Fighting with the power company over IEEE standards

wirenutwirenut Registered Users Posts: 22 ✭✭
I'm trying to help a customer get his formerly off grid system onto the grid as a net metered system. His inverter is a Xantrex SW unit that was installed 10 or more years ago. It meets UL 1741 and it meets IEEE 929. However, since it was manufactured before IEEE 1547, it obviously isn't listed as meeting IEEE 1547.
The power company engineer is saying that because it doesn't meet 1547 they won't let it be grid tied. He readily admits that they have plenty of older inverters currently grid tied to their system that don't meet 1547. They just won't allow any new connections since the new standard came out.
I'm by no means knowledgeable about the internals of these standards. From the tiny bit of research I did it seems that 929 was simply about PV interconnection and 1547 encompasses PV, wind, hydro, etc. Can someone point me to some document that addresses whether or not an IEEE 929 compliant inverter is also IEEE 1547 compliant? Has anyone run into this before?

Thanks for any help you can give.


  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    Re: Fighting with the power company over IEEE standards

    I don't know the details--But some of the older SW inverters would actually back-feed AC power to the grid if the battery was at a high voltage (i.e., being charged from the solar array and not much local usage). I believe there was a GT "kit" that was made to try and make them "GT Legal" at the time.

    I think this was the GT Interface required for use (at the time).

    From the little I know--I probably would agree with the company engineer and require you to install a new Hybrid (or pure GT) inverter that meets the present requirements.

    Also, most electronics are approaching end of life/available parts after 10+ years. I would not suggest spending a lot of time and money on trying to make this older unit compliant.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Sign In or Register to comment.