Cycle Stop Valves
Pump System Questions and Answers => Applications => Topic started by: JEG in Raleigh on July 06, 2019, 10:49:57 AM
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I'm not dealing with irrigation well issues....just the well for my house. I have an 800' deep well (water level 30' below the top of the casing) and had been having problems with the 4-year old 3/4 hp well pump, 8 gph, supplying my domestic water. It had been set at 300' and never provided enough volume if more than one valve was open. The check valve wasn't working either. I have a Well-X Trol 44 gallon pressure tank. I told the pump installer that I wanted more volume and pressure, and a high quality pump. They put in a 1.5 hp Gurundfos producing 10 ghp, and set it at 500'. Well, I'm an idiot, and did not look at what gauge wire was feeding the old pump, and it was only 14/2 (well is 120' from my breaker panel). So, when they installed the new well pump, they ran 8/2 wire down the well and connected that to the 14/2 wire coming out of the panel. The day after the installation, I was running an outdoor hose for 20-25 minutes and I suddenly lose water pressure. I fumbled around flipping the breaker (that didn't work) and was scratching my head for 5 minutes, when the pump came back on. The manual said the pump had a thermal overload safety and at that point I checked the breaker size and wire size against what the manual said and discovered the undersized wire and breaker. So, I'm having an electrician run a subpanel out to the well with 8/2 wire and I want to make sure I'm doing everything I can to extend the life of the pump.
That brings me to the CSV. So now with the more powerful pump being 200' deeper in the well, with 470' of head, someone on another forum suggested I might have a worry with upthrust, and suggested I might need a larger pressure tank, I'm guessing because the more powerful pump will now cycle on and quickly fill the pressure tank, then cycle off too quickly. So, I am trying to figure out the best way to minimize the potential issue with upthrust and reduce the cycling on and off of the pump. I don't have room for a larger pressure tank, but I can add a second pressure tank in the closet behind my utility room where the current pressure tank is.
QUESTIONS:
1. I'm not clear about this.....can I use the CSV with a pressure tank?
2. Will the pressure tank fill up when the CSV is managing a minimal flow, like a single sink valve running or must the CSV not be restricting flow for the pressure tank to fill?
3. If I turn on a bathtub valve to fill a bathtub, and that drains my pressure tank after a number of minutes, and the CSV kicks in and regulates the flow and then I turn off the tub valve and stop all water flow, will the pressure tank fill up again?
4. Will a CSV have any positive effect on minimizing upthrust?
I'm a total rookie here, so answers and explanations like you'd give to a 2nd grader would be helpful. Thanks.
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I don't think the #14 wire will cause the overload to trip. You can actually run a 1.5HP on #14 wire as long as 190'. It will work like a reduced voltage soft starter and should not trip the overload. If it did trip the overload, it would be on start up. Since the pump was running when it tripped the overload, I am guessing it is a flow issue and the motor is not getting cooling. If the pump is set below where the water comes into the well, it is top feeding the pump, and the motor will get hot. Do you know if the well is cased, or where the water is coming into the well?
Upthrust will be a problem. It doesn't matter that the pump is set at 500', it is still only lifting from the water level of 30'. So you have a pump designed for 500' with only 145' of head on it. The only time it will see 470' of head is when the water level has been pulled down to 370'. Having such a deep set pump is such a shallow well means there will be 230 PSI on the CSV and the pipe before the CSV.
Yes a CSV helps with upthrust. But you have gotten such an over sized pump it will take two CSV1A valve to bring it down from 230 PSI to 50 PSI. And yes a CSV works with a pressure tank.
Explanation for a second grader is to find out why it is tripping the overload, because the #14 wire isn't the problem. I am thinking the pump is set too deep to get cooling from below the motor.
Also see our video as to how a CSV works here.
https://vimeo.com/248374194
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Cary, thanks for your reply. I don't understand what you are saying in your comment about upthrust.....I don't understand the math. I have an 8" well casing for my house. The well had recently been bored when we purchased the property. A developer was going to try to develop it into 10 building lots, and they bored the well intending for it to be a community well. It did not produce enough water for that, but according to the well report, the well is 815' deep and the 8" well casing depth is 63'.
