RJ45+ questions on flow

EndlessSummerAZ

Well-known member
May 18, 2023
96
Phoenix
Pool Size
11475
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
Finally got the RJ45+ installed and said goodbye to jugs. A little messy but we’re done. I’m trying to get it dialed in now and have a few questions.

1. Set at 50%. I have a Tristar VS950. I’m trying to figure out what rpm to run the pump at. When I try lower rpm (1200-1500) the no flow light flickers and then after a minute or so the generate light kicks on. Is this normal? My whole point of purchasing this was to run at an rpm as low as possible to maximize electricity savings with 24/7 pump run time. At 1600 rpm it kicks right on but I don’t really want to run that high if it can be avoided.

2. There seems to be a small bubble in the cell. Is this anything to worry about? Tried my best to get a photo.

3. If I can get the SWG to generate at a lower rpm I plan to run 24/7 so I didn’t install an intermatic timer but it’s wired to the same breaker as the pump - is this an absolute no go to not have a timer if pump runs constantly?
 

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Finally got the RJ45+ installed and said goodbye to jugs. A little messy but we’re done. I’m trying to get it dialed in now and have a few questions.

1. Set at 50%. I have a Tristar VS950. I’m trying to figure out what rpm to run the pump at. When I try lower rpm (1200-1500) the no flow light flickers and then after a minute or so the generate light kicks on. Is this normal? My whole point of purchasing this was to run at an rpm as low as possible to maximize electricity savings with 24/7 pump run time. At 1600 rpm it kicks right on but I don’t really want to run that high if it can be avoided.

2. There seems to be a small bubble in the cell. Is this anything to worry about? Tried my best to get a photo.

3. If I can get the SWG to generate at a lower rpm I plan to run 24/7 so I didn’t install an intermatic timer but it’s wired to the same breaker as the pump - is this an absolute no go?
I have RJ60+ and Black & Decker 3HP pump. The speed I need to run is 1600 RPM. In addition to SWCG minimum flow requirement, there is also a need for the skimmers to work. Although my RJ60+ would work at 1500 RPM, I find that the pool surface skimming is inadequate at that speed. At 1600 RPM, B&D pump draws only 1A current / 240W, which is very little.

Does the bubble disappear after the priming phase at a higher speed? Make sure that the o-ring in the pump’s union on the suction side is covered with the silicon grease. The same goes for the pump draining plugs.
 
Finally got the RJ45+ installed and said goodbye to jugs. A little messy but we’re done. I’m trying to get it dialed in now and have a few questions.

1. Set at 50%. I have a Tristar VS950. I’m trying to figure out what rpm to run the pump at. When I try lower rpm (1200-1500) the no flow light flickers and then after a minute or so the generate light kicks on. Is this normal? My whole point of purchasing this was to run at an rpm as low as possible to maximize electricity savings with 24/7 pump run time. At 1600 rpm it kicks right on but I don’t really want to run that high if it can be avoided.

2. There seems to be a small bubble in the cell. Is this anything to worry about? Tried my best to get a photo.

3. If I can get the SWG to generate at a lower rpm I plan to run 24/7 so I didn’t install an intermatic timer but it’s wired to the same breaker as the pump - is this an absolute no go?
Answering your question 3. It’s absolutely fine to power SWCG from the same breaker as the pump. This way you are making sure that the SWCG will not run when the breaker cuts the pump off.
 
I have RJ60+ and Black & Decker 3HP pump. The speed I need to run is 1600 RPM. In addition to SWCG minimum flow requirement, there is also a need for the skimmers to work. Although my RJ60+ would work at 1500 RPM, I find that the pool surface skimming is inadequate at that speed. At 1600 RPM, B&D pump draws only 1A current / 240W, which is very little.

Does the bubble disappear after the priming phase at a higher speed? Make sure that the o-ring in the pump’s union on the suction side is covered with the silicon grease. The same goes for the pump draining plugs.
Not too worried about skimming for my purposes as I use a Betta surface skimmer. I just want to run as low as possible for electricity savings.

Ran at 2800rpm for an hour while the vacuum was going and the air bubble did disappear. Turned it back down to 1200rpm for the last 90 minutes and the bubble is back. Assuming it’s not an o-ring or air leak anywhere since it does disappear at higher rpm but the o-rings were annoying to put on the unions. O-rings didn’t want to stay in place and just kind of sat on the surface so maybe one did slip out of place.

Added an install photo for you all to see how the salt cell is sitting.
 

