Cycle Sensor - Setting the Rapid Cycle setting with a CSV in the system

[JEG in Raleigh]

Hi Cary.  You helped me last summer with a series of problems with a new well pump and I installed a CSV at that time.  It has worked great and I have had no other problems with my system.  Around that time, I also bought a Cycle Sensor and am just now getting around to installing it.  I have read through the documentation and watched the installation video, so I think I'm ready to install it, but I do have a couple of questions about the rapid cycle setting.

In the instructions, it says that 'the "Rapid Cycle" setting needs to be slightly lower than the number of seconds it takes to fill the pressure tank to the pressure switch shut off point'. When you helped me last summer, rapid cycling was a big problem I was having and the CSV took care of that.  Prior to installing the CSV, my pressure tank was filling in 30-45 seconds, and the new 1.5 hp pump that had been installed was too large and as you predicted, it burned up in about 2 weeks.  The replacement pump is a 1 hp pump and with the CSV, it takes around 200 seconds to fill the storage space of the 44 gallon pressure tank.  So when I set the Rapid Cycle setting, should I be setting it at 0.75 X 200 seconds or should I be using the pump run time of more like 0.75 X the pump run time the system would have if it did not have a CSV......like 45-60 seconds?

Another question, just for my understanding.....my pump is a submersible centrifugal 1 hp pump with a 10 gpm output.  If the bypass in the CSV is a 1 gpm bypass, and I have all my water valves in the house shut off, and the storage volume of my 44 gallon pressure tank is approximately 11-12 gallons, how is 12 gallons able to be pumped into the tank able in 3 minutes, 10 seconds if the bypass of the CSV only permits 1 gpm?

And my last question.....with a CSV and now, with a Cycle Sensor, what would be the symptoms of a waterlogged pressure tank with a blown bladder?

Thanks.

[Cary Austin]

With a 40/60 switch and the CSV set at 55 PSI the tank is 3/4 full before the CSV starts to work.  Then the CSV should hold 55 PSI constant for as long as you are using water.  When the faucets are turned off, the CSV only has to put the last 2-3 gallons it the tank to get it from 55 to 60 PSI, which should take 2-3 minutes.  2-3 minutes is about as long as you need the pump to run filling the tank.  So, you can adjust the CSV up to say 57 PSI and it will take closer to 2 minutes.

But whatever time it takes to fill the tank, it should take at least that much time every pump cycle.  So if the pump runs 200 seconds to fill the tank, set the Cycle Sensor for 150 seconds.  When/if you lose air charge in the tank and it takes less than 150 seconds to fill, the Cycle Sensor will shut the pump off.  The Cycle Sensor is sensitive enough to let you know when the tank is just slightly low on air.  It will shut the pump off at 150 seconds, which is way before the tank is waterlogged and causing the pump to cycle every second or two.

[JEG in Raleigh]

Got it, thank you.

[JEG in Raleigh]

Cary, Sorry, more questions.  Please read through this stuff before you answer me.  I have some direct questions, but I also am asking you to confirm that my understanding of how the system works is correct,  or if I'm mistaken, please explain the mechanics of what I am misunderstanding. 

So here is what I did yesterday before I sent the questions yesterday.  I looked at the pressure gauge on my pressure tank.  It was near 40 psi, so the pressure switch was close to being ready to turn on the next time i used a faucet.  I turned on a faucet, and in about 15 seconds, the pressure dropped to the 40 psi kick-on point of the pressure switch.  The switch contacts engaged and the pump turned on.  I turned off the faucet, so now no water was being used in the house.  I also have a pressure gauge installed in between the pump and the CSV, immediately before the CSV.  When the pump tuns on, the pressure gauge before the CSV swings from 40 psi (the turn-on point for the pressure switch and pump) to approximately 150 psi, where it remains while the pump is running.  When the pump shuts off, at 60 psi, the gauge before the CSV drops down to 60 psi, which matches the pressure gauge on the pressure tank. 

