Deer Run RO issue

[Mark-NH]

My Deer Run 250 ran great when put to bed last year. Now she continues to switch off even though I have a full line of permeate coming in. Would this be the “low pressure switch” or could it be something else? If the switch, do I just replace it with a new one or is there a fix?

Thanks for any advice you can send my way. Mark

[MISugarDaddy]

Mark,
Have you tried placing the low pressure switch in the startup position and leaving it there for a couple minutes to see if the problem corrects itself? Although I haven't had the problem you are describing, I wonder if the low pressure switch is adjustable like the high pressure switch. I know the high pressure switch is adjustable because I had to change mine slightly to get it to shut off at 300 psi (Ray recommended I test the setting when I purchased my Deer Run RO). Let us know what you find out in case one us have a similar problem.
Gary

[Father & Son]

My friends D R RO did the same thing and it was the low pressure switch because the gauge showed it was building pressure while holding the start button in. Until he was able to get a new one he put both wires on the same terminal and that bypasses the switch. The only thing you must remember it that now you must babysit the RO while it is running so you don’t run it dry. Just be careful.

[ALSMAPLE]

It could be as simple as a loose clamp or any small leak in the intake line.Also if the water filter possible plugged.That would show up on the pressure guage.

[SeanD]

When I first start my DR RO, I hold the on button in until sap comes in. Sometimes I have to hold it for 5? seconds or more depending on if there are any slugs of air in the line and the new sap works its way through the machine including filling the sap filter chamber. It's not unusual to let go of the button and I have to do it again until all the sap is in and all the air is out.

There are a few ways I've had it kick off on startup - all user error and all related to the low pressure switch.
1. I forgot to open a valve somewhere - at the tank, the big valve on the RO, or the 3-way valve on the RO that switches from wash tank to incoming sap.
2. The sap filter is plugged. This sometimes happens on the second pass with sap that's less than crystal clear.
3. The incoming sap froze.

Another thing is the RO is not self-feeding. The sap coming in needs some pressure behind it, so make sure the sap tank is higher than your RO inlet and that there's enough sap in the tank to give it a push.

If those aren't the issue, you can try adjusting the low pressure switch. I haven't had to do that, but it's probably like adjusting the high pressure switch.

The other ways I've had the RO kick off are related to the high pressure switch. Sap is coming in and I'm tightening things up when it kicks off. That's the high pressure switch doing it. What's been weird is I'll be staring at the gauge and only be at like 255-260 psi and it with shut off. Sometimes I think it just gets a spike for some reason, so I slow down to see if I was rushing it. Other times, I'm going slowly, staring right at the gauge and it will kick off. That's when I adjust the high pressure switch.

To do that, lift off the plastic cap and turn right/downward/tighten to raise the kick off psi. A tiny movement is all it usually needs like 2-3 clicks or what feels like millimeters of a turn.

Theoretically, once its adjusted, I should be all set, but each of the last few seasons, I've needed to adjust it. Not sure why. I'll leave that to the experts.

The other thing you can do is give Ray a call. He's really good about asking the right questions and giving you suggestions. This time of year, call his sugarhouse number during the day and he or his son usually pick up. The house number, you'll have to leave a message and he'll get back to you.

[Mark-NH]

Thanks guys. Some good advice here. My pressure gauge between pre filter and low shut off is not working so I have ordered a new one. This would have helped in determining the issue. I will try bypassing the switch tomorrow and have ordered a replacement in the meantime. Stay tuned for update.

[Mark-NH]

With the good advice of jumping the low pressure switch I was able to identify the switch as the problem. I was also able to run the RO while waiting for the new switch to come in. It should be here today and will be a 10 minute job to swap out. With the new switch I am assuming we will be fully functional again. Thanks for the good advice guys.

[maple flats]

When my deer run RO had a gas engine I used the low pressure switch. When I switched to an electric motor the low pressure didn't work, it was just designed to short the spark. I never redesigned it, I've been running several years with no low pressure switch, but I am never concentrating when I'm more than ear shot from the RO, so I can shut it off. I can hear as it gets close to running out and be ready.

[Father & Son]

Dave,
I think the gas switch and the electric switch are different.
Ray has a newer design switch I think. Might be an easy change out.

[minehart gap]

When my deer run RO had a gas engine I used the low pressure switch. When I switched to an electric motor the low pressure didn't work, it was just designed to short the spark. I never redesigned it, I've been running several years with no low pressure switch,

Dave, I also had a Deer Run with a gas engine that I converted to electric motor. Ray explained a pretty easy way for me to change the wiring around and it works well. Give Ray a call, he can probably get your low pressure switch back up and working.

[maple flats]

I'll check with Ray, thanks. I'm likely going to continue to use my 250 Deer Run until I get old enough that I decide to quit, since I've cut back from 1320 taps. I did finally buy a new set of MES membranes because I detected some funky growth in my permeate tank about 2-3 mos. after the season in a tank with 4-500 gal held for other uses. That told me that even though I got a zero sugar reading in my permeate water even when concentrated to 1/10 original volume it was passing some sugar, since the permeate tank is a fully enclosed 1000 gal SS tank.