Any alternative for limit switch?

Hi Sami,

Hall sensors are often used to sense position of mechanical parts. They can be used as limit sensors as well as rotational position detectors and counters. They are very fast, accurate, and do not have the inherent wear problems of mechanical switches.

https://en.wikipedia.org/wiki/Hall_effect_sensor

John

You could use flow control monitoring sensors or even a simple pressure sensor to detect when the blower is running.

DAB

Can you post a picture of the issue? The geometry may dictate what is a good solution.

Depending on the environment the sensor would be operating in, optical encoders are also a good choice… but given the “soot blower” component, and without being able to see exactly where the sensor would be placed with regard to dirt… I’d definitely agree with jw0752 on the Hall effect sensor route, because they can continue to function (within reason) even when dirty.

You can use an optical sensor with a LED transmitter and a photodiode or phototransistor detector.

I agree with DAB 100% use a sensor to detect presser is a no brainer. 

~~Cris

Is the blower motor controlled by a contactor or a VFD ? The VFD may have enough bells and whistles to flag a motor rotation. 

A Hall effect sensor - magnetic previously mentioned is a good one. It could be applied on the mechanical door vane itself or on the rotating gear.

An encoder on the rotating gear could also be used. 

If there is a photo as mentioned, sometimes a whole new approach improves performance an reliability.