Old Water Heater, 2 hots, no ground or neutral wires.

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  #1  
Old 02-01-06, 04:56 PM
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Old Water Heater, 2 hots, no ground or neutral wires.

I have an old Sears Roebuck, 30 gallon, 230 volt water heater.(not sure of amperage)
It has two wires coming out of it: one black, one red.
Those wires j-box with a 2 wire (w/ground) romex cable.(not exactly sure what guage Romex, maybe 12 or even 10).
In the j-box, the two wires from the heater connect with the black and white of the romex. The ground from the Romex connects to the j-box itself.
The Romex leads back to the main 60 amp fuse box, where the ground wire connects to the ground bus bar. The black and the white wire each connect to a different screw in, 30 amp fuse. So, there is no ground wire or neutral wire to the heater. How is that possible. Does each hot wire use the other as a return path for current? And yes, the water heater works.
 
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Old 02-01-06, 05:27 PM
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Originally Posted by Willg54
(not sure of amperage)
No name plate?

> It has two wires coming out of it: one black, one red.
> Those wires j-box with a 2 wire (w/ground)
>romex cable.(not exactly sure what gauge Romex, maybe 12 or even 10).

#10.

> In the j-box, the two wires from the heater connect with the
> black and white of the romex.
> The ground from the Romex connects to the j-box itself.

So far so good.
Is the box attached by a steel nipple?
A ground to some where on the tin would be appropriate.



> The Romex leads back to the main 60 amp fuse box, where the ground
> wire connects to the ground bus bar. The black and the white wire each
> connect to a different screw in, 30 amp fuse. So, there is no ground wire
> or neutral wire to the heater.

There is a ground.
No neutral is needed.

> Does each hot wire use the other as a return path for current?
That's the essence of 240V instead of 120V.


> And yes, the water heater works.

Copper plumbing that is grounded too?
You're probably safe.


Btw, if ever just one fuse blows, you will still have voltage on both sides of both fuses.
 
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Old 02-01-06, 09:15 PM
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You asked if each wire was the return path for the other. In a way, that is true. If you put a meter across the two hot wires feeding the panel, you should read about 240 volts. If you put the meter across each of the hot wires and ground, you should read about 120 volts. That is why your water heater does not have a neutral. It is only a 240 volt load. A range or dryer have two hots and a neutral because the heating elements use 240 volts, but timers, clocks, motors and lights use 120 volts. You used to be able to use the ground wire as the neutral (hence, a three-wire circuit), since the 120 volt loads are rather small for these appliances, but that is no longer allowed (now they are four-wire circuits). This is a non-technical explaination.
 
  #4  
Old 02-02-06, 06:37 AM
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Originally Posted by fixitron
You asked if each wire was the return path for the other. In a way, that is true. If you put a meter across the two hot wires feeding the panel, you should read about 240 volts. If you put the meter across each of the hot wires and ground, you should read about 120 volts. That is why your water heater does not have a neutral. It is only a 240 volt load. A range or dryer have two hots and a neutral because the heating elements use 240 volts, but timers, clocks, motors and lights use 120 volts. You used to be able to use the ground wire as the neutral (hence, a three-wire circuit), since the 120 volt loads are rather small for these appliances, but that is no longer allowed (now they are four-wire circuits). This is a non-technical explaination.
This is a good explanation of 240 volt stuff - thank you.
 
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