Dryer breaker

[trader_4]

I don't believe you can do #3 and be code compliant. It appears what you're suggesting is to keep the existing 3 wire dryer cord and receptacle and run a separate ground wire from a connection point at the dryer to an appropriate point on the grounding system for the house. Code requires that ground wires be run in the same cable as the conductors. GFRE explained that there is an exception for the case where you are replacing a non-grounding receptacle with a grounding type receptacle. So, if you replace the 3 wire receptacle with a 4 wire receptacle, you would use that exception, ground the receptacle to an allowed point on the grounding system, and then change to a 4 wire cord. Unless you use that exception, a separate ground wire is not code compliant. I think I have that right, GFRE can weigh in.

Purely from a safety standpoint, if you did what you suggested in #3, I don't see it as a safety issue, if otherwise done right, the dryer would be grounded. But safe and code compliant are not always the same thing. And if #3 were done right, while I believe it's a code violation, from a functional standpoint the grounding effect would be the same as #2 and having a ground would be better than #1. The issue here is do you want to now create a code violation while marginally improving a perfectly code compliant, widely used setup? If you go to sell the house, no home inspector would fail a 3 wire arrangement. But if he sees a ground wire coming out of the dryer separately, going who knows where, there is a good chance he would flag it.

Also, I think I still was right, that what Mako suggested, which I believe is actually your #3 method, is a code violation, though I focused on the wrong part of it. He posted:

"Its simple enough to make it better. Use a 4 wire plug or add a supplemental ground wire."

I said that would not be code compliant because the ground would not be in the same cable, assuming it is cable, which is reasonable. As GFRE pointed out, there is an exception that allows that. But to use that exception, you'd still have to change to a 4 wire receptacle and use a 4 wire plug. You can't keep the 3 wire cord/plug/receptacle and just add the ground wire directly to the dryer. That's my interpretation, again, GFRE can weigh in.

[gfretwell]

On a 3 wire connection you still need the bonding jumper in the dryer, no matter what. They used to tell you to run a ground wire to the cold water pipe and some even included a short green wire but that went away years ago. There is still a tapped hole for the grounding screw with the ground symbol in old designs but I assume it is just because they never changed the design for the back cover. If you want to run a supplemental wire from the dryer case to the 120v box for the washer, I am not sure what article you are breaking. It just will not be the only ground you need. Some might argue that you are putting objectionable current on the EGC for the washer (250.6) but having the 2 cases bonded together is safer than not.

[trader_4]

It's safer from the standpoint of the two cases then being grounded and at the same potential. But from a system standpoint, I'd say it is problem, for the reason you just gave. With the dryer now using the washer circuit as part of it's combined neutral and ground path, the ground wire of the washer back to the panel becomes a current carrying conductor for part of the 120V dryer load, something that a person working on the washer circuit isn't going to be expecting.

[Sam E]

[snip]

The connection I described had neutral and ground SEPARATED at the dryer. This new ground wire should never be carrying neutral current.

[Sam E]

[snip]

[snip]

This is a private residence, which I'm not about to sell. I'm more concerned with safety here than code.

I do like the idea of changing the receptacle (and dryer cord) better than just adding a ground wire. I wish I had thought of that. For one thing, it makes it a normal installation as far as the dryer is concerned.

Another problem here is where to connect the ground. The cold water pipe is probably OK for now but there is always the possibility of problems later. The washer receptacle is grounded but only #12.

[trader_4]

Well, I believe GFRE posted that's a code violation, or at least something is wrong with it:

"On a 3 wire connection you still need the bonding jumper in the dryer, no matter what. "

Though I agree that from what I see, if you're going to add a separate ground, you're method would be safer, because there would be no current in the ground. But the 100% code compliant way would be to replace the receptacle and cord with 4 wires, and simply connect the new separate ground wire to the receptacle and attach the other end to one of the approved grounding points permitted by the code exception. It's also not likely to get squawked by a home inspector, where a ground wire attached directly to an appliance that is also plugged in is almost surely going to attract attention.

[trader_4]

Well, you've identified more problems, which is where it's code compliant to attach the ground wire and what size must it be. The water pipe is almost always out, unless it happens to meet the narrow reqts outlined in the exception. Washer receptacle would be OK, but to be code compliant, it would have to be a #10 for a 40 amp dryer circuit. I could live with it being connected to #12, but then I can live with the dryer being

3 wire and 100% code compliant as is, just like millions of homes built prior to about 2000. of the tough

[Scott Lurndal]

IIRC, the grounding connector is permitted be one size smaller than the grounded and current carrying conductors.

[trader_4]

Which is why the #10 ground would be OK for a 40 amp dryer circuit using #8 current carrying conductors, but a #12 would not.

[Tekkie®]

[e-mail] posted for all of us...

Some people just don't get it...

[Chuck Yew]

Happy Festivus

[trader_4]

I think there is agreement here that 4 wires for a dryer is a better method than 3 wire. The fact remains that 3 wire is still perfectly legal per NEC and per all the dryer manufacturer install instructions. And that despite 3 wire being in use for half a century, until ~2000, no one here can point to a single bad thing happening. We don't know how many incidents, if any or what the code change was actually based on. Presumably it;s not all that bad, because they addressed many other things in the code during that half century and only more recently arrived at requiring 4 wire for new circuits.

The remaining question is if you want to live with what is there, that's co de compliant and in widespread use or do something to marginally improve it. If you choose the latter, is it going to be a bastardized, non-compliant solution or one that is code compliant. If you choose the la tter, the two solutions I see are to:

1 - Run a whole new 4 wire circuit, change the cord to 4 wire, change the jumpering in the dryer.. 2 - Change the cord to 4 wire, change the jumpering in the dryer, replace the receptacle with a 4 wire and install a separate ground wire from the receptacle that gets terminated pursuant to the code exception that GFRE cited. And that last part isn't likely to be easy because nearby grounding system points aren't likely to have the required 10g ground conductor.

You could also choose some level of bastardization within choice #2, eg hook the ground to a smaller than #10 grounding conductor, etc. I know what I would do which is to leave it connected as 3 wire, code compliant.

[Hand Wringer]

What amazes me is the in the amount of time some people spend half-assing something when they could do the entire job properly with just a bit more effort.

Peace of mind is priceless.