ECN Forum Forums General Topics of the Trade General Discussion Area Oven hook-up (3 - 4wire)

Its a double convection oven and a has a pigtail with 3 - #10 conductors and a ground. So will go a 10-3 NM 30a ckt new ckt.

But... If there was an old 10-2 ckt already there, I would have to tie the neutral and ground together from the oven at the junction, correct?

If 10/2 you need to repull feed, EGC not suitable for a neutral.

Celtic, I would say it was between who ordered or recieved the order of the ranges, but clearly the persons who installed the cord would be the responcable party for checking that neutral ground bond. They installed the cord, and being as such, any HO or GC could install it themselves and be totally unaware. They keep shipping them 3-wire as replacement units. When what they should do is ship them as 4-wire and note if there is a problem with the cord not matching to call an electrician. Or devise a detachable choice of cords, and a special mating that has the bond on the 3-wire one, or no bond on the 4-wire one.

aldav53, (And NORCAL)
The 4-wire code is only for New Construction.... You might still be able to use it? If, "the grounded conductor is uninsulated and part of a Type SE service-entrance cable and the branch circuit originates at the service equipment." See 250.140, all 4 conditions in it need to be met.

aldav53, I'm questioning your wording on your last post in my head though...

"Its a double convection oven and a has a pigtail with 3 - #10 conductors and a ground. So will go a [/i]10-3 NM[/i] 30a ckt new ckt."

Have you checked the name-plate kW of this "double convection oven"? Just because it has #10 conductors in the pigtail, (which may be aspestos appliance wire rated for high temp) doesn't mean it is a 30A circuit. Odds are that it is a 40-50A unit! Often appliances are wired with much smaller whips in high temp wire insulation rated for a lot more ampperage that thier building/premisis wiring counterparts.

I don't do houses hardly at all... but...

The last one I did (30 months ago) had the electrical work completed long before the appliances were delivered. The appliances were unloaded, moved into place, and plugged in by the appliance guy.

As luck would have it, I was there that day. While these particular appliances had cords that matched the receptacles I had installed, other comments by the appliance guy made clear two things:
-He considered himself to be some sort of electrical guru; and,
-He had no idea what he was talking about.


I see the EC as only being expected to put in the receptacle correctly. What's inside the appliance isn't his concern.
Folks want the stuff hard wired, well, that changes things. Then, I get to put in a disconnect as well.

E57, my comment was directed at 10/2 NM (I know it was not mentioned as nonmetallic sheathed cable)as do not know of any SE cable below 6 or 8 AWG and I still say the uninsulated conductor of a NM cable should not be used as a current carrying conductor.

NORCAL-
I agree, I'd hate to be working in a supposedly dead box, bump the ground, and get a shock.

NORCAL, was meant as no afront..... And neither of us can see it from here. I just love finding thos quirky little exception... One thing I don't understand about that particular code is that SE from a main panel would be OK, (w/ an uninsulated ground) but a simular circuit in NM (w/ an uninsulated ground) would not?

None taken.

Who's responsible?

This isn't an issue we have over here, but speaking for myself, if I were the one installing the cord I would make sure that the jumper is present if I was fitting a 3-wire cord or absent if a 4-wire.

Judging by the number of times this comes up however, I think if I were the EC actually installing the range I would always want to check the connections no matter what type of cord had been pre-fitted.

In the great white north we have never had 3 wire exceptions for any appliances so you would think it is a non issue. We do however have imigration and some US citizens bring their appliances here. If an electricain is involved we usually change the cord to a 4 wire and ensure the neutral is isolated from the frame. It is when the newly landed appliance owner believes he is smarter than a local electrician that we see bootleg bonding.
Actually with pressure from insurance companies mounting to rewire old houses I am seeing more bootleg grounds in an attempt to concele the presence of K & T wiring. Ocationally they bootleg the hot.