Question installing 240V for 5kw heater

[cagullett1]

I have recently purchased the Fahrenheat FUH54 and I've added a designated 30A 240V line for it using 10-2 Romex. The instructions say to hardwire it to the panel, but I've decided to run it to an outlet because we will not be staying in the house longer than 4 more years and would like to take it with me. Being in Texas, a garage heater wouldn't really be considered a selling point for most buyers.

I had an extra 3 prong dryer cord from converting my old dryer to a 4 wire and I'm trying to determine if I can use it to wire the heater. The issue is that 3 wire dryer cords were made to have 2 hot and 1 neutral wire so that a dryer could use 120V and 240V at the same time. This cord/outlet combo was not designed to have a ground. Would I be grounding it correctly if I used the "L" shaped prong as a ground, rather than its intended purpose as a neutral.

Just for clarification, there are 2 hots and a ground from my panel to the outlet, and there will be 2 hots and a ground from the outlet to the heater. I'm just concerned if the outlet (designed to be 2 hots and a neutral), can be used with 2 hots and a ground. I want to make sure my heater is actually being grounded.

My alternative would be to buy a 2 pole, 3 wire (with grounding) outlet, and make the the plug using a whip and the correct plug. This would cost me about $30 more (would go ahead and buy twist lock plug/outlet) than utilizing my dryer cord I already had.

Link to dryer cord:http://www.homedepot.com/p/Whirlpool-6-ft-3-Wire-30-Amp-Dryer-Power-Cord-PT500L/203744345

Link to outlet: http://www.homedepot.com/p/Cooper-Wiring-Devices-Commercial-and-Industrial-30-Amp-Flush-Mount-Dryer-Power-Receptacle-with-3-Wire-Non-Grounding-Brown-38B-BOX/203492460

 

[Random Guy]

Using the dryer plug and wiring it in a non standard way would be a bad idea. Especially when the parts to do it right are only an extra $30, I think this is an easy choice to make.

Alternatively, you could hard wire the heater and just take it out and cover the junction box with a blank plate when you move. I imagine you won't be planning on moving the heater around while you are in this house, correct?

 

[sberry]

I agree, wire it, un wire it.

 

[5mall5nail5]

Ditch the dryer **** and pick up a twist lock setup and do it proper.

 

[cagullett1]

Using the dryer plug and wiring it in a non standard way would be a bad idea. Especially when the parts to do it right are only an extra $30, I think this is an easy choice to make.

Alternatively, you could hard wire the heater and just take it out and cover the junction box with a blank plate when you move. I imagine you won't be planning on moving the heater around while you are in this house, correct?

When you discuss hardwiring it, would you wire as one continuous piece from the breaker to the heater (using conduit in exposed areas), or 2 separate pieces, wire nutted at a junction box? The heater will not being moving once mounted. The only time I would even contemplate moving it is if I needed the space in the summer months and I stored it for the summer (probably won't ever do).

 

[rockwithjason]

put a jbox on the wall and make up there. i am not against using the dryer cord but a jbox is cheaper and easier.

 

[Random Guy]

When you discuss hardwiring it, would you wire as one continuous piece from the breaker to the heater (using conduit in exposed areas), or 2 separate pieces, wire nutted at a junction box? The heater will not being moving once mounted. The only time I would even contemplate moving it is if I needed the space in the summer months and I stored it for the summer (probably won't ever do).

You'd make a run from the panel to a junction box next to the heater. Then you'd have a piece of armored cable to run from that junction box to your heater, to allow for movement (vibration, changing where it's aimed) of the heater. When you move out, just take the heater down, remove the whip, and block the hole where the whip came out of the junction box. That's it, you're done!

 

[cagullett1]

Well a junction box has already been recessed in the wall, are there faceplates that would accomodate hardwiring?

 

[nehog]

I agree, wire it, un wire it.

Absolutely. Takes but a few seconds to pull out the wire, pop out the breaker (if you even want to) and take the heater.

 

[cagullett1]

Well a junction box has already been recessed in the wall, are there faceplates that would accomodate hardwiring?