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I'm a little curious about the flow rate itself. Not my area of expertise, for that I would call on the assistance of @mas985. But I wonder if the issue is not so much the rpm setting of the pump itself, but rather the actual flow rate measured? Sure, the cell seems to be signaling low flow at some point, but is it really? Without a separate flow meter I guess it's impossible to really know. More of a hydraulics scenario and perhaps we can get some clarification.
 
Finally got the RJ45+ installed and said goodbye to jugs. A little messy but we’re done. I’m trying to get it dialed in now and have a few questions.

1. Set at 50%. I have a Tristar VS950. I’m trying to figure out what rpm to run the pump at. When I try lower rpm (1200-1500) the no flow light flickers and then after a minute or so the generate light kicks on. Is this normal? My whole point of purchasing this was to run at an rpm as low as possible to maximize electricity savings with 24/7 pump run time. At 1600 rpm it kicks right on but I don’t really want to run that high if it can be avoided.
Could just be your plumbing has a lot of head loss. But 1600 RPM is not too bad either. The difference between 1600 and 1200 is only about 100 watts for that pump. At $0.15/kwh & 24/7, that is about $12/month difference ($23 vs $11).

What is the filter pressure at pump full speed?

Is all your plumbing 2"?

What is the distance pool to pump?

How many returns are in the pool and do you know what size eyeballs are installed?

Is the flow switch oriented in the correct direction? A slight rotation can change the trigger flow. It looks ok from the picture.

2. There seems to be a small bubble in the cell. Is this anything to worry about? Tried my best to get a photo.
SWGs generate hydrogen & oxygen gas so there is bound to be some in the cell. As long as it remains a small amount, it should not be an issue.

3. If I can get the SWG to generate at a lower rpm I plan to run 24/7 so I didn’t install an intermatic timer but it’s wired to the same breaker as the pump - is this an absolute no go to not have a timer if pump runs constantly?
The risk is if the flow switch fails closed, which sometimes they do, and the pump shuts off, the cell will still continue to generate chlorine which has a byproduct of hydrogen and a little bit of oxygen gas that will build up in the cell. There have been reports of cells blowing up because of this (UV light acts as an ignitor).
 
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Could just be your plumbing has a lot of head loss. But 1600 RPM is not too bad either. The difference between 1600 and 1200 is only about 100 watts for that pump. At $0.15/kwh & 24/7, that is about $12/month difference ($23 vs $11).

What is the filter pressure at pump full speed?

Is all your plumbing 2"?

What is the distance pool to pump?

How many returns are in the pool and do you know what size eyeballs are installed?

Is the flow switch oriented in the correct direction? A slight rotation can change the trigger flow. It looks ok from the picture.


SWGs generate hydrogen & oxygen gas so there is bound to be some in the cell. As long as it remains a small amount, it should not be an issue.


The risk is if the flow switch fails closed, which sometimes they do, and the pump shuts off, the cell will still continue to generate chlorine which has a byproduct of hydrogen and a little bit of oxygen gas that will build up in the cell. There have been reports of cells blowing up because of this (UV light acts as an ignitor).
Thanks so much for your detailed response. You all are the best here.

Filter psi is 7. All plumbing is 2”. Pump to water is about 12ft. 4 returns but unsure of eye size. Flow switch arrows point towards pool.

As for question 3, the timer, if I install an Intermatic, wouldn’t I have to leave it running 24/7 as well since I plan to leave pump running 24/7? Makes it seem irrelevant then if I understand it right? I’m not smart or comfortable enough with the electrical to set up something like a current sensing relay. Definitely don’t want an explosion though.
 
Filter psi is 7.
Is that at 3450 RPM? If not, what is the pressure when the pump is at FULL speed?

As for question 3, the timer, if I install an Intermatic, wouldn’t I have to leave it running 24/7 as well since I plan to leave pump running 24/7? Makes it seem irrelevant then if I understand it right? I’m not smart or comfortable enough with the electrical to set up something like a current sensing relay. Definitely don’t want an explosion though.
You could probably get away without a timer if you plan on running 24/7. Just make sure the SWG is off when you manually shut off the pump.
 
Is that at 3450 RPM? If not, what is the pressure when the pump is at FULL speed?


You could probably get away without a timer if you plan on running 24/7. Just make sure the SWG is off when you manually shut off the pump.

Just checked psi and we are at 13 running 3450 rpm.
 
13 PSI is very low for that pump at full speed.

Does the filter gauge go to zero when the pump shuts off? If you tap the gauge when the pump is running does the pressure change?

