When my square d water pressure switch hits the low setting, about 30 psi, the water pressure drops to almost nothing for a second or two before the submersible pump kicks in. Is this a switch problem. It holds pressure fine when the pump stopps pumping as long as it stays above 30 psi.
Thank you for your help :)

That is more to do with your pressure tank. Allow the tank to empty (through an outdoor spigot with the power turned off) and then check the pressure at the "tire valve" at the top of the tank. It should be 28#. If not, set it to 28#.

I have a v 260 so the specs call for 38, I will give it a try, thanks

The 38# would be if your cutin was at 40#. The V260 is precharged to 38#, but that does not mean it has to be run at 38.

You can, of course, increase the cutin to 40# if you'd like to. Nice to have options!

I appreciate your help, I drained the tank and it was right on 38#. FYI I also run my irrigation system off this. This problem just started about two weeks ago. It ran fine for years with no problem. I can increase the cut in if that is more efficient. Your thoughts?

My tank does the same thing (dropping to zero for a split second when pump cuts in) from time to time. I really don't think it is anything to worry about. You can certainly raise the cut in point to 40#. The upside is better pressure. The downside is more work for your pump, but with the large tank you have, your pump cycles fewer times anyway so it might be a good tradeoff. If you will look on the inside of your switch cover, it will tell you how to raise/lower cut in and cut off points, though it sounds like you already know how to do it. BTW, when mine does this, we don't notice any drop in pressure at points of use. Can you tell, say when you're taking a shower, when the pump cuts in, or does it just seem to show up on the pressure gauge?

The correct setting for a bladder tank is 2 PSI under the cut in pressure set at the control box when the pump's off and the pressure's removed from the system. Therefore Jlisenbe is bang on with the pressure setting. Don't increase the cut in point on the control box, set the correct PSI on the tank. Good luck, Tom

We notice it in the shower, faucet etc, it is pretty dramatic. That is what brought it to our attention. I can reset the tank pressure to 28 (when drained) aas both of you have recommended and see what happens. Thanks guys for your prompt responses.

Let us know how it turns out.

Well, no pun intended, this was not the solution to the problem. I did adjust the tank air pressure to 28# after draining it and reset the range to 30-50. Now the drop in pressure is dramatic, like it stops, Watching the gauge, it does not appear to be holding pressure, from what I have read this could be a check valve problem. Could the gauge itself loose its seal and result in the same symptom?
I have a 1hp submersible in a 4 in well that is 17 years old, assuming it is the check valve, should I replace the pump along with the check valve since I assume they have to bring the whole thing up anyway? How much more life can there be?
Thanks again for your thoughts, encouragement and help!

Em, typically a leaking check valve can be seen when pressure is dropping despite the fact that no water is being used. This indicates the water is simply going back into the well through the faulty checkvalve. You might want to try installing a check valve above ground, between the tank and the well head. That is frequently where they are located anyway. It would not be a major bucks undertaking as compared to pulling up the well pipe. I suppose I would certainly consider replacing a seventeen year old pump if I had to pull it up to get to the checkvalve, but I would want to be sure the valve is my problem before I did that. You don't want to pay someone $1200 or more to replace the valve and pump only to see the problem not solved.

Thanks again, this slow pressure drop when there is no usage is occurring. I like the idea of putting a valve in the line between the well and the tank, has to be cost effective if this is the problem. Do you recommend I call a well guy or a plumber?

I would probably get a well guy. Typically, submerged pumps have two checkvalves. One is installed just above or near the pump, though pumps sometimes have their own valves which does away with the need for that one. The second valve is installed above the wellhead between the tank and the well head. You probably have one there. Here are a couple of sites you will find useful. If you have some basic plumbing skills, you can actually do the job yourself if there is an existing valve in place. The second site is specific to an above ground jet pump, different from yours, but the pictures of the checkvalves will still be useful to you.

http://www.watersystemscouncil.org/V..._FINAL_507.pdf

Water system check valve location & purpose - private pump and well system do-it-yourself repairs

Final thoughts on this, I called the well guy, they said it sounds like the pump is working fine so call a plumber may be check valve problem. I called a plumber I know and he told me to take off the pressure switch and I would probably find it clogged with rust, clean it, and put it back on. Bingo, problem corrected. I have now returned the pressure to 40-60 so my irrigation runs properly. I am going to get a new gauge and make sure I do not have a check valve problem too.
Thanks for following up with me on this one.

Glad you got it worked out. I have no idea how the problem you described (which is common) would cause your pressure to drop when no water is being used, but if it works, it works. There aren't many feelings much better than getting your well working again. Being without water is tough.

Thinking about it, if the pressure switch is closed and there is a constant pressure on the diaphragm because it is clogged up, when the tank pressure drops beolw 30#, the switch stays closed because the pressure is still good because of the clog, when it drops real low, it finally releases and kick the pump on after the almost all of the water is out of the tank.
Yes it feels great!