Press. Tank, Press. Switch Question

[MikeD74T]

jimainiac, You could hire an engineer to give you an exaxt answer, or since your going to move things anyway, just move the tank & see how it works. If the pump short cycles then you have the option of moving the switch or using a larger pipe between the tank & switch.
If you're moving things to prevent freezing remember that even when depressurized a switch diaphram can contain enough water to be damaged by freezing. MikeD74T

 

[GaryQWA]

I'm certainly no expert here but I can't see a problem with the pressure switch located "in the general vicinity" of the tank. Is a few feet going to make a difference?

The pressure tank is there to buffer any surge when the pump comes on. I can't see a big difference in the line pressure over a few feet, of course my pressure switch is only a foot away from the pressure tank.

Maybe a pump guy will chime in, the question has me curious.

The 30-40' is much more than "in the general vicinity"... I am a pump guy with roughly 20 years experience with customers' well pumps and water treatment equipment.

The pressure tank is used to provide the power to move water when the pump is off. It also works as a water hammer arrestor but that is not its purpose. Water hammer is not the problem in having a switch away from the pressure tank

With the switch 30-40' away from the pressure tank, the switch is very likely to slap from off to on and off to on again and again repeatedly until the water use stops, regardless of the size of the pipe for this/the last 30-40'. That KILLS pump motors and spins the electric meter.

Steve mentioned that on off problem before I replied the first time. The only way to prevent that slapping on off is to spread the differential on the switch. I.E. 30-65 etc. The result will be a very noticeable fluctuation of pressure whenever water is used. The size of the pipe or pressure tank doesn't matter. To prevent the fluctuation, use a CSV (Cycle Stop Valve) which gives you many fewer starts on the motor and constant water pressure while using a very small pressure tank.

Also, the switch will have to be set higher than normal the farther away it is from the pressure tank and fixtures because of pressure losses in the pipe and its fittings; albeit the loss will be small.

So run the same ID pipe (probably 1") and put the switch at/on the presssure tank and set the cut-in and out at 30/50 etc. with 1-2 psi less air pressure in the tank than the cut-in setting of the switch with no water in the tank. I.E 30/50 gets 29-28 psi air pressure with no water in the tank. That is a proper installation as per the pump, tank and switch manufacturers. Plus it's the only way to make things work correctly.

If you are going to bury this line, I suggest one piece of 160 or 200 psi rated PE (pollyethylene) IPS plastic pipe using two insert fittings with two opposed SS hose clamps each fitting properly torqued, not over tightened (the main cause of hose clamp failure). No stones/rocks immediately under/over it.

As to the gauge of power cable... 12/2 or 3 w/grd is usually good for 230v up to 600' from the circuit breaker panel to the =< 1.0 hp pump. To check that out:
Please select the company you are looking for and the 4" submersible section of installation IIRC.

Gary
Quality Water Associates

 

[_RaT_]

The 30-40' is much more than "in the general vicinity"... I am a pump guy with roughly 20 years experience with customers' well pumps and water treatment equipment.

The pressure tank is used to provide the power to move water when the pump is off. It also works as a water hammer arrestor but that is not its purpose. Water hammer is not the problem in having a switch away from the pressure tank

With the switch 30-40' away from the pressure tank, the switch is very likely to slap from off to on and off to on again and again repeatedly until the water use stops, regardless of the size of the pipe for this/the last 30-40'. That KILLS pump motors and spins the electric meter.

Steve mentioned that on off problem before I replied the first time. The only way to prevent that slapping on off is to spread the differential on the switch. I.E. 30-65 etc. The result will be a very noticeable fluctuation of pressure whenever water is used. The size of the pipe or pressure tank doesn't matter. To prevent the fluctuation, use a CSV (Cycle Stop Valve) which gives you many fewer starts on the motor and constant water pressure while using a very small pressure tank.

Also, the switch will have to be set higher than normal the farther away it is from the pressure tank and fixtures because of pressure losses in the pipe and its fittings; albeit the loss will be small.

