Generator use Durring a Power Outage, Will I smoke switches?

I just bought a Harbor Freight generator for my whole house it is the 8750W peak/7000W running one, $500, and I am worried that it will cause issues with all of my ST connected devices in my house. I have 15+ GE in wall Dimmers and switches and a couple of other devices and I am worried about when I back feed my Panel with the generator.

I was told that the HF Generators don’t produce a true sine wave and that they are the closest to a box wave you can get, which is bad for sensitive electronics, so I have been doing a ton of research and all of the power conditioners and surge protectors and UPS systems don’t modify the sine wave on the way in and honestly I haven’t found any good information on what to do.

My question is has anyone used a generator to power their whole house though their panel and have you had any issues with your in wall switches or other devices? I am looking for some help before I fry my entire system and end up with $2K in light switch paper weights.

I have had no issues ST r even electronics with mine running on generator for hours. In fact local ST still works great and when then net comes back up I don’t even know I’m on generator. I had to install a grid power alert so I know when power comes up. Running a 4500w portable using a transfer switch to run pretty much the whole house.

Personally I wouldn’t put this anywhere near my house…

The switching power supplies of your computers, TV’s, hubs, router, switches, printers etc. can either run or go for a crap with the massive HF input and leading edge power surge.
I would invest in and AC sine filter if you want to run your house off a 500.00 square wave generator. Too much invested in the connected items.


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Is it a Predator Generator?

They dont make AC sine wave filters large enough for a 120/220V 30 amp generator hookup connection. Is that oscilliscope reading directly from the generator I described above?

No, that trace is from a similar style Gen used in the same fashion. It is more for reference as to what these generators put out.

No just a generic one. Nothing special. But have run my satellite receivers, projector and everything else just fine.

I’m following this thread. I’ve installed a 22KW natural gas generator for my house, but haven’t even tested it yet. Never even thought about it impacting any of my HA stuff!

I have a cheap generater (amico mg7500e) and have used it for several years. Never fried a thing. Computer receivers switches hubs. I do have surge protectors at media devices but 3 days of use and switches didn’t seem to be bothered. Maybe just lucky. Must be cheaper then I thought. I can’t even find my gen when I Google it

Generac 8k here - installed 5 years ago and no issue - though only been on a few times and maybe once since my ST install.

Awesome. I’ve got a Generac Guardian. Random question, do you have the mobile link monitoring on yours? I’m thinking there has GOT to be some way to rig something up with SmartThings and avoid the $300 module and $10 a month fee. :smiley: Cheers!

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The best lead on info for interfacing w/ the generators has been here:
But it has been quiet since Nov 2016.

Came across this too but not much traction:

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No - was not available for mine.

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Thanks for the links! I just posted in the Garden Web discussion, so hopefully I’ll get something back. Cheers!

I found that you can purchase a whole home surge protector/ suppressor and install it in the transfer switch or on the main panel.

It says on their website that it does help with Smart home connected devices so I am going to purchase one and install it in the main panel and it should help with voltage spikes from the generator RPM’s ramping up and down.

Thank you everyone for the feedback I am really nervous doing my test but I figure I have home insurance and if it all goes “POOF” when I connect it then I’ll get all new stuff!

You should be good with a whole house natural gas generator. Is it portable or pad mounted? If it is pad mounted and only natural gas then it should produce a pretty clean sine wave without voltage spikes. The problem here only really applies to portable generators that are cheaply made.

I have a Generac GP5500 generator and I had the unfortunate pleasure of testing it out for 3 days this past week.I live in upstate New York and the Rochester area was hard his with a severe windstorm and over 150,000 customers lost power, including myself. I have about 90 physical devices on Smartthings. 20 Philips Hue light bulbs, 5 light strips, ~20 switches, 6 power meters, outlets, Garden spots,Blink cameras, etc. They all worked while the generator was running (not through Smartthings since there was no internet connection). and they all connected back when power was restored. The only casualties were a Surge protector and the circuit board of a whole house humidifier.


Just to follow up on this post and to close the loop I had my neighbor come over with his oscilloscope and the below is our result….

Standard House Power

Generator Power (Predator 8750/7000) Going through house pannel and tested from garage. I do have the Whole house Surge protector installed that is above and honestly there is no difference when testing it from the generator itself or from the garage with the surge suppressor installed.(more on this below)

Generator power with a table saw running (I know its a motor so it creates feedback but it is a worst case senerio for me and does provide a good source of load)

As you can see it is not a square wave like what was referenced above but it is also not pretty…

So what to do now so I feel safe using it with my smart home…

Buy a used 5kVa 120/240 Isolation Transformer from ebay!!! Mine is on order and will be here in the next 2 weeks and I will post the results from my test once it is all installed. My neighbor suggested an isolation transformer so we will see how it goes and if it cleans up the sign wave as intended.

All in for the predator gennerator ($500), Sub panel ($100), Isolation transformer ($250), and Misc items ($200) I am at $1050 for a whole house generator that provides clean power to the house durring outages. Comparable to the $3K quote I got just for the generator i am pretty sure I am on to a cheap way to provide clean generator power to my house durring an outage.

More to come once the Isolation Transformer is installed and I will post pictures of the setup as well.


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