Odd occurrence

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nizak

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My brother in law called and said his house lost power in a recent storm.

Subdivision was out completely.

Both his neighbors have whole house generators that started and were running.

He proceeds to tell me that while he assumed everything was dead , the digital display on the electric range was on and several different light fixtures were lit with a very faint glow.

He had no means or knowledge of how to check the voltage at his load center and I was made aware well after the fact.

Is there any way that the neighbors generators could be producing current in some way to cause the things to happen that did in his house?

Thanks
 
Yes! If not wired correctly thru a Transfer Switch….it could be backfeeding. This could be putting the linesman in danger if this is the case! Worth mentioning to Neighbors to verify that their generators are wired correctly! I would have it verified by a Licensed Electrician that is familiar with the correct way to install these. If a recent install…I would have original installer comeback and verify. is your Brother in laws house being fed by the same transformer as neighbors house?
 
nizak said:
Is there any way that the neighbors generators could be producing current in some way to cause the things to happen that did in his house?
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I sincerely hope not. If energy from a household generator can energize lights or anything else in another house while the utility power to the neighborhood is out, is is possible, even likely, that the generator could kill a utility line worker trying to restore power. I would report this to the utility immediately.
 
I haven’t been able to get over there and look into it but I do know the following.

Both homes with the Generac systems have automatic transfer switches. I recall seeing them both when I was at his house this Summer for family gatherings. He and I even discussed him getting one since he’s gone for weeks at a time for his job. Both homes were just built no more than 2 years ago and wired by the same EC who wired his.

I would assume all 3 homes are fed from the same transformer which is located in the front yard of one of the neighbors with the Generac.
 
While possible, even with improper isolation of the typical home genset, is is unlikely in most cases that there would be any "back feed" as the genset would likely see this as a short and simply stall or trip its OCPD. Yes, I realize that it could happen but in most cases due to the relative sizes of the grid in that area VS the genset size, in most cases this will not happen.
 
I would say one of the legs had partial power, at least enough to power LED lights.
The ATS in the other homes sensed power loss and came on.
 
charlie b said:
I sincerely hope not. If energy from a household generator can energize lights or anything else in another house while the utility power to the neighborhood is out, is is possible, even likely, that the generator could kill a utility line worker trying to restore power. I would report this to the utility immediately.
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In my opinion that is only possible under a very specific conditions..that being the condition where the improperly connected generator was connected at a point on the utility system where the generator could supply the load without stalling the prime mover. Maybe where the primary was open to a transformer that supplied a small number of homes. In that case there would be primary voltage available on the primary line up to the open.
The transformer that supplies my house supplies 10 other houses. If that primary was open, and a generator was improperly connected, I expect the load of the other 9 houses would stall the prime mover.
 
don_resqcapt19 said:
In my opinion that is only possible under a very specific conditions..that being the condition where the improperly connected generator was connected at a point on the utility system where the generator could supply the load without stalling the prime mover. Maybe where the primary was open to a transformer that supplied a small number of homes. In that case there would be primary voltage available on the primary line up to the open.
The transformer that supplies my house supplies 10 other houses. If that primary was open, and a generator was improperly connected, I expect the load of the other 9 houses would stall the prime mover.
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My point exactly in my previous post.
 
If you can verify with meter, they may still have voltage but no neutral It could be a loose or damaged neutral at POCO pole. I had a family member with similar issue. I had them call POCO first time and they couldn't find anything wrong. I had them call and visit again but I told family member turn on the main breaker when they get there because they cant see what I see with my meter if there is no load on service everything is shut off. I still got 120 240 with breaker off but under a load I didnt get 120v and my amps were off. ......sure enough with the power still on at Main they discover the neutral at the utilities was bad.......... Worth a shot if they are still having issues.
 
It sounds more likely that power outage is due to one leg being out along with neutral and other leg is still hot. It will give dim light conditions if it reading back through grounding especially with water pipe grounding.
 
If the primary is a two bushing 12.5kv : 120/240 transformer and one primary phase got grounded out but the other is ok it would become something like a 7200V : 139/70 V transformer.
 
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