Purclean RO issue

[DavidM]

I'm not familiar with Purclean systems so this maybe an obvious answer.

My unit keeps shutting down with this error message: "Excessive pressure switch trips Unit off!"

Any suggestions on what to check?

I'm not sure what pressure this is monitoring

David

 

[MC3033]

For excessive pressure to be an issue I would imagine it is membrane pressure.

Do you have any gauges?

 

[MEP001]

It should not exceed 200 PSI. Your membrane may be fouled, but you can get by for a while by opening the valve to the drain which should in turn reduce the system pressure.

 

[Toms PTcarwash]

If you try to put to much pressure through the ro membranes they will plug up and let "bad " water get by. Make sure you are not closing the reject water valve. After many years, I have learned that if i run my ro at about 75 psi, with about 2 gpm of reject my membranes last at least a full year and I stay under 5ppm.
I do have a softener and charcoal filter before my RO.

 

[MEP001]

After many years, I have learned that if i run my ro at about 75 psi, with about 2 gpm of reject my membranes last at least a full year and I stay under 5ppm.

Considering your own result, you should rethink this. If things are right, they should last 5-10 years.

 

[DavidM]

Thanks for the suggestions. I discovered that the pressure sensor is monitoring the incoming water feed not the pressurized premembrane feed.
I narrowed the issue down to the charcoal filter and discovered the solenoid on the charcoal filter was not working. I'm not sure how it has worked at all in a very long time. The diaphragm is ripped and the piston is seized in place.

I misunderstood the error. It isn't "excessive pressure", it means excessive trips of the pressure switch. the wording is a little awkward.

Now I just need to find the part number for a repair kit. I haven't had much luck getting a response from Purclean so far.

Thanks again,
David

 

[Toms PTcarwash]

Considering your own result, you should rethink this. If things are right, they should last 5-10 years.

That depends on how much water you run through them and what your tolerance is for less then optimum water. I use a lot of spot free water in my 5 SS bays and autowash. When my tds gets to around 12 -15 ppm, I replace the membranes. Sure they will last longer, if you use less water and are OK with lower quality water. But my Autowash does not have dryers, so I want the best spot free I can deliver.

 

[MEP001]

Except that the TDS shouldn't increase over time. If things are set up properly, it should stay about the same or even drop slightly. The only things I've seen that causes TDS to increase over time is allowing chlorine to reach the membrane, or cleaning it. Those two things plus fouling (which doesn't increase TDS over time) are the only reasons why you should have to replace membranes. I've seen that the systems that run 200 PSI plus have a portion of the reject plumbed back to the pump to make 1:1 product to reject have lower TDS output, longer membrane life, and increased output. IMO you're giving bad advice. In case you didn't know, I've been doing this professionally for 39 years across some 500 sites, not just tinkering at one wash.

 

[APW]

Mep which end should the seal go on the membrane on the incoming or the outgoing side?

 

[MEP001]

It should go on the end where the water comes in. It's a V-seal, and the pressure will always go into the valley of the V to force it open and stop flow around it.

 

[Toms PTcarwash]

MEP001,
I am not here to give bad advice, only to try to help others. Unfortunately I only have 20 years experience with car washes. 35 years with electrical, plumbing and mechanical systems.

I am offering my ideas and opinions if I think they will help others save time and money. These come from my limited experience.

I have no interest in getting into any type of argument with anyone. I don't have time for such nonsense.

I suggest anyone take any ideas or suggestions from any forum and do a little research. For RO systems, you can check with the membrane manufacturers, such as DOW ( that's what I use) and read their recommendations on membrane maintenance and replacement.

It would be nice if the membranes lasted forever, but for me, that hasn't been the case. Maybe I'm doing something wrong.