Author Topic: How much generator watts for my jet pump?  (Read 20476 times)

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rlphoto

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How much generator watts for my jet pump?
« on: September 28, 2005, 05:33:17 PM »
Hello Everyone, this is my first post.


I live in the country and have a 80ft deep well. It is our only source of water. I am trying figure a way to get water out of it when the electric goes out.  The pump is 110/220 3/4 HP. 4.4/8.8 amps. I want to buy a small as possible generator and keep getting conflicting stories on how much wattage it will take to start it and run it. I have read everything from 2000 watts to 5000 watts. I was getting ready to buy a 5000 watter and them read that 5000 is not enough. I am NOT interested in powering the rest of the house when pumping water. I just want the minumum it will take to saftly start ahd run the pump.


Can somebody here give me a strait answer?


Randy

« Last Edit: September 28, 2005, 05:33:17 PM by (unknown) »

bob g

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Re: How much generator watts for my jet pump?
« Reply #1 on: September 28, 2005, 12:07:06 PM »
Randy


the minimum i would consider is a 5 kwatt unit at 220 volt, the problem is the heavy starting current required to get the pump running.


deep wells and pumping into a pressure tank increase the starting load and the required power to do so.


i am not a fan of the box store 3600 rpm gas units, as my belief is they are rated at a level that they cant deliver very long, at least reliably.


better to go for overkill here and be happy, rather than have problems starting, no starts and possible damage to your pump due to low voltage.


another possible solution would be getting a portable welder, with 220 ac capability, some of which are 1800 rpm units that are designed to deliver what they say they will deliver, reliably. And having a welder in the country is always handy.


if you look you can find a good used miller, or the like with an onan for about the same money as one of the box store 5kwatt units, and have electric start to boot! i have seen and purchase units over the years in the 500 to 750 dollar range that have 5 to 7 kwatt capacity ac.


if you look at the generator in a welder as compared to the puny little gen heads on the box store units, you will see the welder gen head is physically twice the size and far better built.


also the welder/generator will run virtually forever, whereas the box store 3600 rpm model will be dead before you know it.


just my thoughts, others may differ


bob g

« Last Edit: September 28, 2005, 12:07:06 PM by bob g »
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rlphoto

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Re: How much generator watts for my jet pump?
« Reply #2 on: September 28, 2005, 02:35:21 PM »
Thanks for the comments. I was a full time welder for 17 years before a career change and I have often thought of having a portable.


Is there an economical solution to getting water out of that hole?  Hand pump would be better than nothing I guess.


Randy

« Last Edit: September 28, 2005, 02:35:21 PM by rlphoto »

TomW

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Re: How much generator watts for my jet pump?
« Reply #3 on: September 28, 2005, 03:26:15 PM »
rlphoto;


There are some pumps that use air "bo jon" I think is one brand [probably spelled wrong]. Maybe with a small motor and a compressor you could raise a fair amount of water. Pretty basic idea. Tube down into water release air into bottom of that tube the rising air lifts water. Probably not super efficient but maybe easy to do with odds and ends from the junkyard??


Cheers.


TomW

« Last Edit: September 28, 2005, 03:26:15 PM by TomW »

DanG

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Re: How much generator watts for my jet pump?
« Reply #4 on: September 28, 2005, 05:14:55 PM »
With variables beyond your 80' well depth like wire size and wire run length and cut-in pressure, beg borrow or rent a small generator and try it out. Your 1060 watt constant running draw can be anywhere from 3200 to 6400 watts load on start up & thats' if the pump is right next to the generator. If you can, try before you buy!
« Last Edit: September 28, 2005, 05:14:55 PM by DanG »

Volvo farmer

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Re: How much generator watts for my jet pump?
« Reply #5 on: September 28, 2005, 05:23:43 PM »
To confuse things further, I believe there are two different kinds of generator heads manufactured for the 3600 RPM generators. I have a "cheapest of the cheap" Harbor Freight 4KW unit. There are no brushes in the generator head. I know this since I had to rebuild it at about 20 hours :-(  This thing has a horrible surge ability, I think only 4500W. It won't start my 120V air compressor, it's rated at 13A which is below the generators rated capacity. So if you're going to get a 3600RPM gas generator, I'd check the surge rating carefully and maybe try and get one with brushes. A nice 10KW Miller Bobcat would do it, my neighbor has one and I'm very envious. He paid about $4K for it however.


