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Electrical Wiring in the Home/Hooking up heater, wrong color wires


Hi Bob-

Finished off the inside of my detached garage earlier this year with upgraded electrical, insulation, and sheetrock. Had the electrician run wires/conduit down from the ceiling for a 240v electric heater that I was going to purchase later. If it makes any difference I was going to have a outlet for a welder at first but changed my mind after he started as I would use a heater more that I would have used a welder.

This weekend I purchase a 240v ceiling mount electric heater with fan. In the process of hooking it up there are 4 wires in the conduit red, black, white, and bare copper. The instructions for the heater show that I need to hook up 2 separate back wires to the power block and a green or bare copper wire to the ground. I know the bare wire would be the ground but what other wire would be the "black" wire? Red or white? Do I do anything with the spare wire other than leave it taped up?



I don't know what wattage your heater is or the size of the line your electrician ran for the welder so I have to assume you know the line for the welder will handle the heater. Having said that you will use the bare copper wire from the panel for the bare or green grounding wire on the heater. You will use the red and black wires from the panel breaker to the two black wires on the heater. It does not matter which black wire you connect to the red or black. Tape the unused white wire and enjoy the heat.

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Electrical Wiring in the Home

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Licensed Master Electrician (32 years) 6165B Contractor in Closter New Jersey with 40 years total experience in Residential - Commercial - Industrial work. Emergency Service - General trouble shooting and repair work - ONAN & GENERAC generator installation - Paddle fans - Kitchen & Bath exhaust fans - AC lines - Smoke detectors - Telephone lines - Cable TV lines - Computer network cabling - Exterior lighting - Recessed lighting - Security lighting - (200 - 150 - 100 amp service up grades) - Electric Heat - New circuits - New appliance hook ups - and more ! FREE ESTIMATES 201-358-1552 Fully Insured


Licensed contractor in Closter New Jersey.

"The Frank Williams School of Electrical Construction". My dear old boss is 100 ! and still going God Bless him. I started working for "Tenafly Electric" right out of high school at 19. He was tough but I learned more working for him in 8 and half years than most guys. We did mostly industrial work while doing some commercial and residential so I was fortunate to be exposed to all 3 areas of electrical construction. The guys I worked with were all good guys and I stay in touch with some of them still. Most of us went into our own buisness's which says something about the caliber of the guys I worked with. We had some interesting clients : Wella Corp. of shampoo fame, Farah Fawcett etc, I didn't buy shampoo for 10 years. It was a great place to work. Pan Am the former airline just before they went under, another great place to work, nice clean environment. C&C Metals, the largest button manufacturer in the US at that time, a not so clean environment but a very interesting place to work, lots of machine's cranking out buttons of all kinds but you had to be on your toes, it was a potentially dangerous place to be . All kinds of action going on around you.

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