Could utility have caused damage to fixtures?

[Hv&Lv]

So did they leave the thing "single phasing" for way too long or did opening/closing the circuit cause a voltage spike that damaged equipment? A little of both?

I don’t know.
I’m a speculator on this one. I don’t know what they have there on the site.
for an UG as long as it appears, they could have it on a GOAB switch or pad mount sectionizer.
I would have to look around at the setup to offer any opinion that means anything.
I would look at the pad mount, look at the fuses for any arcing evidence, or something like that.
many arcing in the main panel?

 

[kwired]

I remember maybe 30 years ago in small town I lived in power went out couple hours before dark. Didn't come back on until couple hours before daylight.

Found out later on that the transformer feeding the entire town distribution had a bushing fail - I think on the primary side.

I remember observing at least for a little while after this all started we did have low voltage as lights kind of were pulsing so to speak but barely noticeable- back when most of them were still incandescent lamps. Once I discovered that I shut the main off figured it wasn't doing any good to some items.

Next day all around town we did have service calls for various items that apparently did see high voltage surge or even longer duration voltage that was too high.

Never really knew exactly what or why on this but guessing this ferroresonance maybe a factor?

Primary side I think 38.5kV probably delta, secondary I know is 2.4/4.16 kV wye.

 

[brantmacga]

How did they deenergize? At pole riser or with elbows in a vault? Sectionalizer?

I talked to the utility engineer this afternoon. He said they pulled jacks at the pole where it transitions underground. There’s a switching cabinet near the pole, they tapped in a single primary phase, set a new padmount, then closed the jacks.


Also, apparently many more fixtures are out than what I saw yesterday. I didn’t go through the whole building. Sounds like 25% of the fixtures are dead. I don’t think the Lithonia is just going to swap them out without asking questions.

This is likely about to get ugly.

The engineer that designed the project told the client today I shouldn’t have installed the GFCI’s, that his plans didn’t call for that, and put blame on me for them losing all the food. He’s right, his plans didn’t call for it on the 120v plug-in freezers, but I’m also not an idiot and bid the kitchen with all GFCI. I sent a nice email about that late this afternoon.

Also haven’t been paid retainage yet on a job I finished in February, so that complicates this even more. As you might imagine that’s a good chunk of money. I’m probably going to end up showing my natural born to someone tomorrow.


Sent from my iPad using Tapatalk

 

[brantmacga]

I don’t know.
I’m a speculator on this one. I don’t know what they have there on the site.
for an UG as long as it appears, they could have it on a GOAB switch or pad mount sectionizer.
I would have to look around at the setup to offer any opinion that means anything.
I would look at the pad mount, look at the fuses for any arcing evidence, or something like that.
many arcing in the main panel?

I appreciate the advice. I will get back to the site later this week to investigate further and take some pics.


Sent from my iPad using Tapatalk

 

[McLintock]

POCO up here was upgrading they sub-station and replacing poles. Got a call form a customer that had their generator running but no power in the house. Went out there and found out two relays in the ATS blew, I thinking it was a surge when they turned power back on.


“ shoot low boys their riding shetland ponies”

 

[mbrooke]

If POCO technicians connected service Line-Line first, and neutral last, then MWBC wired lights could get 480v, and MWBC wired GFCI's could get 208v.

Not with a delta-wye customer transformers I think.

 

[mbrooke]

I talked to the utility engineer this afternoon. He said they pulled jacks at the pole where it transitions underground. There’s a switching cabinet near the pole, they tapped in a single primary phase, set a new padmount, then closed the jacks.


Also, apparently many more fixtures are out than what I saw yesterday. I didn’t go through the whole building. Sounds like 25% of the fixtures are dead. I don’t think the Lithonia is just going to swap them out without asking questions.

This is likely about to get ugly.

The engineer that designed the project told the client today I shouldn’t have installed the GFCI’s, that his plans didn’t call for that, and put blame on me for them losing all the food. He’s right, his plans didn’t call for it on the 120v plug-in freezers, but I’m also not an idiot and bid the kitchen with all GFCI. I sent a nice email about that late this afternoon.

Also haven’t been paid retainage yet on a job I finished in February, so that complicates this even more. As you might imagine that’s a good chunk of money. I’m probably going to end up showing my natural born to someone tomorrow.


Sent from my iPad using Tapatalk

IMO GFCI's don't belong on kitchen equipment. The capacitive leakage to ground will trip them every time there is a high frequency spike on the service.

