3 wire range circuit

Status
Not open for further replies.
G

gserve

Senior Member
Location
New Hampshire
Has 8/2 romex with a#10 bare ground wire ever been allowed to feed a range receptacle? I saw this installation today in a modular home that is a 1979 and that romex was installed by the manufacturer of the home. Is this not supposed to be a 4 wire circuit? Was this ever allowed in a regular stick built house? All I have seen in my area is SEU used for this purpose and the neutral is bare.Bottom line this is installed and they need to replace the range with a new one. So can this be used with a 3 wire cord with the stove ground link attached to the range and the bare #10 used as the neutral and ground for the circuit? Code references and comments please.
 
Re: 3 wire range circuit

Yes, this is a code violation, and a very bad one at that.

I'm pretty sure that manufactured homes have required the 4 wire configuration for quite some time now, but how far back I don't know.

At any rate, a bare wire used as the ground and neutral.....sorry, grounding and grounded conductor, or put another way, used as a current carrying conductor, has always been a code violation in this situation.

There are some sitations that allow it, like the service drop neutral...darn it, I did it again :(

[ February 23, 2005, 05:14 PM: Message edited by: peter d ]
 
Re: 3 wire range circuit

HI guys-

Not always true. Some of the new ovens are designed with a whip and the whites and the ground are crimped together with a typical copper romex crimp. There's a note or tag stating that if you have a four wire system to remove or cut the crimp. This all must meet the UL listing of the applaince or they wouldn't ship it. I think the neutrals for the most part are non load bearing and just grounding pilot lights, clocks etc.
 
Re: 3 wire range circuit

Steve,

You can't connect that wire combination to a bare circuit conductor.

Even if the neutral wire only serves the light bulb in the oven, it is still current carrying and must be treated as such. There is no such thing as a "non load bearing" neutral wire in this situation.
 
Re: 3 wire range circuit

Many moons ago this was the norm. However, today manufacturers of these ranges are providing digital displays and lights that are 120 vac and require a neutral. Many of these ranges and even wall ovens come with the neutral and ground wire bonded at the end of the whip. This is allowed for mobile homes only. If it's a new home installation you'll have to run an 8/3 with a ground. If it's an older installation and a replacement - if you have the capability to install the 8/3 you should do so. If not, you'll have to live with the wiring you have but it can become a dangerous situation.
 
Re: 3 wire range circuit

Originally posted by goldstar:
This is allowed for mobile homes only.
Click to expand...
I don't agree. I'm pretty sure mobile homes have had the "separation requirement" long before it was required elsewhere.

They connect them like that at the factory to account for all the 3-wire installations, but all mobile home installations must have N-G isolated, new or old.

[ February 23, 2005, 05:46 PM: Message edited by: peter d ]
 
Re: 3 wire range circuit

indeed mobiles must be 4 wire and have for as long as i can remember.And all new homes are now 4 wire.I would go after the mfg.of that mobile.There is far to much risk with the amount of steel in a mobile.All mobiles are subpanels do to the disconnect being on a pole nearby.
 
Re: 3 wire range circuit

Looking back at my oldest code book that I have which is the 1981 eddition Art.550-9(A)(1) states that the grounded conductor is to be seprate from the grounding conductor basically the same as in todays code. So I'm suprised that it was wired this way from the factory. As far as wiring stoves this way in stick built homes before the 1999 code change I would wire ranges this way & even now I use 8-3w/G to feed stoves,ovens,or cook tops but you can only land the conductors on 40 amp breakers under the 334.80 you have to down size to the 60 degree table.
612278
Member # 17853 posted February 23, 2005 05:24 PM
--------------------------------------------------------------------------------
HI guys-

Not always true. Some of the new ovens are designed with a whip and the whites and the ground are crimped together with a typical copper romex crimp. There's a note or tag stating that if you have a four wire system to remove or cut the crimp. This all must meet the UL listing of the applaince or they wouldn't ship it. I think the neutrals for the most part are non load bearing and just grounding pilot lights, clocks etc.
Click to expand...
When hooking up new appliances in new installations you need to sperate grounds from neutrals as required by Art.250.140,etc...
 
Re: 3 wire range circuit

I just want to clarify that this is a modular home on a foundation ,no frame underneath.The service is 3 wire SEU with bond screw installed.I just wanted to repair it as a existing installation but was leary about the #10 bare being used as the neutral.
 
Re: 3 wire range circuit

I do many manufactured homes in this area and yes if the range does require a neutral it must be supplyed. This has been code as far back as the "93" NEC cycle which is what the HUD 24 CFR 3280 follows. This code supercides all other codes! As it states here:
3280.801(b)
(b) In addition to the requirements of this standard and Article 550
of the National Electrical Code (NFPA No. 70-1993) the applicable
portions of other Articles of the National Electrical Code shall be
followed covering electrical installations in manufactured homes.
Wherever the requirements of this standard differ from the National
Electrical Code, this standard shall apply.
Click to expand...
And this is about grounding ranges and not using the neutral.:
3280.809
Grounding.

