Looking for a new well pump-

[potatowolf]

Just as an FYI, i'm helping out the homeowner (70+) with this issue and I hope I can help bring about a positive outcome. Also apologies if some of this sounds incompetent as it isn't really put to paper yet.

They started noticing pressure issues for about a couple months, and suspect either the well pump is going bad or was a result of a lightning strike. Still acquiring more information.

1. we both checked the output legs for the motor and its pulling way uneven in amps.
2. Filters got changed at least 2-3 times within a 2 month period. Appeared to alleviate the issue but not a solution.

Some ID on the pump- its a MacDonald 1/2 hp 10GPM, a 36 gallon pressure tank with estimated 11gal? drawdown running at 40/60 pressure inside the house. Will try to verify moving forward.
TDH is like 292, its a 6" casing and the pump is sitting at 285' down.

UPDATE- After a quick ask he said its a 3 wire running on 230.

Looking for a logical equivalent? but they are getting pushed to dab (1/2-3/4hp at 7 gpm) by the reseller.
At this point wondering if we should just do it ourselves somehow and get the pump/wet end etc. NEVER did this before, but willing to put the time in. Also with the pandemic trying to account for delivery issues by 2+ weeks in order to prepare for worst case.

If you've gotten this far thanks for the read.

I've been on here on other occasions but mostly at a lurking capacity, so this is the first time I had to put forward anything.

Lastly -should also mention I've been been looking at grundfos gould meyers macdonald and dab if that matters any.
Best Wishes

 

[Reach4]

Some ID on the pump- its a MacDonald 1/2 hp 10GPM, a 36 gallon pressure tank with estimated 11gal? drawdown running at 40/60 pressure inside the house. Will try to verify moving forward.
TDH is like 292, its a 4" casing and the pump is sitting at 285' down.

Wrong pump for that deep it would seem, tho maybe the water level never falls close to where the pump is. That's probably it.

Anyway, the 7 gpm pump size makes more sense unless there is a backwashing iron filter.

Pumping to 60 psi adds about 140 ft to the head.

Is the well a 4-inch well with steel casing? If so, I would go to a 3 inch pump. A 4 inch pump is fine in 4 inch pvc casing.

 

[Sponsor]

 

[potatowolf]

I failed to mention that I have been looking at pumps and their respective
curves so sizing isnt necessarily the issue. I just was wondering about potential pitfalls we might come across or surprises ( other than the pitless adapter and the state of the hose itself etc)

 

[potatowolf]

Wrong pump for that deep it would seem, tho maybe the water level never falls close to where the pump is. That's probably it.

Anyway, the 7 gpm pump size makes more sense unless there is a backwashing iron filter.

Pumping to 60 psi adds about 140 ft to the head.

Is the well a 4-inch well with steel casing? If so, I would go to a 3 inch pump. A 4 inch pump is fine in 4 inch pvc casing.

thanks for your reply!- ill try to find out but its likely 4" well with steel casing

 

[Reach4]

thanks for your reply!- ill try to find out but its likely 4" well with steel casing

I have 4 inch steel, and while I had my Trimline 4 inch pump put back down, if I get that replaced I am planning on an SQ with a flow inducer. I have some numbers on choosing 3 inch to make a flow inducer.

Some ID on the pump- its a MacDonald 1/2 hp 10GPM, a 36 gallon pressure tank with estimated 11gal? drawdown running at 40/60 pressure inside the house. Will try to verify moving forward.

Pressure issues? Like what? Not reaching cutoff in a reasonable time?
Confirm low pressure on the gauge at the pressure tank. A blockage could be perceived as pressure issues... A clogged filter cartridge would be the easiest to fix.

This table is not for the MacDonald would have a similar table. So if the water is down about 100 ft, you would want a pump with more stages -- a 7 gpm 1/2 hp pump maybe. Or more like a 7 gpm 3/4 hp pump if the water is down a ways. If you will select an SQ pump, we can give some tips. Whichever pump you try to select, you need to know if you need a "230 volt" or "115 volt". Your pump person will know that.

