timer relay issues

John's picture

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Joined: Jan 20, 2021

Replies: 0
timer relay issues
January 20, 2021 - 4:07am

Hello! I've been tasked with adding a strobing alarm to our production area for Hi/Lo glycol temps in our plant. I've got everything planned out except one thing, the silencing function. 

The manufacturers of the pump station say the alarm will continue to go off until the temperatures have been corrected. I don't like that. I don't want production workers dealing with a screaming alarm for 10 minutes while we troubleshoot our chiller. I also don't want to just disconnect the alarm. I'd like to have the ability to press a silence button and the alarm goes away for....lets say 5 or 10 minutes, giving us time to hopefully correct the error by then. Then it can go back to normal alarm mode and hopefully not go off until the next error occurs. 

I plan to use a simple relay circuit. There's a single alarm signal pinout on the PLC, I have that connected up to the coil on a relay so the signal activates the coil, which switches on the alarm. I've never messed around with timer relays, so I am a bit confused as to how to incorporate one into this circuit and what kind I need. Time delay on? Time delay off? Or am I missing something completely? Apologies if this has been talked about a million times before. Just one more time for the new guy. 

Sourav Gupta's picture

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Joined: Feb 12, 2018

Replies: 632

You want to turn off or mute the sound for 10 minutes, but the delay relay turns on or energized the output contact for the set time. You can make this using time delay but you need to admission the reverse feture using wiring or additional circuitry.