« Last Edit: September 28, 2005, 05:23:43 PM by Volvo farmer »
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rlphoto

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Re: How much generator watts for my jet pump?
« Reply #6 on: September 28, 2005, 07:09:19 PM »
Wow, I didnt realize what was involved in getting water out of a hole!  Sure glad I am investigating this now instead of when all hell breaks loose! If it ever does. I hope it dosent however.


Sure glad I didnt order a small one for nothing! Would have been a big waste of money.   It sure would be easier if I had a shallow well or a spring.


Thanks for all the replys,


Randy

« Last Edit: September 28, 2005, 07:09:19 PM by rlphoto »

inode buddha

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Re: How much generator watts for my jet pump?
« Reply #7 on: September 28, 2005, 09:09:29 PM »
Hi Randy, I'm still welding ;)


If it was me, I would err on the side of "too much" and get a genny or something that seems too big. Think about it, you not only have to start the pump, but you also have to push against 80 feet of water (height). How much does 80 feet of water weigh?

« Last Edit: September 28, 2005, 09:09:29 PM by inode buddha »

laskey

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Re: How much generator watts for my jet pump?
« Reply #8 on: September 29, 2005, 02:32:56 PM »
I know this sounds crazy, but why not build one of those old fashioned water pumping windmills, just like you see out on the farm.  Pump your water into a tank as a reserve, use the wind to keep it full.


Although, I have to admit I'd love one of those portable welders myself. :)


Cya,

Chris

« Last Edit: September 29, 2005, 02:32:56 PM by laskey »

rlphoto

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Re: How much generator watts for my jet pump?
« Reply #9 on: September 29, 2005, 02:50:57 PM »
I really dont want to invest a bunch of money into a big generator.  What if I took an old jet pump, rigged a pully on it and ran it from my wheelhorse tractor which I already own? Can I rig two jet pumps on the same lines?


I posted a new thread on this but it disapeared!


If I am going to buy a generator it will be a 2000watt honda just to run my office computers and an ocasional light.


Randy

« Last Edit: September 29, 2005, 02:50:57 PM by rlphoto »

ghurd

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Re: How much generator watts for my jet pump?
« Reply #10 on: September 29, 2005, 03:12:44 PM »
One thread is enough.  We are paying attention.


If you CAN go with 2 pumps, and I have no idea if that is a good idea or not,

Windy Dankoff makes some (a lot of) great DC pumps. They can run straight from a battery.  He makes some AC pumps too.

Some are quite small and not very expensive, so if you just want water to drink and cook, there might be one that will fit down there over top of the other pump to supply an extra faucet type idea.

Some are big enough for the whole house.

He makes a lot of different pumps for a lot of uses and choices.


G-

« Last Edit: September 29, 2005, 03:12:44 PM by ghurd »
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Volvo farmer

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Re: How much generator watts for my jet pump?
« Reply #11 on: September 29, 2005, 06:00:55 PM »
I think the key phrase here is "when the electric goes out". I assume you're on the grid 98% of the time. Another solution is to get a cistern of some sort or variety so you will have a few hundred gallons in reserve should you lose grid power for a while. You could pump out of the cistern (possibly straight into your house plumbing) with a cheap 12V RV pump. Even four 55 gallon barrels would give you 200 gallons in reserve. Don't those little Hondas EU's have a 12V charger built in?  
« Last Edit: September 29, 2005, 06:00:55 PM by Volvo farmer »
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John II

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Re: How much generator watts for my jet pump?
« Reply #12 on: September 29, 2005, 06:01:45 PM »
Hello: Yes in a blizzard a lot of years ago in Colorado (we were without power for 1 1/2 months )We pulled the electric motor from our jet pump rigged a little gas engine to it, and connected the shafts with a piece of rubber hose and hose clamps and pumped water.... worked great.


I would use a worse case scenario of X 6 or X 8 surge to start run it. If it has a starting capacitor on it.... X 6 would be close enough.



