RO unit wiring problem.

[SidneyP]

Hello everyone, I'm building a powered reverse osmosis unit from scratch and I have a very puzzling problem.

On the electrical side, I have a 15A pressure shut off for the faucet, a booster pump, and power supply rated at 2 amps 24vac all Aquatec brand. Wires is about 16 or 18 AWG. It works fine. But when I add a 24w 24vac solenoid valve for the wastewater line, the pump which is set to 100 psi barely pumps to 60 psi(1.43 amps). I replaced the power supply with 75VA about 3.1 amps. Everything are wired in series. I tried reversing the power supply wires with no luck. I removed the solenoid valve snd replaced it with a small relay and connected the coil side. Changed wires to 14g. Again, no luck. Both solenoid valve and pressure switch turns on. The problem somehow seems to be at the pump.

Any help is highly appreciated.

 

[Harald Kapp]

Everything are wired in series.

Putting pump and solenoid in series doesn't work. The 24 V from the power supply are split between pump and valve (the ratio depending on the individual load resistances of pump and solenoid). The correct way is to connect the two in parallel.
The power supply's amp rating needs to be the same or higher as the amp ratings of pump+solenoid.

Compare this to your household installation: everything is in parallel. Or to a string of christmas lights: these are typically connected in series and when one lamp is defect, the whole string doesn't light up.

 

[SidneyP]

Like this?

 

[Harald Kapp]

Exactly.

 

[SidneyP]

Thanks so much Harald. It worked!