Other notes on the well report:
1. WATER LEVEL BELOW TOP OF CASING = 33'
2. WATER ZONES (depth) from 645' to 646' and from 740' to 741' (I don't know what this means)
3. YIELD - 10 GPM
Back to my not understanding what you are saying about upthrust; the water level below the top of the casing is 33' and the well pump is at 500' from the top of the casing. Doesn't that mean the head is 500'-33'=467'? Could you please explain or point me to a link that explains why there is only 145' of head? And you comment that its such a shallow well.....isn't there 300' of water below the well pump that would be cooling the pump? I was thinking that there is a continuous column of water from the bottom of the well at 815' all the way up to the water level below the top of the casing at 33', which would be a column of water 782' long. And with an 8" hole, that would be ~782 x 2.6 gallons per LF = 2000+ gallons of water in the well being replenished at 10 gallons per minute per the well report. If water is entering the well above the pump, wouldn't gravity cause it try to flow downwards towards the bottom of the well and be filling up the 300' space between the well pump and bottom of the well, thereby keeping the pump bathed in water, unless the pump depleted the well? And with the well replenishing at 10 GPM per the well report, and the pump having an average output of 10 GPM, wouldn't it be hard to drain the well? When I had the problem the other day with the pump turning off, I was running one garden hose for about 20-25 minutes and no other water was being used in the house.
How would two CSV1A's work instead of just one? Would one be set at a higher pressure and the second at the target pressure? I want to understand the mechanics of what would be happening. The pump I have is a Grundfos 10S15-21
Thanks very much.
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Water under water doesn't weigh anything. Even though the pump is set at 500', it is only lifting from 33'. 50 PSI is the same as 115' of head so 115' plus 33' is a total head the pump will see of 148' of head. As the water level pulls down the head will increase accordingly. But like you said 2 gallons per foot, a house uses maybe 300 gallons per day, so you are never pulling it down below about 180' or so. Your water is coming into the casing at 645' and 740'. But you will need to pull the water level down from the top before any will start coming in from below. As you are pulling water from above the pump, you can be boiling water 2' lower at the bottom of the motor. Also the pump should have been cycling on and off while just running one faucet. Either or both of those things can cause an overload to trip.
A 4" shroud or flow inducer over the pump makes water go past the motor and keep it cool even when being fed from the top.
With such a high head pump and such shallow static water level, the first CSV1A would be set to 150 PSI, and the second would be set to the 50 PSI you want. That way there is only about 100 PSI difference across either CSV and they will last a long time.
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Thanks for the explanation. Would I install the two CSV's right before my pressure tank, next to each other, in series? My inlet pipe is 40" long and vertical, and 90's horizontal right before the pressure tank tee, and connects to the tee with a 5-inch long piece of horizontal pipe. I don't have room for even one CSV valve attached to the 5-inch long pipe running horizontally, but I do have room to attach both to the vertical pipe. Can they be installed on a pipe that is running vertically?
How good of a job will the CSV's do at mitigating the upthrust?
How would I know if/when a CSV has failed and needed to be replaced?
Thanks.
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The CSV's can be installed in any position you want. The only consideration is that all the pipe before the CSV will see the 240 PSI. You can tell if a CSV has failed because the pump will turn off while you are using water. With a CSV the pump will continue to run as long as a faucet is open.
Each CSV1A will have about 15 PSI of friction loss. So two of the CSV1A valves will add 30 PSI or 69' of head to the 148' we already added up. That would be a minimum head of 217', which shows to keep a 10 GPM, 1HP at less than 16 GPM and below the upthrust limit.
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My house is on a slab, and the supply line is buried in a wall, Where it emerges to feed the pressure tank, the pipe material is 1" pex, which the specs seem to say, has a pressure limit of 160 PSI. Are you saying that right now, before I install the CSV, that pipe is being subjected to 240 PSI?
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Without a CSV all the pipe sees is the 40 to 60 when using a 40/60 switch. With a CSV all the pipe before the CSV will see 240 PSI because you have such a high head pump with water at 33'. The pex won't handle that pressure. It would be best to install the CSV's right at the well head before the pex. The well pipe should be able to handle the pressure, and the pex after the CSV will only see 40 to 60 PSI.
