Power Equipment Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I have a generac 6500 portable generator it was hooked up to house power with the main off during an outage. When the power was restored I accidentally backfed voltage into the generator from the panel. There was a hum and a pop and now it will not generate power. What is the likely culprit and where should I start?
 

·
Registered
Joined
·
137 Posts

·
Registered
Joined
·
269 Posts
It seems worth mentioning. If your setup allowed for back-feeding the generator by mistake, then it likely also allowed for back-feeding the grid by mistake, from the generator.

In this case, fortunately only the generator was damaged. Don't get me wrong, that's still a bummer. But back-feeding the grid could kill someone who is working on the "dead" lines.

Once you get the generator sorted out, please consider taking steps to make sure this can't happen again, for everyone's safety. Relying on instructions, etc, is still subject to human error, especially during a dark, stressful outage/storm.

You can add an interlock switch to your main electrical panel. Or add a sub-panel for the generator, which has a switch so that panel can only be connected to the generator, or the grid, but not both at the same time.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #6
It seems worth mentioning. If your setup allowed for back-feeding the generator by mistake, then it likely also allowed for back-feeding the grid by mistake, from the generator.

In this case, fortunately only the generator was damaged. Don't get me wrong, that's still a bummer. But back-feeding the grid could kill someone who is working on the "dead" lines.

Once you get the generator sorted out, please consider taking steps to make sure this can't happen again, for everyone's safety. Relying on instructions, etc, is still subject to human error, especially during a dark, stressful outage/storm.

You can add an interlock switch to your main electrical panel. Or add a sub-panel for the generator, which has a switch so that panel can only be connected to the generator, or the grid, but not both at the same time.
I do know to have the main off while powering my house through my panel when power was restored I turned on the main before I turned off the breaker that my generator was feeding my panel through So no chance of killing someone only my generator
 

·
Premium Member
Joined
·
220 Posts

·
Registered
Joined
·
269 Posts
Respectfully, if the setup physically allows for the main breaker (to the street) to be on, at the same time that the generator-fed breaker is on, then you definitely could back-feed to the street, and potentially kill someone.

The fact that this time the electricity was flowing from the street to the generator doesn't really change anything. If the street power had still been out, then that same scenario (of how breakers were set) would have resulted in the generator sending power out to the street and the damaged wires.

Unless I'm misunderstanding the explanation. But it sounds as though the only thing protecting against a dangerous situation (back feeding to the street) is remembering to flip switches in the correct sequence. And the damaged generator is evidence that we are only human, and sometimes we make mistakes.

Something that physically prevents both breakers from being on at the same time, like an interlock switch, is much safer. And cheaper in the long run, even if the "only" thing is does is avoid generator damage. Never mind something like injuries.
 
1 - 8 of 8 Posts
Top