Once in a while a power blip hits my house. Sometimes it only affects one side of the split phase - I can tell because the stove clock goes to 00:00. But it also affects a couple of sensors. The ISY doesn't stop or reboot.

I would like be able to detect it using some kind of Insteon device and the ISY.

 

Does anyone know a way to do this?

The 'easiest' way would be two iolincs with a relay connected to the input where the relay coil is 115vac driven by the 'other' leg. So when one leg blips the other leg would see it on the iolinc and generate a signal.

If you have insteon devices on each leg, try making a program that sends a notification on then and else with responding on the if. Assuming that power goes out long enough for the device to know it, like your clocks do, then the isy may be able to notify. Otherwise the dual io link may be the way to go.