Well pump Electric usage tripled

[darbysan]

We have a community well, 4 houses, 8 people total. We use about 1500 gal/day total. We have 3 86 gal pressure tanks, set at 60/40 psi. The well is 650' deep, 8" casing, and has a 5 hp 20 gph pump installed. Static water level is somewhere between 500' ( when drilled) and could be as low as 550-600 ft with today's water conditions. Under normal conditions, we see about 15 pump cycles/day.

Pump , wiring and control box were replaced 7 years ago ($12K). Original pump lasted 20 yrs.
We have been averaging about 150 KWH usage/month for the last several years. Suddenly, usage has gone up to triple that amount in the last two months. Water usage has remained constant at 1500 gal Per day. In checking the Power Company website, I can see usage down to the 15 minute level. When the higher usage started, we saw that the pump was running nearly constantly, as opposed to the 15 cycles / day norm.

Last week it tripped out on overload. We checked capacitors, and replaced the start cap and run caps, although they tested OK. Restarted the well, and it has been running "better" as far as power usage is concerned, but still more than double the normal amount. We are still seeing about 15 cycles/day, but the GPM flow rate is showing about 10 gpm at the start of a pump cycle, and it can drop to about 5 GPM as the tanks near the cutoff pressure. Last 5-10 gals run at about 5 gpm. Amperage is spot on for the 5 hp motor, and no ground faults or leaks detected in the wiring ( Well professional tested for us last week), so the extra usage is in run time for each fill (10-11 minutes).

So, our best guess is that either the pump is failing to produce the flow / pressure required ( maybe failed stages) or there might be a leak in the piping inside the well. Being a deep well, it is expensive to pull the motor, so we would appreciate your thoughts on troubleshooting these issues before we spend a bunch of cash....

Additionally, there was discussion about using PVC piping, at least in the submerged section, to prevent future corrosion issues. Everything I can find says that PVC cannot handle the pressures, or the 5 hp motor. Any thoughts? Is stainless pipe an alternative? How about Lay Flat piping?

The Well company is also trying to sell us on Variable Speed controllers, but again most of what I can find doing research says that it is not a good use of our funds.

Really appreciate your feedback.

 

[Reach4]

Leak in the drop pipe in the well, or even into the ground, could explain this. One test is to turn off the water flow after the pressure tanks. Watch the pressure, and see if it drops.

Another possibility is a failed check valve at the pump. That would behave somewhat like a hole in the drop pipe.


The pressures that the drop pipe feels is a function of how far down the water is, and also what is the pump? 5 hp is part of the story, but the design gpm of the pump is significant too.

I presume you are not using a pitless adapter. That is my expectation.

 

[Sponsor]

 

[darbysan]

5 hp is part of the story, but the design gpm of the pump is significant too.

I presume you are not using a pitless adapter. That is my expectation.

As far as I know, the pump is 5 hp, 20 GPM. Probably a multi stage pump, but we cannot access the paperwork. It functioned well up until a few months ago, where the GPM rate dropped in half or worse. Why we think it may be a pipe leak. No leaks above ground. It was running almost constantly for several weeks, based on the electrical usage chart. The only change since the shutdown last week has been the replacement of the Start Cap, so not sure why that has made the difference going back to 15 cycles/day.

No pitless adapter. Pipe comes up straight out of the top of the casing into flow meter, and then into the storage tanks situated beside the pump.

Currently, with no usage from the houses (late at night), pressure in the tanks is maintained for 7 hours, so if it is a leak above the check valve, then it takes 7 hours for 80 gals to leak down ( or late night toilet flushes!!) to trigger the pump start.

More Electrical Info: From Jan thru June we used .25 kw per charge cycle, about 15 charge cycles per day.
In July and we used .50 kw/charge with still just 15 charges per day.
In Aug, we are using .75 KW / charge, still at 15 charges/day.

Probably a lot more info than you need or want to hear.....

 

[Valveman]

Sounds like a hole in the drop pipe. Many times the hole is in a steel nipple between the brass check valve and the pump. The check valve is holding fine, so no loss of pressure overnight. But when the pump runs most of the water is just being recirculated through the hole in the pipe. Couple wraps of electric tape over those fittings would have prevented it, but doesn't help know. Pump pulling full amps means it is pumping full flow. Just not getting to the top of the well. Hole gets bigger every month, so time to fill the tanks increase with the electric bill every month. Sorry for your problem because even the pump can fall off if it gets bad enough. Pretty deep for PVC. If corrosion is all along the pipe you can wrap everything underwater with pipe wrap. Works but it takes some time. Probably just electrolysis at those fittings with dissimilar metals.