(a) General. Grounding of both electrical and nonelectrical metal
parts in a manufactured home shall be through connection to a grounding
bus in the manufactured home distribution panelboard. The grounding bus
shall be grounded through the green-colored conductor in the supply cord
or the feeder wiring to the service ground in the service-entrance
equipment located adjacent to the manufactured home location. Neither
the frame of the manufactured home nor the frame of any appliance shall be connected to the neutral conductor in the manufactured home.
(b) Insulated neutral. (1) The grounded circuit conductor (neutral)
shall be insulated from the grounding conductors and from equipment
enclosures and other grounded parts. The grounded
(neutral) circuit terminals in the distribution panelboard However, when service equipment is installed
on the manufactured home, the neutral and the ground bus may be
connected in the distribution panel.

(2) Connection of ranges and clothes dryers with 120/240 volt, 3-
wire ratings shall be made with 4 conductor cord and 3 pole, 4-wire
grounding type plugs, or by type AC metal clad conductors enclosed in
flexible metal conduit. For 120 volt rated devices a 3-conductor cord
and a 2-pole, 3-wire grounding type plug shall be permitted.
Click to expand...
Now you notice the requirment "Connection of ranges and clothes dryers with 120/240 volt "

Many manufactures use this to allow only a three-wire connection ( two hots and a grounding conductor) to feed a range that is 240 volts only. It has no need for a neutral. These are a small range that is supplyed by the manufacture of the home and are UL listed for use in a manufactured home only.

Yes all appliances in a manufactured home must be listed for use in a manufactured home as per:
3280.801(d) (d) All electrical materials, devices, appliances, fittings and
other equipment shall be listed or labeled by a nationally recognized
testing agency and shall be connected in an approved manner when in
service.
Click to expand...
So when a home owner goes out and buys a new range that is not UL listed for use in a manufactured home you already have a violation. :roll:
 
Re: 3 wire range circuit

It sort of depends on whether the "modular" home qualifies as a mobile home or not. If it does, then it has to meet the HUD standards.

Some time ago you were allowed to use 2/G SE cable to wire up ranges. this is not longer allowed. I don't believe you were ever allowed to use Romex. All new construction and new ranges are required to have 3/G.

Whether this is a serious hazard or not is another story. I seem to recall that UL had at one time declared they did not have a single case on record of any fires or injuries caused by the 2/G wiring to ranges that were done properly.
 
Re: 3 wire range circuit

Your right Bob I didn't see gserv's clarifications that this is a modular home on a foundation. thanks. A modular home must follow the NEC and local codes unless it has the required "RED" emblem that HUD will put on the home's that fall under the HUD codes.
 
Re: 3 wire range circuit

Thanks for all the replies guys. I was just looking to do a repair on a existing installation and didn't think the romex was allowed. I guess I will do the right thing and run a new 4 wire 8/3 romex back to the board. It just goes to prove when things were done in the past doesn't mean its right.
 
Re: 3 wire range circuit

Yes, for ranges & dryers, the separation requirement of grounded & grounding conductors for mobile homes existed long before it was required everywhere else.

The '96 NEC finally made it required everywhere.

This was a long awaited change to an NEC that had allowed an electrically unsafe practice for many,many years. (I cannot give you a body count.)

Present NEC recognizes those installations of existing 3-wire cord dryers that are out there plus the newer dryers that come with 4-wire cords.

Greatly simplified - If a widget need (3) wires just to operate, then it needs (4) wires to operate safely.
 
Re: 3 wire range circuit

What am I missing? How did the old code that allowed 3-wire range circuits allow SE but not romex? They both have bare wires. Is there some type of SE I've never heard of with 3 insulated wires only?
 
Re: 3 wire range circuit

I replaced a range in my house several years back. It was a GE oven, and it came with 2 hots and the "neutral" was a bolt connected to chassis. They either violate the code or they are using a transformer to derive the 120V. Or, like your laptop power supply brick, an off-line 90-240V converter. For the oldert stoves we know the answer.

Why has this violate been allowed to continue for so long?
 
Re: 3 wire range circuit

Originally posted by bob11746:
Why has this violate been allowed to continue for so long?
Click to expand...
There is a note about this in the 1990 code handbook, after 250-60.

It reads in part:

"...it has been allowed for many years because of the good safety record of these particular appliances... A subcommittee reevaluated this requirement for the 1984 NEC and verified the continued good safety record".
 
Re: 3 wire range circuit

I wouldn't always assume that becuase a home dosen't have a red label on the side that it isn't a mobile. Some one could have removed it. The best way to tell is if it has a frame (carriage) under it, it is considered a mobile whether or not it is on a fondation or not and follows hud code. Modulars on the other hand never have a frame left under them. Modulars follow the NEC and have 1 small article dedicated to them article 545 Manufactured buildings. If in doubt you can look at the data plate that is on both modular and mobile which is located under the kitchen sink, this will tell you what codes the house was built to.
 
Re: 3 wire range circuit

paul32 - I think the only thing you are missing is maybe an older NEC in which to read the rules.

250-60 was pretty clear. (3) conductor Romex with all wires insulated & w/o EG was used for other than mobile homes. SE cable with (2) insulated wires & (1) bare wire could be used if the branch ckt. originated at the service panel & not at a sub panel.
 
Status
Not open for further replies.
Top