Could be a suction side blockage or impeller clog.

Is there any air in the pump basket?
 

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13 PSI is very low for that pump at full speed.

Does the filter gauge go to zero when the pump shuts off? If you tap the gauge when the pump is running does the pressure change?

Could be a suction side blockage or impeller clog.

Is there any air in the pump basket?
Maybe I’m not running it long enough to get up to full psi? Just ran it a quick minute to test. Filter does go to 0 when the pump is off. Nothing changes when gauge is tapped. I’ve turned off the pump and removed the basket to check the impeller with my hand and nothing I can feel clogging it up. When running at higher speeds there’s no air in the pump basket. If I run lower speeds for a long period of time then a bubble will develop.
 
Bubble developing at low speeds in VS pumps is normal, especially with Hayward pumps.

Program your system to run at a speed high enough at least once a day to clear the bubble.
 
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@EndlessSummerAZ …My system is similar to yours (no heater, seems like relatively short clean piping runs to/from pool, larger filter, SWGs - RJ60 for me) your pump is (edited from post below) the same xxxhalf the hpxxx. The SWG switch seems to be the same model.

Air bubble problem aside, I’m surprised that your SWG flow switch requires 1600 rpm to actually “switch on”. Although I run my SWG at 1000 rpm (for skimming action), the switch actually kicks in at the lowest possible rpm of my pump: 600 RPM … at that RPM gpm flow is in the mid-teens.

@mas985 would the pump HP make that much difference? I’m thinking endlesssummer’s SWG switch is not as sensitive or that there IS a flow problem in the system as you seem to be inquiring about.
 
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The RJ series requires 25-30 GPM.

The pump is a Hayward VSP 950 which is a 2.7 THP pump and on typical 2" pool plumbing should have the following operating points:

3450 RPM: 103 GPM @ 76' of head and a filter pressure of 24 PSI

To get 30 GPM, again a typical 2" plumbing system would need only 1000 RPM from that pump.

So something is not right here.

Was the filter pressure the same before the SWG was installed?

Do you have a suction gauge that you can put on the pump basket drain plug?
 
@EndlessSummerAZ …My system is similar to yours (no heater, seems like relatively short clean piping runs to/from pool, larger filter, SWGs - RJ60 for me) your pump is (edited from post below) the same xxxhalf the hpxxx. The SWG switch seems to be the same model.

Air bubble problem aside, I’m surprised that your SWG flow switch requires 1600 rpm to actually “switch on”. Although I run my SWG at 1000 rpm (for skimming action), the switch actually kicks in at the lowest possible rpm of my pump: 600 RPM … at that RPM gpm flow is in the mid-teens.

@mas985 would the pump HP make that much difference? I’m thinking endlesssummer’s SWG switch is not as sensitive or that there IS a flow problem in the system as you seem to be inquiring about.

Called Discount Salt Pools this morning and apparently the flickering no flow light is normal for about a minute when the system is powering on or the pump is starting up. This does align to my only seeing the flickering no flow for about a minute and then the generate light turns on. I’m guessing because I was changing pump timers and speeds that was the reason? Whenever I change speeds or time, my pump turns off then starts up again even if the basket is full of water. One dislike of this pump.
 
The RJ series requires 25-30 GPM.

The pump is a Hayward VSP 950 which is a 2.7 THP pump and on typical 2" pool plumbing should have the following operating points:

3450 RPM: 103 GPM @ 76' of head and a filter pressure of 24 PSI

To get 30 GPM, again a typical 2" plumbing system would need only 1000 RPM from that pump.

So something is not right here.

Was the filter pressure the same before the SWG was installed?

Do you have a suction gauge that you can put on the pump basket drain plug?

Don’t have a suction gauge currently. Filter pressure was roughly the same around 6 at 1200 rpm. Now at 7. PVC was extended some for install. I just replied to the comment above so I’m thinking some of it was user error. However I’m curious now why I only saw 13psi on the max speed. Definitely need to investigate that more. Hoping I just didn’t let the pump run long enough at max to gain full psi. Also wondering why the air or hydrogen bubble remains. It’s a pain not knowing anything about pools!
 
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Head loss in plumbing is proportional to the square of the flow rate. If RPM increases, GPM increases, head loss increases which increases filter pressure.

But as I pointed out earlier, having on 13 PSI at 3450 RPM with that pump is highly unusual. Pressure should be much higher than that (~2x). Assuming the pressure gauge is accurate.
 
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