Apex temerature and MH programming

[Bluefool]

OK...so I had a DC8 die, and while its in process of going back to Neptune, I'm trying to keep my tank going missing 8 controllable outlets *fume*.

Right now, one of my major problems is that my temperature is going to high, and my Metal Halides are turning off. No big deal, thats what they should do...

But the turn on again after 20 min, and then off again maybe 10 min later. So...I basically have a slow strobe light over my tank.

What I want is a way to alter the MH outlet statement so that it waits until temperature falls below a set point, then turns on.....and I can't figure out how to do this.

Here is the programming I have now:

Heater temp:

If Temp < RT+-0.3 Then ON
If Temp > RT+0.1 Then OFF
Defer 010:00 Then ON

MH:

Fallback OFF
Set OFF
If Sun 060/-060 Then ON
If Temp > RT+0.9 Then OFF
Min Time 020:00 Then OFF

It *seems* to me a defer command would work, but I can't figure out the difference between defer and min time....any help?

 

[aquamanic]

Defer keeps the outlet from changing state now.
Min Time lets the outlet change state now but prevents it from changing again for x time.

Personally I wouldn't use the Defer in your heater program but that's your choice. I'd rather the heater cycle on immediately.

You've got the Min Time backwards - it should be Then ON. That will prevent the lights from turning back on for 20 minutes which is what I think you want.

 

[Bluefool]

Ah, no. As clearly stated, I want them to tun off until a set temperature is reached, and then to stay on until it exceeds my set point.

 

[swearint]

Here is a way using the Time command, not sure if it is possible with the Sun command:

[MH]
Fallback OFF
If Temp < x Then ON
If Temp > RT+0.9 Then OFF
If Time 18:00 to 8:00 Then OFF

This will only turn on the lights when the temp is below x. If it exceeds (RT+.9) then it will shut off. If the time is between (sunset) and (sunrise) then the lights will be off.

I agree with Alan, in your heater outlet a Defer of 10 minutes seems excessive. You just want to filter out spurious temperature fluctuations, 30 to 60 seconds should be sufficient. You can use a Defer...OFF as well as Defer...ON.

For Min Time, it helps to ignore the 'Then'. So Min Time 20:00 (Then) OFF keeps the outlet OFF for at least 20 minutes until another condition changes it to ON.

Todd