Help with IntelliChem and VS pump

[bcinsd]

Split by moderator from HERE. jblizzle

Hi, not to hijack the thread, but I have a similar problem. We just fully automated our system with intelliflo VS pump, IC60 chlorinator, intellichem, easytouch 8 and screenlogic.
Unfortunately we are not getting adequate flow to probe unit unless pump running at >2700rpm. Intake is after filter before heater, outlet after heater prior to chlorinator.
Seems ridiculous to run the pump at such high speeds and loses the whole point of a variable speed pump. Contractor's attitude is that the problem is an intellichem design fault.
I noticed that the tubes between the intake and probe unit and back are very long, probably 10 feet in total and am wondering
if that is contributing to the problem by increasing flow resistance (if I correctly remember my college physics, flow resistance is directly proportional to tube length). Would it be better to move the unit probe unit closer and decrease the length of tubing involved?
A second thought I had would be to change the outlet from prior to the chlorinator to after the chlorinator to try to create a greater pressure gradient between intake and output in order to increase the flow rate.
Any advice on these ideas would be greatly appreciated. Thanks in advance.

 

[Patrick_B]

Welcome to the forum!

I'm not sure what to suggest, but blaming this on the pump is a lame excuse. I think there is another answer, and hopefully a bump to your thread will get it noticed by someone who can help with a better suggestion. Sorry no one answered you after the split from the other thread. Best of luck to you.

 

[Bama Rambler]

I'm from TFP and I'm here to help! Oh wait, that's not right.

A pic of the installation would certainly help, but moving the outlet to after the swcg would probably help. They suggest plumbing the outlet just before the swcg so that the acid will help keep the cell clean, so it requires removal and cleaning less often. However, in the real world that doesn't always work.

Shortening the tubing may help a little, but since the feeder works off differential pressure to create flow across the probe, it probably won't help enough to get the pump speeds where you want them.

Like I said, post a pic and I'll see if anything jumps out at me.

 

[bcinsd]

Hi, thanks for replies:
I will post picture but as an update, contractor moved intake to from after to before filter. That helped lower pump speed to minimum of 2300 rpm.
He claims the problem is fixed because it takes 6 hours of flow at 2300rpm for IC40 to generate enough chlorine anyway. Not sure I believe this statement and believe it would be more efficient to run longer pump times at lower rpms. Before we ran into the problem, his guys had it set at around 1950 for 8 hours.. 2300 sounds a bit high - that's the rate that we use for the naviagator cleaner.
Do you really think I need to run the pump at 2300 for 6 hours daily to generate sufficient chlorine for 15k gal pool in So Cali? Was hoping to run pump slower and longer for
better efficiency. FYI present set up has intake after pump before filter and output after heater before chlorinator. Acid injection is a separate line next to the output line.

 

[Bama Rambler]

Something doesn't sound right about that setup. A picture will certainly help.

Do you have an IC40 or an IC60? You say IC60 in the OP and IC40 in the last reply. Regardless, you should be able to run the pump about 1500 rpm and still get enough flow to satisfy the swcg in a properly plumbed system.

The only time you should have to run the pump higher is to run a cleaner. Other than that it could run on low 100% of the time.

 

[Pogueld]

I am interested in what these nice folks help you find out. I have intelliflo as well and have graduated from pool chemistry to trying to learn more about my pump and filter.

I do know mine does not run on high most of the time and chlorinates just fine. I'm not home, but I think it runs at 1100 when the cleaner isn't on and 2400 when cleaner is on and higher than that if the water fall is on too.


[emoji176] Lisa P.
Sent from my iPhone using Tapatalk

 

[Bama Rambler]

I also wanted to mention that moving the Intellichem inlet to before the filter is asking for it to clog with debris from the pool. Having it after the filter is preferred.

Does your heater have a bypass around it? If so, is it open now?

 

[bcinsd]

I have included pictures. Chlorinator is IC40
I was told by both Pentair and my contractor that placing intake before filter would create greater gradient and allow flow thru intellichem at lower rpm. I was told there is a filter on the intellichem intake side that will be easy to clean if clogs. Lowered needed rpms from 2700 to 2300 but not the dramatic effect I expected. Contractor says "problem solved". I'm not satisfied with this answer.

