Installing surface mount dryer outlet question

[Mikepier]

I have to install a dryer outlet in a garage where it has unfinished sheetrock. I purchased a surface mount outlet similiar to this one:

It came with 2 half moon clamps for the wire, and the instructions say for wall mounting, put the clamp on the bottom knockout. For floor mounting, use the knockout on the back.

This would mean that I would have to come out of the sheetrock with the wire, then turn up 90 deg to the outlet. Is this right? Is there any reason why i cant use the rear knockout so I can come inside the sheetrock and through the rear knockout?

[Kevin Ricks]

Use back or bottom whatever makes sense. Why the surface mount? How are you going to mount to the sheetrock? I guess you could slap up a 1x6" board or something spanning a couple of studs and mount the outlet to that, but why not cut a hole for a box and use a box mount outlet and cover plate instead of the surface mount?

Kevin

[John Grabowski]

No, but you should try and get one edge of the receptacle over a wood stud so that you can mount it securely. The larger size outlets don't always hold up well when they are only fastened to the drywall.

Another way to go is with a 4" x 2 1/8" square box with a surface cover and dryer receptacle. This would enable you to get part of the box over the stud and still have space to enter into the back.

[Mikepier]

That's what I was going to try and do, grab a stud from one side of the outlet, but I don't know if the clamp in the rear will get in the way. I can test it on a piece of wood and see if it will work. I guess I could get a square box and surface mount that, or do Kevin's suggestion and cut a box in.I just thought this dryer outlet seemed the easiest and painless.

[Mikepier]

I managed to find a box that steel box that measures 3 3/4" X 2" deep. This looks the same as regular 1900 box but deeper. Would this work with a dryer outlet?

[John Grabowski]

For a dryer outlet you should use a two gang box. 2" deep is barely enough room for the receptacle, but you also need a certain amount of cubic inches for your conductors. Use 2-3.5" deep gem boxes ganged together if you want to go flush mount. Cut the hole next to a stud. Drill two holes in the side of the box. Use Madison bars to secure the box then shoot two screws through your drilled holes into the stud.

Are you using 10/3 copper romex or #8 aluminum?

[franz fripplfrappl]

Whichever knockout you decide to use, make sure you can firmly clamp the wires at the point they enter the receptacle. I came across one install where the wires were not attached properly.

[Mikepier]

Yes, 10/3 w/ ground romex

[Mikepier]

The box is 2", but doesn't the raised cover plate for the receptacle give you an additional 1" or so?

[John Grabowski]

The box is 2", but doesn't the raised cover plate for the receptacle give you an additional 1" or so?

I'm not sure what kind of box you have, but you need at least 2.50 cubic inches for each conductor. For the dryer outlet you will need the equivalent of 4 conductors. Therefore 8 x 2.50 = 20 cubic inches are needed as a minimum for this installation. A raised cover does add some cubic inch capacity. With those number ten wires a little extra room will make it easier to push the outlet into the box.

[Mikepier]

Well, I was at Lowes this morning, and I looked at a regular dryer receptacle, and some plastic old work boxes. They had a single gang deep box I think it was about 20 cu in, and a double gang deep box which was 34 cu in. The receptacle fit inside the single gang, but I purchased both just in case. The retaining clips on these boxes look strong, so it should be OK. Plus I'll try to throw a screw into the stud. This dryer is actually being installed in my vacation home in the mountains 170 miles away, and the nearest hardware store is 15 miles away, so I'm taking up whatever I think I need. I can always retuen what I don't use. Thanks for everyones help.