A Home Generator Question

It's time to buy a generator for my house, but none of the previous threads seem to address my (funky) situation.

We have a 3/4 hp well pump that uses 220V. If I don't power the well pump then there is no fresh water coming into the house. But, the pump only needs to run for about 1 minute each hour to feed water into a pressure tank. The pressure tank then supplies water to the sinks, toilets, etc.

Aside from the well, I only need about 1500 Watts to run the fridge and a TV or some lights. A Honda EU2000i seems ideal, except for that pesky 220V well pump.

Generators that supply 220V start at 4000 Watts and are VERY expensive to buy and run. It seems like a waste to buy a 4KW generator when I really only need a 2KW unit.

Any ideas?---Marc

Perhaps it is possible to buffer the energy needed for the pump? If the pump only works a few minutes every hour, it might be possible to have the generator deliver part of the power to a battery or fuel cell and power the pump from there. It would also help with peak loads when switching on the tv or starting the fridge.

A 110v well pump, if there is such a thing?

powernoodle said:

A 110v well pump, if there is such a thing?

Click to expand...

Nice try, Powernoodle. Unfortunately, the motor for the well pump is already in place. It is sealed in the well 200-feet below the surface of the Earth. I can't change it myself, so pulling it up and changing it would cost several thousand dollars.

Yes. Lots of possibilities. And a 120v pump could be a good solution.

How far to the water surface in your well? Harbor Freight has several small suction type pumps and tanks that would work well if there's not too much lift involved. One is on sale now for $69.99.

I've used several of them and they've performed fine. They're light and easily hooked up. You'll just need a suction pipe (black poly works fine) and a foot valve (available at Home Depot, etc). You don't even have to do any wiring -- they come with a standard male plug.

This is too weird but I swear it's true. Fed Ex just delivered, 30 minutes ago, the $69.99 pump that I ordered as a spare/hurricane backup. no joke.

edit - remember, you're only lifting from a few feet below the surface of the water -- the depth of the well if of no concern. My main well lifts from 10ft in a 330ft well.

Perhaps a european generator from honda? They supply 220v
http://www.fl.honda.be/content/industry/18748_5606_data.php?mv=360

And now that I think of it, there's no reason you couldn't install such a pump in-line in your system. You wouldn't even need to drop another pipe into the well.

Changes my plans for a backup system.

As far as generators and such -- always buy more capacity than you think you'll need.

Your cheapest obvious solution is to simply find another source of water.

But also, the honda eu2000 costs about $800. For that money, you can easily find a 4000+ watt 240v generator @ home depot/etc and still have $ left over. In addition, I don't think a 2000w unit will START and run a 3/4 hp well pump.

The honda is a much more useful generator though. I'd try to find alternate water and go with the honda.

I do speak from experience. I own and have owned several generators: honda eu1000, honda eu2000, honda 7000is (bad boy), generac 4000, miller legend welder/genset.

But the baddest generator I ever saw used a 20,000 watt generator as the exciter coil. :huh: The whole thing was mounted on an 18 wheeler trailer!

BIGIRON said:

And now that I think of it, there's no reason you couldn't install such a pump in-line in your system. You wouldn't even need to drop another pipe into the well.

Click to expand...

Wow, That's a great idea!
I could add a "T" onto the water line between the well and the pressure tank. A second pump, the 120V emergency pump, could be fitted to the "T" and pull water from the well. The water surface is only about 20 feet below the earth's surface, so it could work on suction alone.
Hmmmm. That's definitely something to chew on.

TD I agree on the generators.

Most submersible well pumps, at least all the 240v I've seen, use a external capacitor ("control box") to start so a 2kw set might run it, altho it would be close, particularly if there were other load involved.

Couple 'o points.

Is the well pump the absolute only thing using 220-240 VAC? If so, and you want to be able to use a 110-120 VAC generator for backup, then I think you will have to replace the existing well pump with a 120 VAC model. If there are any other household devices that use 220-240 VAC that you want to be able to run using the generator, then you'll have to get a generator that can output 220-240 VAC.

Next, if your existing 3/4 HP 220-240VAC well pump typically only runs for about one minute in an hour, I think your pump is just a wee-bit oversized.

You could change to a 1/2 HP 120VAC well pump. Just check the specs on the max lift of your existing pump versus the actual required lift and flow rate versus the specs of a possible replacement pump.

Also remember to check the wiring to the pump and verify that it is adequate for the distance and amp demands. Unless you have some really-really-really long distances involved, 14 gauge wire for a 1/2 HP 110-120V pump might be adequate and 12 gauge wire should be just fine.

