water well pump?

swollen tongue · #1 05/21/10, 05:07 PM

what would be the life expectancy of a gould 220v 1.5 horse power submersible pump be? it was installed professionally and correctly, according to the well, etc. It has an 18 gallon pressure tank on it and is used for house and garden use. I have heard about 15 years??

agmantoo · #2 05/21/10, 06:27 PM

Goulds is a quality manufacturer of well pumps. It is not uncommon for some pumps to last for 20 plus years. Some pumps last far less. Reasons that I have seen that caused Goulds pumps to fail vary. The frequency of the starts on a submersible pump are IMO a major contributor to failure. Frequent starts are hard on the insulation of the motor insulation and the start circuit. Each start creates wear and tear on the motor to pump coupling also. I always encourage the use of large storage tanks as the drawdown from such tanks can be a lot of gallons and thus less frequent starts. In you case, I would have never used an 18 gallon tank for example. I do not know if the 18 gallons is drawdown or physical size it is still too small IMO. On farms I see water being provided to animals by a steady small stream from a faucet and often with waste. If such a water system is on a small tank the pump will cycle throughout the day. For example on a hot day a beef farm with 100 cows would use ~3000 gallons. With many waterers having the ability to serve 2 to 4 animals at a time and the animals will drink a minimum of a couple of times a day you get the idea. It is a lot of starts of the pump. You can do the math around your place with the water use. Toilets use anywhere from 1.5 to 5 gallons per flush. Showers use about 3 gallons per minute of use. Washing machines use up to 14 gallons per wash. Whatever the water drawdown is of your 18 gallon tank each time that amount of drawndown is used the pump will start.

Darren · #3 05/21/10, 09:50 PM

I don't recall who the manufacturer was but we're going on 20 years with the original one that's pumped a lot of rusty water.

swollen tongue · #4 05/22/10, 01:13 PM

the tank is a 18 gallons of draw down before the pump starts. if this is to small, what do you reccomend? is it better to just run the pump in the on position if filling a storage tank? or let it trickle in for a few days? the storage tank is what I water the garden with.I thought as long as the pump does not overheat from frequent start ups, it will last some time......... it probably starts about every two hours now on average.
thanks!

agmantoo · #5 05/22/10, 01:23 PM

You need to know the well recharge capacity and try to set the discharge to match or be slightly under so that the pump can run continuously but not to where the output can exceed the amount available. Frequent on/off are more detrimental to the pump than a continuous run. There is no need to be concerned about the pump motor running hot as the water will keep it cool.

With 18 gallons of drawdown and provided the tank is properly pressured the amount of water used per day would influence what I did. Earlier I did not realize you were going to pump the garden water into a storage tank.

swollen tongue · #6 05/22/10, 01:38 PM

yes, it is a low volume well.......here's the stats.........11/4 gallons per minute......420 feet deep,pump set at 410', static water level is 70 feet....4 inch casing........ very good water but low volume. it has a restriction output valve of 2 gal. per minute at the well head at 55 psi with the pressure regulator.pressure tank is charged properly.......supplies the house very good. I figure the casing stores about 340 gal. of water........
so, in order to irrigate my garden and not run the well dry, I have to use a storage tank near the garden and trickle a small amount of water into the 600 gal. tank on a continuous basis, about 8 gallons per hour or so.......... from that I water the garden.........it works pretty good for the last four years............
I just wonder how long my pump will last with this usage.........

agmantoo · #7 05/22/10, 02:15 PM

At that low volume I would possibly install several bladder tanks. Do some math and determine where you get the most drawn down for the money. You can put multiple tanks on a system. You have a good amount of water stored in the casing but I would increase my storage capacity and lessen the starting frequency. Do you have sensor on the system to shut the pump down if you run out of recharge water? That would do more to protect your pump than the things we have been discussing. We do not want the pump running with no water of any consequence coming to it. With the low capacity of the well I do not understand why a 1 1/2 hp pump was installed, any reason? Rather than dribble water why not pump a large part of the casing stored water into the the storage tank then shutoff the delivery to the storage tank? This would reduce the pump starts. Have you ever considered installing a cistern? You sure the well is "1.5 gallons per hour" or is it 1.5 gallons per minute?

swollen tongue · #8 05/22/10, 02:52 PM

i changed a few important facts on the last post.............also, I have a "pump saver" kit on the pump so the pump does not run without water.

thanks in advance!

rambler · #9 05/22/10, 03:44 PM

Well was drilled here in 1971 or 72.

On the 2nd pump down there 260 feet. Going strong. Have 25-50 head of cattle watered too over those years.

Kinda depends on service (the stuf Agman mentioned) and type of water you have. Any sand can wear one out in 3 months....

I think the 1st pump got hit by lightening. This one actually has been down there a long time, 25+ years. When the well screen needed cleaning a couple years ago they said it looked good, put it back down.

--->Paul

agmantoo · #10 05/22/10, 05:47 PM

Like Paul Harvey the rest of the story is known and it changes things.
Erase everything I stated up to now.

I have no idea of why they used the 1.5 HP motor. It is too large and is probably capable of pumping far too much water thus wasting some electricity plus costing more than it should have to purchase. I read that the 2gpm restriction is at the wellhead so to me that interprets that the restriction is on the input side of the bladder tank. Where is the pressure switch located in relation to the restriction/orifice?

