Pressure switch problem??

I just installed a new Square D 60-40 psi pressure switch and for the second time in the 10 days that it has been installed it has let the pressure drop to 0. When I flip the Start lever a few times and hold it at "start" it immediately jumps to 40 psi and builds to 60 right away. Is the switch faulty or did I do something wrong with the wiring or install? I was replacing a previous 30-50. I placed a CSV 60 psi and set the pressure tank to 38 psi precharge.

Sometimes you'll get a sediment build up on the nipple that the pressure switch is threaded onto. I would un-wire the pressure switch, remove it from the nipple that the pressure switch is threaded onto and check for some kind of build-up that is preventing the switch from sensing pressure. If there's a buildup clean it out, re-attach and try it again. You may have to also remove the nipple and clean it out also. If everything is clear I would lean to more of a well pump problem that needs to be resolved. The well itself may also be running low on water. I'm not sure where the lever on these switches trip if the pressure it's sensing gets too low. Try it and let us know if this works. If not you may need to purchase an amp and ohm meter to continue to diagnose the problem.

#1 You have a low pressure cut off type pressure switch that is designed for wells that may pump dry. If your well is a good producer, change that switch out for one that does not have the lever on the side.

Or try the following, which needs to be done anyway.

#2 Let a little air out of the tanks, down to about 30 PSI each, while the pump is off, all the water out, and a faucet open.

#3 Turn power off first. Tighten down on the big adjustment screw in the pressure switch about 4 rounds. You need about 50/70 or at least 45/65 setting so the 60 PSI Cycle Stop Valve can work. It can’t do anything until the pressure is over 60 PSI.

#4 You may not have to after this but, the pressure switch should be mounted close to one of the tanks instead of in between the two. This is probably what is causing the switch to trip out on low pressure.

Teets,
When I installed the new switch I cleaned the nipple out. There was not very much there anyway. The last time it stopped we were not using any water for irrigation or anything and our well does not run low unless we are running a hydrant at 5-6 gal/min.

Valveman,
I will reset the presssure tank to 30psi and the switch to 50/70. The other tank in the picture is not hooked up to any system presently. It is just in the picture. After making these changes I will wait and see if it happens again before I replace the switch. Right? Or should I just replace the switch?

I may be wrong but I thought that the csv would get full pump pressure at the inlet but only allow 60 psi water to flow through it until the flow rate dropped below 1 gpm. So it would be "working" even though the pressure on the outlet side has not reached 60 psi. What am I missing?

If you go up to 50/70 on the pressure switch, then you need about 40 PSI air in the tank. Since your well will pump dry at 5-6 GPM, I would not replace that low pressure cut off switch.

That 60 PSI CSV is just like a piece of pipe when your pressure is below 60. At 60 PSI it regulates the flow to match the usage. Above 60 PSI, it only allows 1 GPM through to refill the pressure tank.

Valveman, what's the reason for 10 psi less air in the tank with a 50/70 switch setting. And what impact does that have on the 'bladder', if any?

Gary Slusser said:

Valveman, what's the reason for 10 psi less air in the tank with a 50/70 switch setting. And what impact does that have on the 'bladder', if any?

Click to expand...

I am guessing about a 7 GPM pump. His well only makes 5-6 GPM. If you have 48 PSI air in the tank with a 50/70 switch, you have no storage above what the pump will produce. Start out with an 8 GPM demand, and your off on low pressure in a couple of seconds. It really doesn't matter much what the low pressure cut off is set at, it will go off when the bladder hits the bottom or 48 PSI. With only 40 PSI in that tank it will deliver an extra 5 or 6 gallons below the on pressure. That gives you 5 or 6 minutes of an 8 GPM demand before you go off on low pressure, which is also now 40 PSI.

We do this a lot on big irrigation systems that run at or aver 100 PSI. We use a 90/110 pressure switch setting with the CSV set at 100 PSI. We also incorporate a separate low pressure cut off switch to shut things down if the lake runs out of water or if there is a main line break. With a 90/110 PS setting, if you put 88 PSI in the tank, that is also the pressure that your low pressure cut off will shut down. This is even if you have the low pressure switch set at 20 PSI. So we only put about 65 PSI air in the tank, and that is where the low pressure cut off works.

