HB (Customer) asked a question.
Using 3 safety sensors with Safety Relay or Controller
I have the following 3 sensors that I would like to shut down the power to my machine when any of them is triggered:
- Emergency Stop button (NC contact)
- Leak sensor (3 wire PNP)
- Magnetic door interlock (Keyence GSM51P, wiring diagram attached)
I am new to safety relays/controllers and trying to figure out which product I need to get, either a safety relay or safety controller that can take inputs from all these 3 safety devices, then if any of the 3 is triggered, shut down a high-current relay between the power supply and the machine.
Do I need a programmable safety controller like MOSAIC, or a DOLD safety relay? Which one of these would work for my application?
Thank you
It is typical for a safety circuit have all safety type devices wired in series between the inputs of a safety relay. Since the devices you wish to use are disparate, the Mosaic programmable is likely the better choice. One word of caution is your leak sensor; is it fail safe? In other words, can you guarantee if it fails, it will into an "off" condition? This is question that you'll have to investigate as all the safety circuits I've done are with devices specifically designed for safety: E-stops and those available in the safety section of the Automation Direct website.
Like Todd mentioned, it's unlikely the leak sense is safety rated device and cannot be used as such. What happens if there is a leak?
You could still use the output of the leak sensor with a safety controller but it would not be able to be rated to any real safety operation level.