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Thanks Cary. I called your company and spoke with a guy to whom I described what I had and the PE piping I had and he said it would not handle the pressure, so I'm SOL. I'm going to visit the pump company that put the new well pump in and talk with them about replacing the pump with a smaller one. This company handles Grundfos and Franklin pumps. Based on the info I have given you (depth 800', 8" bore, static water level at 30', 120' from the well to the house, and water coming into the casing at 645' and 740', what Grundfos pump would you recommend?
Once I get the pump issue resolved, I'll be contacting you to buy a valve.
Thanks for all your help on this. It's been an education.
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That was my son Sam. Yes 240 PSI is more than i like on even 200# poly pipe. But I can't believe anyone would set a pump at 500' on poly to start with. Just at the bottom of 500' you will have 216 PSI, just from the depth.
I would probably set a 10 GPM, 1HP pump at about 300'. Then the regular PK1A will work and poly pipe can easily handle the pressure. You don't even have to change the motor. Just put a 1HP pump end on that 1.5 HP motor and cut off 200' of pipe and wire.
Of course you could always just get a larger or multiple tanks and live with what you have.
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I actually do have room to add a second pressure tank in the closet behind my utility room. I could fit a tank as large as 81 gallons.
Cary, if you are still game to answer my questions, here is some more info I found on the Grundfos website. Here is a product selection tool they have. I plugged my numbers into it based on what you had told me. I have not been able to upload documents to my forum posts, so I am going to email you the screen shot images of what I entered, using their tool. BTW, here is a link to their tool page. https://product-selection.grundfos.com/front-page.html?sizeType=guided&qcid= When I plugged my numbers into the product selector, my pump came up as one of the appropriate pumps.
One piece of info they ask for is the NPSH, which I don't understand, but I found an online calculator for it (big link) https://inventory.powerzone.com/resources/npsh-calculator/%3Aal%3D315%3Aalu%3DFeet%20Above%20Sea%20Level%3Afs%3D1%3Asp%3D470%3Aspu%3DFeet%3Afr%3D10%3Afru%3DGPM%3Avc%3DWater%3Aft%3D68%20Deg~p%20F%20(20C)%3Av%3D0~p999996%3Avu%3DCENTIPOISE%20%2F%20CP%3Asg%3D0~p998%3Avp%3D2~p4%3Avpu%3DKPA%3Apl%3D620%3Aplu%3DFeet%3Apid%3D1%3Apidu%3DInches%3Ahzc%3DPolyethylene%3Ahzfc%3D140%3Arh%3D0~p007%3Arhu%3DMillimeters%3Arfvu%3DFT%2FSec%3Arnu%3DPSI%3Afits%3DTee%2C%20Line%20Flow%7C1!Elbow%2C%2090%C2%B0%20SR%7C1!
I generated an NPSH number using 300' of water below the centerline of the pump and also one using 470' of water above the centerline of the pump. When I plugged the NPSH numbers generated into the Grundfos product selector, my pump still came up as appropriate.
This is a link to more info on the pump: https://us.grundfos.com/content/dam/GPU/Literature/SP/LSPPG001-0212-SP-ProductGuide.pdf I'm emailing a screen shot of a blurb from it about a stop ring that they say protects it from upthrust.
Thanks again.
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I was assuming the 10S15-21 was the pump you have. That pump is good if the water pulls down to 300’. But at 33’ even with 115’ (50 PSI) added is only 148’ of head. If the water pulls down that pump is needed. If the water doesn’t pull down very far that pump is way too big. Either way a big tank is about the best you can do since that pump builds so much pressure with water at 33’.
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Hello Cary, I'm back again with the ongoing saga. So, I went to see the well pump company a couple of days after my last post and they are going to swap out the 1.5 HP 10 GPM pump with a 1 HP, 10 GPM and they will set the new 1 HP pump back at 300', where the original 0.75 HP pump that needed replacement was set. They are installing this tomorrow, 07/22/19.
