Unexpected Utility Voltage reading during test run?

[timg11]

Checklist

• I made sure that there are no existing issues or discussions - open issues,closed issues,open discussion, closed discussion - which may answer my question or that I could contribute my information to.
• I have read the Known Issues Wiki Page and my question / issue is not listed.
• I have provided the version of the software and the operating system in my post.
• If I have an issue with genmon not communicating with the controller, I have read and followed the serial troubleshooting guide.
• I have included the generator make and model in my submission.

Version

Genmon Version 2.0.2, Raspberry Pi 3b VERSION="12 (bookworm)" with pintsize.me hat.

Model Generac Air Cooled
Controller Evolution 2.0, Air Cooled

Have you submitted your log files from the About page? Note that outbound email must be working for logs to be submitted.

I have not submitted logs

What is/are your question(s)?

I have just installed genmon, and have screen captures from its first test run.
When the generator is idle, the numbers look as expected:
Line status 240V, Utility Voltage 240V, Output Voltage 0, Power output 0.

During a test run after installing genmon (while technician was running annual tests), I had unexpected values:
Line status 119V, Utility Voltage 119V, Output Voltage 240, Power output 5.2KW

Seeing the voltages of 119V are unexpected. Is this an issue with genmon, the generator hookup, or something else?
Or is it a side-effect of the generator test being run, using the transfer switch to have it drive the house for a load test, although there was not a mains outage?

The generator starts and runs every Thursday, but does not switch load. I'll have some new data then.

Additional information

[jgyates]

Hi @timg11
That does not sound normal to me. I would look at the dealer menu on your controller. This page describes how to access the dealer menu. Once in the dealer section look at the Dealer - > Display section. You can view the Utility voltage and the output voltage. Your output voltage looks good, but your utility voltage is half of what it should be which could mean that 120 leg sensors is not reporting. Genmon simply displays what it read over modbus but looking at the utility voltage reading in the dealer menu will give you what the controller thinks the value is internal to the controller.

In North America for residential utility voltage, there are two legs of power, both around 120 when combined makes the nominal 240V that should be reporting. It looks as if one leg is not reporting properly. The default threshold voltage (the voltage that below which is considered an outage by the controller) is 143V so unless your controller is trying to turn on the generator when in Auto mode, then at least part of the controller is reading the utility voltage correctly.

FYI, the line status tile just repeats the utility voltage so the only value that is not reading correctly is the utility voltage.

Another thing to try is to power cycle your controller: https://github.com/jgyates/genmon/wiki/Appendix-I-Power-Cycle-the-Evolution-or-Nexus-Controller

[timg11]

Is it possible that the technician disconnected one leg of the utility supply as part of the testing, and that's why it reads that way? I was inside watching genmon while he was doing the testing outside. He started the generator, performed a transfer switch cutover to the generator, ran under load for a few minutes, and transferred back to the utility supply without causing any detectable outage inside. I did the screen capture during the test run with load, and after.

[gm58]

@timg11
Sounds like that is exactly what happened. The tech pulled N1 or N2 fuse, instead of turning off the main breaker, to perform the test. Pulling the fuse kept you from seeing the outage.

[timg11]

Follow up - the generator just completed its first exercise run with genmon attached.

The engine ran at 1959rpm, 32 Hz output, 113V output during the exercising. Can others with a similar Generac configuration confirm that is the expected output during exercising?

Logged data from Genmon:

[jgyates]

I don't have an air cooled model, but that does appear a bit low. For exercising, if quite mode is enabled, the output is in the ballpark of 2/3 of the normal output. If quite mode is not enabled then it runs at full speed.

I would get a reading of just running in Manual mode (generator runs at full speed without the transfer switch connected) as a baseline.

[jgyates]

you should be able to see if quiet mode is enabled on the Maintenance page where it shows your exercise schedule.