Thanks & Automation Questions - Heat Pump & GPM calibration

[johnjmattingly]

Howdy folks,

Pool newbie here. First I'd like to say thanks to all of you. Because of this forum, I've learned how to maintain crystal clear water and all of my physical pool equipment. You've also given me the courage to download SLConfig and re-program my EasyTouch, which is now working just as I'd like it to. So, thanks! Special shout out to @Jimrahbe and @JamesW for their guidance and insight related to programming the EasyTouch! Your posts have been super helpful.

I have two final questions related to my pool's Automation System.

First - I have a Pentair Ultratemp 140 H/C. The heat pump is setup on the Solar circuit of my EasyTouch, so I can set the temperature range that I wish to keep the water within. I'm in Austin, TX, so mostly dealing with chilling now that the summer has finally arrived. I've noticed (and have read here that this is an issue) that occasionally my pool temp as read by the automation system can oscillate at the high end of the set temperature range such that the heat pump turns itself on / off every few minutes. I don't want to burn out my equipment, so I've been manually monitoring when my heat pump turns on to chill the pool during the day, and sometimes adjusting the upper boundary so that the system just remains on vs. the on/off cycle. Eg. Upper bound set at 88 degrees, automation system reads temp at 89, then back to 88, then back to 89. So I reset the upper bound down to 86 until later in the afternoon when I manually put it back up again. I'd like to figure out if there is a solution to this. I believe I've seen some threads about a possible hardware / software solution, but I can't seem to track it down. Any help appreciated!

Second - The gallons per minute reading visible on my ScreenLogic app is different from the flow meter physically attached to my pool plumbing. I have an inline FlowVis flow meter located just after heat pump exit and just before the main and paramount in floor return valves. The reading on the FlowViz is typically about 10GPM higher than what is displayed in ScreenLogic. Eg. When I look at the Flow (GPM) reading in ScreenLogic, it shows me say 46GPM @2500 RPM on the Intelliflo. When I look at the FlowViz I see between 55-60GPM. I've asked my PB about the calibration of the EasyTouch/Inteliflo flow sensor, but he's not been able to provide an answer to me. My questions are, where does the flow value displayed by ScreenLogic come from (the Intelliflo, a sensor?) and is it possible to calibrate the sensor? I'm assuming for now that my FlowVis is what is accurate, due to the fact that the Ultratemp has never refused to turn on due to lack of flow (I always keep the flowvis at or above the 30GPM min for the Ultratemp, even though the ScreenLogic will show approx 10GMP less) and it's a physical gauge. But, I really don't know for certain which reading is the most accurate.

Any help appreciated, and thanks again!

John

 

[Jimrahbe]

John,

I'm pretty sure the neither the FloVis nor the IntelliFlo is all that accurate when it comes to "flow" measurements.. And.. looking at the big picture is matters very little.. I am not a fan of the VF option as it just leads to too much effort for too little gain. If this were my pool, I would not set the flow rate to some magic number in a manual, I would set it to what makes the system work..

A good example for me is the flow through my SWCG.. I'm sure the manual has some magical number, but I don't have a clue what it is and I just don't care.. I slowly ramp up the RPM until the flow switch in the SWCG turns on.. I add 100 RPM and call it good.. Has worked great forever.. It does not matter to me if I am running a little too fast or a little too slow.. All I care about that it works, in my pool, with my plumbing, with my pump, etc..

I am pretty sure there is no flow "sensor" in the pump, it just uses math and electrical parameters to determine what it thinks the flow rate is. Close is just close enough for this application.

I don't have a heater or heat pump, but it seems to me that you can set the range for your set point temperature.. So you can make the window of "approved" temperatures wider or narrower.

Thanks,

Jim R.

 

[johnjmattingly]

John,

I'm pretty sure the neither the FloVis nor the IntelliFlo is all that accurate when it comes to "flow" measurements.. And.. looking at the big picture is matters very little.. I am not a fan of the VF option as it just leads to too much effort for too little gain. If this were my pool, I would not set the flow rate to some magic number in a manual, I would set it to what makes the system work..

A good example for me is the flow through my SWCG.. I'm sure the manual has some magical number, but I don't have a clue what it is and I just don't care.. I slowly ramp up the RPM until the flow switch in the SWCG turns on.. I add 100 RPM and call it good.. Has worked great forever.. It does not matter to me if I am running a little too fast or a little too slow.. All I care about that it works, in my pool, with my plumbing, with my pump, etc..

I am pretty sure there is no flow "sensor" in the pump, it just uses math and electrical parameters to determine what it thinks the flow rate is. Close is just close enough for this application.

I don't have a heater or heat pump, but it seems to me that you can set the range for your set point temperature.. So you can make the window of "approved" temperatures wider or narrower.

Thanks,

Jim R.

Thanks, @Jimrahbe. This context is helpful. I've found myself working toward your approach of running my pump 24/7 at lowest possible rpm (I don't really use the variable flow option on my VSF, just stick with RPMs) while programming the EasyTouch to kick up the speed for things like chiller and cleaning cycles (I don't have SWCG). But, the recommended 30GPM flow min on the heat pump is the last obstacle I've been working through. The pump requires a pretty high rpm and power use to keep that flow rate according to FlowViz and ScreenLogic. So, I'm now dialing into running the pool 6am to 7pm, with a clean cycle first thing in the morning and higher rpm for the chiller as required during the day, pulling double duty as additional cleaning / circulation and good throughput for the chiller. With a little more experimentation, I think I'll have it optimized.

I suppose I could run the chiller and slowly lower the pump rpm to see where the heat pump cutoff actually happens in order to establish my min rpm, but I've been hesitant to do this so as not to damage the heat pump. I've been told by my PB that there should be no problem - it has a low flow safety switch for this very thing. But, I've already had to replace the chiller once - first one was nuked in the winter freeze - so I'm hesitant to do anything that might jeopardize the equipment. Thoughts?

 

[Jimrahbe]

John,

It is your pool and you should run it the way you want...

I was just trying to make the point that actual pool operation is more important than running as some specific GPM or flow stated in an equipment manual.

You are certainly not hurting running at a specific flow... If it works for you, it works for me..

Thanks,

Jim R.