I'd like to pick your brain about a few other things with this situation. Since the original episode back on 07/03/19 where the new 1.5 HP pump had shut down after watering some plants for 20 minutes......then came back on again after 20-25 minutes, we have used water sparingly and not run a garden hose for more than 5-10 minutes, and we have not had any pump problems. Then, the afternoon of 07/19/19 I was dialing in a dosing pump for a H2O2 injection system. I had the water running at about 3 GPM for 20-25 minutes, and I lost water pressure. This time, it was the breaker in the panel that tripped, as opposed to the thermal overload protection on the pump. In earlier posts that you responded to, where I explained the current wiring, I mistakenly told you it was 14/2 wire running 120' from my panel to the 8/2 wire at the top of the well casing, then 8/2 down the hole 500' to the pump. It is actually 12/2 wire running from the panel to the top of the casing. So, the breaker that tripped is only a 20 amp dual pole breaker. The breaker would not reset. Over 4 hours, I tried several times to reset it and the panel would hum for 10 seconds then the breaker would trip. I called the pump contractor and he said let it sit longer and try it again. The manual calls for a 35 amp breaker. NEC says 20 amps max for 12 gauge wire, but I was just trying to get through the weekend before the new pump was installed on Monday, and from what I read online, I could go to a 30 amp breaker in some situations, and so I figured I try it to see if I could get the breaker to stay reset and see if the pump would run. I tried it once, and the 30 amp breaker tripped. I did not try it again until this morning. I reset the breaker and it stayed reset and the pump did not run....dead. I turned the breaker off and re-installed the 20 amp dual pole breaker that should be on that wire size. Hold that thought......
The specs on the new 1 HP pump say it needs a 25 amp breaker, which I cannot use with my 12/2 wire and be in compliance with the code. In a previous post, I mentioned that I have no way to get larger wire in to my panel without jack-hammering up concrete in my carport. But my meter base is a remote meter base pedestal and I can trench directly from it to my well, and have a sub panel run from the meter base pedestal to supply the well with power. I had my electrician out today to go over installing the sub-panel and proper size wire to supply the new 1 HP well pump. The present setup has wire from the pressure switch running directly to the well and down to the well pump. Since the new power supply will come from the sub-panel, we will use the current 12/2 wire running from the house panel to the well, as the control wire to activate a pump start relay that will be on the new sub-panel pedestal being installed by the well. Here are my questions:
1. In the Grundfos manual, there is a note that says "Single-phase motors (thermally protected): Use with approved motor control that matches motor input in full load amperes." WTF! The well pump installer installing the 1.50 HP pump turned that 20 amp dual pole breaker on and off half a dozen times during the installation, clearly seeing that it is not a 35 amp breaker. And he connected that 12/2 wire to the 8/2 wire he ran down the hole and saw without question that there was no motor control anywhere! There is no starting capacitor to give the motor the 62 amp jolt that the motor needs at start! Does it also need a run capacitor? I think the motor is fried after 2 weeks of being started without a start capacitor and then in addition, with inadequate voltage being delivered by the undersized wire. Am I likely right about that?
2. On Friday, when the breaker blew and the pump was down on the main house, I needed to get water into the house for the weekend. We have a separate garage with an apartment over it 120' away from the main house, and that garage has its own well and well pump. I connected a string of garden hoses from a hose bib on the outside of that building and ran that length of hose down to the main house, in through a window, and made an adapter to connect the male end of the garden hose to the drain cock on the pressure tank of the main house. I opened the drain cock on the pressure tank and the hose from the garage filled the pressure tank of the main house. This provides adequate water and the pressure tank is pumping up to 50-55 psi. So, we can function this way. Here is my question: The electrician is not going to be able to do the work on the sub-panel for 3-4 weeks. Am I correct, that if I start using the new 1 HP well pump that will be installed tomorrow, without a motor control, then I'm going to fry that pump too? Is there any work-around to not screw up the new pump, or do I need to use my garden hose water supply for the next 3-4 weeks?
3. I don't trust the pump installers that they know what they are doing. I want to make absolutely sure I get the correct motor control for the Grundfos pump, and I have been completely unsuccessful in getting any information from Grundfos. I can't speak to a person.....only a recording, and I certainly can't speak to an application engineer. Who can give me accurate information about which pump start relay I should buy and which motor control panel I should buy?