 

[darbysan]

Thanks for the inputs. Group will have to get together and discuss how to proceed, but probably going to have to pull and inspect. Pipe replacement is probably necessary, and if we pull the pump, should we replace it as well (8 yrs old)?

 

[Reach4]

More Electrical Info: From Jan thru June we used .25 kw per charge cycle, about 15 charge cycles per day.
In July and we used .50 kw/charge with still just 15 charges per day.
In Aug, we are using .75 KW / charge, still at 15 charges/day.

That sounds like it could be that your electricity rates went up. Does the well have its own meter? See if you can compare the kWh numbers, rather than dollar amounts.

Also, when the pump runs, how long does it run?

I suggest that you get a clamp-around ammeter. Is your pump supplied by common 240 VAC? Seems likely. I would expect about 23 amps when the pump is running.

Are you getting more air coming from the faucets in the houses?

I suspect your water is around 300 ft down.

 

[Fitter30]

When my drop pipe had a leak there was never any air in the system. Leak was below the water level. Replaced 7 lenghts of galvanize pipe and the 17 year old pump.

 

[darbysan]

That sounds like it could be that your electricity rates went up. Does the well have its own meter? See if you can compare the kWh numbers, rather than dollar amounts.

Well is on it's own meter. Info I reported is in KW hours used, as I can see that in 15 minute intervals on the Energy website. It's easy to see when the well kicks on and runs , as there are usually about 15 Spikes in the usage, from o KW to .75KW.

Also, when the pump runs, how long does it run?

The Pump Runs about 10-11 minutes to refill the 3 tanks, reading about 90 gal on the water meter. Timing the fill, you can see that it starts out at about 10 GPM when the tank pressure is 40, but as it gets nearer to 60, the GPM falls to 5 GPM. I believe that this reduced GPM rate is what is causing the pump to run longer, and thus the higher electric usage.

I suggest that you get a clamp-around ammeter. Is your pump supplied by common 240 VAC? Seems likely. I would expect about 23 amps when the pump is running.

I have one, and the pump was registering 21 amps. I've taken this reading 6 times now, same result. Well guy said is was registering 24 amps, but I wan't here when he measured.

Are you getting more air coming from the faucets in the houses?

No Air.

I suspect your water is around 300 ft down.

Static water level when the well was drilled was 500'. With the drought, I believe it has fallen. Nearest "measured" well that the city reports , if the water is the same Aquifer and at the same level, would indicate that our static is now somewhere near 590'. Total well depth is 650'.

 

[Valveman]

A 5HP, 20 GPM pump should be able to pump 20 GPM from 700' deep. And from 21-24 amps I believe it is pumping 20+ GPM, just most of it is going out the hole in the pipe. If it were pumping the well dry the amps would drop by 50% or more.

 

[darbysan]

Thanks. Consensus seems to be a hole in the pipe, which makes a lot of sense.

 

[Reach4]

https://www.slpipe.com/product/drop...ng-and-depth-chart-for-pvc-threaded-drop-pipe has some numbers for PVC drop pipe. I got that link from https://terrylove.com/forums/index.php?threads/pvc-or-galvanized-well-pipe.87621/#post-628488 #7.

I expect you would use schedule 120.

 

[darbysan]

Based on the numbers I have been able to get, Schd 120 PVC is only good to 360 psi in 1", and only 2 hp. We would just get by at the 360 PSI number, but not with the HP. For 5 hp, you have to go up to 2" , and then the PSI goes way down to the 200 range. I know people fudge these specs, but it gets pretty expensive at 650' to have to pull it up if there is an issue.

 

[Reach4]

Thanks. Consensus seems to be a hole in the pipe, which makes a lot of sense.

Not quite a consensus. I am not so sure.

I think measuring the deadhead pressure could be informative. I am thinking if there is a hole in the pipe, that would limit the deadhead pressure. But do get a buy-in from Valveman before doing the deadhead pressure test.

If you do pull the pump, take pictures of the two labels.

 

[Valveman]

Yeah, I'm afraid you need to stay with galvanized. I have used fiberglass and all Stainless pipe when needed, but they are expensive. With static at 500' a 20 GPM, 5HP will make 216 PSI at the surface. But deadhead pressure will probably just push more out the hole and not build much pressure. Amps would be low if it was a worn pump or dry well.

