Just picked up an PM-5E... output question

I have an application that I may be able to use the PM-5e.

The only question I have, is on the PID control, can I use that to “pulse” on of the 0-10v AO’s?

I have a chiller that runs the compressor at 100% bypass when the system is on, and uses PID control to pulse a LL solenoid valve. Their issue is the output for the LL solenoid is constantly failing.

I wanted to use the 0-10v AO to pulse 10V to a solid state relay to operate the LL solenoid. This will stop the wearing out of the output from rapid switching.

So, if I have a 20second cycle time, and the valve needs to be 100%, it would apply 10V for the 20seconds, or until the PID reduces the percentage.

If I need 20%, it would apply the output for 4 seconds, then wait the rest of the 20seconds out to do it again.

I think I have the programming about right, going to play with it on the T3b I have, but just interested if anyone had any suggestions on the PID section.

The scenario you mention isn’t quite covered in the normal configuration settings but a new & improved PM5 is very close, it should be sampling in a month. It will be fully programmable like the other controllers here and a PWM with low duty cycle like that is no trouble. I’ll suggest a solid state relay to do the switching. You could do a trial install with the Tstat10, its basically the same thing but wall mount.

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