So run the same ID pipe (probably 1") and put the switch at/on the presssure tank and set the cut-in and out at 30/50 etc. with 1-2 psi less air pressure in the tank than the cut-in setting of the switch with no water in the tank. I.E 30/50 gets 29-28 psi air pressure with no water in the tank. That is a proper installation as per the pump, tank and switch manufacturers. Plus it's the only way to make things work correctly.

If you are going to bury this line, I suggest one piece of 160 or 200 psi rated PE (pollyethylene) IPS plastic pipe using two insert fittings with two opposed SS hose clamps each fitting properly torqued, not over tightened (the main cause of hose clamp failure). No stones/rocks immediately under/over it.

As to the gauge of power cable... 12/2 or 3 w/grd is usually good for 230v up to 600' from the circuit breaker panel to the =< 1.0 hp pump. To check that out:
Please select the company you are looking for and the 4" submersible section of installation IIRC.

Gary
Quality Water Associates

Of course you could simply toss the "old fashioned" method and do what I have been doing and convert to a drive unit. No large pressure tank, no pressure switch, you get almost constant pressure, ramped start/stop, low water or no water protection, current overload protection, voltage over/under protection. For 600' run of wire remember that is equivalent to 1200'. I would upgrade to at least #10 depending on the current draw of that 1HP pump. No more then 5% voltage drop should be allowed.

Frequency Drive Units;

Residential model;
Goulds Pumps Water Technology | AQUAVAR Pump System and Aquavar CPC

This drive unit has replaced our 5000 gallon pressure tank as well as provide superb pump performance and protection.
GP10 AC Drive

 

[GaryQWA]

I don't know equivalent.

Franklin Electric Submersible AIM Manual - Application - Single-Phase Motors - Page 11

That is a chart of various wire gauges and distances for 230v cable based on the motor hp. The length is actual from the circuit breaker panel to the motor.

Variable frequency/speed pumps are not lasting long and have a high repair cost, if you can find anyone to repair them. You could have done much better price wise and repair cost wise had you gone with a CSV Cycle Stop Valves, Inc. and a regular correctly sized submersible pump. I was a Gould's dealer for years but I stayed away from the variable pumps, there's too much to go wrong and I hear it is.

Gary
Quality Water Associates

 

[jimainiac]

Well, it's sounding like having the tank and switch in different locations could be a problem, so I guess the safest thing is to move the switch along with the tank and rewire it. I was hoping avoid a little work, but not at the expense of a poorly operating system.

 

[WayneB]

I'm going to winterize a seasonal cottage, and need to relocate the water line that comes in from the well to a different location. I plan to put the pressure tank where the pipe comes in, about 40 feet from where it does now. It's going from the kitchen to a bathroom, so the plumbing will still be connected inside the house. I wonder if I can leave the pressure switch where it is, to avoid a bunch of rewiring? Is there any rule about the pressure switch being within a certain distance of the pressure tank? The way I see it, the whole system will have about the same pressure, so it shouldn't matter, but maybe I'm missing something?

When I read this I am a little confused? Reading the posting I think you wish to use the camp in the winter and not winterize it for use in the other three seasons! Not knowing what type of pump you are talking about, I assume it is some type of jet pump.

On all of the ones I have used there is a pressure ¼” hose (pipe) that runs from the pump to the pressure switch. This is a small feed of water that activates the pressure switch that is connected to the pump. It doesn’t take too much cold air to freeze this little pipe and the pressure switch.

The tank is mainly a storage unit and could be placed anywhere, but the farther away from the pump the more pipe that is included in the storage vessel. So if your tank is 40 feet away from the pump you have to be careful not to have any sags or elbows, as it will reduce the flow pressure.

If your pump is a shallow well pump I wouldn’t recommend locating the tank away from the pump.

You could locate the pump and the tank in a new location, but that would require pulling water the additional 40 feet. I believe if you size the pipe large enough you would be able to pull the water 40 feet on the level. This would mean going deep with the pipe, I think 11/2” or 2” pipe should be used. My pump book states that if the horizontal piping from the well to the pump is up to 25 feet then use 11/4” pipe, 25 to 50 feet use 11/2” pipe and for 50 to 200 feet use 2” pipe.

