Grid Tie Inverter and Generator

[SriramP]

Hi,

I own a shop and I had invested on 1KW Solar Grid tie and has been generating around 850Watts avg power every day. Now my current area power distribution company have proposed a 3 hour powercuts to commercial lines everyday. Since my shop consumes approx 5KW peak. I have planned to go for a Diesel Generator of 5KW. With this generator, Can I connect my Grid Tie inverter? Also, is it safe to connect the Grid tie inverter with Generator power line?

The grid tie inverter has Islanding option and stops power generation if the grid power is off.

[inetdog]

Hi,

I own a shop and I had invested on 1KW Solar Grid tie and has been generating around 850Watts avg power every day. Now my current area power distribution company have proposed a 3 hour powercuts to commercial lines everyday. Since my shop consumes approx 5KW peak. I have planned to go for a Diesel Generator of 5KW. With this generator, Can I connect my Grid Tie inverter? Also, is it safe to connect the Grid tie inverter with Generator power line?

The grid tie inverter has Islanding option and stops power generation if the grid power is off.

Depending on the frequency and voltage stability of the generator the GTI's anti-islanding test may or may not accept it in place of the grid.
But if it does, you still cannot use it that way if your load on the circuit would ever drop below the GTI output at that moment.
The GTI would try to feed its excess power into the generator, with potential very bad results. In the best case the generator frequency or voltage would go out of tolerance and and shut the GTI down. In the worst case it could damage the generator or its voltage regulator.

To avoid this problem, you should connect the GTI to the grid side of the transfer switch so that it will neither feed your loads nor backfeed the generator when the transfer switch is set to the generator position.

There are several other requirements for the installation of a manual or automatic transfer switch which will depend on the electrical code applicable to your location.

Also, if your peak demand is ~5kW a 5kW generator might not do the job. It depends on what the starting surge current will be for the largest motor in your shop and whether you will try to start that motor when all of the other loads are already turned on and consuming full power.

[SriramP]

Totally agree to your post. Thanks for this piece of advice.

Also, if your peak demand is ~5kW a 5kW generator might not do the job. It depends on what the starting surge current will be for the largest motor in your shop and whether you will try to start that motor when all of the other loads are already turned on and consuming full power.

Yes, my lighting and AC uses around 3.2KW Peak, and currently is expected to surge as soon as the generator is started and the manual switch turned on.

Thanks, Really appreciate it.

[Mike90250]

You may want to consider purchasing a new inverter and battery Charge Controller, since your GT solar will be shut off when the grid fails.

You could look at the XW6048 hybrid inverter, which has 2 internal 60A AC transfer switches, and a 6Kw output. It can couple with your 5Kw genset to sustain 11KW for some minutes (how long can your genset surge for)

It means nearly all new solar gear, but it will keep the power on during outages, seamlessly , and not having to start the generator for lighter loads.