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JLD612 AL2 Blinking

Posted: Sat Oct 18, 2014 2:11 pm
by donema
I am trying to configure my JLD612 for output mode 1. I want to use the J2 relay to control a 24V gas valve. After a few minutes of operation the AL2 light starts blinking and I believe it is opening and closing a relay. I will test which relay is operating with a meter, but can't find anywhere that talks about why it would be blinking.

thanks

Re: JLD612 AL2 Blinking

Posted: Sat Oct 25, 2014 8:00 am
by donema
OK, I've read a lot more on PID controllers and now understand that the "blinking" is actually the relay turning on and off as designed. I've seen several suggestions that a PID controller can be configured as an on-off controller but haven't been able to find specific parameters. I would like to use the JLD612 to turn on and off a gas controller -- if temp is below SU turn on, at SU turn off. 1 or 2 degree deadband would be good.

I will keep researching but any help would be appreciated.

Re: JLD612 AL2 Blinking

Posted: Sun Nov 02, 2014 2:50 pm
by richiem
Use Outy setting 4, with relay J2 as the controller. See fig 3 on page 4 of the manual I have. I assume you know that you need an external power supply hooked through relay J2 to operate the valve...

Re: JLD612 AL2 Blinking

Posted: Mon Nov 03, 2014 6:39 pm
by donema
Thank you very much for replying, now I think I understand. The key is differential vs. PID. Can't wait to try this tomorrow. Yes I understand I need and external power supply for the valve. I have a 24V transformer to power the valve. Again thank you for replying -- seems obvious now that I look back at manual.

Re: JLD612 AL2 Blinking

Posted: Tue Nov 04, 2014 7:28 pm
by donema
Richiem: thanks again, outy=4 is what I was looking for. I think I'm good but have a couple questions, not really important just trying to understand. Can you explain AL1 and AH1 specifically for heating mode with outy=4. If my SV=168, would AL1 be below 168, say 163; and AH1 be above 168, say 173. Alarm is lit if temp is below 164 or above 172?

Also curious about HY. There is a parameter for HY. I set for 2 assuming that makes the dead band 4 degrees, 2 above SV and 2 below. However the manual says HY = AH-AL

thanks

Re: JLD612 AL2 Blinking

Posted: Wed Nov 05, 2014 3:14 pm
by richiem
To the best of my knowledge, the manual is entirely correct about alarm functions; for heating, its straightforward, for cooling, a bit counter-intuitive. Correct also for the Hy instructions. Follow the manual and all should be well.

I call Outy=4 the thermostat mode -- it works exactly like you would think, except with the added advantage of being able to program the on-off hysteresis. The SSD or proportional control is not good for electromechanical relays -- really only for use with SSDs which can tolerate the constant openings and closings of short duration.