Homemade single 4” RO problem

[AVALLES]

So I went ahead and built a single post 4” RO for this year. I tested it with Permeate to see how it would run and can not figure what’s wrong. My problem is when I start closing the needle valve to bring the pressure up, I can get it to about 50psi and the motor which feeds the Procon high pressure pump slows down and labors till it stalls. What am I doing wrong?? I have a 1/2 hp marathon motor feeding Procon pump. Any ideas or suggestions?

[Bricklayer]

Does your pressure go up past 50 psi as you close the needle valve?
Are you getting permeate flow at 50 psi?
From what I can see the plumbing looks fine. And it’s connected to the right inlets/outlets of the membrane.
I’m thinking you might have a problem with your needle valve. Or pressure gauge.
It sounds like it’s deadheading your pump. Or your motor isn’t wired properly.
I would start at the motor. Check the wiring. We’ve all hooked up
a motor wrong.
Then take off your needle valve and just put a ball valve on it and slowly close it to see if pressure builds. If it does and pump dosnt stall motor it’s your valve.
Check your membrane and make sure the gasket is on the top side of the housing where your inlet is.
Also check your tube going from the procon to your bucket. It might be collapsing on itself

[AVALLES]

I get very little permeate flow at the outlet at 45-50 psi and if I close the needle valve any further it stalls the motor. The concentrate outlet it is running very hard with the needle valve open and slows as I close it. I also feel that it’s plumped properly and that there are no collapsed hoses. I will check into motor wiring and gaskets. Thanks for your suggestions!

[Bricklayer]

I’m leaning towards the wiring of your pump.
What model procon do you have?

[AVALLES]

It was a wiring issue. I have a Procon 330. I can now get pressure up to 150 psi with permeate before the motor start laboring. From what Ive read I should be running at 250+ psi, not sure if that will change once I run sap through it. I also do not have a pump feeding the Procon, i was trying to gravity feed it. Not sure if that’s the issue with the pressure or not. Thank you for your response!!

[iby]

I don’t feed my Procon either... not necessary.
I have a 3/4” marathon. I run it hard but never have had it labor or slow down. If I run it at 250psi for more than 3 hours, the motor does a thermal shutdown though. Figuring a voltage drop, so I rewired it today for 220

[AVALLES]

I’m having a hard time figuring out why I can only get my pressure past 150 before my motor won’t handle it anymore. Like I said before it’s a brand new 1/2 hp marathon. I can hear the pump slowing down considerably once I get up to 125 psi as Im closing the needle valve to bring the pressure up. The motor is also very warm to the touch from working hard. I’m hoping by adding a feed pump at 40psi that will take care of the problem otherwise perhaps I need a 3/4 hp motor? Wasn’t expecting to have a problem with this but that’s how it goes.

[halladaymaple]

You are under powered with only 1/2 horse. Check Procon’s site for specs but you should have minimum 1 hp if you want to push 250 psi.

[Clinkis]

You are under powered with only 1/2 horse. Check Procon’s site for specs but you should have minimum 1 hp if you want to push 250 psi.

Agreed, 1/2 horse is way to small for a 330 procon. I’m running 1.5 horse on my 330 procon and I can make it labour if I really crank up recirculation. It will also thermal shutdown on occasion when running it hard on long days.

[maple flats]

Different pump and plumbing, but on my 2@4x40" membrane RO I run a 2 hp motor. It does 275 and 280 PSI and never shuts down or gets much temperature rise on the motor. I also use a 1 hp feed pump which increases the total performance, but even if I shut that pump off the RO still does what it was designed to do.
I suspect you just under powered the Procon 330. Over the years I've always tended to go slightly larger than needed on motors and engines, they seem to run more efficiently.

[AVALLES]

Thanks to everyone for the responses! I’m going to make some changes based on the feedback and see what happens.

[Mead Maple]

Was searching through some RO threads as the seasons SSC begins to drop. How did you make out with the current 1/2 HP pump and did you end up upgrading and/or add a feed pump?


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[ddociam]

Did you get it figured out? The motor may be to small for your pump.


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[OGDENS SUGAR BUSH]

I’m having a hard time figuring out why I can only get my pressure past 150 before my motor won’t handle it anymore. Like I said before it’s a brand new 1/2 hp marathon. I can hear the pump slowing down considerably once I get up to 125 psi as Im closing the needle valve to bring the pressure up. The motor is also very warm to the touch from working hard. I’m hoping by adding a feed pump at 40psi that will take care of the problem otherwise perhaps I need a 3/4 hp motor? Wasn’t expecting to have a problem with this but that’s how it goes.
there is no way a 1/2 hp pump is going to run a 330 procon and after reading your post again, go with at LEAST a 1hp motor