delay timer statement

[sidewinder770]

I've been trying to figure out the best way to add a second chiller to my program. what I am wanting to do is have the first chiller (ch1) turn on at 80.3 degrees and off @ 79.6. Chiller 2 (ch2) to also come on at 80.3 degrees and off at 79.9. That part is easy to do but what I am also wanting is for chiller 2 to come on slightly after chiller 1 so they are not both starting up at the same time- anywhere from 15 seconds to 2 minutes delay would be fine just so long as they don't both start at once. I know I can put a delay start relay in the circuit after the x10 outlet but I would rather not have a 'hardware' solution.

If Temp > 80.2 Then CH1 ON
If Temp < 79.6 Then CH1 OFF

If Temp > 80.2 Then CH2 ON
If Temp < 79.9 Then CH2 OFF

Any ideas?

When the add on module comes out I imagine I will be able to specify a temp probe to accomplish this correct? Something like this-

If Temp1 > 80.2 Then CH1 ON
If Temp1 < 79.6 Then CH1 OFF

If Temp2 > 80.2 Then CH2 ON
If Temp2 < 79.9 Then CH2 OFF

This is on a III PRO if that matters.

 

[clp]

I can't think of a way to do this other than to stagger the on/off temperatures. The commands will be staggered by about 1 second as they are sent out serially.
The expansion box probes are referenced by the expansion box letter. The first box is 'A', the second is 'B', etc. So the commands become:

If Temp > 80.2 Then CH1 ON // temp probe in base unit
If Temp < 79.6 Then CH1 OFF

If TempA > 80.2 Then CH2 ON // temp probe in first exp box
If TempA < 79.9 Then CH2 OFF

Curt

 

[sidewinder770]

Actually that would work perfect. Now all I need is an expansion box . Just one more reason to add me to the list of buyers when they are available- the second pH probe will be nice too! Thanks Curt!

 

[laverda]

Why do you want to chillers coming on at the same temp? I could see having the second one come on at say 80.4. I would think you will have both your chillers cylcing on and off often with your set up. My tank temp will change more then .3 degrees in less then 5 min with just fans switching on.

 

[sidewinder770]

Well, I keep my house temp at 81 during the day since I'm not at home and I have a closed canopy as well (with 1000w of MH). Add to that having all my equipment (sump, skimmer, frag tank, fuge,etc) in the garage which gets about 125+ degrees during the day. I have a DIY 1 ton chiller that is able to keep up but I have a second for backup. Instead of have the one chiller work for 1.5 - 2 hours to cool everything down I think it would be better for both chillers to be on at first and keep their running time down to 30-45 minutes instead. Once the temps cool down again (Septemeber) I am going to go back to one on at 80.3 and the second on at 80.4 as a backup but for the summer I think it would be better to have them both running.