Our entire home is run like a UPS. Power is always on as long as we have battery power. The batteries are recharged via solar panels and the grid. I need a device that can be connected to the grid and will send a signal to eisy when power is on or off. This would allow, eisy to switch our home to a more conservative power level should the grid be out (such as turning off non-essential devices). I could use a relay tied to an Insteon door sensor. But that would mean that the relay would be on all the time the grid is on - which is most of the time: the relay would most likely burn out over time. And this seems like a waste of power. Looking for a more eloquent solution. Maybe a Hall Effect Sensor in the transfer switch box. Has anyone done something like this? Or does anyone have any thoughts on a better solution? Thank you

I have a ZOOZ Range Extender https://www.thesmartesthouse.com/collections/zooz/products/zooz-800-series-z-wave-plus-range-extender-zac38 that reports power loss. It connects via z-wave and has a battery backup.

Maybe something like that connected to the grid side of your power?

A relay coil draws mere milliamps and will not overheat or deteriorate because it's on for long periods. I wouldn't worry about that.

Use a 120VAC solid state relay, not an electromagnetic one. The only downside is the output contacts don’t behave like the dry contacts on a electromagnetic relay in that they don’t pull down to 0 ohms.