GFCI TRIPPING ON A DELTA SYSTEM PANEL

[yordanys]

Good Morning Everyone,

I have a THREE PHASE 120/240V 4 WIRE OH delta system coming from the utility with a high-leg on B phase. All the new double and single-pole GFCI Breakers for this new commercial kitchen are tripping. Can anyone ever be in this situation before, Any solution? Many thanks

YT

 

[zbang]

Are they tripping on arc-fault or ground-fault?
First thought is either the neutrals are being shared or are mixed up between circuits, can't to that with AFCI/GFCI devices.

 

[synchro]

What they all have in common is that they're connected on the line side to the neutral bar. So I would have measurements made of the L-N voltages, preferably with unbalanced L-N loading using regular single-phase breakers if necessary. Also, the integrity of the feed connections to the neutral bar should be checked.

 

[hbiss]

Are they tripping on arc-fault or ground-fault?

There wouldn't be AFCI in a commercial kitchen... yet. So obviously GFCI breakers and ground fault trip.

-Hal

 

[don_resqcapt19]

Note that GFCIs are not permitted to be connected to two pole circuits where one of the legs is the high leg. They are only suitable for use where the voltage to ground does not exceed 150 volts.

 

[zbang]

There wouldn't be AFCI in a commercial kitchen...

Don't know how I read A into the first post- seems like most of the tripping problems these days are with AFCIs. Time for more coffee.

 

[hillbilly1]

Note that GFCIs are not permitted to be connected to two pole circuits where one of the legs is the high leg. They are only suitable for use where the voltage to ground does not exceed 150 volts.

That’s probably the issue.

 

[jap]

Note that GFCIs are not permitted to be connected to two pole circuits where one of the legs is the high leg. They are only suitable for use where the voltage to ground does not exceed 150 volts.

That's interesting.

So if the electronics inside the breaker doesn't know what phase or voltage it will be connected to, and, the neutral connection is needed for the electronics for it to work, what would keep the breaker from being smoked as soon as the breaker was turned on?

Or will it?

Never really thought of this scenario.

JAP>

 

[jap]

Don't know how I read A into the first post- seems like most of the tripping problems these days are with AFCIs. Time for more coffee.

Well if you haven't had your coffee, and, you work part time and are periodically snoozing in a commercial kitchen, one might mistake it for a dwelling unit.

JAP>

 

[don_resqcapt19]

That's interesting.

So if the electronics inside the breaker doesn't know what phase or voltage it will be connected to, and, the neutral connection is needed for the electronics for it to work, what would keep the breaker from being smoked as soon as the breaker was turned on?

Or will it?

Never really thought of this scenario.

JAP>

I think the electronics will be smoked if they are powered by the high leg.

 

[jap]

I think the electronics will be smoked if they are powered by the high leg.

I feel the same.

That's why it would seem odd to me that the Delta configuration would have anything to do with the GFI's simply tripping.

I would have thought If he installed a 1p GFI on the wild leg he would have smoked it.
and,
On a 2p GFI it would have smoked also if the electronics caught the wild leg.

That doesn't seem to be the case here.

JAP>

 

[yordanys]

Thank you for all your comments, I'm thinking to add a sub-panel just to balance my load feeding that sub-panel from a double pole breaker on phase C-A Leaving phase B HIGH LEG alone. WHAT DO YOU THINK ABOUT THIS GUYS?

 

[jap]

Thank you for all your comments, I'm thinking to add a sub-panel just to balance my load feeding that sub-panel from a double pole breaker on phase C-A Leaving phase B HIGH LEG alone. WHAT DO YOU THINK ABOUT THIS GUYS?

I would figure out what's causing your GFI's to trip first.

If they're tripping in the main panel the problem is not going to resolve itself in the sub panel.

JAP>

 

[Little Bill]

I would figure out what's causing your GFI's to trip first.

If they're tripping in the main panel the problem is not going to resolve itself in the sub panel.

JAP>

I wouldn't wait on finding what's causing the trip, it's already been stated that GFCIs can't be on a high leg. So a subpanel is going to be required or careful placing in the main panel. A subpanel would cut down on confusion when adding circuits so as not to hit the high leg.

 

[jap]

I wouldn't wait on finding what's causing the trip, it's already been stated that GFCIs can't be on a high leg. So a subpanel is going to be required or careful placing in the main panel. A subpanel would cut down on confusion when adding circuits so as not to hit the high leg.

Nope,

He indicated all the 1p and 2p gfi's were tripping.

If the 1p were installed on the wild leg they'd be toast,,, not tripping.

Something else is going on.

An extension of what's already there is not going to solve this.

JAP>

 

[jap]

GFI's that are not installed on the wild leg should function as normal.

Need to find out why they're not functioning correctly first.

JAP>

 

[Little Bill]

Nope,

He indicated all the 1p and 2p gfi's were tripping.

If the 1p were installed on the wild leg they'd be toast,,, not tripping.

Something else is going on.

An extension of what's already there is not going to solve this.

JAP>

You failed to read what I said in total. I never said not to find out what was causing the trip, I said I wouldn't wait to find out before adding the sub for the reasons mentioned. I don't see how any more damage/tripping would be caused by adding the sub. Since we, including you, were unaware of GFCI not allowed in a high leg system, we won't know if something from the high leg is causing the trip unless a sub is added with no high leg.

 

[jap]

You failed to read what I said in total. I never said not to find out what was causing the trip, I said I wouldn't wait to find out before adding the sub for the reasons mentioned. I don't see how any more damage/tripping would be caused by adding the sub. Since we, including you, were unaware of GFCI not allowed in a high leg system, we won't know if something from the high leg is causing the trip unless a sub is added with no high leg.

It's not so much that I wasn't aware as much as it was that I never install a breaker of any type for any circuit that requires a neutral connection on the wild leg.

No one ever said a GFCI was not allowed on a high leg system.
It is allowed on a high leg system, just not on the high leg.

I know better than to install any breaker of any kind on the wild leg that requires a neutral.

To say that we wont know if something from the high leg is causing the trip unless a subpanel is installed with no high leg is simply incorrect.

If you can't keep the gfi's from tripping in the main panel when installed on the "Non High Leg" bussbars, extending those "Non High Leg" phases to a Subpanel is not going to solve it either.

JAP>

 

[yordanys]

It's not so much that I wasn't aware as much as it was that I never install a breaker of any type for any circuit that requires a neutral connection on the wild leg.

No one ever said a GFCI was not allowed on a high leg system.
It is allowed on a high leg system, just not on the high leg.

I know better than to install any breaker of any kind on the wild leg that requires a neutral.

To say that we wont know if something from the high leg is causing the trip unless a subpanel is installed with no high leg is simply incorrect.

If you can't keep the gfi's from tripping in the main panel when installed on the "Non High Leg" bussbars, extending those "Non High Leg" phases to a Subpanel is not going to solve it either.

JAP>

Hi guys,

I really think a Delta system in this building is just creating problems in this commercial kitchen, B phase with the high leg on it is useless and very dangerous for this building generally. I will point to the electrical engineer to add a transformer to change the system from a delta configuration to a Y System configuration. This is the only solution I see at this point. Please if you have any other Ideas please bring them to the table, I'll greatly appreciate all your advice.

YT

 

[jap]

Delta systems aren't a problem and they are no more dangerous than any other voltage source.

You just have to know how to utilize them.

JAP>