Just figured I would bump this... I plan on hardwiring it now but not sure how I'm supposed to cover the box since my SJOOW wire has to come out of the face of the box because it is already recessed in the wall.

 

[MrMark]

There are blank covers (metal) designed with a KO to take a conduit fitting. This is the best way to proceed. It is the same way a range would be done. The fitting may be a 90 if it works better for your app. Cord is not allowed to be used as building wiring.

 

[cagullett1]

There are blank covers (metal) designed with a KO to take a conduit fitting. This is the best way to proceed. It is the same way a range would be done. The fitting may be a 90 if it works better for your app. Cord is not allowed to be used as building wiring.

Thanks for the help. I didn't realize there was covers with knockouts in them.

 

[Speedy Petey]

Ditch the dryer **** and pick up a twist lock setup and do it proper.

How in the world is a twist lock any more "proper" than a straight blade in this application??

IMO, I agree that hard wiring is more "proper" than anything.

 

[cagullett1]

How in the world is a twist lock any more "proper" than a straight blade in this application??

IMO, I agree that hard wiring is more "proper" than anything.

Because the outlet required when using a dryer cord is intended to be a 3 pole, 3 wire (no grounding) outlet. It would not be used for it's intended purpose. There is nothing wrong with a straight blade, just that particular straight blade. I figure if I'm going to have to buy/build a new cord, I might as well go with a twist lock.

Either way, I'm hardwiring it tonight. Found a faceplate with a KO this morning for a double gang box. Definitely wish I would have used a single gang box. For some reason when I bought the box, I thought it would be difficult to fit the 10G wire with connections and outlet all into the box. Unfortunately with the hole in the wall already cut, double gang it is.

 

[5mall5nail5]

How in the world is a twist lock any more "proper" than a straight blade in this application??

IMO, I agree that hard wiring is more "proper" than anything.

I would not want to have a straight blade 240v anywhere that I might be moving around and risk dropping something on. I have a 5kw heater and with the proper gauge service cord its pretty heavy - the weight would make pulling it down and out of a straight blade 240v receptacle pretty likely, opening up the possibility of something metal dropping onto the exposed blades.

I did a ceiling mounted twist lock and have no regrets. Hard-wiring is great too, but then you have a 240v junction box using a double breaker in your panel and you can't use it for anything but the heater... even in summer, without "undoing" the heater. I can put an adapter together on the end of a twist lock and use my plasma cutter, TIG welder, etc., from the heater receptacle any time. It's more diverse and twist lock is less dangerous. It's supposed to be hard-wired, but if you're going to put a plug on it, I'd put a twist lock for the reasons above.

 

[sberry]

Would have bored a hole in the cover with a uni bit but,,, one of the main reasons I am an advocate for the simple wire nut is that it is good for continuous loads and its simple easy and can be done without additional cost, works just the same or better without tossing another 30 at it plus the time, possible delay. I probably want to use it today.

 

[MrMark]

Because the outlet required when using a dryer cord is intended to be a 3 pole, 3 wire (no grounding) outlet. It would not be used for it's intended purpose. There is nothing wrong with a straight blade, just that particular straight blade. I figure if I'm going to have to buy/build a new cord, I might as well go with a twist lock.

Either way, I'm hardwiring it tonight. Found a faceplate with a KO this morning for a double gang box. Definitely wish I would have used a single gang box. For some reason when I bought the box, I thought it would be difficult to fit the 10G wire with connections and outlet all into the box. Unfortunately with the hole in the wall already cut, double gang it is.

What's wrong with the double gang box?, that's what I would have done too.

I have a question now. What would one do to hardwire if the box were plastic? Is that what the ENT tube is for?

 

[cagullett1]

What's wrong with the double gang box?, that's what I would have done too.

I have a question now. What would one do to hardwire if the box were plastic? Is that what the ENT tube is for?

There isn't anything wrong with the double gang, it's just that there are cleaner looking options for single gang faceplates with 1/2" KO, completely cosmetic.

