Hello -

I am installing a 240V wall heater in my basement. I want to plug it directly into the existing 3-prong 240V outlet that is used for the dryer. I have run the 10/2 wire (two hot and a ground) from the heater to the outlet, but need some help figuring out how to hook this up.

From what I understand, the 3-prong outlet has two hot lines and a neutral. The heater requires two hot lines and a ground.

So, I was going to run the two hot wires from the outlet directly to the heater. That seems pretty straight-forward. But what do I do about the ground? The heater requires a ground connected to its frame, but I don't think I can simply connect the ground wire to the neutral on the outlet. I might be wrong!

Should I connect the ground wire to the outlet neutral? Connect the neutral to the metal wiring box at the outlet side? Leave off the ground (probably a bad idea!).

Any help would be great!

If the neutral wire is connected to a buss which shares the ground wires, then you are OK. You will have to verify that. And no, you should not leave off the ground wire... it is there for a purpose. Is your heater intended to be plugged in, or is it supposed to be hard wired?

If you have a 3 slot dryer outlet, (cable will be 10/2 with ground) the third slot is a ground, not a neutral.

MISSOURIBOUND - The heater is supposed to be hard wired, but I don't want to run another 240V line. Basically, the heater will only be plugged into the outlet when we have a guest staying in the finished basement, otherwise the dryer will be plugged in. I have done 10/2 wire from the heater through conduit across the basement to the room with the outlet. There I will connect the 10/2 wire to a 30A 3-prong dryer plug so that we can swap whether the heater or dryer is plugged in, at will.

HKSTROUD - Thank you for your response, I will try to use what I thought was the neutral as a ground and see whether it works.

If you have a 3 slot dryer outlet, (cable will be 10/2 with ground) the third slot is a ground, not a neutral.HK, The odd slot in a 3-prong dryer receptacle is a neutral, NOT a ground.

The old code allowed the neutral to serve the purpose of both neutral and ground, not the other way around.

My house was built in 1987, so I am assuming it's still the old code? That is, the 3-prong dryer receptacle neutral can serve the purpose of both neutral and ground?

Thanks for any confirmation - I'm not sure what would happen if I'm wrong about this, but I would rather prevent testing it!

Oops!! Sorry, don't know what I was thinking. Must have been thinking water heaters. Won't let happen again.

HKSTROUD - are they interchangeable? Can I use the neutral as a ground?