4. With this new pump.....1 HP, 10 GPM, pump set at 300', well depth 800', static water level 30', well produces 10 GPM, water inflow at ~650' & 700', 44 gallon pressure tank, 40/60 pressure switch, can I now use a CSV?
Thanks!
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With a 1HP, 10 GPM pump and static at 33' there will be 155 PSI on the pipe prior to the CSV1A, which is fine. So, yes you can use a CSV1A on that pump. I doubt the small wire had anything to do with the failure, unless it was skinned and shows a short somewhere. The control box is a standard capacitor start box for 1HP pumps. !.5HP and larger usually have a start and a run capacitor, but not always. Yes a 1HP needs at least a 25 amp breaker, 30 would be fine.
I will bet when you pull the pump the problem will be obvious. If not, send some pics and I will help try to figure it out.
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Cary, the pump contractor changed the pump today. You predicted a couple of weeks ago, that upthrust and cooling would be problems, and that premature failure would occur, and the 1.5 HP pump motor was indeed toast and had failed. The new 1 HP pump installed today was set at 300' and I made a cooling shroud out of 4" PVC pipe that the contractor installed over the pump. I put a 25 amp 2-pole breaker on the 110' of 12/2 wire supplying 300' of 8/2 wire down the hole. The 25 amp breaker on 12/2 does not meet NEC, but is temporary for a few weeks. My electrician will be installing a sub-panel by the well that will be fed by 25 amp 2-pole breaker and 100' of 8/2 wire coming from a panel on the meter base.
I'm ordering a CSV today. Thanks for all your help and patience over the last couple of weeks with this project. It's been an education!
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I love it when a plan comes together! :)
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Cary, I'm quoting another post from your forum because it pertains to questions I have following a conversation with Sam today (see it below my questions). I called your office today and spoke with Sam, and told him I wanted to buy a CSV and make sure that it would now work with my new pump. He told me it would subject my pipe to 150 PSI, and he asked me the type of pipe I have. The pump is now at 300' and I have 200 psi polyethylene pipe with SS barbed fittings, and the barbed ends of the fittings looked to be about 2" long when I was watching, and they used 3 beefy hose clamps on each connection and used a cordless impact driver to tighten them. I know you would not use that pipe at that length, but that's what I'm stuck with. Sam was concerned that the back pressure from the CSV could blow the pipe off the fittings. That being said, for the 2-3 weeks that I had the 1.5 hp pump that failed, THAT pump was set at 500' with that same pipe and fittings, and back on July 6, you replied to me and told me that that I had 230 PSI of pressure being generated by that 1.5 hp pump at that 500' depth with the 30' static water level. When the failed pump was pulled today, there was no sign of fitting slippage or pipe failure. So, since the new setup, with a 1 hp pump at 300' and a CSV would generate 150 psi.....80 psi less than what I had with the 1.5 hp pump......do you think I'd be OK with the CSV?
quote author=IanInCo link=topic=1897.msg2722#msg2722 date=1381537078]
I just had a new pump installed. The old 1 1/2 HP Red Jacket finally burned out after 18 years. Replaced it with a 1 1/2 HP Stainless Steel Franklin Electric.
Well is 400' deep, pump sits at 360ish and static water is 250ish.
I watched them pull the old one out and I noticed the 1" PVC that is in there is rated I believe for 125 psi.
If that's the case and I put in a CSV, wouldn't the back pressure exceed that rating when I'm running say a sink or flushing the toilet? The last thing I want is a burst line 300' down. I'm already out $2,000 for the new pump and labor.[/i]
Is my concern valid when using a CSV?
Thanks for any info.
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This can’t be right. I guess it is possible that your pump man screwed up and used 125 PSI pipe in that well, but I doubt it. Assuming you have a 10 GPM series, 1.5 HP pump the pressure from just being set at 360’ is the same as 155 PSI, then add the 60 PSI that the pump will build before the pressure switch shuts it off and you have a total of 215 PSI on the bottom joint of pipe. That is 215 PSI with the old style pressure tank only system, so the pipe needs to be rated for more than that.
