Intermittent low amperage on submersible pump - troubleshooting suggestions.
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Hardyh
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I will try for that, what am I looking for (to be out of the ordinary)?
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Voltage drops below 219? I am not feeling a cause for your symptoms. But what if something intermittently adds a resistance. That would be reflected in a lower voltage at L1-L2.
Hardyh
Member
I get 230V on the cycle sensor while the pump is running at the lower amps. Just to test I dropped the 'dry' shut-off limit for the sensor to 4.5 amps and observed; for a particular cycle while water was being used (shower) the pressure dropped to 40, pump kicked in and ran at 6.6 amp for a minute then drifted down to 4.7 and stayed in that area for 1-2 minutes while the pressure kept building although it slowed down around 50psi and couldn't quite reach the 60psi cut-out at that amperage.
Hardyh
Member
I didn't try the control box, I will try again.
Hardyh
Member
Ok, it took this long for me to observe another 'event'. Not to say they didn't happen in between but if the water pressure doesn't drop off too much then we don't notice and the cycle sensor does it's thing to allow to pump/well to catch up and bring us back to normal pressure. Anyway, I measured the L1 & L2 going into the control box - 230 V and I also measured the three wires at the junction box by the well and black/red was also 230V (I checked the other two wires; the red/white was about 270V or so and the black/white was 180-190V).
Hardyh
Member
Is it possible that the new pump (replaced this April) was undersized, that the full volume of discharge piping wasn't accounted for? This system does have more than average piping distances (see original sketch), and the previous pump in there was a 10GPM 3/4 HP. This was replaced with a 5GPM 3/4. I know that our well output is considered low but could the smaller GPM rating cause excess wear on the pump in that short amount of time?
We're now at a point where the pump is falling down to 4.5 amps within 30 seconds of starting, every time, and the system is not able to get above 40psi with the cycle sensor kicking in so quickly.
We're now at a point where the pump is falling down to 4.5 amps within 30 seconds of starting, every time, and the system is not able to get above 40psi with the cycle sensor kicking in so quickly.
The 5 GPM pump will actually build twice as much pressure or lift twice the height as a 10 GPM pump. I would try to restrict the flow to 2-3 GPM with a ball valve right on the pump head and see if it will keep running. There should be a point where you restrict the pump to the same flow rate as the well is making and the system will continue to run and maintain pressure. That is how you test a well, which is what you need to do and see how much it is really making.
Hardyh
Member
So our well is a pitless adapter type well head, do you mean to dig down to where the distribution pipe connects to the well and install a ball valve down there?
You can install a ball valve anywhere before the pressure tank and pressure switch to restrict the pump output.
Hardyh
Member
OK, I already have one installed where the line comes into the house, before the switch/tank. Would that potentially change the sudden amp drops I am seeing during every cycle, like with enough restriction the pump should continue pumping at the 6.5amp level (as long as the pump isn't bad)?
Restricting will cause an amp drop. Even 4.8 is fine because we know it is not pumping air until 4.4.
Hardyh
Member
So I restricted the input valve, and it did have a different response. at about 1/3 open the pump would continue at 6.5 amps and reached full (60psi) pressure. But it was running for at least 7 minutes.
Good. 7 minutes sounds about right at a flow of 2 GPM with a 40-50 gallon tank that holds 12-14 gallons of water. But don't let it fill the tank. Leave several faucets open so the pump will keep running. Open the ball valve a little bit more every few hours until the well pumps off, then you will know how much you can and can't use, and how much to leave the ball valve open.
Hardyh
Member
Good, should I also be restricting the valve at the upper house (see picture)? For the test is it ok to use the yard hydrant instead of faucets in the house?
If you can close a valve going to each house you can do all the testing with the yard hydrant. The yard hydrant can restrict the flow just like a ball valve as long as valves are closed and water cannot go anywhere else.
Hardyh
Member
Ok, I'll do it that way thank you. By the way, can you explain the reason why restricting the flow between the pressure tank and the pump is letting the pump run more reliably (until I can take a day off later this week I have just left the valve at 1/3 open and although it isn't perfect yet it does keep up with the basic water usage for now). How does the partly closed valve enable the pump to run longer without the amps dropping?
Without the restriction from the ball valve the pump is always producing max flow like 10-12 GPM even when you are only using a 3 GPM shower. The pump just fills the pressure tank at max pump volume. The well can be pumped dry just filling the pressure tank. The ball valve is restricting the flow the pump can produce closer to the amount the well is making., but the amps should be dropping.
Hardyh
Member
Thank you for the explanation.
I am seeing about 6-6.5amps for the first minute or two and then it goes down and eventually stays in the 5-5.5amp range for the remainder of the 7 minutes it takes to reach 60psi.
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