Home Backup Generator - Reporting?

I don't think I have seen this topic so . . .

We have a generator (Generac) that runs off natural gas. I would like to get a notification when it's running. It basically runs under two scenarios: (1) commercial power fails, the power transfer switch signals it to start and, once up to speed, switches the house load over to the generator; (2) once a week it runs a self-test/exercise for about 15 minutes. When it is doing the self-test/exercise it does not involve the transfer switch.

I am reluctant to hack into the wiring of this thing so I would like to see if I could determine that it is running by monitoring vibration or noise. I doubt I will have much luck with a sensor inside the housing as it is aluminum and I would think it would be difficult to get a signal out. It's located fairly close to the house so it is likely within range of z-wave or zigbee. It should be feasible to attach a weatherproof plastic box to the housing.

I've been looking and haven't seen sensors specifically for vibration or sound.

Generac apparently has an app and a wireless interface. The Generac community has pretty much panned it as trash. And it is fairly expensive. And it requires a subscription.

Any ideas? Alternative suggestions?

Smartthings Multipurpose sensor should work for this. I use one on my dryer to detect vibration.

I know they detect movement, I use one on a door that way, I didn't realize they were sensitive enough to detect vibration. I have one on the way for my dishwasher project so I should be able to test with that one.

The sleek multipurpose sensor detects open/close, vibration, orientation, and temperature allowing you to monitor several areas of your home.

They do a great job at detecting vibration. Sometimes a little to sensitive. At one point I was using one to detect my doorbell being rung by placing it above the bell. My dog barking and walking down the stairs gave me false alerts.

With the dryer I avoid the false alerts by incorporating a check that the vibration has been active for a minimum of x minutes.

That sounds like it should work. I will give it a try. Thanks!

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Any chance you could just measure the current coming out of it using a clamp to see when it's running?

I don't think I have a place I could do that until the transfer switch kicks in and that only happens when it actually transfers the load over. I am as interested (maybe more) in whether the self-test/exercise runs.

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The Raspberry PI based Genmon works excellent. GitHub - jgyates/genmon: Generac Generator Monitoring using a Raspberry Pi and WiFi

There was someone selling it on ebay, but it was easy enough to build and install. It has more features than the Generac monitor. The developer is very responsive to requests, and to bugfixes.

The only minor downside is it doesn't directly integrate with smart hubs, but there is a MQTT option in the software if you know how to utilize that.

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I had not seen that project. That is awesome! And I have some extra Pi laying around (no thanksgiving joke intended). Thank you very much!

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Use a low voltage current relay.
when it see's current a contact will close ! what you will get is a (open or closed circuit )

Put a temperature sensor near the exhaust. Maybe a qubino.

It looks like he's already created a module to send messages via Pushover - that would have been my choice anyway. This looks really good. Major thanks to you!

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Perhaps you could use a door/window sensor to detect when the generator is running. The detectors generally have a reed switch which is sensitive to magnetic fields. I suspect you have a transfer switch inside your genset housing or near your electric panel. The transfer switch is a mechanical relay operated by power from the generator. If you place the D/W sensor near the coil of the transfer switch it should pull in the reed switch and send a signal to your Hubitat. The transfer switch should only energize during actual power loss. Food for thought.

Yes, something like that would work, but I would also like to know when the exercise/self-test is running and there is no power transfer when that is running. I am going to experiment with a door/window sensor to see what I can see.

I've got GenMon all working. It's a very nicely documented project. I just started my generator from the web interface and I have all the log data - very helpful. Now I may play around with mqtt . . .

Thanks again for the lead on this.


I am a MQTT dummy, so if you discover anything useful, it would be cool if you post your findings here. I would love to use generator status to turn off things like the televisions, or appliances that are not mission critical.

Glad you liked Genmon, I have been using it for probably close to a year and it has been pretty flawless.

I am too! I grabbed a spare pi and loaded mosquitto on it - so that's my MQTT Server. I enabled the MQTT on GenMon and have the generator pointing to the MQTT Server. I put a piece of client SW on a windows machine called MQTT Explorer. I can now see the generator topic and the items the generator is "publishing". Now I just have to figure out how to suck that into Hubitat (without crashing it).

I am not sure, but couldn't you use the same PI for the MQTT and Genmon? It is not like PI are expensive, but it is nice to only have to maintain one device than multiple ones.

I think you could. It's not much of a load. I had one sitting in the corner so . . .

So could you put this on your generator, if it kicks on this would send a notification?

Download the Hubitat app