Now adding a CSV will put more pressure on that pipe. But the 10 GPM series pump can only build 251 PSI total, even against a closed valve. So there is only 36 PSI more pressure on the pipe when using a CSV than when not using a CSV.
I think what you saw was 1” SCH 120 on the pipe. That is much more common for drop pipe, and is what your well needs because of the depth. SCH 120 pipe has a rating of 360 PSI. On top of that the burst pressure of any plastic pipe is usually 2 to 5 times the working pressure rating of the pipe.
Pressure rating of the pipe is important when using a CSV, but isn’t as much of a problem as you would think. Drop pipe has never been an issue with a CSV because as stated above, it has to be strong enough to handle the depth and pressure of the pump anyway. The CSV doesn’t usually add much pressure to the drop pipe.
The pipe from the wellhead to the CSV is usually more of a concern than the drop pipe. But you can subtract the static water level from the total pressure the pump can build, because it has to lift this much to get water to the surface, so you don’t see that much pressure on the underground pipe. In your case, if I am right about the 10 GPM series pump, your underground pipe before the CSV will see up to 142 PSI. Even SCH 40 PVC or 160# poly is rated for more than this, so you should not have a problem.
You are smart to ask this question as it is one of the only concerns when using a CSV on such a deep set pump. But once you see that your pipe is rated high enough to handle the pressure, you should realize the extra backpressure from the CSV is good for the pump. The extra backpressure from the CSV is what keeps the pump from cycling itself to death. The CSV puts just enough backpressure on the pump to make it pump exactly the amount of water you are using, so the pump is not cycling on and off while you are using water at any flow rate. And that is the best thing for the pump.
Also the CSV eliminates water hammer from the pump starting and stopping. Water hammer happens in a fraction of a second, but can be 10 times the pressure that the pump can build. A water hammer “thump” when the pump starts or stops with the old conventional tank only system can cause a pulse of 2500 PSI on your pipe. So not only is the backpressure from a CSV a good thing for the pump, but it is also good for the pipe. The CSV makes the pipe see a max pressure of 251 PSI with that 10 GPM pump, but that is much better for the pipe than water hammer pulses of 2500 PSI from an old conventional pressure tank system cycling on and off.
To sum it all up, if that is 125 PSI pipe in the well you will have problems even without a CSV. But if it is Schedule 120 as it should be, then backpressure from a CSV is not the problem, it is the solution.
[/quote][/i][/color]
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Please let us know how you like it.
thanks
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I'm sorry....I probably shouldn't have quoted that long post because I'm not sure if you saw my question.
I called your office yesterday and spoke with Sam, and told him I wanted to buy a CSV and make sure that it would now work with my new pump. He told me it would subject my pipe to 150 PSI, and he asked me the type of pipe I have. The pump is now at 300' and I have 200 psi polyethylene pipe with SS barbed fittings, and the barbed ends of the fittings looked to be about 2" long when I was watching, and they used 3 beefy hose clamps on each connection and used a cordless impact driver to tighten them. I know you would not use that pipe at that length, but that's what I'm stuck with. Sam was concerned that the back pressure from the CSV could blow the pipe off the fittings. That being said, for the 2-3 weeks that I had the 1.5 hp pump that failed, THAT pump was set at 500' with that same pipe and fittings, and back on July 6, you replied to me and told me that that I had 230 PSI of pressure being generated by that 1.5 hp pump at that 500' depth with the 30' static water level. When the failed pump was pulled today, there was no sign of fitting slippage or pipe failure. So, since the new setup, with a 1 hp pump at 300' and a CSV would generate 150 psi.....80 psi less than what I had with the 1.5 hp pump......do you think I'd be OK with the CSV?
Thanks.
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Is the new 1HP pump at 7 GPM or a 10 GPM series, and how deep is it to water?
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It’s 10 GPM set at 300’ with a static water level 30’ below the top of the well casing.
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A 10 GPM, 1HP can only build 164 PSI even if the static level is at the surface. That pump will work fine with the CSV and poly pipe.
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GREAT, thank you!