running solar controller on the same circuit/timer as a pump?

[Diver]

I recently got the Pentair SolarTouch for my in-progress solar build and after reading the manual I have few questions I hope knowledgeable folks on this forum can help me with.

My set up is very simple. I have a 2 speed pump with a manual hi/low switch. For the sake of this discussion it’s a single speed pump. It runs for 6 hours in the middle of the day and that’s the time when sun is available and when I want my solar to be on. I don’t have neither I need a booster pump, special cleaning needs or anything else.

I can hook up the controller to the same timer circuit as the pump (240V) or to be always on a different circuit (120V). There are few diagrams in the manual mentioning either cleaner or solar boosted pumps wired thru the controller (solar pump or cleaner pump relays), but it seems to be for a slightly different purpose. As far as I can see, I don’t need to hook the pump thru the controller. I just need controller to engage the actuator when pump is on and that’s all I need from it.

Here are my thoughts on my options:

1. Controller is on all the time:
Positives: dedicated circuit, no abrupt power losses/start-ups.
Negative: I might be wrong here, but I assume the controller will keep engaging the actuator/valve if sun comes/goes out while the pump is off. Resulting in extra wear on actuator and the 3way valve.

2. Controller is on the pool timer:
Positive: Everything is off when pump is off, no waste, no wear. The settings are persistent when power is off, no worries there
Negative: Not sure if the electronics on the controller will love being on the same circuit as the pump when it starts. Also not sure what happens if power is cut when actuator is either half thru the operation. I assume mechanics/electronics in the actuator handle that on the next start. I also assume that if controller tells the actuator to move the valve to a specific position and valve is already there, the actuator also handles it gracefully.

And another question. When solar switches off while the pump is still going, will the panels drain by gravity? My panels will be basically pump level, so there won’t be much gravity help.

 

[gwegan]

We need to understand what you are planning to answer your question. A diagram and pictures would be good.

Generally there is a temp sensor on the panels and one in the water. When the solar is on and the difference is temp is sufficient the controller starts the pump and opens the solar.

Your panels should drain with a vacuum valve.

 

[donaldm823]

I also have a Pentair SolarTouch and it is on its own 120v circuit independent of the pool pump. The solar touch will not rotate the solar valve if the pump is OFF. It senses no flow and interrupts the circuit. Also, the SolarTouch must meet the various temp trips for the solar heater on the roof and set pool temp.

Mine works fine on an independent circuit.

As for question #2, the way my solar installers plumbed the solar circuit, the solar panels only drain if the pump is off since the solar lines are pressurized via the return line-also the solar valve itself has a small bleed bypass internal to the valve so the solar panels see pump pressure. Of course to get flow, the pump pressure (speed) must be high enough to overcome the solar panel head

 

[Diver]

I apologize for longish post but i guess i was a bit too short in my original post.

i guess the diagram would help, especially with the second question. here is what i will have, except the communication cable to the pump from the controller (pump is not compatible) and no aux heater:

Generally there is a temp sensor on the panels and one in the water. When the solar is on and the difference is temp is sufficient the controller starts the pump and opens the solar.

"starts the pump" implies that either pump is compatible with the controller (mine is not) or pump power is connected thru controller. the latter seems to be for cleaner and solar boost pumps:

I want to avoid hooking up the pump the the controller. So pump is on when timer says it's on. So the original Q was do I have the controller on the same timer in that configuration or not..

The solar touch will not rotate the solar valve if the pump is OFF. It senses no flow and interrupts the circuit.

donaldm823, can you elaborate on the sensing part? the only way I could think the controller might do that is via water sensor between the pump and the filter. but i'm not sure if that sensor can do that though. i think it's strictly temp sensor, no? Also why pentair says it needs to be between the pump and the filter? can it be right after filter?

As for question #2, the way my solar installers plumbed the solar circuit, the solar panels only drain if the pump is off since the solar lines are pressurized via the return line-also the solar valve itself has a small bleed bypass internal to the valve so the solar panels see pump pressure.

there are two way for the panels to drain - intake pipe thru leaky 3way valve and partially thru return. i think both the small valve in the 3 way diverter (the one that makes it leaky) and check valve in return line will be closed as long as pump is on. so the panels will stay full of water. they might drain a bit to find a new pressure equilibrium with the pump head. but i think they will stay full mostly.

the controller manual also has this diagram, but i think it's for solar override. which i think is when the controller turns the pump when sun shines but timer doesn't call for filtering. which, again, not my case...

 

[pooldv]

You can skip the solar booster pump wiring and the cleaner pump wiring since you don't have either one. I would wire it to come on with the pump timer. Then it can open the valve when solar heat is available. No need for it to be powered up when the pump isn't on. I think it will automatically close the valve when it is powered off. Also, I don't know how the water temp sensor in the plumbing line will act when the pump is off. Don't know why the temp sensor is recommended to install between pump and filter. Mine is and it works fine, but it seems like it would be OK installed after the filter.

 

[Diver]

pooldv,

Thank you for on point answer! Seems like running on the same timer doesn't have much negative impact.

I think it will automatically close the valve when it is powered off.

i wonder how it does it. the valve/actuator doesn't have a spring that would require for the actuator to be powered while open and close it when power is lost. maybe the controller has a capacitor that might power the actuator when power goes down?

 

[donaldm823]

pooldv,

Thank you for on point answer! Seems like running on the same timer doesn't have much negative impact.
I think it will automatically close the valve when it is powered off.
i wonder how it does it. the valve/actuator doesn't have a spring that would require for the actuator to be powered while open and close it when power is lost. maybe the controller has a capacitor that might power the actuator when power goes down?
xxxxx


i wonder how it does it. the valve/actuator doesn't have a spring that would require for the actuator to be powered while open and close it when power is lost. maybe the controller has a capacitor that might power the actuator when power goes down?

My SolarTouch needs power to shut the solar valve. No spring return on mine. I lost house power one day and the valve stayed open. But, when the pump shuts off with power to the SolarTouch, the valve goes closed

 

[chiefwej]

My solar controller has its own circuit. When heat is called for the controller opens the valve and activates the pump at the preset speed for the solar system. The solar control overrides any pump timer settings. When it's done it closes the valve and returns control to the pump timer.

 

[pooldv]

My solar controller has its own circuit. When heat is called for the controller opens the valve and activates the pump at the preset speed for the solar system. The solar control overrides any pump timer settings. When it's done it closes the valve and returns control to the pump timer.

This is how mine is set up too. Won't work for OP, he doesn't have the same pump.

My SolarTouch needs power to shut the solar valve. No spring return on mine. I lost house power one day and the valve stayed open. But, when the pump shuts off with power to the SolarTouch, the valve goes closed

Maybe I am wrong about the valve closing on power shut off. I am not certain about it. Maybe I am remembering the valve closing when I power off the Solartouch with the power button. I'll try to go test it tomorrow.

 

[pooldv]

Bad news on the valve closing. I turned my Solartouch on and it was in solar heating mode, valve open and pump ramped up to speed 2. I cut the power to the Solartouch only at the breaker and nothing changed except the Solartouch turned off. Valve stayed open and pump stayed on speed 2. When I powered it back up the valve closed and the pump went back to solar hold mode.