Help Selecting a Submersible Pump for 360' Well

[Zane Bridgers]

Hmmmm tough decisions. I literally may not have enough money to hire this out, but I am going to call around for quotes. Still have to pay the final installment to the driller, which has set me back $20k. The driller also seems to be fudging the depth a bit - he said it was 455' right after drilling but on the bill and well log he said 480', and logged that extra depth as dry... Could really use that extra thousand bucks right now, but not sure there's anything I can do.

I've now heard that Poly can be dangerous at these depths from a few sources. Why is that? Is it just that everything is dangerous for a homeowner at this depth, or does the poly pose a particular hazard.

I suppose if I laid out and threaded all the Sched 80/120 drop pipe, taped off all the wire, bought the pump and pitless at the best prices I can find, and just hired an installer to actually drop it, it may not add that much all told, but even just the supplies may be more than I have.

 

[Valveman]

I show 1 1/4" poly full of water weighs 1.08 per foot. That would be 500# plus the wire and pump, which could be another 300-500#. Having 800-1000# of weight and being slick and nothing to hold onto is the problem. That much poly can also stretch a lot, requiring some slack in the wire. Probably not going to find a pump man that will install equipment he didn't sell. They don't make much charging 500 bucks for just the labor. They want to make enough to justify being out all day with expensive equipment and employees. Tough spot to be in. Just a little deeper than a normal DIY job. It can be done. Just got to be careful. If you drop or stick something it could cost a lot more than just letting a pump man install everything to start with.

 

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[Zane Bridgers]

Hmmmmm.... I've been investigating a few other options. One would be borrowing or renting a mini excavator/backhoe with an electric winch + hoist rigged up and a well pipe clamp. The other would be trying to get a hold of a machine like the PumpTrax or EasyRiser pump puller. The final option would be to live without water for a while until I can fork out for a professional installer. I understand that one mistake and it could end up costing more trying to do a homeowner install.

In the meantime, could I get some suggestions on wiring? I read in a Franklin Motors PDF that a 2HP pump should have a 25A Breaker. It also suggests 10awg is only good to 390' for a 1.5KW/2HP motor. My original calculations neglected the power factor, so the draw is significantly higher than 6.3 Amps, closer to 10A. Unfortunately, jumping to 8awg tray cable adds significant expense. Adding a ground to the 3C wire also adds expense. I'm referencing page 14 & 16 of this PDF: http://www.franklinwater.com/media/110562/M1311_60_Hz_AIM_12-14-WEB.pdf

What gauge would you guys install for a 2HP at 430-440'. I'm seeing a voltage drop of just under 9V for 10awg @ 440', which is the "full load" for a 2hp motor. The motor would see ~231V. There is also a maximum load category however which would push 13A to the yellow @ a voltage drop of 11v (229V @ the motor). Is this liable to damage the motor? Are there other issues at play here besides voltage drop, like melting insulation, etc.?

 

[Valveman]

Book says 390' max with #10 on a 2HP. But 440' is pretty close. I think it would be alright. If nothing else you might consider a 50' piece of #8 up top.

 

[Reach4]

The motor would see ~231V. There is also a maximum load category however which would push 13A to the yellow @ a voltage drop of 11v (229V @ the motor).

Rhetorical question: what is the nominal voltage for that motor?

 

[Zane Bridgers]

Yeah, I noticed that the Franklin PDF permits using multiple wire gauges. 50' of 8awg seems like a safe bet. No worries about a splice? I guess there's one at the pump anyway, and that's underwater to boot. Seems you could run 8/3 with a ground for 50' to please mr. inspector and then just run 10/3 since I take it the grounds are just another liability ploy.

It's a good question Reach4. If people routinely run 230v motors on 208, we know it will probably run, but hard to say what the long term impact is, especially if the sub-panel isn't really seeing 240v.

 

[Zane Bridgers]

Sorry if this is a bit anecdotal, but I had a few questions come up for you valveman.

One was that I was reading some of your other posts about pressure tanks and saw you mention that big tanks will not give constant pressure when used with a CSV because it won't kick in until the pressure drops to the set level. I assume you recommended a large tank and CSV because this combo will give the absolute maximum life to the pump by limiting the cycles, even if the constant pressure benefits are not fully realized. Is this correct?

Second question was that I saw in one of your posts somewhere that you recommend against pumps that have been sitting for an extended period of time because the glycol/water will drain out the tiny weep hole in the bottom that is there to equalize pressure. Is this true of new motors that have been stored as well? And how long is too long - I'm sure supply houses often stock motors for several months? I've used extremely fine syringes for winding very small BLDC motors before and wonder if something that size could be used to refill it through the weep hole.

