CSV, Cycle Sensor and Tuning Minimal Run Time

[hdude]

Just installed new cycle sensor and figure I have a problem with the rate the pressure tank fills, so far the best I can get is 20 to 25 seconds when shutting off demand to pump shutting off.  Should I get an additional storage tank and/or are there adjustments I can make to prolong the time the pump runs after demand is shut off.  Seriously, when a toilet is flushed - the pump kicks in and only runs about 1/2 minute - probably due to the size pump.  If I bump up the CSV, the pressure tank fills even faster.   If I drop the CSV, then it starts to impact the pressure I would like to otherwise have.

System:  CSV1A @48psi at the well head (w/3/4" spigot opened fully).   
2HP Franklin Motor w/ 20GPM Sta-rite Pump.   
10 gallon (PSIkick) pressure tank - @40psi when empty. 
Pressure Switch set to 42/62. 
With minimal GPM (pump running), I have about a 4psi drop from the pump to the household.
Wen running about 7-8GPM through my GSHP (geoThermal) I have 32psi at the house and 50psi at the pressure switch.

CSV is set to 65PSI at 2GPM.  Pressure switch is 50/70.   Tank PSI is 48

[Cary Austin]

I have almost the exact same set up at my house and I get 1 minute and 15 seconds of run time.  A 3/4 spigot running wide open is probably too much flow to adjust the CSV.  So if you set it at 48 PSI with that spigot running, the CSV is probably set more like 52-54 PSI when running only 2 GPM.  I don't think you want to adjust the CSV down, so turn the pressure switch up.  Tighten the large adjustment in the pressure switch about two full turns to the right and get it up to about 50/70 setting.  Then up the air charge in the tank to about 45-48 PSI, and you will get a lot longer pump run times.

[hdude]

Set to 50/70 and tank at 47. I am getting about 10-15 seconds more tank fill time. 
For now I am setting the Cycle Sensor to 25 seconds from 15 because before it would "recyc" sometimes after only a setting of 20 seconds.

Question(s)
1.) Is the Cycle Sensor displaying amps?  My Cycle Sensor shows pump running @ 8.2 amps (@gpm) down to 7.8 when demand shuts off and as tank fills.  My solar logging software shows the pump running 2.4kW at 240 volts (kW/V =10amps), down to 2.2kW till tank fills.
2.)  When the pump stops, the Cycle Sensor usually drops to .01 / .02 which is normal.  Several Times is only drops to .6 and then to .02 next cycle.  Should I be worried?

Notes on Installation:
1.) The Cycle Sensor module holes do not align with hold in NEMA box.  Just as well - because using the knockout on inner bottom would prevent the sensor from fitting to the holes.
2.) There is no ground lug.  My wiring has ground through the breaker box, to the pressure switch to the control box to the pump.  I just used a twist tie for grounding through the Cycle Sensor.

[Cary Austin]

If you are still not getting 1 minute of run time the CSV can be adjusted down a few PSI and fill more of the tank at 1 GPM.  But if the CSV is holding 60 PSI or less when using one kitchen sink, it should take a minute to fill the tank to 70.

It is normal for the Cycle Sensor to read 0.1-1.2 or so when the pump is off.  It is really reading stray voltage on the line.  It actually displays amps times the power factor, which is very similar to watts, as you can see.

I tried to show on the Cycle Sensor installation video to use the self drilling screws included to make new holes in the metal back plate where needed.  Also you can ground to one of the screws in the metal back plate if you want instead of just twist locking the grounds together.

Since you are on solar you may want to look at a different pump end for that motor someday.  Where that Pentair pump is causing the amps to drop from 8.2 to 7.8 when the demand decreases, a pump made like a Grundfos brand would drop amps from 8.2 to 4.0. 

PS; Also want to set the Cycle Sensor for about 5 seconds less than it takes to fill the tank when no other water is on.

[hdude]

you may want to look at a different pump end for that motor someday...

Yea - . Just installed all the CycleStopValves bells and whistles (CSV, FlowInducer, Tank, CycleSensor) - I am hoping that "someday" will not be in my lifetime. 