 

[darbysan]

Thanks so much for all of the help. It really helps to get the advice of experts, since I know little about wells.

Starting the process of getting bids to fix the problem. I would like some input from you folks so that I can speak intelligently to the bidders, and also so I know what to ask for, and what to not consider...

1) Pump. 5 hp, 20 or 25 GPH ( 4 households, so 5 gph = 20 total??) Any specific brand or specification we should be looking for? We've heard that the new pump quality has diminished since the original install back in '95, so recommendations on brand, etc would be appreciated.

2) Standard pump controller with Caps/Relay vs newer Variable Speed Drive. Some of the drillers here are highly recommending the VSD, but my research says it really doesn't do much, and it is 4-10 times more than standard.

3) Replacing bad sections of pipe with Galvanized. Think the sections that are above the static line should be ok to reuse ??

4) Any specific type of pipe connector to use, especially under the static level? Want to minimize pipe failure in the future

5) Wrap the pipe under static level? Wrap with what, and is it effective? Expensive?

6) Wrap the connections? Under the static level, or all of them. Wrap with what?

We've also been told that with 4 households we should have an above ground tank and jet pump. I suppose that would take a little pressure off the pump, not having to overcome the pressure of the Well Tanks, but our water usage is pretty low (1500 gal/day). I worry about stagnant water. On the plus side, adding a tank and jet pump now might let us continue to use the current pump and piping , but for how long? With a leak in a pipe, I assume it will just continue to get worse.

Thanks for your inputs.

 

[Valveman]

If it was mine I would pull the pump, fix the leak, and put the pump back in. Of course I would test the pump out first. That pump is probably better than any new one you can buy these days. They make pumps cheaper and try to talk you into a VFD, because the VFD is 4-10 times higher and along with the cheap pump makes things last 3-5 times less than a normal full speed pump set up. I would swap the pipe, putting the pipe that was in the water up top and vise versa. Get me some 3" wide pipe wrap tape and tape everything below the water line.

If there was anything wrong with the pump or motor I would replace it with a 25 GPM, 5HP instead of a 20 GPM pump. The 25 GPM will cost less, build less back pressure, pump more water, and still give you everything you need from a depth of 600'. With a static level of 50' or deeper you could even use a Cycle Stop Valve with the 25 GPM pump and only have 130 PSI back pressure. Where the VFD makes pumps not last as long a CSV increases the life of the pump while doing a better job of maintaining strong constant pressure to the houses. The CSV1A-3GPM is all you need for that size pump and is only 224 bucks. That is why the pump guys are pushing a VFD and not mentioning a CSV. Lol!

Now, the cistern is also a good idea, but a completely different can of worms. I would use a 2HP, 10 GPM pump set on sch 120 PVC. A 25 GPM pump in the cistern is plenty for 5 houses. You can get a 33 GPM, 1HP for 170 bucks that works very well. Add to that pump a PK1A pump control kit with at least a 10 gallon size tank to feed all the houses.

 

[Valveman]

If you can run wires from the float switch in the cistern to the well pump is would look like this.

 

[LLigetfa]

1) Pump. 5 hp, 20 or 25 GPH ( 4 households, so 5 gph = 20 total??)

I'm sure you meant to write GPM and not GPH.

 

[darbysan]

If it was mine I would pull the pump, fix the leak, and put the pump back in. Of course I would test the pump out first. That pump is probably better than any new one you can buy these days.

Thanks for the reply. Just to clarify, the current pump is about 7-8 yrs old. Would that still be in the timeframe for the "better Quality" pumps?

Only quote we have gotten so far is to replace both the pump and the motor ( two separate prices). Any chance one or the other existing parts should be good enough to trust going forward.

 

[darbysan]

received two quotes to repair / replace the system. Prices were similar. One uses Franklin Pump 5 hp, 20 GPM, the other uses Grundfos Pump 5 hp, 35 GPM.

Any thoughts on which might be a longer lasting pump? I'm leaning toward the Grundfos- had good luck with them on other applications....

Also, is there a way to test the pump / motor when is is pulled to see if it is still usable? It's at the age where they are going south here in Vegas, and since it is a community well I can't just throw the dice and say re-use unless we can test and see if we can get 3-5 more years out of it. Otherwise, might as well replace and save the labor ($1500+).