Third would be the easy rise pump puller. I saw that you recommended it to someone elsewhere. They say they are good to 600', but no specs on pump or pipe size. I assume these only work for poly pipe, since the stainless adapters on sched 80 would get hung up?

Many many thanks!

 

[Valveman]

While it is true that a large pressure tank with a CSV is the best of both worlds as far a cycling is concerned, the large tank is not necessary. As you said the large tank means the homeowner will experience longer periods of low pressure, waiting on the tank to drain from 60 to 40 PSI. Then as soon as the pump comes on the CSV will start delivering 50 PSI constant. With a small tank the pump is on and the CSV holds the pressure at a constant 50 PSI very quickly.

With a CSV and a small tank the pump does not cycle for a toilet flush alone. It takes time for the toilet to refill, them more time for the little pressure tank to refill, before the pump shuts off. In this time if you wash your hands, turn on the shower, or a washing machine starts, the pump just keeps running until everything is finished using water.

Those upsy-dazy type pump pullers will usually just roll right over a coupling, so it will pull any kind of pipe.

Motors stored for a period of time do not leak water out the bottom hole. That is a pressure compensating hole that has a rubber diaphragm underneath, so the pressure inside the motor will equalize with the water pressure outside the motor. However, water will just evaporate through the Stainless Steel can of the motor, or it can leak out around the shaft seal. Any motor than has been sitting for more than about 6 months should have the water topped off before installing. Removing the bottom end bell, adding water, then reinstalling the rubber bladder and end bell is the best way. Sometimes you can use a syringe and add water through the upper vent after removing the little screen.

Here is a chart on cycling with house use only. Notice the CSV and small tank cycles less than a 20 gallon tank without a CSV. Plus anytime you are using water outside or for long term like watering with a hose, there is no comparison to the one cycle the CSV will cause to the multiple cycles without a CSV.

 

[Zane Bridgers]

Wow that was incredibly helpful - thanks valveman! The CSV is brilliant. Seems the VFD's should be obsolete, but I guess there's an appeal to selling more inexpressive pumps more often.

 

[Valveman]

VFD's have there place. Just pumping cool, clean water at a constant pressure is not one of them. I started with VFD's more than 30 years ago. We came up with a CSV to replace VFD's, because VFD's were expensive and caused a lot of problems. People have been telling me VFD's were going to make CSV's obsolete for 25 years. Had a local pump guy I have known since he was in diapers tell me that again yesterday. I just laugh and tell them they are 25 years behind. I don't know how many pump guys have told me after five or so years of VFD's they were done with them. But every new pump guy has to go through the same five years of trial and error before they figure it out. In 25 years I have even had some CSV's replaced with a VFD, only to be replaced with another CSV in a short time. People forget all the problems with VFD's, or someone new buys the house, and they have to go through the same learning curve all over again. Told the last guy that fell for the VFD hype he should put the old CSV on the shelf, as he would be wanting to re-install it before long. Happens all the time.

 

[Zane Bridgers]

Haha that sounds about right. I'd imagine the marketing counts for something. People have it in their minds that VFD's are the ferrari of pumps, without thinking about the upkeep and other long term expenses. I think it's an interesting detail that VFD's came before CSV's, because it's natural to assume the mechanical system came before the fancy electronics. Often, a simple mechanical system is more resilient and performs better than a bunch of fancy electronics. To extend the car analogy, a lot of cars these days don't even have a dipstick and then the sensor glitches and there is no way to check the oil. Happened to me this spring when visiting family.

Thanks for all the help valveman. It's really a privilege!

 

[Reach4]

Haha that sounds about right. I'd imagine the marketing counts for something. People have it in their minds that VFD's are the ferrari of pumps, without thinking about the upkeep and other long term expenses.

You could also apply that "without thinking about the upkeep and other long term expenses" to the Ferrari of cars.

 

[Zane Bridgers]

Haha I was thinking the same thing because this rich guy recently was showing off his convertible ferrari and tried to roll the roof down but it got stuck, and then the trunk wouldn't open. He got a little embarrassed and parked it back in the garage all tweaked out

 

[Zane Bridgers]

So I got a good deal on a year old 10GS20 and bought it. I was planning to pair it to a Franklin Super Stainless 2243019204 2 hp, 230 volt, 3 wire motor, unless anyone would advise otherwise.

I was wondering if anyone could comment on the "deluxe" control boxes (2823018310) with magnetic contactors. Is this required for use with a CSV or standard pressure switch? It mentions external pressure switches...

Also would be curious to hear brand recommendations for the well seal (5" PVC), pitless, splice kit, pressure tank and check valve (if recommended) for right above the pump.