We do even larger variations when boosting city water for these same type systems. The city comes in at 50 PSI, and we boost to 100 as described above. We have a bypass that allows the 50 PSI from the city to supply low demands and leaks. So the pressure switch setting is 40/110, with a Cycle Stop Valve setting of 100 PSI, and only 30 PSI air in the tank. Most have lasted 10 years or better by now. The over stretching is apparently is not nearly as hard on the bladder as number of cycles. Most of these systems only cycle once or twice per day, so no telling how long the bladders will last.

About the extra volume of draw down gals in the pressure tank by decreasing the air volume. Just so people don't misunderstand and think less air in their pressure tank is a good idea.

As Boerdoc says, when he goes to Start on the switch, immediately the pressure goes from 0-40 psi. It's actually 0-38 but happens so fast we see 0-40 and that's because he has 38 psi of air pressure and the pump running. With less psi, the gauge is going to from 0 to the lower psi reading is instantly.

So the only time he gets more draw down is if he has to go Start the pump from 0 psi because the safety switch shut off the pump during the last water use.

Guys, the goal is to prevent the pump from being shut off because of a lack of water and to keep the air pressure set 2 psi less than the cut in setting on the switch. Otherwise the bladder suffers.

Boerdoc, do you know what pump you have and the recovery rate gpm of the well, the depth of the well and the depth of the pump? How about anything about the pump, hp and gpm?

Gary Slusser said:

About the extra volume of draw down gals in the pressure tank by decreasing the air volume. Just so people don't misunderstand and think less air in their pressure tank is a good idea.

So the only time he gets more draw down is if he has to go Start the pump from 0 psi because the safety switch shut off the pump during the last water use.

Guys, the goal is to prevent the pump from being shut off because of a lack of water and to keep the air pressure set 2 psi less than the cut in setting on the switch. Otherwise the bladder suffers.

Click to expand...

Again with low producing wells you want at least 10 PSI less air in the tank than the pressure switch cut-in. Not only does this determine what pressure the low pressure cut off will activate but, will also give you additional draw down to use when needed. Bladders can take a lot of stretching as long as they don't do it too many times. My examples above show how drastically you can stretch a bladder without problems as long as you limit the number of cycles. See this quote and link from the Water Systems Council.

"When the pump can meet the system demand, it will operate between the pressure switch settings. When the pump cannot meet the system demand, the pressure will drop below the cut-in pressure. The supplemental drawdown is supplied by the tank at a pressure between the tank precharge and the cut-in pressure."

http://www.watersystemscouncil.org/VAiWebDocs/WSCDocs/9884303Sizing_a_Pressure_Tank_FINAL.pdf

Gary,
I do not know what pump I have. What I know is that the well is 80' deep with the pump at 75'. Static water level is 15'. It is a 6" well with 80 ' of 4" pvc liner. It has a pumptec or another type of pump protection in case it runs dry. When new, the well produced 30 gpm. Now I can't run a 6gpm hydrant for longer than 30 min without the pressure dropping. You are better at calculating the recovery rate than I am, but that is the best info I have. When I do not run irrigation we do not usually have water pressure issues. I have 6 kids and we have 3 showers going at once.
BTW- I used to have both pressure tanks connected to the system. One is a welltrol wx-250 (44 gal) and wellsaver Lpt86 (86 gal) Drawdown 16 and 31 respectively. Now I am using the LPT86 only. The other will be used when I hook up the submersible to the cistern later.

Boerdoc, three showers @2.5 gpm = 7.5 gpm, plus a toilet or sink running, and you have no problem; and usually most showers are usually run for 10-15 minutes.

But run a hydrant at 6 gpm for 30 minutes and you're out of water because of the Pumptec if it is working correctly OR the low pressure safety cut off switch but the real cause is not enough water in the well OR the pump you have can not pump from the depth the well is being drawn to. Which is my guess.

I don't know pumptecs but I wonder why a safety switch with one.

