improper oven connection ?

[RustyShackleford]

I'm remodeling my kitchen. When I pulled the oven out, I found the following in the box where connection is made between the Romex (from the breaker box) and the harness coming out of the oven. The Romex is 10-2 plus ground (white, black, bare). The leads coming out of the oven include neutral (white, black, red, bare). The electrician simply bonded both the neutral and the ground from the oven to the Romex ground.

romex bare -> oven bare & oven white
romex white -> oven red
romex black -> oven black

I'm pretty sure this would be considered unacceptable today. The oven harness wouldn't have included neutral unless there's some 120v load in there, so therefore current is being sent through the "equipment grounding conductor" (aka. ground, aka. the bare wire in the Romex). Probably not much current, just the clock and the light, I imagine.

Anyhow, am I correct that this is screwy ? I'm going to go ahead and reconnect it as such (it's been fine for the last 25+ years) in the temporary setup I have now. Then I'll deal with it properly when I do the final new installation (probably with a new oven) in the next month or two.

 

[DougA]

AFAIK, you are correct that the 120v is only used for the clock, etc. but most ovens also have 120v outlets on them. I'd be more concerned about using the outlets when improperly wired, especially if you are near to a sink with water.

 

[seige101]

Before the 1996 or possibly 1999 code it was legal for an oven and dryer to 'share' the neutral and ground within the appliance. Perfectly legal install at the time.

Now a days you would run a 10-3 (black, red, white, bare (ground))

Why it is a hazard now is that you are putting current on the ground system, if you make a better ground between the appliance case and another ground you can get shocked.

If you want to bring it up to code and make it safer, run a 10-3 romex and disconnect the bond between neutral and ground in the oven

 

[RustyShackleford]

Thanks for the confirmation, guys.

For sure I'll run 10-3 when I do the final hookup (unless I get an oven with no neutral, dunno if such a thing exists, but no reason the clock and light couldn't run on 240v, although I guess it'd be a pain to buy a lightbulb, except it's probably LED now).

Yeah, I understand what the issue is. Crazy that such a thing would've been allowed (this dates from when house was built in 1988). At least there's no 120v outlets on the thing like you suggest is sometimes seen).

 

[Highbeam]

When you buy an oven or dryer it doesn't always come with the cord. The oven maker doesn't know if you have a three prong or a four prong outlet and there are lots of houses built before 1999. So the manufacturer will tell you to buy the appropriate cordset (3 or 4 prong) and then they will tell you how to wire it to the appliance. Your old outlet remains old.

You don't have to run 10/3 to make this right but if you can, I would recommend it and use the new four prong plug.

 

[RustyShackleford]

You don't have to run 10/3 to make this right but if you can, I would recommend it and use the new four prong plug.

Yeah, I'll do that for sure when I finish this remodel and install a new oven.