Next, in combination with changing the well pump, you could change your pressure tank(s) to have more capacity in them also. Result is more stored water before the pump has to turn on, but then the pump has to run longer to refill the tanks(s).

Next, even a 1/2 HP 120VAC pump will take most, if not all, of the available generator capacity of a 2000W-class generator at start-up. How much interaction and switching of plugs/cords/devices do you want to tolerate with your set-up? Do you want to be able to feed generator-produced 120V into your house and be able to judiciously just turn things on when needed in an 'emergency' situation? If so, you need a transfer switch/box wired into the main circuit panel.

Do NOT-NOT-NOT-NEVER-NOT-NOT-NOT back-feed a generator into a house's wiring!! It's dangerous to do so, to your wiring, the generator, and utility workers who would be working on the lines trying to fix the problem that caused you to start-up the generator in the first place. The danger to the wiring is possibly feeding excess current into a branch circuit and overloading the wiring in the wall. The danger to the generator is when the main AC power comes back on and feeds back into the generator if the circuit breaker panel main disconnect breaker is still connected.

Only use a transfer switch/box to feed generator power into a house. Or use an individual cord-and-plug arrangement for each device powered by the generator.

Next, remember to allow for start-up surge demands when sizing your generator needs. Most AC motors will have a start-up surge of about twice the running demand. So a typical fridge/freezer with an 800 W run-time demand will need about 1600-2200 W at start-up. So a 2000W-class generator will -just- be able to handle it with some minor other things going as well (a few lights to see, etc). If/when the fridge and the pump kick on at the same time and you have everything enabled at the same time on your transfer switch/box, OOPS!

If you want to have the house receptacles and devices running pretty much as 'normal' while using the generator and transfer switch/box and not have to worry about manually opening/closing individual branch circuit breakers so that only limited branches are live at a time, you pretty much need to move up in capacity from the 2000W generators to the 4000W+ machines to run a household. IMHO. The 2000W-class machines can run most common household devices, but can only run one major household thing at a time.

You have to decide how much:

- you want to spend
- you will put up with transferring cords or branch circuits around

New generator - $500-$1000 or so, big whole-house units will be more
Transfer switch - $300-$500 plus installation
New 110-120VAC well pump - $500-$1500 plus installation

See http://www.backwoodssolar.com/Catalogpages2/pumps2.htm for some 110-120 VAC well pumps.

One thing to remember about using an in-line pump in addition to the "sump" pump is that you will lose some flow; the sump pump will lose efficiency pushing water through the inline, and the inline will have to be powerful enough to draw through the sump pump. But with household water flow rates this could be a non-issue.

Maybe cheaper to use a 110v to 220v transformer for the sump pump? I'm sure you can find them with appliance-type power ratings (not the hair dryer travel converters that plug into the wall outlet).

I'm only a fan of Horrible Freight tools for one-time use generally speaking, but their top of the line generators use Hitachi gen heads and Robin (Subaru) engines. They look real nice and you can often find them on sale for $100 of their already decent price.

Too bad I have no need for a genset because I've always wanted to build one out of like a 1.5L Honda automotive engine, powered by propane.

I would get 2 generators. The big 4kw units use gas like it's going out of style, you do not want to run that just for your fridge unless you can also run a pipe to a gas station next door.

What you want is a used 4kw genset and a transfer switch just to run your well pump. If you can get an electric start unit you might even automate it with the pressure switch so that it would start automatically when needed. Though that could be dangerous! But to go out and push the button on the genset when you need more water is not a big deal.

Then spend your real money on a good quality honda or kipor or yamaha 2kw inverter generator. They sip gas, are quiet for leaving on all the time and provide high quality power for your fridge and if you decide to use the computer or something else. You can run extension cords for the fridges and such you only need a transfer switch for the pump. Small transfer switches like that are relatively inexpensive compared to big units.

This is pretty much exactly what I'm trying to work out the details of too.

I'm going to plumb the back-up pump into my well system and test it. Maybe this weekend if time permits.

Here's how I plan to do it -- I have an 1 1/2 inch line coming from the pump to the pressure tank/distribution system. I'll install a ball valve in the line. The closer to the well, the better for pumping - maybe not for power supply. I'll install "T's" (bushed to 1")on each side of the valve. I'll then install cutoff valves on each "T" and then hook up the pump to the cut off valves. (I want the cutoffs so I can remove/reattach the pump easily. ) When using the backup, I'll close the valve in the main line so I'm not pressurizing the suction side. When not using the backup, I'll just open the main valve and shut the cutoffs, negating the choke effect of the b/u pump.