So, when the pressure in the pressure tank drops to 40 lbs.....the turn-on point of the pressure switch.....isn't the storage area of the tank pretty much empty....like 10-12 gallons has been used to drop the pressure down to 40 psi?  In your reply to me this morning, you said that with a 40/60 switch and the CSV set at 55 PSI the tank is 3/4 full before the CSV starts to work.  Well, when the pressure switch kicks the pump on at 40 psi, I see the second pressure gauge that I have installed in front of the CSV immediately swing up to 150 psi, and I was thinking that this back pressure indicates that the CSV is actively doing something at that point....is that not correct?    I don't have any water running in the house at this point, because I turned off the faucet as soon as the pump came on,  so am I'm guessing that what the pump is doing is filling the pressure tank, and nothing else at this point, is that correct?   So, if the tank was essentially empty when the pressure hit 40 psi, how did it become 3/4 full before the CSV started to work?  As I said yesterday, I timed the run-time on the pump when it came on at 40 psi, and that was 200 seconds.  What you said about the tank being 3/4 full before the CSV started to work, and with the 1 gpm bypass working, the 200 seconds of pump run time makes sense, if the tank was 3/4 full.   But I don't understand how the tank became 3/4 full.  The entire run time of the pump was 200 seconds.....from a reading of 40 psi on the pressure tank. So.....not understanding how the tank is 3/4 full at the 40 psi point.....it seems to me that 11-12 gallons is being pumped into the tank in 200 seconds, despite a 1 gpm restriction on the flow rate because of the bypass. 

And one other question....let's say I have water running for 5-10 minutes in the house, like a shower head.  The pressure tank drains, the pump kicks on, the CSV starts working  and my pressure rises to 55 psi, where it holds constant with the pump continuing to run, and the CSV maintains that psi pressure.  Could you please describe the mechanics and route of the water that is coming out the shower head at 55 psi?  There, of course, is a tee on the pressure tank.  The "top" leg (if looking at the letter "T", the leg that would be considered the horizontal leg), is connected on one side, in a straight line to the water line coming from the pump and the the main water line supplying the house exits out the other end of the horizontal leg.  The "vertical" leg of the tee (if looking at the letter "T", the leg that  would be considered the vertical leg) attaches to the pressure tank.  When a faucet is open and the pump is running, is the water just shooting by the intersection of the horizontal leg and vertical leg of the tee and continuing to the open faucet?  And if the open faucet is only demanding 2 gpm, does the CSV close down so that only 2 gpm is going past the valve? So,  does the tank only fill once the the water to the faucet is shut off?  If what I am describing here is indeed what happens, then I go back to my question about how does the tank become 3/4 full so that once the water faucet is shut off, only 1/4 of the tank remains to be filled?

Thank you.

[Cary Austin]

All sounds about right.  Except with a 44 gallon tank (10 gallon draw) using a 40/60 switch and setting the CSV to 55 PSI it should take about 30 seconds before the tank is filled to the 3/4 full level and the CSV starts working before you see the 150 PSI on the inlet side. 

And yes the water just goes right past the tank and straight to the shower or faucet, as the CSV is only producing exactly the amount being used.  There is no extra water produced to go into the tank, so it goes right to the faucet.

If the shower is on and the CSV is holding 55 PSI steady, it should also take 30 seconds before the CSV starts working after the pump is started at 40 PSI.  But that part happens really fast with a 44 gallon tank, so you have to be watching quick.

[JEG in Raleigh]

When the pump starts, the pressure gauge in front of the CSV does not swing to 150 immediately.  It does indeed take probably 30 seconds or so to slowly climb to 150 and the pressure gauge on the tank is climbing to 55 psi during that time also and then holds at 55 while the shower is running.  So then the tank is filling up until it hits 55 psi while the shower is running, is that correct....and at that point the CSV is working and the volume of water is cut back by the CSV to the amount being demanded by the shower, so the tank is not filling further, is that correct?

Before I had the CSV and my old new pump was in the process of burning up 2 weeks after it was installed, how was the system operating?  I thought that the pump would fill up the tank then shut off, and the shower would draw down the tank, then the pump would turn on and fill it up again, then the shower would drain it, and so on.  So the short duration of on off on off was frying the motor. I know the actual flow rate coming into the house is not the 10 gpm rating of the pump, but to keep the math easy,  In that scenario....without the CSV..... is the 10 gpm flow rate of the pump simultaneously feeding the shower and filling the tank?  So 2 gpm would go to the shower and 8 gpm would go to the tank?

Thanks.

[Cary Austin]

Yes, yes, and yes.  I wish everyone understood how the CSV works as well as you do.