By the way, I found a good supplier for threaded Schd 80 drop pipe and SS couplings (Southwest Piping Supplies for those that live in the area), so thanks for the advice. I'm going to steer clear of the poly and build a heavy duty tripod hoist with a 2500# winch.

 

[Reach4]

You would be looking for a well cap rather than a well seal to go above your pitless adapter.

 

[Valveman]

Franklin motor is fine. Deluxe box recommended, but not required. A regular pressure switch can handle a 2HP load, so the deluxe isn't really needed, but still takes a lot of load off the pressure switch points.

I would use the PK1A with the 10 gallon pressure tank, which is the same as I use on the 2HP at my house.
See here. https://cyclestopvalves.com/pages/pk1a-pside-kick

 

[Zane Bridgers]

Interesting - so the deluxe box saves the pressure switch points, but doesn't affect the pump motor? I remember reading one of your posts where you pointed out you can't soft start a submersible motor because it needs ~95% of its torque to start spinning the pump.

Got the pump and motor today. Do you recommend any thread locker/lock washers on the mounting nuts? I would assume dry fit the splines. Surprised and a bit disappointed to see 14 AWG aluminum wires from the motor. Should I cut them right above the pump and switch to some double jacketed, or just wrap the pump wires in a bunch of Scotch 33? I would assume most of the chafing happens a little higher up.

Could I get a brand or supplier recommendation for a pitless? Is there an advantage to the wrap around style on PVC casing?

The PK1A with a 10-20 Gallon Well-X-Trol tank sounds good. It seems the tanks that lay on their side would cause the bladder to rub and wear out quicker, but I don't know how the internals work.

 

[Valveman]

Interesting - so the deluxe box saves the pressure switch points, but doesn't affect the pump motor? I remember reading one of your posts where you pointed out you can't soft start a submersible motor because it needs ~95% of its torque to start spinning the pump.

Got the pump and motor today. Do you recommend any thread locker/lock washers on the mounting nuts? I would assume dry fit the splines. Surprised and a bit disappointed to see 14 AWG aluminum wires from the motor. Should I cut them right above the pump and switch to some double jacketed, or just wrap the pump wires in a bunch of Scotch 33? I would assume most of the chafing happens a little higher up.

Could I get a brand or supplier recommendation for a pitless? Is there an advantage to the wrap around style on PVC casing?

The PK1A with a 10-20 Gallon Well-X-Trol tank sounds good. It seems the tanks that lay on their side would cause the bladder to rub and wear out quicker, but I don't know how the internals work.

Yeah the thrust bearing in a submersible motor doesn't get the film of water it needs between the thrust pads and plate until the motor is up to 50% speed. Plus because head is lost by the square of the pump speed, most submersibles don't start pumping water until they are up to about 90% of full speed. So a slow ramp up speed is not possible with a submersible motor. However, you can still reduce the starting torque and inrush current by using a reduced voltage start. Simply using the longest length of the smallest wire possible for the horsepower of the pump will act like a reduced voltage soft starter. The small size of the wire limits the starting current and reduces the torque the same or better than an expensive reduced voltage starter or a VFD. So unlike pipe, over sizing wire is not a good thing.

Stainless Steel lock washers under the mounting nuts is a good idea, but most don't use lock washers or thread locker. A little grease on the splines won't hurt, but again not necessary.

I hope the leads on the motor are copper with a silver coating, not aluminum wire? The 48" leads are long enough. Wrap them in tape well before taping them to the pipe, as they can chaff below the splice.

Mass Midwest is one pitless I use and don't really care for the wrap around style.

And yes I believe the diaphragm in a horizontal tank will wear when a vertical tank will not. And bladder style tanks wear no matter their orientation.

 

[Zane Bridgers]

Ah interesting! That makes sense that a long length of minimum gauge wire acts like a resistor and softens the start current. One of those valuable insights that wouldn't necessarily come to mind unless you were designing a system from the ground up.

After looking more closely at the wires, it appears there is copper on the inside. I'd have expected more of Franklin so that makes sense.

I can only seem to find Maass Midwest pitless adapters in weld on and wrap around. This is 5" PVC casing, so not sure what is standard in this case. I understand it's common practice to have a second layer of metal casing down to a certain depth, but that doesn't seem to be the standard here in the desert southwest. That, or the well driller figured he'd get away with it. I could believe either. In any case, torquing the pitless through the PVC wall alone does not inspire confidence.

 

[Valveman]

Those pitless units mounted through the casing will hold as much weight as you need. Here is a link to Merrill pitless units, as they are good ones as well.
https://www.merrillmfg.com/shop/pitless-units-kits-and-adapters/pitless-adapters