  1. 4A X 220v = 968w run watts
  2. w X 6 = 5,916 rounded to 6 kw
  3. w X 8 = 7888 rounded to 8 kw


I would suggest a generator that can surge from 6 kw to 8 kw.


Also as previously mentioned... there are some cheep generators out there that have absolutely no surge abilities. so with those you would want probably a 8kw unit.


John II

« Last Edit: September 29, 2005, 06:01:45 PM by John II »

John II

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Re: How much generator watts for my jet pump?
« Reply #13 on: September 29, 2005, 06:12:59 PM »
Hello Volvo Farmer:


You said :


" I have a "cheapest of the cheap" Harbor Freight 4KW unit. There are no brushes in the generator head. I know this since I had to rebuild it at about 20 hours :-( "


Hey I have one of these only its a 10kw. Please let me know what failed on yours.


Knowing what falls off of the thing ahead of time would be helpful to me.


Thanks in advance...


Sincerely,


John II

« Last Edit: September 29, 2005, 06:12:59 PM by John II »

bob g

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Re: How much generator watts for my jet pump?
« Reply #14 on: September 29, 2005, 07:58:39 PM »
most if not all jet pumps dont have a really substantial brg on the shaft to support belt drive side loading, this might be a problem.


getting back to the portable welder idea.


look around for a miller portable welder, either an older miller 1E or a 2E


the 1E is usually powered by a 12hp kohler, with a 3.5 kwatt 110 volt capacity with good surge capacity. these units go cheap as most are quite old. If the thing welds at all and burns oil like heck it can be cheaply rebuilt using a new rod, piston and rings. I have bought a couple of these for around 200 to 400 bucks. They produce ac power at 1800 rpm and weld at 3600 rpm, welding current is around 180 amps ac which is not bad. Also they are 12 volt electric start.


The 2E series usually have around 16 hp tecumseh engines, and will produce around 5 kwatt ac, some of which were 1800rpm units, so check on this, most also are 225 amp ac machines although there are variants that are ac/dc units. they can be had for around 500 bucks, they are also electric start.


miller also makes newer units, but check to see if they generate ac at 1800 rpm (preferred) and are powered by 2 cylinder onan's. and often are available for around 500 to 750 bucks. and of course are electric start and generally ac/dc welders.


most of the lincoln welders are 3600 rpm units, some briggs and straton powered and other onan powered. they are electric start and good machines but run at 3600 rpm welding and producing power. prices on these are in the 500 to 750 range also.


of course all of the examples above are used units.


as far as i am concerned they provide a huge bang for the buck and are very well designed and built. Far better than any box store unit at twice the price.


i have a 40 year old 1E i bought 20 years ago, and still use it to weld with. works flawlessly and at 1800 rpm for power is a real workhorse. i think i paid around 300 bucks for it, and installed the rod, piston and rings, honed the cylider and ran every since.


just my opinion


bob g

« Last Edit: September 29, 2005, 07:58:39 PM by bob g »
research and development of a S195 changfa based trigenerator, modified
large frame automotive alternators for high output/high efficiency project X alternator for 24, 48 and higher voltages, and related cogen components.
www.microcogen.info and a SOMRAD member

kurt

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Re: How much generator watts for my jet pump?
« Reply #15 on: September 29, 2005, 08:19:05 PM »
if you want to go with a hand pump they make pumps that fit down your well casing along side your submersable electric pump. here is a link to one i found by googling for deep well hand pump. http://www.survivalunlimited.com/deepwellpump.htm
« Last Edit: September 29, 2005, 08:19:05 PM by kurt »

JYL

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Re: How much generator watts for my jet pump?
« Reply #16 on: September 29, 2005, 09:11:31 PM »
I have a 5Kw, 9HP B&S engine.  I am pumping from 115' at 32PSI without problems.


I believe my pump is 1/2 HP -- 220 Volts.


Now, I know that this generator is not perfect when it come to electric induction motors.  For example, without special procedure, it can't start the Washing Machine (11 Amp 110V), one of my Columns Drill (2.5 Amp 110V), a specific sump pump ( 3.3 Amp 110V).


