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  1. #1
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    Red face shocking electric water heater

    I replaced an electric water heater today with gas so I went to disconnect the wiring at the timer they had installed. The power enters from the distribution panel on the left and exits to the heater on the right. Note the neutral wire was never connected to the WH. The water pipes completed the circuit. Oooh, baby!
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  2. #2
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    Don't water heaters run on straight 240v? Neutral is only needed for 120.
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  3. #3
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    Red face clarification

    I shouldn't have referred to it as the 'neutral' but in the case of 220/240 vac it serves as a grounding conductor which 'should' be connected here at the timer bonding. I also didn't clarify there was a loose hot wire inside the WH where it slipped out of the Marrette and was about to energize the WH. Normally, the pipes would complete a ground but it was broken by some PVC without a bonding jumper. The two hot wires are hot to the thermostat and swap phases once the stat closes on a call for more hot water. However, in this case, the loose hot wire inside the cabinet where the cable enters the WH would not be grounded by the two hot wires. Anything that gets electricity really should be bonded regardless IMHO.

  4. #4
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    Dec 2007
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    not anywhere close to your issue, but saw one today, there for the furnace, that they installed the ball valves onto the nipples at the water heater.

    the funny thing is there is a union, water flex and nipples on both sides above the water heater, somebody was not thinking.
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  5. #5
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    Quote Originally Posted by hearthman View Post
    I shouldn't have referred to it as the 'neutral' but in the case of 220/240 vac it serves as a grounding conductor which 'should' be connected here at the timer bonding. I also didn't clarify there was a loose hot wire inside the WH where it slipped out of the Marrette and was about to energize the WH. Normally, the pipes would complete a ground but it was broken by some PVC without a bonding jumper. The two hot wires are hot to the thermostat and swap phases once the stat closes on a call for more hot water. However, in this case, the loose hot wire inside the cabinet where the cable enters the WH would not be grounded by the two hot wires. Anything that gets electricity really should be bonded regardless IMHO.
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  6. #6
    Join Date
    May 2006
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    I also dont see a green ground wire to the ground screw on the timer frame it self
    Quote Originally Posted by hearthman View Post
    I replaced an electric water heater today with gas so I went to disconnect the wiring at the timer they had installed. The power enters from the distribution panel on the left and exits to the heater on the right. Note the neutral wire was never connected to the WH. The water pipes completed the circuit. Oooh, baby!

  7. #7
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    Yea, I've touched too many appliances and said.....whoa, sheet.....wtf?
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  8. #8
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    Quote Originally Posted by pctech View Post
    I also dont see a green ground wire to the ground screw on the timer frame it self
    The screw is there, upper right...nothing's hooked to it, but the screw is there.
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  9. #9
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    May 2006
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    also dont see a green ground wire to the ground screw
    the point was NO GROUND WIRE is hooked up to the ground screw

    Quote Originally Posted by DLZ Dan View Post
    The screw is there, upper right...nothing's hooked to it, but the screw is there.

  10. #10
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    Dec 2010
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    Quote Originally Posted by pctech View Post
    also dont see a green ground wire to the ground screw
    the point was NO GROUND WIRE is hooked up to the ground screw
    I know..maybe the screw wasnt green enough for the installer.
    Every customer you take for granted today will be someone else's tomorrow.

  11. #11
    Join Date
    Jul 2004
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    Well, looking at the picture I see BX cable, not MC so the armor serves as the ground. Hence the reason for no green wire in the cable and the presence of the bonding wire, meant to keep the armor from heating in the event of a ground fault. Now if the locknuts are not made up tight or the cable is not properly inserted onto the connector then the ground is compromised.

    Also, if the motor in the timer is 120v, that would explain the need for the neutral on the feed. If the motor on the timer is in fact 120v then you cannot use the white wire as a ground as it is being used as the neutral for the timer motor. Basically, if you connected the white wires together in the timer and bonded the white at the water heater to use as a ground and the white wire was also connected to one side of the timer motor, then a fault in the white wire between the panel and the timer would make the water heater hot literally!

    Using the latest codes if the system is metal pipe then there should be a bonding jumper across the heater piping. The reason for that is so that if the water system has a continuous ground regardless of whether the water heater is present, absent, plastic or metal.

    With all that said I agree, I hate BX cable and agree that a ground should be a wire in the cable and not the sheath of the cable. But there are millions of BX installations going strong to this day.

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