I was told that for the new 2005 code that (NM) romex for applainaces ie; water heater, ac disconnect, dryer must now be in 3 wire. Is this true and if so can some one please state a code # reference. I am racking my head trying to find this but have been unable.

There is no such NEC requirement, a 2 conductor with ground is all that is needed

Roger

You can not feed a 240/120 dryer with a 3 wire.

One must ask the question right, to get the answer right :-)

At one time- not so long ago- it was the practice to "ground" the case of a range or clothes dryer by bonding it to the third wire- which also served as the "neutral" for any 110 loads the appliance might have had.

This is no longer allowed on NEW dryers and ranges, nor is it allowed to run NEW circuits this way. Section 250.140 is the place to start reading...

So, today, we no longer bond the case to the "neutral" wire. We run an additional wire to serve as the ground wire.

If an appliance has no 110v loads, then the third prong of the plug is a true "ground" prong.

so renosteinke
then would you or wouldn't you use 3 wire?

i have done several ovens micro/convection over the last year where they came with a set up of a black , a red, a neutral and a ground? for a 220 set up 30 amp and man i must say i love this place that was quick 3 responces in no time. Gotta love it thanks kenny

Whoa, I only (stopped reading at) read "water heater and ac disconnect", shame on me.

Iwire and John are correct, on 120/240v appliances, a three insulated conductor with equipment grounding conductor wiring method must be used.


Roger

but john says yes and i wire says no?

Two hots, one neutral and one ground (very untechnical I know) require two hots, one neutral and one ground feeding it.

NJ Wireman, actually I think John and Iwire are saying the same thing,

Iwire said
I think Iwire means there must be four conductors

John said
Roger



[This message has been edited by Roger (edited 12-12-2005).]

I see i thought when he said three wire, i mis understood. I thank all for their help.

My understanding is that dryers, ranges, and ovens need 3 wires plus a ground. A/C, well pumps, and cook tops can use 2 wires plus a ground.

That "the war is over" thing was 3 cycles ago. They decided in 96 we didn't need to save the EGC copper on dryers and ranges anymore. (It started in WWII)

I have heard of cooktops needing a neutral.

This does underscore the need to be specific..."3 wire" is sort of vague. For example, 12/3 NM and 12/3 MC do not have the same numberof wires! One does not 'count' the ground.

Not to be a pain in the neck, but out of curiosity, has any of our members ever come across any real deadly situations where the older ranges or dryers using 3 wire hookups were a problem vs if they had of been 4 wire instead? I am actually for this code change, but was wondering if there was any reality based substantiation for the change, or was the change based on apprehension, foresight, or were we aligning ourselves with Canada's code as I have heard it rumored.

gfretwell,

I had heard somewhere that originally "Code" required 4 wire before WWII and the ground/neutral was combined to save copper. Is that true and is that what you were referring too?

On another note, I have never seen a real problem w/3 wires in my years.

Steve

I once went for a short ride when I stood at a sink and touched a range case that had a loose aluminum ground in the panel. NOT FUN! I always recommend updating when I see 3 prong ranges and dryers.

Ground wires should not carry current under normal circumstances. The ground system, including its wires, is (first of all) a safety system.

Bonding neutral to ground in the appliance, or in the receptacle (even having neutral and ground conductors, or using the ground wire as neutral-ground) will cause current circulation through the ground wire and could become a real hazard if the neutral-grounding circuit is interrupted (the chassis of the appliance could be “hot” now).

Joe.-