Settings for temp controller

[trustyrusty]

Hi I have got my temp controller and doing some tests, after the temp hit 19 and switched off still dropped to 17.2. I this is raw, as I am going to put probe against liquid and maybe bubble wrap to insulate, so I don't see temp changing that much. The question is what settings do you use? Essentially what variances do you set and found that work the best. I would imagine if liquid reaches temp. it should take a while for it to move in a fridge?

I have 0.5 degree for high and low and 3 minutes for compressor time gap , pt I think it is. I think if 1 degree that is quite a big gap as it might get 1.5 change before it started to come back? Thanks

 

[koshari]

Hi I have got my temp controller and doing some tests, after the temp hit 19 and switched off still dropped to 17.2. I this is raw, as I am going to put probe against liquid and maybe bubble wrap to insulate, so I don't see temp changing that much. The question is what settings do you use? Essentially what variances do you set and found that work the best. I would imagine if liquid reaches temp. it should take a while for it to move in a fridge?

I have 0.5 degree for high and low and 3 minutes for compressor time gap , pt I think it is. I think if 1 degree that is quite a big gap as it might get 1.5 change before it started to come back? Thanks

there are a plethora of factors that can effect this so your going to have to post a lot more details of your setup,

where is your temp probe located now?
is the probe it subjected to airflow variance?
what sort of controller is it?
does your controller have a relay or SSR output?

cooling and heating liquids is a VERY long control loop time and increases with bigger liquid batches.
the power output of your heater makes a large difference as well,

is your heater an immersion type or are you heating the airspace around your vessel?
was the controller 19deg and falling or 19deg and rising?

3 mins is a pretty acceptable compressor protection delay time. having a compressor delay suggests something like a stc1000 controllers that dont use PID control algorithm so the control band is not terribly precise, pretty much just proportional control.

 

[trustyrusty]

Ha ha, this is what happens when a noob asks a question!

Probe will be insulated against wall of FV with bubble wrap so to measure temp of liquid as close to as possible, ie insultated as much as possible from airspace temp.
Will heat airspace around FV - 23 litre Stainless Steel
Is an inkbird ITC - 308

I guess if I have 0.5 degree Hi - Lo - do I need compressor delay (This is what I am trying to understand - because I think for liquid to change 0.5 degree will take a long time - say 1/2 hour? I don't know, but if compressor going on and off a lot will stuff it)

I guess I am asking in general if people set 1 degree or 0.5 degree in Hi - low temp, and if they use compressor delay.. etc etc


Thanks

 

[trustyrusty]

I have had this working for 3 days now,

18 degree
0.5 HI / LO
2 minute PT

Every time I go to check the fridge is not on, and around 18 mark, is coming on now and again, but never seen it yet, so is not going on and off a lot at all. The fridge is in an insulated room to which helps..

Cheers