When the pump gets pulled, note the water line on the drop pipe to know how far down the water is.

 

[potatowolf]

I have 4 inch steel, and while I had my Trimline 4 inch pump put back down, if I get that replaced I am planning on an SQ with a flow inducer. I have some numbers on choosing 3 inch to make a flow inducer.
Pressure issues? Like what? Not reaching cutoff in a reasonable time?
Confirm low pressure on the gauge at the pressure tank. A blockage could be perceived as pressure issues... A clogged filter cartridge would be the easiest to fix.

This table is not for the MacDonald would have a similar table. So if the water is down about 100 ft, you would want a pump with more stages -- a 7 gpm 1/2 hp pump maybe. Or more like a 7 gpm 3/4 hp pump if the water is down a ways. If you will select an SQ pump, we can give some tips. Whichever pump you try to select, you need to know if you need a "230 volt" or "115 volt". Your pump person will know that.

When the pump gets pulled, note the water line on the drop pipe to know how far down the water is.

---
thanks ill keep that in mind @Reach4
SQ with flow inducer? is that like a flow screen or sleeve?
somewhat offtopic but-
I'll try to confirm lo pressure if anything, he also mentioned a strange thing tank had higher pressure than it should have at one point, and swapped the pressure switch that day.
After combing through some records original static level was stated at about 200ft and they set the well at 285. I was guessing at a 9 stage 1/2-3/4 hp unit.
I like the build quality on the dab pumps so far but i havent seen one that our needs as of yet.
macdonald is the one we have, hope they havent gone bad quality in this time. Will start looking at pumps over next few days as well. Will probably need an extra garbage can to fill with water and clean the pump once it comes out.

anyone's experience on a 1 vs 3 phase ( electrical) pump?

 

[Reach4]

SQ with flow inducer? is that like a flow screen or sleeve?

Sleeve. Routes water right by the motor, even if the well is top-feeding. But by routing the water close to the motor, you maximize cooling, even on bottom-feeding well.
In addition, if the well is not cased, reduced turbulence at the intakes so a semi-hard bore won't be eroded right there.
Can let sediment from above pass by. If this is a major purpose for the application, you can make the tube longer.

When the pump is out, consider taking photos of both labels.

I was guessing at a 9 stage 1/2-3/4 hp unit.

The HP you can estimate by the current drawn. Use a clamp-around ammeter around one power wire while the pump runs.

 

[potatowolf]

Sleeve. Routes water right by the motor, even if the well is top-feeding. But by routing the water close to the motor, you maximize cooling, even on bottom-feeding well.
In addition, if the well is not cased, reduced turbulence at the intakes so a semi-hard bore won't be eroded right there.
Can let sediment from above pass by. If this is a major purpose for the application, you can make the tube longer.

When the pump is out, consider taking photos of both labels.


The HP you can estimate by the current drawn. Use a clamp-around ammeter around one power wire while the pump runs.

---

thats really good stuff I will let them know- i'd have to compare with macdonalds spec for amperage but-
i also might have to look at the TDH again- i followed macdonalds recommendation pdf and i got 292- the website gives me 320.
this might be a foolish question- but there is no info as to what connector size is atm(1 1/4"? ) for the house.

 

[Reach4]

this might be a foolish question- but there is no info as to what connector size is atm(1 1/4"? ) for the house.

I think you are asking what pipe size runs to the house. 1 inch SIDR polyethelene is fairly common, but 3/4 is big enough for most houses.

The SIDR adapters usually have barbs on one end and pipe threads on the other.

10 gpm pumps usually have 1-1/4 inch at the pump, but that often gets reduced to 1 inch for the trip up. 7 gpm pumps usually have 1 inch at the pump.

 

[potatowolf]

thanks for your observations so far-
they are pushing a dab 1/2 hp 2 wire 7pm pump for replacement for the macdonald 10gpm 3wire and when I asked if they had a 10 they said they don't carry those is that actually a thing?

