My experience with Enphase Generator Integration

Last month I was assigned the commissioning of a Enphase generator integration, this was my first time so I had to do a bit of research. The first step was to visit Enphase University where I took the mandatory course called "Enphase Storage Generator Support". I didn't know this, but you must have this course passed before attempting the commissioning, or else you won't be able to (*as a side note, check before doing yours, soon Enphase will charge a flat fee for this feature).

In this course you will learn how to size, connect and program your gas generator into the Enphase ecosystem. I won't get too much into details but I'll give you a summary of what I did during this process:

First I made sure that the generator installed was one approved by Enphase, there is a list in the tech brief attached below . (LIST AS OF 08/11/2022, PLEASE CHECK FOR FURTHER REVISIONS)

In my case I had a Generac Eco-Gen 7163 that worked beautifully.

Next I made sure the generator nameplate power would not exceed the IQ System controller max. input. In the case of the IQ System controller V1, the maximum generator current is limited to 48A continuous (60A breaker). In the case of IQ System controller V2 the maximum generator current is 64A (or 80A breaker). In our case we had the version 1, so a 60A was installed. Notice that even if a larger generator is installed, the max. current pulled by the IQ Controller will be limited to 48A or 64A respectively.

It is important to mention that there is a minimum generator size, that in the case of Sunlight Backup mode with IQ8 is equal to 100% of the PV array rated AC power output.

In the case of IQ8 micros with IQ Batteries, the minimum generator nameplate rating must be the higher of the 2 following:

a) 100% of the PV array rated AC power output

b) 143% of the IQ battery array

In our case, we had an 33 IQ7+ with 23 kwh battery on site. for that we used the following table:

The minimum generator nameplate for a 23 kwh is 12.8 kW. We had a 15kW so we are OK here. This output rating will also be asked by the Enphase Toolkit App, this information will be used by the Gateway to limit how much it will pull from the generator.

The next step is ensuring that the generator output circuit was properly sized and connected to the correct terminals in the Enphase IQ System Controller. A new pair of CTs must be installed in this circuit and must be connected in parallel with the existing consumption CTs.

Now it comes the part where I spent over an hour trying to figure out since it is not as intuitive as it might seems. In order for the System Controller to operate the generator, a two-wire communication method is used. In simple terms, some generators have the option of turning ON or OFF based on the voltage between 2 wires, if the voltage is near infinity (open circuit) the generator will be OFF, if the voltage is near zero (short circuit) the generator will be ON. Other popular method is based on grid voltage, this was not applicable for our case.

The hard part to figure out is to find this 2 wires in the generator since they are not usually labeled and you are forced to go to the installation manual.

I would recommend visiting the Enphase Tech Brief that includes diagrams for the most popular brands of generators, and then if this 2 wires are not clear, review the generator manual for further information. Before moving forward just make sure that this 2 wires work properly, with the generator already commissioned and in "Automatic" mode, connect these 2 wires together, the generator should Start.

After connecting the 2-wire to the auxiliary contacts it is time for system commissioning. We added it using the ITK, it was a very simple process. I just added the generator information, set the exercise time, and most importantly, set your Smart profile. Basically telling it when to turn ON or OFF in case of an outage. I added it based on battery SoC, starting on battery at 15%, and ending when battery is at 70%

After all this steps, it is time to test it!. Main breaker OFF and let the magic happens:

Generator is taking ON the full load of the house and the rest is being used to charge the batteries. Just wonderful.

One thing I noticed is that the micro-inverters take a while to turn ON, some times it took 5 minutes, others 10 or even 15 min. Nevertheless once they are running, the whole energy flow is just amazing to see.

In conclusion, my initial experience with integrating this type of generator has been nothing short of impressive. The capabilities of this technology are truly astounding and I am excited to see how it will continue to be utilized by contractors in the field. Through this article, I have aimed to provide a comprehensive overview of my first encounter with this generator integration, and I hope that it has been informative and beneficial for you. If you have any further questions, please do not hesitate to reach out. Thank you for reading!