I probably could have asked "what's the best pump and motor combo" for my needs and done it right.   The question about "best" I've seen asked my times on the forums, but generally see the response that Goulds/Pentair are OK and can last with a CSV.  I see Grundfos are generally recommended but they are much more a mystery and have various caveats?  I avoided VFD and went with what was already installed on my research as well as recommendation of my pump guy.  (also wanted to get water flowing again ASAP)

[hdude]

use the self drilling screws included to make new holes in the metal back plate where needed

I didn't realize the back plate was plastic coated metal.  All the same, I didn't have any problems mounting.  As far as setting the CycleSensor up - just followed the instructions and kept refining the settings along with the pressure adjustments we discussed to get the run times up. 

[Cary Austin]

The Pentair pump will be fine with the CSV, it is just not as efficient at low flow as some other brands.  You did good!

[hdude]

Still having problems.    Flush Toliet (1.6gpm per flush).   Pump Kicks usually kicks on.   Maybe 40 seconds run time.  Had two flushes within a couple minutes this morning - both kicked on pump.  Yesterday the CycleSensor shutdown when cycling was set @35 seconds.   Current setting:  CSV1A @52 while running 6-8GPM in house (130+ foot away and up 10ft 1-1/4 lines).  Pressure Switch @ 50-70.   10 gallon Tank @49psi.   

Could I be having a problem with the CSV passing as much as 2GPM when demand stops?   Something wrong with my pressures or settings?

I am about to bite the bullet and buy an additional tank; probably 20 gallon.  With the CSV1A and Pressure Switch setting, I don't think I will have any noticeable fluctuations (shower) as the pressure tank draws down to start the pump.

[Cary Austin]

A 10 gallon tank holds about 2.2 gallons of water.  So even if the CSV is passing 2 GPM, it should take longer to fill the tank.  Setting the CSV at 52 while using 6-8 GPM means the CSV is probably set at 55-57 or so while using 2 GPM.  So it is only filling the last half of the 2 gallon draw tank at reduced flow, but means you should still be getting 60 seconds of run time.

Try running your hose at whatever flow rate is needed to keep the pressure at 68-69 PSI, without letting the pump shut off.  At a steady 68 PSI you are letting out the amount that the CSV bypasses to fill the tank.  Measure the amount coming out of the hose and you will know the tank fill rate from the CSV.

Also measure with the hose and bucket how much water you get out of the tank before the pump comes on.  It could be the tank is not holding 2.2 gallons as it should for some reason.

If the CSV is bypassing too much flow or the tank is not delivering 2 gallons of draw, I can replace them.  You shouldn't need a larger tank.

[hdude]

Couldn't get a flow to run @68psi without shutting off. (did you mean 58psi?)

Pressure Tank drained about 2.2 gallons.  Pressure switch 50/70
Set a hose at the pressure tank manifold and throttled it to 2GPM.  Checked the CSV at the well and it was 68psi.

Turned down the CSV to 60psi  (opened CSV over 1 full turn from 68 - doesn't seem right - minor adjustments of a couple psi were 1/4 to 1/2 turn).
With the CSV @60psi -  tank hose @2GPM - it still took only 35 seconds to fill pressure tank after pump shutoff.
With the CSV @60psi - w/GSHP running (6-8GPM?) - CSV pressure is down to 40psi,  house manifold is 20psi.  Shower only flows 1GPM.
After pump shuts off @70-psi (Pressure drops some). I checked the 3 gauges @CSV=66psi, @pressure tank=66psi, at house manifold=66psi

Doesn't sound like constant pressure to me.  (before CSV guage dropped from 68psi @2GPM to 52psi @ 6-8GPM -  Now from 60psi@ 2GPM to 40psi @ 6-8GPM ).

I would like the flow at least where it was  (CSV @68psi and HVAC @30psi and shower running @2GPM or better).

[Cary Austin]

If you can't get a hose open enough to keep the pressure at 68, yes 68 without the pump shutting off, then the CSV is set too high (too far to the right / clockwise).  The tank has the 2.2, so it is good, and your pressure switch is 50/70 also good.

Now while running 3 GPM somewhere after the CSV, adjust the CSV to hold a constant 58 PSI.  So then it should hold 58 constant for a shower, and 48 constant if are using the full 20 GPM your pump can produce.  And yes the adjustment bolt doesn't need much as 1 full turn is 14 PSI change.