GoldenCityMuse · #11 05/22/10, 07:27 PM

Electric surges are the main way of burning up pumps. That and a broked pipe as you run the well dry. BTDT.

fishhead · #12 05/23/10, 07:16 AM

I had a 6" 5 hp Berkley submersible at the farm. It was put in in 1998 and is still running. The pump averaged about 15 million gallons a year. Most of the time when it was turned on it was left running for days or weeks.

A couple of years ago I noticed it wasn't pumping very fast so I had it pulled. It turns out that my screen was clogged with rust and that allowed the pump to run out of water when pumping. When the water filled enough to reach the pump again it caused the pump to slam down on the thrust bearing and ruined it. The pump guys said that they could replace the bearing for $500-750 (I forget) or they could slip a penny in for a spacer for free. I gambled and said do the penny trick. It's been working fine ever since.

swollen tongue · #13 05/23/10, 08:38 PM

Agmantoo
the 2 gpm restrictor is on the main pipe coming up from the pump, before the pressure switch and tank. The guy who drilled well and installed the pump said he put this restrictor on it so the pump could run longer without running out of water. Without it he said it would pump alot more water out in less time..........Tell you the truth I don't no why it is a 11/2 horse pump. maybe because of the lift? Maybe that's what he had in his shop??? Water is very good tasting and clear, and no sand at all.......pressure switch is set at 35/60psi. I use in the summer months about 10,000 gal. per month for everything(garden,animals,house). From Sept. to April I use about 2500 gal. per month.....I know this because I have a water meter on the output side of the pressure tank. Water is like "gold" here in these parts, so I use it sparaling anyway. Thanks for all the input.................

agmantoo · #14 05/23/10, 09:14 PM

When the bladder tank empties to the point the well kicks on how is the low water supply observed in the home; adequate, low, could be better, etc?

There are two things I rather not have with the setup. One is the 1 1/2 HP pump running extended time to only get 2 gpm.

The second is the 2 gpm per minute feeding the home once the 18 gpm bladder tank drawdown is exhausted.

fordy · #15 05/23/10, 11:41 PM

................Wouldn't it be better too allow the pump too pump freely at it's rated capacity ? An 18 gallon pressure tank obviously prevents the pump from pumping the reservoir , dry , and doesn't restrict the motor at the same time . fordy

swollen tongue · #16 05/24/10, 02:57 PM

the water pressure is adequate at the low side in the house........it does not actually restrict the motor, it restricts the flow of the water after the pump, other than that I don't know why........

agmantoo · #17 05/24/10, 05:09 PM

The current setup is limits the output of the pump. This restriction forces the motor to drive the pump for a longer period of time. An example that would sufficee for demonstration purposes would be that if the current pump at its depth had the ability to deliver 6 GPM it would take roughly 3 minutes to fill your bladder tank. With the 2 GPM restrictor in place where it is located the pump would have to roughly run 9 minutes to fill the tank. Obviously the longer run time uses more electricity.

I understand why the installer wanted to limit the output of the pump and i understand his approach was cheaper for the installation. The additional costs for the electricity consumption is not all that great but I do not like using unnecessary power. Restricting the output of the pump is not all that harmful to the pump either. It is cost prohibitive to change the pump/motor at this time. Should you have a failure at some point I do recommend to size the pump to the task however. The only thing that I possibly would do is to install a second bladder tank between the restrictor and the pump. This would let the new tank fill at the existing pump rate capacity and fill the existing tank simultaneously. The end results would be twice the drawdown before the pump kicks in and a reduced run time for the total volume of water available between pump cycles. This would cut pump cycles to about 1/2 the current ones.

Micahn · #18 05/25/10, 04:07 PM

It is very common for pumps to last 20 plus years if not much longer. A submersible pump chances are will last longer then one above ground because it is kept cooler from being in the water.

The larger the tank most times the better as you can use more water between pump starts. I would never put one smaller then a 36 gal (That is a common size at say Lowes) on a home.
I have a 52 gal on my own and my last home had a 80 gal one.

One thing to make sure of is the air pressure in them no matter what size you have. Here is how to make sure it is right.
Find out at what pressure your pump starts at. You can open something and watch the pressure gauge ( if you do not have one that should be your first thing to add to your system) I would let it cycle a couple of times to make sure you know at what pressure the pump starts at.

Shut off the power to your pump.

Drain the water down until it stop.

Check the air with a tire gauge to see what it is at. some place on the tank you will find a Schrader valve (you know like on a tire where you check the air) It should be towards the top of the tank.

It should be 2 psi below what the pump start pressure is. So say your pump starts at 35 psi your tank air should be set at 33 psi.

If you ever change the pump pressures for any reason make sure to adjust the air as well.

You would be shocked to learn that even a lot of pump professionals do not know the right way to adjust the air in bladder tanks. Over the years I have had countless calls from people who all they needed was air added or taken from their bladder tanks when they thought they needed a new one. The only time you would need a new bladder tank is if the bladder burst for some reason. You can tell if that has happened as water will come out of the Schrader valve.