My box is an "old work" plastic double gang box. I'm not sure why this would be a problem...?

 

[MrMark]

I see. You can see this outlet. My bad.

It is my understanding that you can't install metal flex conduit to a plastic box. Your whip was metal flex, no?

You would need to have some internal means to bond the metal conduit in the box. Maybe someone will chime in on how that can or cannot be accomplished.

 

[cagullett1]

Here is a link to the whip I bought. It is a rubber water hose type material.

http://www.homedepot.com/p/AFC-Cable-Systems-Liquidtite-1-2-in-x-6-ft-AC-Whip-8015-HD/202286686

Now that you mention the conduit being bonded to the box, is it an issue that I'm using a metal faceplate on a plastic box?

 

[MrMark]

Technically yes. Everything metal has to be bonded.

 

[cagullett1]

Technically yes. Everything metal has to be bonded.

Can you elaborate on how I can go about doing that?

 

[MrMark]

You could switch to a plastic plate with knock out. Or, it the metal plate is used you would need a lug on the plate that you could attach the branch circuit ground wire to. Basically, everything metal must be bonded in an electrical system to avoid touch hazards and for fault clearing, in other words, a short circuit that will trip a breaker and not remain an energized open..

 

[cagullett1]

Yeah I understand the concept of having to ground all metal parts... I guess I just didn't think about it when I bought the metal faceplate. There is no "normal" way of going about grounding a faceplate considering metal faceplates are intended to be used with metal boxes, hence how the faceplate receives its grounding. The only way to ground it is by jerry rigging a grounding clip or drilling a hole in the faceplate for a grounding screw. That doesn't sound like great ideas to me. Looks like I will be making a trip to HD to pick up a metal 4x4 to replace the plastic, double gang (old work) box I had installed in the ceiling. I'm not sure why I thought an old work box meant for 2 devices would be a good route for this application. Needless to say, my box is mounted no where near a stud, so I will probably be patching the drywall, and cutting a hole next to a stud so that I can move the metal box into that.

Is there any other tips or is there anything else I'm missing?

 

[MrMark]

Well, I think a metal box is superior but if you have to cut sheetrock why not just get a plastic plate with knock out in it? I like that nonmetalic flexible whip you bought. I saw those in Lowes tonight prepackaged with 10 awg. Perfect for a 5 HP compressor. Surely, there is a plastic plate that goes with that? Now, if you go metal realize that you will need a mud ring too.

I also have a feeling there are metal cover plates with bonding means. There are also lock nuts with integral ground lug. Perhaps you could switch your plastic nut to the metal nut which would bite into the metal plate on such a device.

 

[sberry]

Drill a hole and put a pigtail on with nut and bolt. I like those whips, no waste, got just what you need, great for J Hobby, no extra **** to store.

 

[cagullett1]

I've searched the big box store and have had no luck with finding a plastic plate with knock out. I haven't came across a metal faceplate with any sort of bonding options either. I didn't think about using the metal locking nut on the whip to attach the ground to the faceplate.

What would be the most "correct" way of fixing my issue?

Those whips are definitely the most economical way of installing large appliances for a homeowner. Glad I stumbled across it!

 

[MrMark]

Look up "grounding bushing".

 

[cagullett1]

Well, I think a metal box is superior but if you have to cut sheetrock why not just get a plastic plate with knock out in it? I like that nonmetalic flexible whip you bought. I saw those in Lowes tonight prepackaged with 10 awg. Perfect for a 5 HP compressor. Surely, there is a plastic plate that goes with that? Now, if you go metal realize that you will need a mud ring too.

I also have a feeling there are metal cover plates with bonding means. There are also lock nuts with integral ground lug. Perhaps you could switch your plastic nut to the metal nut which would bite into the metal plate on such a device.

Just noticed this... why would I need to use a mud ring if I went metal?

 

[MrMark]

Because the metal box mounts flush with the framing and the mud ring brings the box out flush with the sheet rock. If this was surface mount you wouldn't need the mud ring but this is finished work you said.

 

[cagullett1]

Got it... thanks for all of the helpful information!