However, this generator has no problem starting the air compressor (13 Amp, 110V)... Go figure.


Special Procedure:  I load the generator by running another electric motor or powering a few 100W of lights.  Then all induction motors start easily.  (Warning: I never use this procedure with the washing machine that stop and start very often...)


It look like that when the motor is at 3600 RPM with no electric load, the actuator is too slow to provide the necessary boost in power.  Actually, this is probably the reverse:  The actuator call for adding to much gas and the carburetor can't deliver it.  The engine almost stall when this append.

« Last Edit: September 29, 2005, 09:11:31 PM by JYL »

Dreadstar

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Re: How much generator watts for my jet pump?
« Reply #17 on: September 29, 2005, 11:19:11 PM »
how about a Liebert gxt-1500rt it is a 1500va UPS with just the stock 4 7.2ah batts with your 484 watt pump that is 50% load it will run for 15 minutes.


Modify the unit to take 4 35ah external batteries instead and it can run for about 2 hours. These ups are 48vdc units. If your power doesn't go off for more than this. It will do the job nicely.


A gxt-2000rt will do aswell but they are 96vdc units 27 minutes for the gxt-2000 with just the stock batteries.


 If you have solar power some other modifications to one of these units and you can put as large of an external bank as you want just charged from the re power.


I have seen these on ebay for under $100 new ones of course are more.

« Last Edit: September 29, 2005, 11:19:11 PM by Dreadstar »

Volvo farmer

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Re: How much generator watts for my jet pump?
« Reply #18 on: September 30, 2005, 04:56:24 AM »
Hi John.


Mine is the $469 Chicago Electric one with the Robin engine. It was getting all rattly at about six hours and I noticed the four bolts that hold the generator halves together were loose. I tightened three of them, went to tighten the top bolt and it snapped right off like it was made of plastic. I ran the thing anyway and about five hours later it stopped making power. Eventually took it all apart and found a bunch of black dusty stuff all around. I found some scrape marks on the stator as well. I think the top bolt missing let the rotor crash into the stator until something electrical failed. The good news about cheap Chinese generators is that a new rotor and stator cost a little more than $100. I drilled out the top hole in the casing and have a nut and bolt on it now.


Also thought I was screwed until I figured out how to flash the field with a 12V battery. It wouldn't make power with the new parts until I did this. Hope you don't need to go through this. I might have avoided it if I had fixed it right when I broke that bolt.


 

« Last Edit: September 30, 2005, 04:56:24 AM by Volvo farmer »
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BoneHead

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Re: How much generator watts for my jet pump?
« Reply #19 on: September 30, 2005, 09:43:49 AM »
My dad told me he saw a 10kw head at Northern Tool in Macon (I live in GA)for $300. He may have seen it wrong but I doubt it, he's normally pretty good about that stuff. If you could get a hold of one, and scrounge up a 20 - 24hp gas engine, it sounds like you could get off for less than $500... Maybe. They're normally rated for 20hp and above.


All I could find from them online is a 5.5kw for $400. http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=9040
&R=9040 .The other one may have been a refurbished one or something. The 5.5kw requires 11hp.


If you have a tractor with a PTO, and can fabricate a shaft you might could get off for less than $700. Just another possible option. Here's a 7.2kw PTO gen for $750. http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=2003
08467&R=200308467

« Last Edit: September 30, 2005, 09:43:49 AM by BoneHead »

elvin1949

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Re: How much generator watts for my jet pump?
« Reply #20 on: September 30, 2005, 12:33:30 PM »
I have been using air injection for 35 years.

It is the only way to go.

NOTHING in the well but an air line [1/2 in plastic pipe].Air compressor, storage tank-pressure pump and pressure tank all above ground.

 Anything brakes it is in plane view and easy to fix.

later

elvin
« Last Edit: September 30, 2005, 12:33:30 PM by elvin1949 »

nickelbender

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Re: How much generator watts for my jet pump?
« Reply #21 on: September 30, 2005, 06:36:31 PM »
Different AC motor types may require more staring current than others....


