Advice on Variable Speed Pumps for Spa

[JohnASmith]

Big Dave, I too have roof mounted solar. I am having trouble understanding how that could effect the controller in a variable speed pump, can you expand on that? Thanks.

[BigDave]

My solar system has a valve (vacuum check?) that lets air in the system to allow the panels and piping to drain back down when not in use. Because of this the panels need to primed each time the controller moves the diverter valve sending the pool water to the panels. While the pipes and panels are filling, the flow rate slows significantly because the pump is overcoming the static head as well as the dynamic head in the piping system. Once the pipes, panels, and return lines are filled, the static head is equalized by the weight of the water in the pipes coming down from the roof.

The SVRS (Safety Vacuum Release System) function saw this low flow to be an entrapment event (somebody stuck in the drain) and shut the pump down to release the suction.

[JohnASmith]

Thanks