retrofit - adding SWG to pool/spa/solar

[RocKKer]

Friend of mine has a 25-30 year old pool, he wants to add an SWG, re-plumb the solar side to replace out the old solar and check valves (which don't seem to be checking!), along with adding solar shut-offs and a bypass valve to control the water pressure to the solar panels (it sometimes blows the rubber couplings!)

A couple questions -

Should we plumb/power the SWG to run while the spa is on? - (I think we should). His concerns are to much chlorine will be generated while using the spa. My contention is that is exactly when you need it the most!

Should we plumb the solar computer to only be powered when the pump has power? - (I think we should). Currently it's powered all the time and his concerns are the electrical shock to the solar computer's circuit board when the pump and solar computer starts up simultaneously and that could somehow harm the circuit board inside. I explained that the solar computer will be actuating the solar valve needlessly (ie: pump not on and no water going to the solar), this wastes several rotations of the actuator/valve daily, (my system powers the solar on/off with the pump and has been working for 3 years this way without issues).

 

[JasonLion]

You don't want the SWG to be on when the system is in spa only mode, unless you have a controller that automatically lowers the percentage setting in spa mode. A SWG is normally configured to make enough chlorine for the entire pool. If it is producing chlorine at that rate when you are in spa only mode it will be way too much chlorine for the much smaller volume of water in the spa.

The two most common ways to setup a solar system are to either power down the solar system when the pump is off, or to have it automatically turn the pump on when there is heat available from the solar panels. Setting it up so the solar is on and the pump stays off isn't a great idea, although it won't cause any significant damage, just a little extra wear.

 

[RocKKer]

Great thanks Jason.