Well - Pump - Generator Question

Gatorboy · Apr 23, 2004

With the recent posts regarding pumping water out of a pond, I got to thinking about my well.

I have no electric on my land, but I have a 300' well that was drilled years ago. Does anyone have experience to tell me if it is possible, or how difficult it would be to install a submersible pump that could be run off of a generator to give me water when I needed it?

Is this a job I could do myself, or should I get a well driller to set me up?

Brian_Stephens · Apr 23, 2004

( With the recent posts regarding pumping water out of a pond, I got to thinking about my well.

I have no electric on my land, but I have a 300' well that was drilled years ago. Does anyone have experience to tell me if it is possible, or how difficult it would be to install a submersible pump that could be run off of a generator to give me water when I needed it?

Is this a job I could do myself, or should I get a well driller to set me up? )

I have a 350' well and the pump in it is 3/4 HP... With all the power failures we've been having I was going to buy a genny and make sure I had water.... The requirements to start the pump worked out to about 6500 Watts ( yes 6.5 Kw) but it's only for a split second.... As of yet I haven't bothered I'm going to put in the 400 gallon holding tank in the house and then I can run a pressure pump from it... it will require about 400 watts...

techman · Apr 23, 2004

Just be careful in your selection of a generator. The motor start-up in-rush may be for a second or less, but generators don't have much surge capacity. This is not a function of the available momentary torque (which is available by virtue of the flywheel/rotor inertia), but rather it is the limitations of the windings and magnetic laminations in the generator. Most residential generators are designed without a lot of reserve to keep costs down. As a result, under heavy peak loads, like starting a motor, the current that is delivered under this load falls way short of what is required to start the motor (magnetic saturation is the biggest culprit). The motor never comes up to speed, voltage out of the generator drops and if left in this overloaded state, damage to the motor or generator can result.

A good rule of thumb is to take the full load amperes of the motor and multiply it by 3 or 4 to determine the minimum generator current output.

paul

_RaT_ · Apr 23, 2004

Well pumps run very easily off a generator. I have a 1/2 HP pump that easily starts off a Honda 3500 watt generator. Starting current for well pumps is considerably less then many other motors. Honda generators while providing very reliable service, are not known for having high current starting capabilities. They are but a small few group of companies that use a brush type generator. The advantage is lower idle voltage, drawback, lower maximum intermittent current available. The thing to remember is to have a generator with 240V capability. A 5000 - 6500 watt generator would work well for most well pumps.

Egon · Apr 23, 2004

Gatorboy:

Old well been sitting for a long time. Do you know what rate it will produce at? Will you be installing a pitless adapter?

It may be easiest for a well driller to set you up as he will be able to flush the well and determine flow rate so you get the proper size pump.

Otherwise any reputable pump supply company could give you all the facts and supply the equipment.

Egon

Junkman · Apr 24, 2004

I did the complete install of my pump system from the pit-less adapter to installing the wiring and piping to the house. It isn't very difficult and the biggest problem is getting the pipe into the well if you are working alone. I put a torque suppressor just above the pump and have the plastic centering guides every 15' on the pipe going into the well. Try to locate the pump about 20' off the bottom of the well and make sure that you have a good quality safety cable attached to the pump before you drop it into the well. I used plastic coated stainless steel aircraft cable and clamps for mine. I don't know how to fish a submersible pump out of the bottom of a well if the plastic drop pipe ever breaks, so I made certain that mine is well attached. At the top of the well, I have a eye bolt that holds the cable and the weight of the pump is suspended from this cable. That way, there is no stress on the drop pipe. Mine is a 220 volt 2 HP Teel submersible pump. It has a separate control box for the capacitor starting and I have spare electrical components for those times that lightning knocks out the control box. This has happened a few times and sometimes it has also taken the pump with it. /forums/images/graemlins/frown.gif If you have a Graingers catalog, you can find most, if not all the parts that you will need. Don't forget to disinfect the well when you are finished installing everything. This is done by putting chlorine into the well and circulating the water back to the well through a hose connected to the house. If the well isn't going to be used for a while, you might want to consider disinfecting it now before you need it by pouring some chlorine into it. Water is constantly flushing through the well even if it isn't being used, so the chlorine will dissipate with in a couple of months. Don't forget to make sure that the well cap is properly attached so small critters don't get into the well casing. A couple of summers ago, I had to take the well cover off and found that there was an active wasp nest hanging from the underside of the cover. I was unhappy to find this, but not as unhappy as they were for being disturbed.

Gatorboy · Apr 24, 2004

( Do you know what rate it will produce at? )

17 GPM

Gatorboy · Apr 24, 2004

Junkman,

Good advice -- I think it is best to have more than 1 person installing that pump -- I can imagine that 300' of pipe, pump, electric cable, can start to get pretty heavy as it is getting lowered into the well.

cisco · Apr 24, 2004

Ah yes, me too. I've a 1/2 hp (and 120 volt) well of 200' for irrigation on my property, and for awhile I had no power line. So, a 3500 watt Honda worked fine. Now that I'm getting a garage/apartment built, I'm putting in a second well, with a 1 hp motor requiring 220 currrent, so the generator I'm putting into the garage, and hooking up to the propane supply via an adaptor Honda makes, is a 5000 watt Honda - not only for the well, but also for lights and refrigerator when needed (stove, water heater, dryer are propane). Honda has ? 3 lines of generators - make sure you get the residential, or even quieter computer grade, units, or the generator noise becomes an issue. When I eventually build a house further forward on the property (for the view, on intracoastal waterway), I'm going to pull the pump in the newer well, substitute a 2-3 hp pump, and upgrade the generator to 10,000 watts (for pump, AC, etc; SamsClub sells on its web site the Generac powered whole house units). Sat down with well and electrical folks to figure this stuff out, and have a 2" water line, out-sized well shaft and holding tank coming out of well to accomodate increased flow needs in future. You also need to make sure the power line you run from a dwelling to the well can accomodate a larger pump motor if needed, and it sure is more convenient if you bury it at the same time you dig the water line ditch.

_RaT_ · Apr 24, 2004

This Well stuff is a deep subject.

Cisco, I'm fortunate in that I only need to use my well for domestic water. All my property is fed by a pressurized pipe which is fed "ditch water" Really a great way to do it as it gets none of the ultra purifying utility water must provide thus far less costly. We buy it by the miners inch which is about 12 gpm/inch. Being on a party line, we have over 100 GPM available in a 4" line. Pressure is about 120 PSI static.

Running a pump like a 2HP well pump can cause problems for folks with a well capacity of only 15 GPM unless it is needed because of the high head pressure from a very deep well. It sounds like you have your situation well figured out.