 

[Valveman]

Max head on a 1/2HP, 10 GPM is about 280' total. You will need 138' of that to make the 60 PSI on the pressure switch. That means you water level cannot be any deeper than 142', and there is no reason to set a pump like that any deeper than 150-170' deep. The 1/2HP, 7 GPM woul dbe best for that total head. Do not get a three phase motor. That would mean you would need a VFD to convert your single phase normal house power to three phase to run that motor. They can make a VFD sound inviting, but it is really designed to cost you three times more money in a short period of time.

 

[potatowolf]

I am having difficulty trying to reply to this due to a few reasons mainly my lack of understanding on my part- I'd have to re-evaluate the TDH that i had originally estimated, in order to give you the right info. Now assuming I'm getting this right, from our pump documentation was
MacDonald 1/2 hp 10GPM, 36 gallon pressure tank running at 40/60 pressure inside the house (verified).
TDH is like 292? unit is in 6" steel casing
some other stuff from drilling documentation.
well depth 300
drawdown 200
gpm 10
wl before 60
wl after 260
water zone 1 ft 285
confirmed with owner he said they set it at 285.
wanted to get a 230 3 wire motor as that's based off of what kit they already have,
I'll skip on the 3 phase. thanks @valveman.

 

[Reach4]

wl before 60
wl after 260

I assume wl=well level, describing depth to water.
I assume that at the time of the test, 60 was the static level and pumping 10 gpm dropped the water level to 260 ft after what might have been hours. Your post does not say, but the level may have stabilized at that. That testing was probably done with a test pump and not a 1/2 hp 10 gpm pump. The testing would be done with water let out at the surface, so about 0 psi.

You said "they are pushing a dab 1/2 hp 2 wire 7pm pump " I am not finding info on such a pump. When I search on Dab pumps, I keep finding above-ground pumps. Can you find a URL? One thing I wanted to check is its diameter. If it is 3.9, I would not put that into a 4 inch steel casing. If it is 3.75 "trimline" or "slimline" pump, you could consider that. That is what mine is. But next time it will probably be a "3 inch" 2.9 inch diameter pump.

Do you understand the table in post #5? A typical 10 gpm 1/2 hp pump can pump and provide pressure from water at 60 ft and maybe even 1oo ft. But it will not develop enough water pressure at 200.

So why do you want a 10 gpm pump? Backwashing filter needs it would be a good answer. But otherwise a 5 or a 7 would usually be better for a house.

For you I am thinking a Grundfos 5SQ05-180 would be good. If you need higher flow for some reason, I am thinking a 10SQ07-200. Those are smaller diameter, so are less likely to get stuck in a 4 inch steel casing. I would use a flow inducer sleeve.

FYI, a 10 gpm pump is usually cheaper than a 7 gpm pump, because it has fewer stages.

 

[potatowolf]

I assume wl=well level, describing depth to water.
I assume that at the time of the test, 60 was the static level and pumping 10 gpm dropped the water level to 260 ft after what might have been hours. Your post does not say, but the level may have stabilized at that. That testing was probably done with a test pump and not a 1/2 hp 10 gpm pump. The testing would be done with water let out at the surface, so about 0 psi.

You said "they are pushing a dab 1/2 hp 2 wire 7pm pump " I am not finding info on such a pump. When I search on Dab pumps, I keep finding above-ground pumps. Can you find a URL? One thing I wanted to check is its diameter. If it is 3.9, I would not put that into a 4 inch steel casing. If it is 3.75 "trimline" or "slimline" pump, you could consider that. That is what mine is. But next time it will probably be a "3 inch" 2.9 inch diameter pump.

Do you understand the table in post #5? A typical 10 gpm 1/2 hp pump can pump and provide pressure from water at 60 ft and maybe even 1oo ft. But it will not develop enough water pressure at 200.

