Extending dryer outlet for a garage heater

[bhatt]

Hello all,

I have searched the forum and looked online, and have come up with a plan on how I want to wire my garage heater. Want to verify that I'm not violating any major rules or electrical code that I could easily fix at this point by modifying my plan.

The current situation:
I have a 200A panel in my house, and there is a LARGE circuit breaker for my dryer (Either 40, 50 or 60A, can't remember and will have to look). Wire runs from this breaker in the panel to my laundry room. I believe it is 8/3 wire, off the top of my head.

I use a gas dryer, so this outlet is completely unused. I turned the breaker off 10yrs ago when I bought the house and haven't touched it since.

Garage wall backs onto laundry room wall. So I have poked a hole in the wall and pulled the dryer wire through into the garage.

Where I am right now:
I have an 8/3 wire sticking out of my garage wall, connected to a (safely turned off) large breaker in the panel.

What I want to do:
I need to go up the wall with wire about 8-10ft, then across the wall about another 6-7ft. Then I want to mount a box and plug in a Fahrenheit FUH5-4 (clone of the Dayton G73)

My plan:
1. Cut a square hole in the garage wall and pull the "dryer" wire into a box and install the box in the wall
2. Pull type MC (armored) cable (10/3) into the box and connect the matching leads to the dryer wire. So this will be a junction box. Install a metal cover plate and make sure the box is accessible in the future.
3. Now pull the armored cable up through the wall and over to where I want to mount the heater. Will drill holes through studs and the entire thing will be hidden behind drywall.
4. At the end of the armored cable, I'll mount a surface mount box with a NEMA 14-30R receptacle and appropriate cover plate.
5. Heater comes with a 14-30P cord, which I will plug into the receptacle installed in #4 above.
6. Flip on the breaker and hope for the best

Questions:
Q1. I will be pulling about 17-20' of new cable (will buy a 25' spool of armored cable) so am I OK using 10/3? The existing wire is most likely 8/3 but I'm only extending it a short distance. Is there some reason why I need to match the armored cable gage to the existing romex gage? (like building code requirements?)
Q2. Am I good running a 30amp receptacle and 30amp heater (I believe the heater actually pulls 22A but it requires a 30a receptacle) with a 50 amp or 60 amp breaker? I thought I read somewhere that I needed to rip out the existing breaker and replace it with a 30A one.. but that makes no sense to me.. is that true???

Other info:
-I prefer to use armored cable inside the wall even though not required. I'm scared that I'll zap myself down the road hammering in a nail to hang a picture if I pull romex instead of armored!
-This doesn't need to be 100% to code, as it won't be inspected, but I want it to be as close as possible. Missing cable straps or cable straps too far apart doesn't bother me for example. Anything more does!
-I'm in Canada (Ontario) if it matters for building code purposes. But if I meet US building code, I'm pretty happy because if it works for 300 million Americans, I figure it should be safe, right?

 

[Alchymist]

Don't mix wire size. Use the same size wire to extend from the junction box. The breaker is sized to protect the wire, in this case. # 8, so the whole circuit should be #8.

 

[pattenp]

If you use a 30A outlet then you need to downsize the breaker in the panel to a 30A. And if you downsize the breaker to 30A then the #10 added to the #8 is fine. Just don't put a 30A outlet or a #10 wire on a 40A or greater breaker.

 

[bhatt]

OK cool.. I think I'll buy a 30A breaker, and some 10/3 to add to the 8/3 as pattenp suggests above.

Reason for avoiding the armored 8/3 is that Home Depot online shows only a 50' spool which is $170. They have 10/3 armored in a 25' for $50. So huge difference there.

I'll grab a 10/3 armored 25' spool + 30A breaker and I should be good to go!!!

Additional question: any need for the plug/outlet combo at the heater? The heater is actually designed for hardwiring, so I could probably run the armored right into the heater. I can't imagine ever needing to unplug the heater.. if something were to go wrong (ie. fire, etc.) I could never get the ladder over there and climb up to unplug it fast enough anyway. It would be way easier to run to the basement and quickly shut off the breaker.

