I'm wanting to use an ambient temp sensor to control a relay connected to a pool pump. Ive been reading different posts about similar setups and wanted to see if this can be done by a rule.
If temp drops below 34 degrees...turn pool pump relay on
Once temp rises above 34 degrees again.. turn pool pump relay off.
Started thinking that this should be pretty simple but then started to see the posts about the different challenges.
Im trying to think of any other scenarios that would cause problems with this rule.
once below 32.....will the rule temp triggering..and if so - will that create a problem? Using a HSM 200 which reports temp every minute....i don't suspect that will create an undue amount o traffic on the network?
Any way to disable the rule if there is another activity going on?....as an example. Might want to use the hot tub in colder weather and in that case the pump relay will be turned on via a manual with on the relay or form the dashboard......can i pair the rule with a VS that is activated when the pump is turned on so the rule i inactive?
A RM rule could definitively work for this. Add a condition that if a certain Virtual Switch (VS) is on, the rule should not run. A Basic Rule would also work with the same.
You probably know to avoid excessive on/off cycling of that pump; so consider your temperature thresholds that allow for some hysteresis. Once my low temp threshold (28F) is reached I don't cease precautions until temps have risen back through 33F. Generally speaking this might mean some pre-dawn hours of protection or in a colder climate it could mean days (I suspect not where you live).
Why 28F? Well, based on An Investigation into Freezing and Bursting Water Pipes in Residential Construction | IDEALS I've learned that generally (as long as plumbing is not exposed to windchill) 32F is NOT the magic number to fear. Why not start at 32F? Well, the air temperature often hovers around there and doesn't dive further right away. That saves you some pump running.
Lastly, buried plumbing is generally well protected...so consider "just enough 100watt bulbs" in the space your pump plumbing is housed as an alternative to actually running the pump.
IF this is all about keeping a skim of ice off the pool itself then NEVERMIND all that I've said.
