I have a freezer in my garage which is all on one circuit.
on occasion a contractor or someone will plug a compressor or something in that will kill the power on that circuit.
is there. a smart plug that can notify me if it looses power? my Honeywell AC tells me if it looses connection to WiFi which usually means power is out at the house. I asked Chamberlain if MyQ could have the garage door opener could notify me if its on battery backup and they said that would be a new feature
Contact sensor that accepts external contacts such as the Ecolink Contact or Monoprice Contact and this:
https://www.amazon.com/gp/aw/d/B017743I7S/ref=ppx_yo_mob_b_inactive_ship_o0_img?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B01N5HB4U5/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1
I have a patent pending App that will notify you within 30 seconds when power is lost to the SmartPlug.
I am giving away one smart plug free with the purchase of the App called GFI Notify. Intended for GFI trips but it will send notifications to a cellphone when power is lost to the smart plug plugged into any outlet. Should be ready in less than 30 days.
not sure I get this … how would this tell me that power was out?
Battery powered contact sensor with external contacts is wired to normally open relay. The relay is activated by a 120VAC power source.
If the power goes out for that outlet, the relay is deenergized, causing the battery powered contact sensor to report an OPEN status, meaning the power is out.
(I just wrote a really long post on the assumption that your problem was the contractor unplugging the freezer in order to plug in their own equipment. But now re-reading @rontalley ‘s post, I realize that I was wrong on that. It sounds like you were talking about someone plugging something in to a different outlet on the same circuit and for some reason that is causing the circuit to trip. Is that it?
If so, Ron’s suggestion or some variations of that should work. )
Removed.
I had setup something a long time ago that used to work, but I just tested what was working for me and it no longer works. Probably a change with they’re firmware or app updates. To bad, now I’m back to the drawing board.
already posted
I should have been more descriptive but @ogiewon nailed the explanation. I added his quote for anyone else who may happen upon this thread.
I have two of these setups and they work great. I have a couple of UPS to keep the internet and other important devices on so when those occasions that the power goes out, ST can still send the message. Every-time it does, which is way more than it should, I get the notifications almost instantly. Solid no fuss device and the Ecolink sensors are super reliable.
I also use one of those relays to turn on/off my fireplace. So darn cool!
is there a more detailed instructions somewhere on this? My google-fu is failing me 
Lots of good information in this thread…