240v 4 Wire Conduit to 240v 2 Wire Water Heater

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Old 09-25-11, 04:24 PM
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240v 4 Wire Conduit to 240v 2 Wire Water Heater

I am trying to replace an ancient 240v 30 amp water heater with a new 240v unit. The conduit to the old heater has four 10ga. wires inside, black, red, blue and yellow. The new water heater has only a black and red wire with a green screw for the ground. Is it possible to wire this existing conduit to the new heater or do I have to have a new conduit run from the panel.

This is in Connecticut, USA.

Thanks in advance for any help.
 
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Old 09-25-11, 04:34 PM
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Welcome to the forums! With conduit that is continuous to the panel you have your equipment body ground, and you only need two current carrying wires. I would cap off the yellow and blue on both ends of the conduit in the boxes and connect the black and red to the water heater leads and to the breaker. What are the other two wires being used for, now?
 
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Old 09-25-11, 04:38 PM
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Currently all four wires are connected to the old water heater (to wires corresponding with their color).
 
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Old 09-25-11, 05:07 PM
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Are you saying there are two 30 amp 240v breakers in the the breaker box and each 240v breaker has two of the wires going to it? Is there a mystery box or a timer associated with the water heater? Do you have peak load metering?

Is the conduit to the water heater metal?
 
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Old 09-25-11, 05:11 PM
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The conduit runs to the main panel and is on a 30 amp breaker that takes up two slots on the panel (as opposed to the other 15 amp breakers that just take one).
 
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Old 09-25-11, 05:15 PM
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Originally Posted by TDHKC View Post
The conduit runs to the main panel and is on a 30 amp breaker that takes up two slots on the panel (as opposed to the other 15 amp breakers that just take one).
Are you saying all four wires are connected to that breaker, two wires under each screw?
 
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Old 09-25-11, 05:51 PM
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I pulled the panel face off and checked. Only the blue and the yellow are attached to the breaker (one at each screw). No idea where the black and red are originating from. The conduit goes straight to the panel without any branches, mystery boxes, timers etc.
 
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Old 09-25-11, 07:17 PM
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Time for some pictures! kjgfodfs,vcs[
 
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Old 09-25-11, 07:22 PM
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Originally Posted by Furd View Post
Time for some pictures! kjgfodfs,vcs[
And I second that motion. http://www.doityourself.com/forum/el...your-post.html
 
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Old 09-26-11, 07:55 AM
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I hid in the bushes and waylaid my electrician neighbor this morning. After promising him a 12 pack of his choice he's going to stop by this evening and check out the situation.

Thanks for all of the help.
 
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Old 09-26-11, 08:29 AM
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Excellent. Let us know what he says.
 
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Old 09-27-11, 09:14 AM
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After looking at it last night with my neighbor it appears that the old water heater was a dual element unit with the blue/yellow wire connecting to the bottom element and the red/black feeding the top. At some point it looks as if the previous house owners needed space on the panel and disconnected the black/red combo (sacrificing the top element) which we speculate was on a separate breaker and left just the bottom element connected. The black/red combo are capped right as the conduit enters the main panel and register as dead with a tester.

Looking at the new water heater he said I should be fine with capping the black and red at the appliance end and using the yellow (hot) and blue (neutral) to run the new machine.

I'm going to switch the two heaters tonight.

Thanks for your help, Ray and others.
 
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Old 09-27-11, 09:53 AM
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using the yellow (hot) and blue (neutral)
A blue or yellow can not be used as a neutral but assuming this is a 240v water heater you don't have a neutral. You have two hots. Blue and yellow is fine. The blue is connected to the breaker not the neutral buss, correct?
 
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Old 09-27-11, 10:48 AM
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Sorry, you're correct. I got my terminology confused.
 
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Old 09-27-11, 12:48 PM
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Just wanted to make sure.
 
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