) rated circuit to feed it. If you need a 30 amp circuit with 240 volts, you would need a 60 amp circuit with 120. The costs of the equipment needed is considerable higher so they use the higher voltage. Last edited by nap; 10-30-2010 at 04:56 PM.

 10-30-2010, 06:30 PM #4 Member   Join Date: Feb 2006 Location: portland, OR Posts: 151 Rewards Points: 150 thank you Nap for that explanation. Oh BTW Bobelectric, I meant to say 8 romex not 10 as my water heater is on a couple of 40 amp breakers. The part I'm not clear on is if we only need the equipment ground to run a pair of 120 legs, why do we have separate neutral and equipment grounds on 120 circuits? Probably a dumb question but I'm no Einstein. __________________ I'm gonna hurl myself against the wall because I'd rather feel bad than not feel anything at all Warren Zevon
10-30-2010, 06:36 PM   #5
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Quote:
 Originally Posted by handifoot The part I'm not clear on is if we only need the equipment ground to run a pair of 120 legs, why do we have separate neutral and equipment grounds on 120 circuits? Probably a dumb question but I'm no Einstein.
the egc (equipment grounding conductor) and the neutral must be isolated from each other any place other than the first means of disconnect for the service. The neutral is a current carrying conductor and needs to be treated as such.

so, anytime you run a 120 volt circuit, you have to have a neutral.

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