Power Outage and surge damage

[ecborgoyn]

Well it finally happened at our house.  A power outage and related voltage surge and damage.

Last Sunday evening, a narrow line of storms passed through the western Pennsylvania area. Some lightning/thunder, but mostly strong winds (50+ MPH gusts).

Around 8:30pm my wife was on the phone with a friend a few miles across town, and their power had just gone out. This was more or less the peak intensity of the storm.

Around 9:00pm, we just started to watch a video, when our power went out 'with a bang'. We attributed the bang to a transient on the A/V system. The power went out sharply. I even said that it was like it was turned off, probably for repairs....

OK, we have a small, manual genset to maintain a few circuits in the house like furnace, network, refrigerator/feezers, etc. So we're OK with the genset running occasionally throughout the night and next day. Around 6:00pm on Monday, we see that the neighbors have power, but we don't... Hmmm.

Before this point, never opened the cover to the service entrance panel. The genset feeds the house via a manual transfer switch outside of the service entrance panel.

Opening the panel cover, I see a distinct arc burned area on the cover and around the surge protector. I installed the type of surge protector that installs in a two-pole circuit breaker position, at the top of the bus-bar. And this SPD took a hit and tripped the 200A main breaker. Probably the sharp cutoff of power...

I wanted to get power restored, so I tried to reset the main breaker.... Well, another arc-flash from the SPD that just about knocked me off of the step-stool... Obviously the SPD was still shunted to ground. Looks like only one pole of it.

OK, so I removed the sacrificial SPD and replaced it with a spare two-pole breaker just to fill-up the space. THEN the main breaker was able to be reset, and we had shore-power.... Or so I thought so.

Looking at the branch CB's I saw several in the tripped position.... Did the surge trip them? Or did the power restoral trip them?? In fact, breakers tripped in several sub panels around the house. There's a 100A sub panel in a mechanical room. This feeds a 60A sub panel that houses a GFCI breaker for the spa. ALL breakers in this chain had tripped. The 100A feeder in the main panel. A 100A main breaker in the sub panel. A 60A breaker in this sub panel, and the 60A GFCI breaker in the spa disconnect panel.... Interesting.

And two branch circuits are still bad. One 15A lighting circuit won't reset. Breaker only trips. This circuit has a couple of electronic dimmers and timers. Maybe one of them is damaged. Another 20A circuit breaker 'buzzes' when I try to reset it. Damaged breaker?? This circuit only has two receptacles. One with a table lamp. Nothing sensitive.

Still investigating...

But we have learned that some of the neighbors in the area also had circuit breakers tripped.

Anyway, interesting situation... But looks like the house SPD took the brunt of the damage.
 

 

[pete_c]

Thank you for sharing ecborgoyn.  Hopefully you are up and running soon.
 
Curious what SPD you were using?   Do you have overhead or underground electrical at the service entrance?

 

[ecborgoyn]

underground service to the house
 
this: https://www.amazon.com/Cutler-Hammer-BRSURGE-Surge-Arrestor/dp/B003S63AWS device.
 
I'm still doing a complete 'inventory' of devices around the house assessing damage.  Found one additional non-functional duplex receptacle.  But it's on an otherwise functional circuit.  Might be unrelated.  Still haven't assessed the two 'broken' circuits.
 
The 'broken' lighting circuit has one additional piece of evidence.  It has a in-wall timer on the circuit.  The timer has a fold-down cover on the front to cover the controls.  And after the 'event' the cover was opened.  So this device may have suffered some trauma.
 
In my inventory, I even found some tripped breakers in a sub-panel in our shed, about 30' from the house.
 
But so far, no appliances damaged.  I recently added two additional 'tiers' of SPD's on the main electronics rack and network closet.  These may have helped.  Both 'damaged' circuits are in the main service entrance panel.  Just thinking about this:  I should look at the positions of the branch breakers.  It looks as if only one pole of the SPD 'tripped'.  The other looks intact.  Should see if the tripped/damaged circuits are on the same pole as the blown SPD...   Good thought while typing,,,

 

[pete_c]

Would you say the SPD failed?

 

[ecborgoyn]

Would you say the SPD failed?

Not sure how to answer this.  Yes, it was destroyed by the event.  But it may have shunted the surge to ground and protected other devices.  So I can't say that it failed...
 
Looking at the two 'broken' circuits, one is on each pole of the line... 
 
Completed my inventory and didn't discover any additional issues.  I DID see that a two GFCI's were tripped.  Both on circuits that experiences some 'event'.  One is on the 'broken' 20A circuit.  Another tripped GFCI is in the barn, on a circuit where the circuit breaker was tripped due to the event.  These circuits experienced some trauma.
 
Next I need to investigate the two 'broken' circuits.....

 

[ecborgoyn]

OK, did my repairs today.
 
One circuit was tripped due to a blown GFCI receptacle.  Removed the recep and the circuit resets.  Need a new GFCI recep.  The recep showed some internal arcing damage.
 
As I suspected, the in-wall timer took a major hit.  This device was shorting a lighting circuit.  Replaced the timer with a switch and now this circuit is back working.  The dimmers and the motion sensor fixture fixture on this circuit survived.  Interesting that this in-wall timer was due to be replaced anyway with a new z-wave switch.  So no real loss here.  Looking inside the timer showed major arcing damage.  Even the cover plate around the timer had some soot.  This device is the closet to where we were sitting at the time of the surge event and may have been the 'bang' we heard.
 
Net damage:  One in-wall timer, one GFCI recep, and the BRSURGE SPD that was in the service entrance panel.
 
To answer Pete's question:  I'd say that the SPD worked.  It could have seen a lot worse.  Talking to my next-door neighbor today,  they lost a 14 month old refrigerator.  And a neighbor across the street lost two GFCI's and a plugin SPD device.  And others in the area probably lost stuff as well.  Unless I'm missing something, we lost about $100 worth of items, including the SPD.  I DO have one piece of A/V equipment that is acting a bit strange.  But it was working earlier today and I'm confident it's not related to the surge event...  One internal audio path isn't working correctly.
 
I'm probably a stronger SPD advocate as the result of this event....

 

[Neurorad]

Glad to hear it wasn't too bad. I also have Cutler-Hammer/Eaton SPDs, though no surges yet, that I'm aware of, in the last few years since they were installed. I Ave the Eaton 3-pack - 1 each for power, coax, and POTS.

 

[pete_c]

Good news that the damage was minimal.
 
A few years back one rainy night heard a pop and then a buzz in the home then darkness.  The pop came from behind the house adjacent to the family room  I went outside and the outdoor AC condenser was flaming a bit.  Inside many breakers tripped and just about every one of the Insteon switches ceased functioning.  Looking at the AC condenser in the morning looked like the contactor shorted out and the heat generated melted the AC compressor lines.  It was just a blackened piece of metal by morning.  The brick adjacent to the outdoor condenser was fine.
 
Replaced AC condenser and Insteon switches and no other damage occurred that I could see. I did add an SPD to the outdoor AC condenser.
 
Our homeowners insurance covered the AC condenser and new switch replacement.  I installed the replacement switches.
 
I had been procrastinating on the replacement of the failing Insteon switches any how...
 

 
The fuse panel SPD never triggered that night. 
 
Using an Eaton inside and installed the Supco outside.