How do I find out the power is out at the barn?

Why ordinary sensors miss outages

A Wi-Fi sensor needs the router, and the router needs power. When the power goes out the sensor simply stops reporting, and most apps do not treat silence as an alarm. You find out when you walk in.

What an outage alarm needs

• A battery, so it is still running after the lights go out.
• Its own cellular connection, so it does not depend on the router.
• A power-sensing input on the utility supply, so it knows the power has failed.
• A "stopped reporting" alert from the service, in case the panel itself goes down.

One phase out is worse than all three

On three-phase service, losing a single phase leaves the lights on in half the barn while motors overheat. Ask for phase monitoring if you have three-phase equipment.

The alert when power comes back

The second alert matters as much as the first. It tells you whether the outage was two minutes or two hours, and whether you need to go and check that everything restarted.

If you have a generator

An automatic generator that fails to start is found the same way a dead compressor is: too late. A status input shows whether the generator is running, and for how long.