Any issues having grid-tied microinverter (APSmart) with an existing Generlink?

[JonahJimson]

Hi All,

Helping my neighbour with planning his solar project. He has one of those Generlink meter socket things for whole house backup power, will there be any issues installing a grid tied APSmart DS3-L microinverter system connected at the main panel through a PV breaker?



From what I gather, the main concern is the solar backfeeding into the generator and blowing it up, but that doesn't seem to be an issue since the generator is not able to produce power in a stable or within the right frequency range long enough that the solar would recognize it as Grid, so no reason it would start up and backfeed anything.

But what about the generator power flowing to the solar system through the PV breaker? I know that once Grid cuts out, APSmart will go into anti-island mode but it doesn't sound like it'll actually trip the PV breaker or the AC Disconnect, so since there's no physical isolation, is there a risk of the system being damaged from generator power? If so, can the PV breaker or AC Disconnect be configured to automatically disconnect through the use of CT's or any other solution?

I've read somewhere APSmart won't honour the warranty if they find out you have whole house generators, don't want my neighbor to end up getting shafted if anything happens.

Thanks in advance.

 

[timselectric]

From what I gather, the main concern is the solar backfeeding into the generator and blowing it up,

Correct

but that doesn't seem to be an issue since the generator is not able to produce power in a stable or within the right frequency range long enough that the solar would recognize it as Grid

It must be a pretty crappie generator.

so no reason it would start up and backfeed anything.

That's an expensive gamble.

But what about the generator power flowing to the solar system through the PV breaker?

Not an issue as this is its normal design.

I've read somewhere APSmart won't honour the warranty if they find out you have whole house generators, don't want my neighbor to end up getting shafted if anything happens.

Makes sense that they would want to protect the warranty.

I would add a relay or contactor, to make sure that the micro inverters were disconnected whenever the generator was running.

 

[JonahJimson]

Correct

It must be a pretty crappie generator.

That's an expensive gamble.

Not an issue as this is its normal design.

Makes sense that they would want to protect the warranty.

I would add a relay or contactor, to make sure that the micro inverters were disconnected whenever the generator was running.

Thanks for the reply Tim. Sounds like a solution would definitely be needed as you say it's an expensive gamble. About the relay/contactor, can you expand on that? How would we go about doing this? Through the use of CTs at the GenerLink inlet, and then the relya/contactor wired in series with the PV breaker? This would also mean the generator would always have to plugged to the GenerLink for the CTs to be hooked on the power cord?

 

[timselectric]

I would keep it simple.
Whatever triggers the generator to start, can probably be used to control the relay or contactor.

 

[JonahJimson]

Well that's the thing, I don't think the utility sensors or relays on the GenerLink can be modified to control the PV breaker relay/contactor. Is there any other way to achieve this?

 

[timselectric]

The coil of the relay can be powered from the generator feeder.
Whenever the generator is running (producing power), the relay would open the circuit for the micro inverters.