GE 2 pole breaker on 240V delta

[hillbilly]

Hey, I've got a quick question.

I'm installing a small 20" wide range in a commercial building...<6KW.
It's straight 240V and doesn't require a (grounded) neutral .

The electrical service to the building is 240V/3 phase Delta with a center tapped leg supplying the neutral.

It's a GE panel, and one of (the only 2) spaces available in the panel is the high leg (208V to ground).

I'm looking at a GE THQL 2 pole breaker and the breaker specifications list 120V, 120/240V, and 240V.

Is it OK to use this breaker in this application?

Although it's a slash rated breaker, it also has a straight 240V rating (the way that I read it anyway).

I plan on installing a 3 prong receptacle and cord, although there's a 4 wire circuit available that I can use, (I'm finishing someone else's job :-?) The range already has a 4 wire cord attached and the white and green are bonded to the range chassis. :roll:

What do I need to do with the white circuit conductor in the 4 wire cable?
Cut it off..... mark the cable as being fed with a 240 Delta.....or just assume that the next electrician knows that there is chance of making a big mistake if he trys to utilize the white wire (neutral) without doing a little investigation?
This part is strictly from a safety stand point for the next guy.

Anyway, I don't work on this type of service very often, actually very rarely.
Any tips are appreciated.

thanks
steve

 

[LarryFine]

Is it OK to use this breaker in this application?

Yes.

The range already has a 4 wire cord attached and the white and green are bonded to the range chassis.

The presence of the white means you can't use the high leg. It can't be 240v-only and have a white wire.

What do I need to do with the white circuit conductor in the 4 wire cable?

Use a 4-wire circuit. You'll have to find a load that can use the high leg, relocate that breaker, and use the opened-up space with two 120v lines for the range.

Cut it off..... mark the cable as being fed with a 240 Delta.....or just assume that the next electrician knows that there is chance of making a big mistake if he trys to utilize the white wire (neutral) without doing a little investigation?

This would be the mistake. Don't do it. If the range didn't require the neutral, it wouldn't be in the cable. Therefor, you cannot use the high leg.

Note: In theory, if you made sure any 120v load in the range only connected to one line, and you made that line the non-high-leg, you could do it. But, I wouldn't risk another range being plugged in and not matching.

 

[curt swartz]

A GE THQL2150 is rated only rated for 120/240 volts. A THQL22050 (rare and $$) is rated for 240 volts. Even if you have the second breaker I question weather the range is listed for more than 120 volts to ground. I have also never seen a range that didn?t require a neutral conductor. The controls and oven light are usually 120 volt.

 

[hillbilly1]

Most ranges I've installed do require a neutral, as others have said lights, timers, and so on require 120. If its just a cooktop, those usually are straight 240 volt. If the white is jumpered to ground, this jumper will have to be removed.

 

[hillbilly1]

If it truely is straight 240 volt I would change the cord and receptacle to the proper configuration. Someone may eventually change the range out for one with a neutral, and procede to burn it up with the combination of the open neutral, and high leg.

 

[hillbilly]

Yes.

The presence of the white means you can't use the high leg. It can't be 240v-only and have a white wire.

Use a 4-wire circuit. You'll have to find a load that can use the high leg, relocate that breaker, and use the opened-up space with two 120v lines for the range.

This would be the mistake. Don't do it. If the range didn't require the neutral, it wouldn't be in the cable. Therefor, you cannot use the high leg.

Note: In theory, if you made sure any 120v load in the range only connected to one line, and you made that line the non-high-leg, you could do it. But, I wouldn't risk another range being plugged in and not matching.

The 4 wire cord was installled by some person after the range was purchased, it was not a factory install.

The wiring schematic is located on the rear of the small range, and shows a straight 240V hook-up.
There is no neutral shown on the schematic, and there is no white wire at the range wiring terminal (center lug), so I'm positive that there is no neutral required.
There is only a single red wire on the left terminal and a single black wire on the right terminal.
The 4 wire cord that's presently installed has the white wire connected to this center terminal, and the green grounding conductor is connected to a green chassis grounding screw.
There is also a bonding strap between the center lug and the green screw.

It's set up like any regular range with the three screw terminal plus green bonding screw on the rear of the range...just no white (neutral) wire anywhere on the range.

I installed it yesterday.
I disconnected the branch circuit neutral (white wire) from the receptacle, and attached a note to it saying "Caution 240V Delta Supply" and marked the high leg conductor with orange tape.
I also marked the high leg on the breaker with orange tape.

I suppose that I could install a 3 wire cord and receptacle, if it's really necessary (code requirement).

The range works properly with just the 2 hot circuit conductors and the chassis ground.
There are only (2) red indicator lights on the range, one for the oven and one for the surface elements.
These lights must be (rated for) and operating on 240V.

Nothing digital on the range, no clock, and only manual rheostat control for the heating elements.

I got the spec. for the GE breaker from the GE web site.
The THQL breaker is marked 120/240V, but the GE web site lists the breaker as 120V, 120/240V, 240v.

Thanks for the response.

steve

 

[augie47]

That is an odd marking on that breaker since, as Curt points out, the Delta breaker carries a different catalog number.

 

[hillbilly]

That is an odd marking on that breaker since, as Curt points out, the Delta breaker carries a different catalog number.

I've got to read more closely....cause I made a mistake.

The 240V 2 pole breaker that I need is model # THQL22040

The one that I selected is model #THQL2140.

What a difference a number makes.::roll:
Got to get the correct breaker today!

Luckily, the store is closed till Monday.

What would happen if there was a high leg (208V) to ground fault with the 120/240 breaker installed.
Would it open?

steve

 

[augie47]

It would open. I've seen this misapplication countless number of times.
I do not know the difference in the two breakers although I imagine some of the breaker gurus on the Forum do.
From a safety "liability" standpoint the fact is the breaker has not been NRTL (UL) tested for the high-leg application.
I have often wondered other than the marking and the cost :smile: was there a difference.

 

[hillbilly1]

It would open. I've seen this misapplication countless number of times.
I do not know the difference in the two breakers although I imagine some of the breaker gurus on the Forum do.
From a safety "liability" standpoint the fact is the breaker has not been NRTL (UL) tested for the high-leg application.
I have often wondered other than the marking and the cost :smile: was there a difference.

I believe you are correct, it is just marking and cost, I do not see anything they could change internally to make a difference, the voltage between the contacts is the same, only the voltage to ground is different. I doubt the case insulation is any different.
The only thing that might make a difference would be higher fault current to ground, but then again the fault current between the legs would be the same as the fault current to ground.