Addition dilemma - Electrician Talk - Professional Electrical Contractors Forum

kbsparky · 09-11-2009, 11:13 AM

We are on a project where an addition is being built on the end of a house. The meter box will have to be moved, as it will be enclosed by the addition.

So, we have placed a meter/main box on the outside of the addition, and are installing a feeder conduit back to the existing panel, making it a sub-panel.

While separating the grounds from the neutrals, we discovered that the range circuit is fed with SE cable -- having a bare neutral, with no EGC. This of course was legal before, since the circuit originated at the service equipment, but now it is originating from a sub-panel.

So what would do in this case?

Tape up (insulate) the range neutral and keep it at the neutral
Move the range neutral to the new ground bar
Relocate the range circuit outside to the Meter/main
Replace the range circuit with 4-conductor wire, new receptacle, new cord
Nothing - keep the range neutral connected where it is

480sparky · 09-11-2009, 11:34 AM

I voted for F: Contact your AHJ.

manchestersparky · 09-11-2009, 01:47 PM

do it correctly and replace the range circuit with a 4 wire cable.

user5941 · 09-11-2009, 04:33 PM

If you have priced the range upgrade then do that. If not place the range grounded cunductor back on the grounded buss bar.

william1978 · 09-11-2009, 04:40 PM

Replace with 4 wire.

steelersman · 09-11-2009, 05:07 PM

It has nothing to do with the fact that it came out of the main panel vs. a sub-panel. It has to do with the fact that it used to be legal to have a 3 conductor, but now it is supposed to be a 4 conductor. I would ask the AHJ though like 480 said, because I wouldn't want to change it to 4 wire if I didn't have to.

MDShunk · 09-11-2009, 06:18 PM

EVEN WHEN it was legal to feed a range or dryer with 3-wire SE cable, it was NEVER legal to use 3-wire SE out of a subpanel. To tape up (or heat shrink) the bare neutral in the SE cable would be an attempt to comply with an old code that NEVER EXISTED.

What I'd do it either replace the range cable with 4-wire OR tap onto it and extend it over to the new service panel. The second option is not exactly compliant today, but would at least comply with the old codes related to feeding a range with 3-wire SE cable.

blueheels2 · 09-11-2009, 06:24 PM

Replace with 4 wire and hit them with an extra.

kbsparky · 09-11-2009, 07:10 PM

Quote:

Originally Posted by MDShunk

EVEN WHEN it was legal to feed a range or dryer with 3-wire SE cable, it was NEVER legal to use 3-wire SE out of a subpanel. To tape up (or heat shrink) the bare neutral in the SE cable would be an attempt to comply with an old code that NEVER EXISTED....

Ahhh ... but therein lies the dilemma. IF that range (or dryer for that matter) had been wired with romex, that contains an insulated neutral conductor, then it would have been acceptable even fed from a sub-panel. So, from a safety point of view, what is the difference here?

Quote:

....
What I'd do it either replace the range cable with 4-wire OR tap onto it and extend it over to the new service panel. The second option is not exactly compliant today, but would at least comply with the old codes related to feeding a range with 3-wire SE cable.

OK, taking this a step further. We have a conduit that connects the new main outside panel with the old (now sub-)panel. In it will be the 4 feeder wires required for a complaint installation. I should be able to install 3 additional conductors in that conduit to "extend" the circuit to the service panel; OR I could install a 2nd piece of SE cable from the old panel out to the new panel. I would end up with 3 wirenuts in the old panel, with the circuit breaker for that circuit outside in the service panel.

How is this any more safe than simply leaving that circuit in the existing panel?

MDShunk · 09-11-2009, 07:35 PM

Quote:

Originally Posted by kbsparky

Ahhh ... but therein lies the dilemma. IF that range (or dryer for that matter) had been wired with romex, that contains an insulated neutral conductor, then it would have been acceptable even fed from a sub-panel. So, from a safety point of view, what is the difference circuit outside in the service panel.

it was NEVER legal to feed a range or dryer, ungrounded, from a subpanel. Romex or SE.

steelersman · 09-11-2009, 07:37 PM

Quote:

Originally Posted by MDShunk

it was NEVER legal to feed a range or dryer, ungrounded, from a subpanel. Romex or SE.

They're grounded when you use a 3 wire. They just don't have a seperate grounded conductor.

MDShunk · 09-11-2009, 07:46 PM

Quote:

Originally Posted by steelersman

They're grounded when you use a 3 wire. They just don't have a seperate grounded conductor.

Nope! A range or dryer that is fed with three conductors is ungrounded!

drsparky · 09-11-2009, 07:53 PM

Shunk is 100% correct. Do it right, you will feel better about it in the morning.

Black4Truck · 09-11-2009, 07:55 PM

I have wired hundreds of stoves using 8/2 seu and many dryers using 10/3 plain which had black, red, and white conductor

The neutral was bonded to the frame with a strap

That was the accepted way around here in the 70's until the code changed to 4/wire

But NEVER from a sub-panel.. what Marc is talking about

MDShunk · 09-11-2009, 07:59 PM

Quote:

Originally Posted by Black4Truck

I have wired hundreds of stoves using 8/2 seu and many dryers using 10/3 plain which had black, red, and white conductor

The neutral was bonded to the frame with a strap

That was the accepted way around here in the 70's until the code changed to 4/wire

But NEVER from a sub-panel.. what Marc is talking about

You are 100% correct, but it was NEVER legal to pull that kind of circuit from a subpanel.

leland · 09-11-2009, 08:13 PM

(Going on gut and poor memory)

Once you alter that ckt (extend),Does it not have to come into current compliance?

Black4Truck · 09-11-2009, 08:17 PM

Quote:

Originally Posted by leland

(Going on gut and poor memory)

Once you alter that ckt (extend),Does it not have to come into current compliance?

No.. existing wire is grandfathered unless changing to sup-panel

steelersman · 09-11-2009, 08:38 PM

Quote:

Originally Posted by MDShunk

Nope! A range or dryer that is fed with three conductors is ungrounded!

Please explain how it's ungrounded when the bare conductor is connected to ground. I already know why it's inferior to 4 wire since the 3 wire method makes the frame of the appliance have current flow through it. But it is still grounded.

MDShunk · 09-11-2009, 09:45 PM

Quote:

Originally Posted by steelersman

Please explain how it's ungrounded when the bare conductor is connected to ground. I already know why it's inferior to 4 wire since the 3 wire method makes the frame of the appliance have current flow through it. But it is still grounded.

You seriously asking this question?

What you're sorta saying is that it would be okay to jumper the neutral to ground on each and every receptacle in the house.

MDShunk · 09-11-2009, 10:14 PM

Quote:

Originally Posted by steelersman

Please explain how it's ungrounded when the bare conductor is connected to ground. I already know why it's inferior to 4 wire since the 3 wire method makes the frame of the appliance have current flow through it. But it is still grounded.

That bare conductor you talk about is an UNINSULATED NEUTRAL... not a ground. It happens to be jumpered to the chassis at the appliance.