 

[Bama Rambler]

what does your filter pressure run?
How many and what size eyeballs do you have?

 

[bcinsd]

Filter pressure is about 10PSI at rpm of 2300.
There are 2 returns to pool and 1 to hot tub. No eyeballs, just cut pvc at wall surface. Don't ask me why, that's how pool was built 30 yrs ago.

 

[Bama Rambler]

The issue is that you don't have enough pressure differential between the inlet and outlet of the intellichem. You could try moving the outlet to after the salt cell, but I'm not sure if that would get you as much flow as you need at low pump rpm, however it would help some.

 

[bcinsd]

Yes, I agree that the problem is insufficient pressure gradient.
My gut tells me that even moving outlet to after salt cell and shortening intake and outlet lines will be insufficient to produce the desired effect.
My plan is to move the intellichem outlet to the pool intake pipe (prior to the pump). From what I've read, it sounds like that will provide a large gradient. Someone suggested attaching the outlet directly to the pump basket drain hole, I figure that by placing the outlet prior to the spa/pool intake valve rather than the pump basket, the intellichem probes will be protected from the potentially dangerously high gradient that might occur with running the pump at high spa rpm speeds (>3000rpm).
Any thoughts on this idea?

 

[Bama Rambler]

Moving the outlet to the suction side of the system will definitely create enough flow through the unit. You can partially close the valves on the unit to limit the flow through the unit.

 

[bcinsd]

Thanks for your help.

I've discovered a new problem that has me more upset with the contractor.
I was wondering why the pool pH wasn't dropping despite increasing dosing of acid via intellichem.
Overrode system and noticed acid pump not doing anything. Turned on acid pump manually and pump started running. Thought I had it discovered the problem and that intellichem would turn off the acid pump when I turned off override, but instead pump kept running delivering huge bolus of acid before I manually stopped it.
I'm guessing they didn't wire system up correctly as it doesn't seem like intellichem has control of acid pump!

Also, noted that I have no control of intellichem schedule in screen logic. In the screen logic manual it shows intellichem as a programmable option, but mine doesn't. Is that the way its supposed to work? Also noted intellichem comes on automatically when pump on pool or spa circuit but not on cleaner circuit. That seems weird. Don't want it dumping acid into spa while Im in it! I'm beginning to think that this thing was wired up completely wrong.

 

[Bama Rambler]

So the acid pump doesn't run automatically even when the pH gets higher than the setpoint? If that's true, that is a problem.

It's normal to have the intellichem come on when in either pool or spa mode. Honestly the acid pump doesn't add acid fast enough to be a problem if the spa is occupied.

 

[bcinsd]

Ok, thanks. I really appreciate your help with this.
Is it normal not to have scheduling control of intellichem in screenlogic2? Seems like it intellichem is on whenever the pump is on, but I guess that might make sense....

 

[Bama Rambler]

As I remember that's normal. I can't remember right now, but you might be able to adjust the target pH, but not the schedule.

 

[bcinsd]

I called Pentair and they explained it to me and it seems correct. They were helpful and explained how I could rewire intellichem on an independent relay so that it displayed as a separate circuit on screenlogic but having it connected to the pump relay seems simpler.
So now I am trying to get the contractor to come back and fix acid pump control.

I was hoping someone could advise regarding my plan to connect intellichem output to suction side of pump and whether it would be better to connect it to pool inlet prior to pool/spa valve or after valve. Before valve would potentially protect probes from large change in gradient (from pool setting at 1500 rpm to spa setting at 3000 rpm) however after valve would expose to large changes in pressure gradients but allow for some chemical mixing in spa mode. Recommendations?

 

[Bama Rambler]

There are a couple of considerations to think about. If you put it before the valve then the acid pump needs to be off when in spa mode. I don't think putting it after the valves is a problem. The specs for the unit only list the low flow number and a max pressure of 25 psig. There's no high flow or low pressure number. It probably won't take full vacuum, but it most likely won't have a problem with whatever that pump can produce.

 

[jtech1]

Also, it is important that the IntelliChem is ONLY on when the pump is on... since you don't want it dosing acid without water flow. If I remember correctly, the instructions state that it must be connected to the pump relay for safety purposes.