I would not set the air pressure lower in my pressure tank because I don't think that an extra 1-3 gallons if that much, is going to matter because your pump will be putting out 2-3 gallons in under a minute and you're out of water anyway. But Valveman knows more about that than I do because he does it and I have never done it. I do know that with your large tank, or two tanks, when the pump is off your pressure won't be as good with less air as it would be with the right pressure in the tank and, you'll draw down the tank(s) slower which kind un does the constant pressure and other benefits of the CSV.

So I'd check out the pumptec to see if something is wrong with it and the static water level in the well and depending on the pump's age, look into maybe something wrong with it or I suspect it's undersized.

If the pumptec worked right you wouldn't need the safety switch and getting rid of it would stop you from going to reset it.

What was the need for the liner? Maybe the pump is getting hot and the thermal overload is opening, shutting off the pump while you're using water at the hydrant and the switch opens. That's a good probability with a 4" pump in a 4" liner.

Gary Slusser said:

when the pump is off your pressure won't be as good with less air as it would be with the right pressure in the tank and, you'll draw down the tank(s) slower which kind un does the constant pressure and other benefits of the CSV.

Click to expand...

Even with a lower pre-charge in the tank, the pressure switch and pump are still working at 50/70, so you won't notice any difference in the pressure in the house. The tank will actually give you a little less draw down between 70and 50 when you have a lower pre-charge, so the constant pressure of the CSV will happen sooner. The only difference you will see with a lower pre-charge, is that the low pressure cut off won't trip until you get down to the pre-charge pressure. With a lower pre-charge you will also get a few more gallons of water from the tank after the well has been maxed out, or during a power outage.

I agree that if the pumptec is working, you don't need the low pressure cut off switch because they both do the same thing. And I think you mean 4" casing instead of a liner.

I do not know much about the well except what was in the report.
View attachment 7751

Why the need for a liner? I do not know. I seriously doubt that the pump can't keep up. The well is located uphill from us and if we open the hydrants at house level without the pump on we can actually siphon the water out. Works great in case of power outage. Thus it is pumping "downhill".

I do agree that the low pressure cutoff switch is redundant so I guess that I should replace it with one that does not have the "lever" on it.

We have Water saving shower heads and showers are quick. If my 19 y/o daughter is not monitored then we would run out but that does not happen often.

Valveman, while running the risk of someone accusing me of fighting...or insulting someone...

Again, I was talking about when the pump is off and the compressed air in the tank is providing the power to move the water. Lower air pressure (40 psi) = less water and a longer period of low pressure.

With an 80' well and the pump set at 75' and the house downhill from the well, I suspect he doesn't have a 7 gpm pump. Any ideas why is he having this problem with the pump not running?

I get an error with the attachment: Invalid Attachment specified. If you followed a valid link, please notify the administrator

The well report was attached that came back invalid attachment. When I previewed the pic it worked fine. here it is again.

You had a static water level of 10', 4" liner to 40', 30 gpm recovery rate.

As far as your current problem, the log gives you no usable info IMO, but some drillers strongly believe in them and suggest everyone get their well log for many problems. Hopefully one or more of them will jump in here.

If you were looking for information on pressure switches, or to buy a pressure switch, you should visit Madison Company's website. They have a large variety of switches and sensors, and also a lot of information that I think that you might find helpful.
Good Luck!

Liners!

Guys, For your information. . .

Many drillers in the North and Central USA install a PVC Liner in their wells. Except for the surface casing (usually 6") don't usually case a grantite well to the bottom. However some do install a 4" or 4-1/2" PVC liner (casing) inside the well through an area of fractured granite that suspect could drop a fractured rock in the well locking the pump from being removed in the future.

This is a standard practice in the Sandia Mountain area of New Mexico, except they usually install the liner from the top to the bottom. It's landed on the bottom because the pump is usually set near the bottom. They set PVC slotted well casing (screen) at several locations in this liner. A liner does not have a gravel pack around it.

In this case I don't know why only a 40 foot liner in an 80 foot well when the pump is set way below the liner?

Porky, MGWC
www.dci-inc.us