Quick question - Using range ckt for dryer

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  #1  
Old 08-22-11, 03:18 PM
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Quick question - Using range ckt for dryer

I'm renovating our townhome (built in 1979), and have one quick question..

The existing setup is for an electric range in the kitchen and a gas dryer in the laundry room. I'm switching to a gas range and want to use our existing electric dryer. Since the kitchen is directly above the laundry room, I'll I have to do is grab the existing cable and route it down the laundry room wall in conduit to a new receptacle for the dryer.

I'm thinking that the existing cable is either #6 or #8. Any idea what size of conduit I need? I know how to do conduit fill calculations, but I'm not sure what kind of cable is typically used.
 
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Old 08-22-11, 03:34 PM
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What color wires at the range. Is it cable or metal conduit. What size breaker. You have to have two hots a neutral and a ground to do this. The ground may be part of a cable or derived from a metal conduit that is electrically continuous to the panel.

I'm thinking that the existing cable is either #6 or #8. Any idea what size of conduit I need?
Best practice is to not run cable in conduit except for short sections as protection. If you are going to use conduit you would use THHN individual conductors. The breaker would be changed to 30a and #10 would be used.
 
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Old 08-22-11, 03:42 PM
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Let us know if the old cable is copper or aluminum, and how many insulated and bare conductors it has inside. Do you have access along the path of the cable to the panel?

Also does your townhome have its own electric service or is it shared from a main building service?
 
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Old 08-22-11, 07:05 PM
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I'm renovating our townhome (built in 1979), and have one quick question..
I am thinking you'll find the old range circuit to be a 3 wire circuit and not have all 4 wires you need to be in compliance with today's codes. If I recall correctly, 2 hots and 1 neutral conductor were all that was required in 1979 for both ranges and dryers, grounding was done through the neutral back then. Today you'll need 2 hots, 1 neutral and 1 ground; 4 wires total.
 
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Old 08-23-11, 01:06 PM
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Ok, I gathered more data..

Existing cable is 2 #8's, stranded aluminum with a bare ground type XHHW. I know that's not current code, but the city inspection department approved my permit application which said that I'd re-use the existing cable. I forgot to check existing breaker size.

I have the whole cable route exposed, so I could replace it with current up-to-code cable if I really had to. What are the advantages?

Secondly, the reason I'm interested in conduit is so I can drop the cable down to a receptacle in my laundry room (on a concrete block wall).
 
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Old 08-23-11, 01:59 PM
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You're just best to replace that old stuff. There is no ground either.
 
  #7  
Old 08-23-11, 02:28 PM
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Hmmm... from what I can tell, the old 3-wire configuration basically connects the dryer chassis to the neutral bus. I'm not liking that idea, so I'm leaning towards updating the wiring since it's all accessible.
 
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Old 08-23-11, 02:34 PM
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Originally Posted by Spaceball1 View Post
Hmmm... from what I can tell, the old 3-wire configuration basically connects the dryer chassis to the neutral bus. I'm not liking that idea, so I'm leaning towards updating the wiring since it's all accessible.
Yes. So when theres enough resistance in the wire and you touch the case you get a nasty shock.

I wouldn't think twice about replacing it.
 
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Old 08-23-11, 04:10 PM
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Originally Posted by Spaceball1 View Post
Hmmm... from what I can tell, the old 3-wire configuration basically connects the dryer chassis to the neutral bus. I'm not liking that idea, so I'm leaning towards updating the wiring since it's all accessible.
That was typical prior to the 1996 electrical code. Existing circuits are allowed to remain as-is, however any updates to the circuit (as you propose to do) require compliance with modern code so you're looking at replacement of the circuit under any circumstance.

The inspector does not do a complete plan review on small jobs to catch mistakes upfront, but I guarantee he would red flag the job on final inspection with the old cable reused.

The new four-wire circuit is a safer option because it eliminates a risk of shock when touching the metal dryer frame and another well-grounded object (plumbing, concrete flooring, etc).
 
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Old 08-23-11, 09:04 PM
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Existing cable is 2 #8's, stranded aluminum with a bare ground type XHHW.
And that was used on a range circuit?