I have a barn well that is about 70 feet from the barn and I pull water to the pump using 2” black plastic pipe. We have it 4’ in the ground and then at the will there is a 90 degree turn and the pipe goes down about 10 feet into the shallow well. We have never had a problem with the pipe or foot valve pipe freezing. It is on the level so the only height head is about twelve feet to the bottom of the foot valve.

(My surface well is approximately 16 feet deep, so I put the foot valve about 1to2 feet above the bottom and pipe enters the well approximaely four feet down from the surface ground level).

I use a 40/60 PSI valve and a small captive air tank (6 gallon). This is less water storage, but all I care about is the pressure and not the turn on of the pump. The bigger the tank the more water you have stored so the pump will not kick on when you turn on a facet just for a drink of water. The downside of this is when the pump does kick on it will run longer to fill the tank.

Just my two cents.

 

[_RaT_]

I don't know equivalent.

Franklin Electric Submersible AIM Manual - Application - Single-Phase Motors - Page 11

That is a chart of various wire gauges and distances for 230v cable based on the motor hp. The length is actual from the circuit breaker panel to the motor.

Variable frequency/speed pumps are not lasting long and have a high repair cost, if you can find anyone to repair them. You could have done much better price wise and repair cost wise had you gone with a CSV Cycle Stop Valves, Inc. and a regular correctly sized submersible pump. I was a Gould's dealer for years but I stayed away from the variable pumps, there's too much to go wrong and I hear it is.

Gary
Quality Water Associates[/quote

Gary, could I pick your brain here? I have a customer with a interesting water/pumping issue. I must admit my experience with frequency drive units is limited to commercial applications. I have read the info at cycle stop before and their take on variable speed pumps and more importantly to me, their take on VFD's. It seems a bit inaccurate in that our 72 amp max 30 HP 1700 RPM 3 phase 240V pump/motor drops current down to a current draw into the mid 20's when pumping at low volumes. Their claim is that VFD's don't save energy and the "emperor is still naked" comment just is not our experience. Anyway, my question relates to a booster pump at the bottom of a hill. Can I PM you with my issue?

 

[_RaT_]

Well, it's sounding like having the tank and switch in different locations could be a problem, so I guess the safest thing is to move the switch along with the tank and rewire it. I was hoping avoid a little work, but not at the expense of a poorly operating system.

Jim, I simply have never had the need or oppourtunity to experiment with this since its not the standard way one would do it. If however I needed to do it for myself, I would at least experiment. My gut feeling is that you would not experience the pressure switch slapping even with a 60/40 PSI cut out/cut in setting. But Gary makes a good point, if it does, its the last thing you want, well that and under voltage situation and maybe lack of no water protection, well perhaps over current protection....

 

[jimainiac]

Just to clarify, what we have for a system is a shallow well five well tiles deep, with a deep well pump set at the bottom. The pipe and wire is buried nice and deep, but when it gets to the camp it comes up through an unheated space under the floor. It's been fine, 'cause we just use it in the summer and fall, before freezing, then we drain 'er down for the winter. We want to retire there, so we're going to add on, and at the same time move the place where the water comes in to a safer location. I'm going to put the pressure tank where the well pipe comes in, but I thought it might be possible to leave the pressure switch where it is, under the kitchen sink, rather than rewiring it. I don't like to do any more work than I have to, if possible. I'd rather spend the time out on my pony.

 

[turnkey4099]

Jim, I simply have never had the need or oppourtunity to experiment with this since its not the standard way one would do it. If however I needed to do it for myself, I would at least experiment. My gut feeling is that you would not experience the pressure switch slapping even with a 60/40 PSI cut out/cut in setting. But Gary makes a good point, if it does, its the last thing you want, well that and under voltage situation and maybe lack of no water protection, well perhaps over current protection....

You are correct, there won't be any 'slapping'. The most that will happen is that the pump may turn on a bit early if the tank is down near the cut-in pressure already and -may- turn off a bit later due to water colume lag but I doubt it would even be noticeable.

The pump will kick in when the switch detects the low pressure setting. It _will not_ turn off then until the high pressure cut out setting is reached. The only way you would get 'slapping' is for the water in the vicinity of the guage to be fluctuating rapidly over a 20 psi range.

Harry K