Though in your defence if there was a long duration sustained over voltage it might have actually saved the kitchen equipment and freezers from costly control board and compressor damage.

With that said, I'm sorry your in the middle of all this at no fault of your own. My condolences. Keep us posted!

 

[brantmacga]

IMO GFCI's don't belong on kitchen equipment. The capacitive leakage to ground will trip them every time there is a high frequency spike on the service.

Though in your defence if there was a long duration sustained over voltage it might have actually saved the kitchen equipment and freezers from costly control board and compressor damage.

With that said, I'm sorry your in the middle of all this at no fault of your own. My condolences. Keep us posted!

210.8(B)(2)

It’s a commercial kitchen. Fryers, grills, ovens… Just can’t believe the project engineer is apparently talking trash.

Sent from my iPhone using Tapatalk

 

[mbrooke]

How are the devices doing that were not on GFCI? Do/did they have damage of sorts?

 

[brantmacga]

How are the devices doing that were not on GFCI? Do/did they have damage of sorts?

The only failures I’m aware of is the lighting, but I will need to further evaluate once I’m back on site


Sent from my iPhone using Tapatalk

 

[mbrooke]

The only failures I’m aware of is the lighting, but I will need to further evaluate once I’m back on site


Sent from my iPhone using Tapatalk

I'm leaning toward ferro as well vs a poor neutral.

 

[Hv&Lv]

I appreciate the advice. I will get back to the site later this week to investigate further and take some pics.


Sent from my iPad using Tapatalk

Also take note of the connections.
Delta wye vs wye wye.
Wye wye is MUCH less susceptible to ferroresonance.
Delta high side puts the capacitor in series with the inductor.

 

[mbrooke]

The only failures I’m aware of is the lighting, but I will need to further evaluate once I’m back on site


Sent from my iPhone using Tapatalk

Before I forget- what is the kva of the POCO trafo?

 

[oldsparky52]

I have to warranty replace all of these now.

HOLD UP THERE!!!

That is an honorable attitude, but it could be costly. How is this a warranty claim? It sounds like force majeure and I just don't see how that can be a warranty issue.

I would suggest you take the stand that the PoCo did it and it's not covered under warranty.

 

[brantmacga]

HOLD UP THERE!!!

That is an honorable attitude,.

Less honor, more contractually bound.


Sent from my iPhone using Tapatalk

 

[gadfly56]

Less honor, more contractually bound.


Sent from my iPhone using Tapatalk

If the equipment failures are due to the actions of a third party, especially one acting on behalf of your customer, how does that obligate you? If aliens came down and nuked all the GFCI's, would you be liable?

 

[gadfly56]

Ferroresonance has to have three things. A capacitive (long URD cable) and inductive reactance that are real close in value in series with each other. With no load on the transformer, a blown or opened fuse on the riser pole for a relatively extended time will start the transformer to rattling, which is the magnetostriction in the coil you are hearing, and oil heating enough to bubble paint.

Going back to a post by electrofelon, when I looked at the cut sheet for the URD it was definitely twisted. Wouldn't this reduce the capacitance issue?

 

[brantmacga]

If the equipment failures are due to the actions of a third party, especially one acting on behalf of your customer, how does that obligate you? If aliens came down and nuked all the GFCI's, would you be liable?

I’ll clarify and say at this part of the process I am obligated to warranty unless denied by manufacturer.

After speaking with supplier this morning, they’re going to deny it..

The comment should have been, “the customer expects me to warranty it.” Anything that fails within 12/mo of substantial completion is a warranty claim.


Sent from my iPad using Tapatalk

 

[Hv&Lv]

Going back to a post by electrofelon, when I looked at the cut sheet for the URD it was definitely twisted. Wouldn't this reduce the capacitance issue?

Not on primary cable. It is an excellent capacitor.
The primary cable has a conductor in the center with a wrapping of semi conductive material, followed by an insulator with another wrapping on semiconductive layer, then a concentrically would neutral cable.
URD secondary (600V cable)is twisted.

 

[hillbilly1]

Not on primary cable. It is an excellent capacitor.
The primary cable has a conductor in the center with a wrapping of semi conductive material, followed by an insulator with another wrapping on semiconductive layer, then a concentrically would neutral cable.
URD secondary (600V cable)is twisted.

That’s why I’m thinking maybe a fault on the outer with hv, momentarily raising the voltage on the secondary neutral? Not my expertise, just throwing it out there.