[RE-wrenches] generator tripping GFCI

[Kent Osterberg]

Jay,

Agree with Ray that two neutral ground bonds can cause strange behavior. 
But the timing near the end of the charge cycle makes me wonder if the 
issue is related to one inverter shutting down the charger before the 
other. The VFX 3648 charger mode is a terrible load and will cause weird 
output wave forms on most generators, and when only one inverter is 
charging, the harmonics will show up on the neutral.

Kent Osterberg
Blue Mountain Solar


On 12/19/2020 2:33 PM, jay wrote:
> HI All,
>
> I have a client with a older Kohler 8-10kw generator, VFX 3648 stacked inverters, newer rolls batteries. its been installed and operating normally for 10+ years.
>
> Customer had to upgrade the house for code, which involved installing GFCI outlets and GFCI breakers.
>
> Since then the  GFI outlets trip every time the generator starts but only after 3-30 minutes.   They work normally on the inverters. And if you do a bypass/generator direct the GFI outlets don’t trip.
>
> The GFI breakers trip when the generator is about to turn off, not during warm down but say 30 minutes before it will turn off.  So charging current is at the lowest. And again they all work normally on the inverters and all the rest of the charge cycle.
>
>
> Voltage is a bit high, around 254v-259v from the generator but it is the whole time and seems to stable voltage. But if the voltage was the issue the outlets would keep tripping.  If it was too high for the breakers, why at the end and not the beginning?
>
> I’m thinking its possibly a control board in the generator that’s not working well.  Can’t keep up with the PF for the inverters, etc.
>
> Buts its a new issue I’ve not run across.
>
> Any ideas?
>
> thanks
>
> jay
>
> peltz power
>
>
>
>
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