Could utility have caused damage to fixtures?

[oldsparky52]

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

That's what I would do if I was the customer. If the EC rolled over and took care of it as warranty, I'm golden.

 

[ATSman]

Interesting discussion. In all my years in this business I have seen and investigated many incidents where customer equipment was damaged due to anomalies from the Poco (rectifier blown power fuses, 480v GF Relay trip light alarms, circuit board damage to VFD controllers, ATS voltage sensing circuits, memory loss and damage in PLCs, fire alarm panel motherboard damage, elevator controller damage, etc, etc.) Yeah, sure we can all speculate as to the exact cause of the damage but I don't think there is anyone on this forum that can deny that in the majority of cases the root cause can always be related to voltage transients and solid state devices. As to what causes these transients is pure speculation but unless there is a sophisticated power line disturbance analyzer monitoring the power lines to customers then the magnitude of these damaging voltages can not be quantified. But damage to equipment can be documented.
I was called out last week after a customer's facility was running on generators due to Poco line voltage problems. Aside from what caused the generators to run and not shut down, one piece of equipment was a PLC that lost it's program as part of a vacuum pump alternating panel. I opened a post in the Controls and Logic forum here titled Eaton C-H D100 PLC and in post #11 I describe briefly what I found.
There is no doubt in my mind that the damage that is described in the OP is due to anomalies caused by the Poco. I would take the advice offered by Larry in post #3.

 

[kwired]

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.


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If you can prove there was a surge from utility, why should you have to warranty anything other than you may decide it is best for relationship with the client?

As much as has been effected is pretty obvious it wasn't likely product defects or improper installation - which is mostly what your warranty is supposed to cover.

Then comes what did you have for surge protection and what warranty might be associated with that?

As mentioned if transformer looks like it maybe been heated up by whatever happened, then it was more than just a brief transient and you maybe have good case of possible wrongdoing by POCO. They probably not admitting to anything unless you show the evidence. There may be more equipment that is damaged but hasn't totally failed yet as well.

 

[Todd0x1]

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.

Dumb question, but did they pull all three?

 

[synchro]

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.

Since the utility knew there was a long primary cable to the pad mount (and it would therefore be susceptible to ferroresonance ) it seems negligent if they didn't take measures to minimize that possibility when they pulled cutouts on the pole. For example, they might have disconnected the transformer first using pull elbows if available, as Hv&Lv mentioned. Also, having a significant resistive load on the transformer would help prevent ferroresonance when a cutout was opened. For example, by having the customer turn on ovens and grills in this case, or with a load bank. And while it wouldn't prevent ferroresonance from occurring, switching off breakers feeding other loads would likely prevent them from being damaged. And at the very least, knowing that their procedures might trip GFCI breakers, they could have notified the customer about that beforehand. If there were a lot of small customers involved that might not be practical, but that doesn't appear to be the case here.