Improper Panel Usage

[Teaspoon]

About a week ago I went out to an older home, to check the wiring.
the 100 amp panel was in a small basement.When I opened the panel door I discovered that it was a 3 phase panel. Some hack was useing 2 legs of the,
main breaker for this single phase residence. The lady wanted some receptacles added was the reason she called me.I told her I could not add anything to this panel.That it would have to be changed out to a single phase panel before I could do anything further. Gave her a price on a change out. haven't heard from her.

 

[peter d]

I wired a 3-phase panel once just like this. Only it was for a garage. The panel was salvaged and supplied by the homeowner of course. And the homeowner was a friend of my dad's.

Am I forgiven?

 

[Minuteman]

I was in a industrial shop once that had a 240 delta service, but one sub panel was fed single phase and the panel had A and B phase jumpers with the same leg, and C had the other leg. I had about the same response as you.

 

[petersonra]

I'm not sure I see anything wrong with such an installation. You would just have 1/3 of the spaces not usable.

 

[Minuteman]

I would guess they did it for breaker space. With twice as much load on one leg as the other.

 

[cadpoint]

Did you call the AHJ? I've seen these types of panels in action! I've seen other threads on this and I've frankly always wonder about this myself (the panels I've seen)?

Many panels have dual listing and 110.2 Approval is what your looking for maybe 110.3(7) will be their reply.

 

[goldstar]

Gave her a price on a change out. haven't heard from her.

And you probably won't ever again. I'm not sure if you did the right thing or the wrong but doing additional work in this house would only serve to put you on the liability list in the event anything went wrong (electrically speaking that is).

The panel was salvaged and supplied by the homeowner of course.

And there-in lies the problem. I'm sure the same thing happened in Teaspoon's case. Some friend of a friend who's brother-in-law was working on a commercisl job and took the 3-phase panel that was being thrown out, gave it to the HO's cousin that installed it as a replacement for her fuse panel.

I'm not sure I see anything wrong with such an installation. You would just have 1/3 of the spaces not usable.

Peter, I'm not sure you read the O/P correctly. One of the phases was jumped over to the 3rd phase. In this case all breaker spaces would be used but one phase could potentially be over-loaded and thereby unbalancing the service. You'll have to beg forgivness from a higher authority.:grin:

 

[infinity]

Peter, I'm not sure you read the O/P correctly. One of the phases was jumped over to the 3rd phase. In this case all breaker spaces would be used but one phase could potentially be over-loaded and thereby unbalancing the service. You'll have to beg forgivness from a higher authority.:grin:

Sounds like he saying that one phase will not be used:

Some hack was useing 2 legs of the,
main breaker for this single phase residence.

 

[Pierre C Belarge]

As per the OP, I do not see a code issue with using 3-phase for a single-phase system, as long as the installation meets code.


When an installer uses practices that are code compliant (code compliant can be the worst job possible to pass), but are not to anothers liking, is not necessarily hack work.

 

[steelersman]

I'm not sure I see anything wrong with such an installation. You would just have 1/3 of the spaces not usable.

I was thinking the same thing. Seems like no real safety issue.

 

[steelersman]

Peter, I'm not sure you read the O/P correctly. One of the phases was jumped over to the 3rd phase. In this case all breaker spaces would be used but one phase could potentially be over-loaded and thereby unbalancing the service. You'll have to beg forgivness from a higher authority.:grin:

Actually that wasn't the OP's, that was minuteman's post that had the jumper.

 

[Dennis Alwon]

When you do some solar stuff you will find that the installers often use 120v because of the cost of the extra equipment to get 240. Thus we just wired to one phase of the panel. I don't see an issue.

 

[chris kennedy]

When I opened the panel door I discovered that it was a 3 phase panel. Some hack was useing 2 legs of the,
main breaker for this single phase residence.

Violation of 408.3(E)?

(E) Phase Arrangement. The phase arrangement on 3-phase buses shall be A, B, C from front to back, top to bottom, or left to right, as viewed from the front of the switchboard or panelboard.

 

[Dennis Alwon]

Violation of 408.3(E)?

So for single phase panel it is okay? :smile:

 

[steelersman]

Violation of 408.3(E)?

I don't think that is a violation of that code. Because the 3 phase panel is arranged that way. It's just that C phase would be dead.

 

[Teaspoon]

Did you call the AHJ? I've seen these types of panels in action! I've seen other threads on this and I've frankly always wonder about this myself (the panels I've seen)?

Many panels have dual listing and 110.2 Approval is what your looking for maybe 110.3(7) will be their reply.

This panel was not Dual Listed. I did Call th A H J. He said that the only way this wrong could made right,would be to change out to single phase panel.
This made my decision for me not to touch it, for liability reasons.
It is working but panel is full.Only being able to use 2/3's of the buss bar.
Thanks for all the replys.

 

[ivsenroute]

This panel was not Dual Listed. I did Call th A H J. He said that the only way this wrong could made right,would be to change out to single phase panel.
This made my decision for me not to touch it, for liability reasons.
It is working but panel is full.Only being able to use 2/3's of the buss bar.
Thanks for all the replys.

Good decision, I commend you for your ethics and professional attitude.

I agree with both your and the AHJ