mattrennert

Recipes 

Its that time of year here in Wisconsin where it was 80deg Sunday and going to be 30deg this weekend. I have a cheap temperature controller that I use for the keezer and it works well, so i bought another one for my fermentation chamber. Since there are huge temperature fluctuations it would be nice to not manually switch between heat and cooling modes. I believe there is a way to run both cooling and heating off it using one output for cooling and an alarm function to run a heat source, but i ran into a wall and could use some help figuring out the settings within the controller.

Here is the manual:
http://www.temperaturecontrolwiki.com/classifieds/pictures/80805437-XMT7100-Temperature-Temp-Controller-SSR-Output-Drive-Arizona-Phoenix_3.pdf

Quick sketch of my plan:


Thanks for any help...

audger

Recipes 

"SSR out" only outputs an 8v, 40mA signal as a means to trigger a SSR. its not possible to do what is in your drawing. I have that same PID controller- the software does not support both heating and cooling.

kc9bvl

Recipes 

Actually i think you may be able to do both heating and cooling. You need to operate in mode "2: Relay J1 as alarm output; SSR PID controlled 12 Volt output. Know as No Contact controlled". Where the SSR would be pid controlled and drive your heating element, and then when your process value became to high the alarm output would trigger a cooling element. There are parmeters that would have to be adjusted. Also you are going to need a SSR for your pid output, and more than likely and interpolating relay for the alarm output (it is only good for 3 amps). If you need more assistance with parameter specifics i would be glad to assist you.

mattrennert

Recipes 

Yea, there would be a SSR in there, I just forgot to draw it... Could using the alarm work both ways? Cooling then alarm triggers heater? Or only heating and alarm triggers cooling? I think over the summer I would be cooling more often.

kc9bvl

Recipes 

I would think that would work just fine. Just manipulation of parameters to get the alarm to trigger on the low side instead of the high side.