Swimming Pool Success and Fright

I had “Heath Robinson’d” the pool solar water heater as a test bed to see if the modified wiring and pump will work with the solar controller.  The original cheap pump lacked the power to raise the water onto the shed roof.  To temporarily resolve this I plumbed in the larger 12V pump I use for the camper trailer shower.  The plumbing now looks very Heath Robinson.  But the pump works!

However this resulted in the solar controller not recognising the load (ie, the pump) and nothing worked.  After thinking about it I wired the Thermocouple (ie, water temperature switch) into the pump electrical circuit rather than the solar controller circuit.  This didn’t fix the issue.  More thinking resulted in me wiring the pump to the small 12V battery.  Initially I was concerned the pump would run off the battery and flatten it when there was no sun light to send power to the battery via the solar panel and controller.  However I realised my logic was flawed.  If there was no sunlight to power the solar panel then there would be no sunlight to heat the water and the Thermocouple wouldn’t turn on the pump. 

A – Solar Controller

B – Battery

C – Temporary pump

My guess is the “Load” terminals on the solar controller are incapable of handling the electrical demand from the pump.

I’m satisfied the system is configured correctly and will work.  However the wiring and plumbing won’t be tided up until a new pump is delivered.

Later in the day I returned to check on the system and was delighted to hear the pump running.  The return pipe from the water heater panels on the shed roof was too hot to hold.  I waited to hear the pump stop running when the hot water in the panels was replaced with cold from the pool.  It didn’t happen!  That’s when I realised the main pool pump wasn’t working…..  FRIGHT!!!

The previous day I’d completed the weekly pool clean and also decided to do an annual clean of the pool filter cartridge.

 

I restarted the main pump and after a longer than usual delay it primed before suddenly stopping.  What had I done wrong during the reassembly of the filter?  I stripped and reassembled the filter three times and each time the main pump would cut out after initially priming.  Where was the blockage? 

Having recovered from my fright I started to thinking logically.  The pump primed, but then almost immediately stopped.  Was the blockage before or after the pump.  “Look for the simple things first!”  I went to the pool and examined the leaf catcher to see if leaves had blocked it. That’s when I realised the water level in the pool was quite low.  After many recent sunny and hot days the water level had dropped 4 inches through evaporation.  The pump was attempting to suck more water than the pool could supply which resulted in the pump safety cut-out activating!  All that was required was to add more water to the pool.  I was relieved to realise I’d done nothing wrong.  Lesson learned