If you want 68 PSI while running the heat pump and a shower at the same time, you will have to adjust the CSV to hold about 75 PSI at 3 GPM flow.  To set the CSV at 75, the pressure switch will need to be turned up first to about 65/85.  With the pressure switch at 65/85 the cap on the PRV valve will need to be removed and tighten the adjustment so the pressure relief doesn't leak, and the tank will need about 60 PSI air.  The higher the pressure switch setting, the less water the tank holds, but you should still get close to 1 minute of run time after turning off all the faucets.

A lot of the last stuff you posted doesn't make sense to me, especially why the house is 20 PSI when the CSV is at 40?

[hdude]

It seems to me that my CSV is not delivering constant pressure.  The only benefit I am seeing from the CSV is the system does not cycle.

The 2HP Pump (L20P4HS) is rated to produce minimum of 20 GPM @60psi  for 150 lift. 
The pump is set@ 140' and my static is about 70' (I'm allowing for an additional 10' lift to house 150' away). 

With CSV set to 68psi @2GPM - Then turn on GSHP using 6-8GPM - the pressure at CSV gauge drops to 50psi   (I am only getting 30psi at the house)
With CSV set to 60psi @2GPM - Then turn on GSHP using 6-8GPM - the pressure at CSV guage drops to 42psi.  (I am only getting 20psi at the house)
With CSV set to 60psi @2GPM - Using only a faucet in house - I show about 56psi at the house

What explains why the pressure at the CSV drops almost 18PSI when the flow goes from zero to 6-8GPM

I'm perplexed about the pressure drop to house, but once I get constant pressure at the CSV - I can adjust the pressure to what I want.  Or is the CSV working properly?

Note:  Well and supply to house are 1-1/4".  At the house the supply pipe is reduced to two(2) 3/4" PEX lines running about 25' to manifold.  The GSHP is then feed through a 1/2" copper and 6.5GPM Taco Geo Valve (although I think I am getting more flow than that). I have monitored for leaks - none pressure holds steady when not in use.   Not many bends or couplings or other restrictions.

[Cary Austin]

There is a chart for the reduced pressure loss in the CSV1A here.
https://cyclestopvalves.com/pages/csv1a-specifications

But you should only have about a 5 PSI loss at 10 GPM, and to loose 18 PSI you would need to be flowing 25 GPM.

At 10 GPM there should only be 5 PSI friction loss in the CSV1A.  Your 2HP, L20 pump should also be doing about 25 GPM at that 80' head and 68 PSI pressure.  So the only thing that makes sense to me is that your heat pump is using about 25 GPM.  And except for the Delta T or temperature difference, the heat pump will work with 6-8 GPM or 25 GPM and not know the difference.  Can  you check the dump rate after the heat pump?

[hdude]

The GSHP discharge after 150' of 3/4" black tubing at a 3/4" hose bib tested @5GPM.  The TACO valve is rated at 6.5GPM and I'm giving it all it wants.  So probably some loss of flow where I am able to test.  I have a 20 degree temperature delta (65in 85out).   My 5 ton GSHP system really needs more flow (10GPM+) as temperatures out here are 105plus the last few days and it barely keep the house at 76 degrees.

I can adjust the CSV to a higher pressure which the pump can/has provided.  The CSV just does not seem to be delivering constant pressure under increasing demand, at what ever pressure I've set it to.  I can work around this by setting the CSV to 70, pressure switch to 55/75 and have good enough pressure in the house and get 40psi available while using GSHP somewhere at 6GPM.  But I don't think this is how the CSV should be working (or not).

[hdude]

Cross Check:   GSHP off.    Sequentially turn on faucets in the house.  GPM flow test @ 2GPM at each faucet and flow didn't diminish that much as faucets were added.    Gauges are both new and identical.

Faucet#      PSI@CSV    PSI@House Manifold
1  2GPM             65              58
2  4GPM  (+2)    58              44
3  6GPM  (+2)    53              35
4  8GPM  (+2)    50              30   
5 13GPM (+5)    46               ?        Turned on 3/4 Drain Bib @ tank on full (5+GPM est)

Note:  When only GSHP is running house PSI is at 30 PSI - so the above confirms it is running @ 8GPM.  (Also per the CycleSensor amps below)
Also:  I noticed that Amps were about 7.6@2GPM,  7.8@4GPM  8.0@6GPM  8.2@8GPM and 10.1@13GPM.

To me it looks like the CSV is not working correctly to maintain "constant" pressure.  CSV1A spec says pressure falloff should be 5PSI for 10GPM.  This test shows I have plenty of flow available.