If you can find old Repulsion Induction motors they produce the most starting grunt per amp than any other motor, however they are less efficient than modern motors (and haven't been manufactured for 40 years). Capacitor start motors come next followed by switchless capacitors motors. Your most efficient and easiest to start induction motors will be cap start - cap run. To muddy the waters further some electric motors are manufactured with special rotors with higher or lower resistence rotors, the higher the resistence the more staring grunt they have and lower starting current but less efficient they are.


In order here are the NEMA rotor types:

A - lowest resistence, not common, high inrush current but low slip, highly efficient most often seen in fans.

B - General purpose, most common type.

D - Super high staring torque, low inrush and high slip and watt wasters.

F - Special duty high torque/low inrush current motors for aps like fire pumps designed to never trip brakers and run on untill they stall and the fire burns them up....

« Last Edit: September 30, 2005, 06:36:31 PM by nickelbender »

rlphoto

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Re: How much generator watts for my jet pump?
« Reply #22 on: October 01, 2005, 07:50:08 AM »
Thanks to all for the info.  I will be considering all these options in the weeks to come.


I am definely thankfull I didnt waste any money!


Randy

« Last Edit: October 01, 2005, 07:50:08 AM by rlphoto »

Nando

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Re: How much generator watts for my jet pump?
« Reply #23 on: October 02, 2005, 08:27:55 AM »
Sometimes is easy to get a solution for those emergency cases.


A rope pump can be hand or motor driven and it is easy to build.


A rope pump (Nylon) with plugs every foot can bring water to the surface and is long lived.

A PVC pipe down to the well water level with a rope guide to direct the plug into the pipe, bringing the water up to the surface.


This type of pumps are now quite common in many countries, like in Center America and Africa, some are hand or foot operated and some electric motor or wind mill driven.


A Google search for "rope pump " may give hundreds of hits to show how to build one.


http://www.animatedsoftware.com/pumpglos/liftdisk.htm shows the profile of one, to give an idea how the unit works.


For electric motors soft current start, there is an electronic circuit that increases the AC voltage at a rate that the current does not go higher than twice the running current.


Regards


Nando

« Last Edit: October 02, 2005, 08:27:55 AM by Nando »

Ungrounded Lightning Rod

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Re: How much generator watts for my jet pump?
« Reply #24 on: October 04, 2005, 03:50:47 PM »
My well is about 180 feet deep and has a submersible pump down it.


The motor on the pump is three-phase and the controller for it is a hunk of electronics (a "balanced flow" controller) that uses a DSP to generate a variable-speed three-phase waveform to spin the motor up gradually to a desired speed and thus hold the desired pressure directly, minimizing the need for a pressure tank (which only needs to maintain pressure until the pump comes up to speed - which means it's the size of a small pumpkin rather than a small oil drum).


As a side-effect this produces a "soft start" property, eliminating most of the inrush on startup.


"Soft-start" controllers are also available for motors for ordinary start-stop service.  Try Goulds Pumps to see if they have a controller or controller/motor combo suitable for converting your existing pumping system.  At least one of the well dealers in your area should carry their products.


Going to a soft-start controller should let you use a generator rated for just a tad over the run power of the pump, rather than requiring a massively oversize genny to handle the starting inrush without "sucking out" its excitation.  (It will also eliminate the surge in your house wiring when the pump starts even when running on line power.)

« Last Edit: October 04, 2005, 03:50:47 PM by Ungrounded Lightning Rod »

Davesdiesel

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Re: How much generator watts for my jet pump?
« Reply #25 on: July 17, 2006, 11:49:03 AM »
Here's what I did.


I went to Lowes and got the Troy-bilt 3550 genset.  $500.00

Then I wired it from 240 volts to 120.

This gives 28 amps max output at 115 volts.


Rewiring is easy since the manual shows the skymatic.  Rewiring is done in the outlet box.   No need to go into the generator wiring.  Took me 2 hours to do mine.  I was taking my time.


I then wired the hotwater heater to 120 volts.  Instead of 4500 watts it uses 1100 watts.


During Power outages, I would run the genset 14 hours a day.   By sequencing the loads I have all I need.  As far a gas.   The 6.7 hp does use a lot less than a 10 hp.   That's why I did it.  

« Last Edit: July 17, 2006, 11:49:03 AM by Davesdiesel »