So why do you want a 10 gpm pump? Backwashing filter needs it would be a good answer. But otherwise a 5 or a 7 would usually be better for a house.

For you I am thinking a Grundfos 5SQ05-180 would be good. If you need higher flow for some reason, I am thinking a 10SQ07-200. Those are smaller diameter, so are less likely to get stuck in a 4 inch steel casing. I would use a flow inducer sleeve.

FYI, a 10 gpm pump is usually cheaper than a 7 gpm pump, because it has fewer stages.

i found a pdf link for dab here https://www.dabpumps.us/sites/dabpumps.us/files/catalogs/USA_GENERAL CATALOGUE 60Hz_2021.pdf
the stuff i was reviewing was on pg 63 on for submersible. hope i didnt screw anything up willing to comply w forum rules.

I guess my reasoning is simple as to the why. I'd replace like for like in order to maintain pressure and overall consistency of the system. You guys seem to have a much better handle on this topic so I will gladly hear anything out. I cannot verify if there is a filter but if theres silt sand etc i wouldnt be surprised geographically speaking there notes of sand/gravel at 164ft and grey ss until 300 ft.

ill look into 3" pumps based on this new information thanks a lot for your help.

 

[Bannerman]

https://www.dabpumps.com/en/products/submersible-pumps-and-motors/submersible-pumps

 

[Reach4]

i found a pdf link for dab here https://www.dabpumps.us/sites/dabpumps.us/files/catalogs/USA_GENERAL CATALOGUE 60Hz_2021.pdf
the stuff i was reviewing was on pg 63 on for submersible.

On page "66" (actual 68/226) it says "Pump maximum diameter 3.9 in". That is not appropriate to 4 inch steel casing IMO.

So anyway, you are saying that over the years, your well has had enough water for a 10 gpm 1/2 hp pump to serve you well. The available pressure was sufficient for you. So the implication of that is the water stayed high enough, and as the water dropped, the available pressure dropping was not a problem for you. It maybe signaled to use less water, or the well may just produce enough water to keep the level between 60 and 80 ft.

So in practice, the water in the well stayed quite a bit above the pump.

Looks like DAB is owned by Grundfos.
https://www.sustainabilitymatters.n...ent-responsibility-of-the-dab-brand-750874492

https://dabpumps.us/en/dabpumps

DAB Pumps has five production plants in Italy, one in China, and one in Hungary as well as numerous sales offices around the globe.​

 

[Valveman]

That 1/2HP, 10 GPM Dab pump has a max head of 240'. No sense in setting it any deeper than 100'.

 

[potatowolf]

Ok guys - i made a serious error on the casing diameter as i am not on-site. its actually 6"steel casing! not 4" . geez. really sorry about that. I had documented a 4" pump and left out the support information.

 

[potatowolf]

On page "66" (actual 68/226) it says "Pump maximum diameter 3.9 in". That is not appropriate to 4 inch steel casing IMO.

So anyway, you are saying that over the years, your well has had enough water for a 10 gpm 1/2 hp pump to serve you well. The available pressure was sufficient for you. So the implication of that is the water stayed high enough, and as the water dropped, the available pressure dropping was not a problem for you. It maybe signaled to use less water, or the well may just produce enough water to keep the level between 60 and 80 ft.

So in practice, the water in the well stayed quite a bit above the pump.

Looks like DAB is owned by Grundfos.
https://www.sustainabilitymatters.n...ent-responsibility-of-the-dab-brand-750874492

https://dabpumps.us/en/dabpumps

DAB Pumps has five production plants in Italy, one in China, and one in Hungary as well as numerous sales offices around the globe.​

ok i think its finally starting to gel for me based on the previous information from everyone. thanks for your patience. so I have on file a dab 1/2 hp 7gpm pump and ill look at that grundfos pump equivalent later this afternoon. I didn't know grundfos owned dab!

 

[potatowolf]

this is an offshoot question i guess but- is there any reason a pump would be set that low(285) in practice ?