I have never seen a bare ground type XHHW. How can it be bare if it has XHHW insulation?
 
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Old 08-23-11, 09:34 PM
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And that was used on a range circuit?
Joe, you would love some local range circuts then.
 
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Old 08-24-11, 09:45 AM
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Originally Posted by CasualJoe View Post
And that was used on a range circuit?

I have never seen a bare ground type XHHW. How can it be bare if it has XHHW insulation?
It could be that the third conductor was just stripped back to where it's insulation wasn't visible. I didn't look that close.

So the plan is to go back with new 10/3 and a four wire receptacle. The drop in wire size requires that I reduce the breaker size from a 2 pole 40A, to a 2 pole 30A. New breaker is only $16, so that's no big deal. I also have access to the subfloors and everything, so this is actually turning out to be a pretty minor job. Everything I've read says that a GFCI breaker wouldn't work for this application and is not required since a) a dryer is considered a fixed appliance b) the new receptacle will be at least 6' away from the sink and c) this receptacle will be the only one for the circuit. Agreed?

I have some questions on other circuits, but I'll put those in another thread..
 
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Old 08-24-11, 09:50 AM
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Originally Posted by CasualJoe View Post
And that was used on a range circuit?

I have never seen a bare ground type XHHW. How can it be bare if it has XHHW insulation?
Sounds like an SE cable. ...............................................
 
  #14  
Old 08-24-11, 11:02 AM
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Probably an SEU cable marked XHHW on the outer skin.
 
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Old 08-24-11, 03:21 PM
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Yep, it was marked SE as well.. You guys are good..
 
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Old 08-25-11, 09:50 AM
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I finished most of the work last night. I forgot to buy conduit to route the cable down the unfinished wall, so I'll do that today. Anyone have a link to a wiring diagram for the receptacle handy? I also discovered that the cable from my dryer is set up for the 3 wire configuration. The dryer is pretty new though (2007, i think) so I expect that I can convert it with another cord..
 
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Old 08-25-11, 10:09 AM
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When you convert the dryer to 4 wire you will need to remove the bonding/grounding jumper from the center terminal of the dryer.

The receptacle should have a wiring diagram included with it.
 
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Old 08-25-11, 10:19 AM
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Originally Posted by Spaceball1 View Post
Anyone have a link to a wiring diagram for the receptacle handy?
The white goes to the "L" shaped prong in the top center usually marked W; the black and red go to the straight blades on either side usually marked X & Y, doesn't matter which; and the bare goes to the round prong usually marked G.

I also discovered that the cable from my dryer is set up for the 3 wire configuration. The dryer is pretty new though (2007, i think) so I expect that I can convert it with another cord..
Yes you can convert it. Get the 14-30 cord from the store to match the recetpacle. Inside the dryer wiring compartment you will need to remove a bonding strap, screw or wire that connects the center neutral terminal to the metal chassis. After that it's a simple matter of black-white-red on the screw terminals and green to a ground screw on the chassis.

e: pc beat me to it!
 
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Old 08-25-11, 10:47 AM
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Originally Posted by Spaceball1 View Post
Yep, it was marked SE as well.. You guys are good..
Sounds like time to ask for another raise. What do you think Ben?
 
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Old 08-25-11, 12:25 PM
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Originally Posted by pcboss View Post
Sounds like time to ask for another raise. What do you think Ben?
But we don't get paid.
 
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Old 08-25-11, 12:49 PM
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Maybe YOU don't get paid, Justin but I get paid every time someone posts a thank you.
 
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Old 08-25-11, 01:02 PM
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Originally Posted by Furd View Post
Maybe YOU don't get paid, Justin but I get paid every time someone posts a thank you.
Yeah, that feeling that you've helped someone?
 
  #23  
Old 08-25-11, 03:01 PM
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I think that 10% raises are in order for everyone..
 
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Old 08-25-11, 03:35 PM
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Originally Posted by pcboss View Post
Sounds like time to ask for another raise. What do you think Ben?
Ask!?! I say we demand it!
 
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