In my zone power is failing frequently and I had been solving the issue with an inverter generator and a manual transfer switch.
However, I don’t have a means to know when power comes back.
My plan is simple: energize a WeMos D1 Mini from the line that will always have power (regardless of the position of the transfer switch) and energize the 2 relays, one from the mains and another from the power generator. Then connect a DC line output from the WeMos, in series across both relays snd returning to the WeMos. It there’s continuity, then it means that both relays are energized.
I can program this WeMos with ESPHome as a sensor to tell me that I need to turn off the power generator.
My question to this group is, what are the cheapest, lowest consumption relays or equivalent devices that I should be using for this? I found this:
Tnisesm 2PCS Power Relay SPST(1 NO) AC120V Coil, 30A SPST 120 VAC with Flange Mounting and 8 Quick Connect Terminals Wires Mini Relay HF105F-4-AC120V-8X https://www.amazon.com/dp/B087G3FWVT/ref=cm_sw_r_apan_glt_i_511WK5JF8ER9Z1FYK8NZ?_encoding=UTF8&psc=1
But it doesn’t mention how much power does the coil consume.
This other one specifies, but doesn’t include the cables:
American Zettler Power Relay, SPDT, 30A, 115v, Mini, 30A SPDT 120VAC AZ2280-1C-120A( Pack of 2) https://www.amazon.com/dp/B07587NZTC/ref=cm_sw_r_apan_glt_i_EDY24QGQEYA1NDRB1M1F?_encoding=UTF8&psc=1
I already have the WeMos laying around, but another question is do you have a simpler way to solve this problem?