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View Full Version : How to tap 120V out of 240V heater circuit


Tech_User
Mar 10, 2008, 01:24 PM
Hello,

I need to tap 120V out of the existing 240V baseboard heater wirings to use a 120V 3-prong washer (the heater itself was removed, only the wiring left. I do have a 120V outlet nearby but on the other side of the doorway so I don't want to use it)

Currently there are 5 wires at the 240V wirings: 2 blacks (twisted together), 2 whites (twisted together), and a bare ground wire. There is no neutral wire.

I can light up a 120V bulb using 1 of the hot wire (white or black) and the bare ground. But I am not sure it is right/safe way to tap 120V out of the existing wiring. Please show me how.

Otherwise should I use 1 hot wire from the existing 240V (+ a bare wire for ground) and just a neutral wire from the nearby 120V outlet (safer to cross the doorway?)

Thanks

stanfortyman
Mar 10, 2008, 01:43 PM
The ONLY way to do this safely and correctly is to re-configure this WHOLE circuit to 120v, IF you are sure you will not need it for 240v.
DO NOT attempt to do this any of the ways you suggest. PLEASE.

Since you have two sets of "2-wires" this circuit obviously extends elsewhere. Did it feed more than one heater?
What about the thermostat? Is it still in place, or was it mounted on the heater itself?

Tech_User
Mar 10, 2008, 02:07 PM
Thank you for taking my question.

Quote: "Since you have two sets of "2-wires" this circuit obviously extends elsewhere. Did it feed more than one heater?
What about the thermostat? Is it still in place, or was it mounted on the heater itself?"

Yes the circuit feed another heater in the next room and the thermostat is mounted on the heater (which has been removed)

Can you please explain further, what is wrong with the option "I use 1 hot wire from the existing 240V (+ a bare wire for ground) and just a neutral wire from the nearby 120V outlet (safer to cross the doorway?)"

Thanks

stanfortyman
Mar 10, 2008, 02:39 PM
The conductors for a given circuit MUST be in the same conduit, raceway or cable. For several reasons it is not safe to just grab a neutral from anywhere. This is not like DC automotive work where all grounds are the same.

Tech_User
Mar 10, 2008, 03:26 PM
I really thought that I can "borrow" the neutral from the nearby outlet. But since this is also no good so, for now, may be I have to use the extension across the door way then.

Thanks again for your suggestions

Stratmando
Mar 10, 2008, 04:20 PM
You should be able to reidentify wires hook to 120 volt breaker, neutral, and ground, and you could have a 120 volt recepticles at each location and thermostat location if wire #12
(20 Amp beeaker) or #14 on a 15 Amp Breaker.

dragon90815
Sep 12, 2009, 04:57 PM
Tappinga 240v to 110v 2 wire

stanfortyman
Sep 12, 2009, 06:03 PM
tappinga 240v to 110v 2 wire
?? :confused:

wayne1yahoo
Feb 20, 2013, 05:53 PM
To operate 120 volts A/C you need the proper wire size and Amp load. This requires one 120 lead normally black wire, one neutral wire normally white, and a ground normally bare. I would strongly advise you to run the proper wire and install to the proper single amp breaker in your panel box. You will get the Amp load off the item you want to hook up. If you are not using this 240 circuit make sure the wires are properly protected and the breaker is off. The last thing you need is someone getting electrical shock and a fire resulting from improper circuit. Do not tap off this 240 circuit.

stanfortyman
Feb 20, 2013, 06:05 PM
wayne1yahoo, the post you are replying to was made 5 years ago.