I know my 1.8KW portable gen will run it, cause I've run a similar pump with it before. I have a 4.5 genset that will run the regular pump on 220v, but this way I don't have to wire it into the well system.

Something's gotta be wrong here. This is too simple.

There is another solution here.

You already HAVE a several thousand watt generator at your house. It's called your "car".

Find a 240v inverter and run it off your car battery. If your pump REALLY runs that little, your car can handle the load, especially if you crank the engine.

Also, I tought I would mention this.

We all talk about the honda eu2000, and I have bought about 6 of them for myself and people I know.

Yamaha makes a competitor to it, a STRONG competitor. It's the yg2800 I think.

Same inverter design. Same noise level. It has a roll cage frame instead of plastic, not that either is 100% superior.

BUT!

It's got a 3 gallon tank instead of a 1 gallon and includes a fual gauge.

It has a separate fual valve so you can run the carb dry for storage.

It outputs 2800 surge and 2500 constant instead of 2000 surge and 1600 constant. That's roughly 50% more powerful each way.

And it only costs $100 over the honda.

Still only 110v though.

And I have bought 3 of them. They are nice.

I say simply get a 4,000-5,000 watt overhead value generator from homedepot or other box stores. you can find them for $450-$650 range with 220 output.

yes a 4,000 watt genset will eat more fuel, but so what. if it's for backup only. if it's a primary source, then that's another matter.

genset availability has changed greatly within last year or so. there's several Chinese 2,500 watt overhead valve gensets available for $225 range. these units basically duplicate 2,000 watt honda class gensets do.

don't get me wrong for camper long runtime requirements. Honda 2,000 is still the one, but for backup usage. lower $$ units will do just fine.

I'm running 5700 watt 11hp Honda, 4,000 Yamaha and 1,000 Yamaha. when power goes down, I'm cranking up the big honda. I've got a freezer and large fridge that's got to stay up. it does cost me an extra gal of fuel per day, but that's a small price to pay. especially when backup situations occurs 2-3 times per year.

Everyone that lived through katrina with a generator still has horrors about finding fuel for it.

I loaned a honda eu2000 to some family.

They were able to run:
fridge
tv
satellite
2 fans
2 lamps
deep freeze
microwave (provided fridge/freezer were not on)

This stuff ran with no cord-swapping for 3 days straight. All in all, the honda ran for 5-6 days straight.

I guess it does depend on what kind of emergency you plan to be using it for. If it's just storm related power outage of a couple of days then gas should be still available locally, but if you plan on storing gas for longer term usage, say up to 2 weeks, it becomes a huge task and a huge tank for one of these non-inverter generators.

If my power goes out it will be because of a near miss from a hurricane most likely (if it goes out due to a direct hit of a hurricane it wouldn't matter as there wont be anything without several square miles of the coast anyway) but lets assume chaos and every little bit of gas I can save will go a long way.

Harbor Freight has a 5200 WATTS PEAK/3000 WATTS RATED rated generator on sale right now for under $500. Claims a 5 hour runtime at half load. There is no way I could store a weeks worth of gas to run it, though it would definitely start my well pump and run the fridge, it's not good for really extended outages where gas might be scarce. Or you can pay more than double that for the yamaha (which looks GREAT by the way) and store half as much gas but get a little less power.

I"m afraid that this year I wont be able to come up with $1300 or so for a fancy one, but I might scrape $500 for this, and upgrade next year.

T-240 - Auto Transformer
I got one of these
I got this thing to balance the 240 volt output from the diesel gen, while suplying maximum amount of power available to the house and the 120 volt inverter and chargers... It handles about 5000 watts. Though I had to switch out my 1/2 hp pump for a 1/3 hp because the 1/2 hp used over 50 amps on start-up which overloaded my inverter 1 out of 5 start-ups (!) sometimes it supplied enough energy to start the pump sometimes not -- the Trace 2500 watt 50 amp sinewave inverter is rated to fifty amp; the pump to fifty one or two! really, I called Grundfos and spoke to the specifications lady..seems the 1/2 hp operated right on the digital cut-off point of the inverter.. the 1/3 hp works fine.

I doubt the Honda 2000 watt could start a conventional 1/2 pump. There are some 'slow start' pumps out there that demand less on start up.


Xantrex
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The T240 is a great way to operate 240 VAC power tools and water pumps from a single inverter. 120 VAC is supplied to the T240 which steps it up to 240 VAC. This versatile auto transformer can also turn 240 VAC into 120 VAC. This allows the full output of a 240 VAC generator to be used by our 120 VAC battery chargers.
Applications
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