Grid Tie System with Standby Generator

[GlennT]

Solaredge Grid Tie Inverter and Generac Standby Generator

Real simple, if you loose commercial power, the solar PV turns off, the automatic transfer switch (ATS) operates to isolate you from the grid as designed and to electrical codes, and the generator picks up the load in the house.

The PV system will not reconnect until commercial power has been restored for about 5 minute without interruption. Once commercial power is restored, the generator turns off, the ATS re-connects you back to commercial power, and then the PV system will turn on when all is clear

This is an old message I found while researching my situation, and I wanted to see if you still maintain it works this way. I've found conflicting information on how this may play out. How does the PV inverter differentiate between grid power and generator power? I've been told that my Generac power is "grid quality".

Thanks.

[russ]

of course.

One time I sat on a podium where the company was promoting a stock offering - I was told, "Don't say anything, we will answer for you". I was only there to show the foreign participation in the project meaning it was OK.

[inetdog]

TThen the other 1000 are promptly ignored and the agreeable fool given a promotion.

And asked to provide testimonials to potential investors, of course.

[russ]

I guess if you ask the same question 100 times someone will give you the answer you are looking for.

This is a standard technique in his country - keep asking until you finally fund someone who says what you want. Then the other 1000 are promptly ignored and the agreeable fool given a promotion.

[SunEagle]

He is history already.

I guess if you ask the same question 100 times someone will give you the answer you are looking for. He always believed that the Solar GTI would see the Generator as "the grid" and keep on working along side the DG thus giving him enough power to run all his loads.

The anti-islanding safeties on a GTI seems to be outside the grasp of a lot of people not familiar with this technology no matter how many times you try to explain it to them.

[russ]

You just lost all credibility with that statement.

He is history already.

[Sunking]

Hi Technoyogi

While my knowledge is very limited in solar, but I strongly feel that you should use a battery system than a Grid Tie.

You just lost all credibility with that statement.

[jainsushant]

Hi Technoyogi

While my knowledge is very limited in solar, but I strongly feel that you should use a battery system than a Grid Tie. As you mentioned that the grid supply is very erratic, it will mean that your GTI will not be doing any work most of the time. And if you are from India (Like me), the main power cuts are normally during the peak afternoons only which means production may be near zero only. A battery system will be more expensive, but still will be worth it.

Regards

Sushant

[jainsushant]

Hi

Though I am asking this question in another thread also, but I wish to know if I am certain that my consumption will be much more than what my PV panels can generate and there will be then no chance of PV current reaching generators, then will it not be better for me to connect the GTI on the common output of Mains and DG? i.e. when Mains fail, the GTI will consider DG output as grid and keep producing electricity and save me fuel?

Regards

Sushant

[inetdog]

How do You isolate the solar panel's breaker from the Backup Generator? If the solar starts producing power ,won't it will feed into the generator and short something out?? In other words , wouldn't I have to turn the Breaker off that feeds the solar panel inverter to prevent accidental back feed??

If you have an automatic or manual transfer switch between the POCO service connection and your building main panel, and you feed your generator into the other input of the transfer switch, then if you legally connect your grid tie inverter output to the POCO side of the transfer switch there is no way that it can end up connected to the generator.

If instead of a transfer switch you use an interlock between the main breaker and the generator breaker, the again you connect the PV on the POCO side of the main breaker (with its own service rated disconnect). Then when you open the main breaker before closing the generator breaker you cannot end up with the PV connected to the generator.

If, on the other hand, you feed the PV into the main panel through a load side breaker, just as the generator is fed in, you need to come up with a mechanical interlock that requires BOTH the main and PV breakers to be open before you can close the generator breaker.

Piece of cake until you try to get it inspected and approved.

[ahec2222]

How do You isolate the solar panel's breaker from the Backup Generator?

How do You isolate the solar panel's breaker from the Backup Generator? If the solar starts producing power ,won't it will feed into the generator and short something out?? In other words , wouldn't I have to turn the Breaker off that feeds the solar panel inverter to prevent accidental back feed??

[stumpy40]

Gotcha....so if I installed the solar subpanel line side tap...could I still make it work?

[Sunking]

Sunking, I have same exact situation. I have a gen that I want to use to power entire house during storms. I have installed a GT 16kw system. How would the ATS be located?

The only place it is allowed to go, immediately after the meter disconnect.

[stumpy40]

Sunking, I have same exact situation. I have a gen that I want to use to power entire house during storms. I have installed a GT 16kw system. How would the ATS be located? I have a 400A main with 2 200A subs in the house. The solar subpanel is a 125A and is line side tapped. Would this method of install pose any problems?

[Mike90250]

That is a whole different type of inverter, a hybrid off-grid/Grid tie. Sunny Boy makes one ( sunny island), and Xantrex makes a line (the XW series)