I am.having 220v brush less motor based exhaust fan.i wish to monitor it's failure and want it failure signal to be transmitted to controller with digital input which sense NO/NC output and raise a alarm.
What automation is required to be connected to exhaust fan?
You really need to define "failure" before you can engineer something to monitor it. Is failure overheating? Is failure running backwards? Is failure running with no power applied? Is failure running too slow or too fast? Is failure not running when power is applied?
Paul
A microswitch attached to a vane in the fan exhaust might be a good way to detect any
sort of failure, if the air isn't flowing the switch switches, whether the motor is working or not,
and presumably that's all you really care about.
I like the vane and microswitch idea. Brilliant.
Current sensor on one or more the motor phase wires.
Current sensor on the motor controller.
Light source / sensor on either side of the fan. If it stops flickering the fan has stopped.
Magnetic sensor on the motor either detecting ferrous metal rotating or sensing the magnetic field in the motor.