I was thinking of dispensing entirely with the plug/receptacle and just running the armored right into the heater itself. Any cons of running it this way? What do I gain by having a plug? It's not like I'm gonna want to plug a welder in 10' off the ground some day -- if I did or if I wanted to get rid of the heater, I could just disconnect it and install a receptacle at that point.. right?

 

[pop pop]

What you've been told is OK. I'd do it differently. I'd put a single 30A breaker or fuse box at the termination of the #8 and then connect the #10 in that box and run hard wired to the heater. That gives you a disconnect on the wall at the junction for the heater, visible from the heater if you need to work on it.

 

[bhatt]

Thanks pop pop.. good idea!

Only issue is that the junction box is on the wall behind my garage cabinets. It's not covered by them, but it is on the wall between the upper and lower cabinets (think of where a kitchen backsplash would go)

So I don't mind a small covered metal junction box there or in the laundry room, but I'm hesitant to have a breaker/fuse box there because it will likely get bumped and shut off all the time. It's in my prime work area, so everytime I spin something around on the workbench, it will for sure shut my heater off. I also have very little space so I don't want anything sticking off the wall into my work area.

If I have to work on the heater, it should be pretty rare, so i don't mind going to the basement to shut it off. Replaced some exterior garage light fixtures last weekend, and had to do the same thing. I figure if I have to go to the bsmt to shut off power to change light fixtures, I don't mind doing it for a heater!

 

[wyliesdiesels]

I'm in the US, so I can't comment on the code aspects in regards to Canadian code. Having said that, if u use #10 wire, the breaker feeding it MUST BE 30a! Not 40, 50, etc... Second, for a 240v only load, u will only need 2 conductor plus ground such as 10/2. But I would use 10/3 so if u ever decide to use the outlet for something else that needs a neutral, you will be all set. Also keep in mind that the wall between the house and garage is a firewall, so u need to seal all penetrations/holes to maintain the firewall! As far as zapping yourself if u ran romex, that won't be possible if u use armor plates where the wire runs through studs!

 

[bhatt]

wyliesdiesels,

Thanks for the feedback..very helpful!

Some comments from my end:
-Yes, I will definitely replace the larger breaker with a 30A for sure.
-The 10/3 was what I was thinking too.. just in case. Hard to re-run cable inside a wall so why not do it properly?
-As far as where the armored cable goes from the house to the garage, since it is a common wall between garage/laundry room, I'm thinking of dispensing with a separate junction box entirely. Here's how:
-Since the existing dryer in the laundry room already has a box in the wall, I'll just remove the receptacle and put a cover plate on the box.
-I will then run the armored cable through the common wall to where it needs to go, and then poke it out of the drywall. I can seal the drywall carefully at the point where it pokes out.

So basically, the existing dryer box will have the existing cable coming into it from the bottom, and a piece of armored cable leaving it from the top. The armored cable will snake up through the wall and pop out a the top (to be technically accurate, it will go around a corner, but that will all be re-drywalled after I do the work).

All you will see when I'm done is a dryer outlet with a brand new coverplate on it, and piece of armored cable sticking out of the wall in my garage where I'll be wiring the heater in.

THANKS ALL FOR YOUR HELP!!

 

[pop pop]

Thanks pop pop.. good idea!

Only issue is that the junction box is on the wall behind my garage cabinets. It's not covered by them, but it is on the wall between the upper and lower cabinets (think of where a kitchen backsplash would go)

So I don't mind a small covered metal junction box there or in the laundry room, but I'm hesitant to have a breaker/fuse box there because it will likely get bumped and shut off all the time. It's in my prime work area, so everytime I spin something around on the workbench, it will for sure shut my heater off. I also have very little space so I don't want anything sticking off the wall into my work area.

If I have to work on the heater, it should be pretty rare, so i don't mind going to the basement to shut it off. Replaced some exterior garage light fixtures last weekend, and had to do the same thing. I figure if I have to go to the bsmt to shut off power to change light fixtures, I don't mind doing it for a heater!

I'd think you could find a flush wall mount box for the junction switch. Also, don't know code for residential but we used to have to put a lockout switch in full view of the device being served.