Inverter generator with well pump ????

[IXLR8]

We have been without power for a few days now and when the dust settles I am thinking of picking up an inverter generator vs one that screams at 3600 rpm all the time. I was wondering how well an inverter generator would handle the loads of a well pump. When a well pump kicks in the initial inrush is large and the generator may be at idle and will take a certain amount of time to spin up and increase it's output to match. I was not sure how well the generator, or pump motor, would handle the miss match in generator output vs pump input demands. Any recommendations, thoughts or experiences are appreciated.
Thank you

 

[hosspuller]

Be aware of voltage requirements. Many well pumps run on 220 volts while the inverters that produce 220 are somewhat rare in smaller sizes. A high capacity inverter producing 220 would have little problems starting a well pump.

Another solution is to disable the throttle function of the inverter.

 

[CobyRupert]

Even without considering the inverter aspect of it, sizing a generator for a starting motor can be tricky. Go big and don't worry about it. But when you're cutting it close a lot comes into play.
Motor side : 1) Inrush of motor: For a given horsepower, different types of motors will have different inrush. (Example: A high efficiency motor will have a higher inrush than a standard motor.)
2) A variable torque or constant torque load. Being a pump, the mechanical (water) resistance is near zero when it starts (vs. say a rock crusher where there's immediate torque required at start up.
Generator side: Things that can vary from one-brand to another: 1) There's a flywheel effect of the genny's rotor and motor that will help overcome starting surge.
2) The responsive-ness of the governor to react can vary.
3) The fuel type (gas, natural gas, diesel?) The different power-torque curve of each type of engine will respond differently to overcoming starting surge.
Most (bigger) generator manufacturer's have free software or a website that (if you know your load(s)) can calculate voltage dips (or voltage crash!) at startup.
The starting sequence of your loads can also effect if generator sizing. Example (making up numbers here) a 100 amp genny might be able start a 50 amp motor and then run (3)- 10 amp loads. But if those (3) 10 amp loads are already running, it won't be able to start the 50 amp motor because of the starting inrush. This is important to know if a bigger load (like a pump) is cycling on and off.

 

[HEC]

Even without considering the inverter aspect of it, sizing a generator for a starting motor can be tricky. Go big and don't worry about it. But when you're cutting it close a lot comes into play.
Motor side : 1) Inrush of motor: For a given horsepower, different types of motors will have different inrush. (Example: A high efficiency motor will have a higher inrush than a standard motor.)
2) A variable torque or constant torque load. Being a pump, the mechanical (water) resistance is near zero when it starts (vs. say a rock crusher where there's immediate torque required at start up.
Generator side: Things that can vary from one-brand to another: 1) There's a flywheel effect of the genny's rotor and motor that will help overcome starting surge.
2) The responsive-ness of the governor to react can vary.
3) The fuel type (gas, natural gas, diesel?) The different power-torque curve of each type of engine will respond differently to overcoming starting surge.
Most (bigger) generator manufacturer's have free software or a website that (if you know your load(s)) can calculate voltage dips (or voltage crash!) at startup.
The starting sequence of your loads can also effect if generator sizing. Example (making up numbers here) a 100 amp genny might be able start a 50 amp motor and then run (3)- 10 amp loads. But if those (3) 10 amp loads are already running, it won't be able to start the 50 amp motor because of the starting inrush. This is important to know if a bigger load (like a pump) is cycling on and off.

Very well said ----I have an old 5000 watt gas gen. and was trying to run a 220 pump and my boiler at the same time and ended up replacing both the well pump and boiler motor shortly there after . I can only guess it was the gen. as it was really luging down when they both would run at the same time . Lesson learned the hard way .

 

[Tig]

We've been through some extended outages and I dislike more than just the noise of a generator. But reality is, I need water and a hot shower sure hits the spot. I bought a 9000W surge, 7200W running, generator. It's not quiet by any means, but it runs my pump and HW tank at the same time at 65% of it's rated running capacity. I use it as required. A couple hours in the morning, same in the evening. Just enough to keep us fed, clean and the freezers frozen.
I have DC backup for my home office electronics and I have even acquired a DC water pump which I will try to use to draw water from my shallow well. The less I can use the generator, the better.

Edit: It's also been my experience that generators are hard on the switches that control motors. Arcing will burn them out given a chance. This may be a phenomena of cheap or somewhat defective generators, but in any case it plays to my less use is better philosophy.

 

[IXLR8]

I have solar panels for hot water, propane for cook stove and wood stove for heat. My two big draws are the refrigerator and the 1/3 hp well pump. I have 3 neighbors who are running 3600 rpm generators.... we are getting really tired of listening to them. I wanted to get an inverter generator so I was not adding to the noise and they are much more efficient and longer lasting.

 

[IXLR8]

Very well said ----I have an old 5000 watt gas gen. and was trying to run a 220 pump and my boiler at the same time and ended up replacing both the well pump and boiler motor shortly there after . I can only guess it was the gen. as it was really luging down when they both would run at the same time . Lesson learned the hard way .

This is exactly what I am afraid of.... will an idling inverter generator be able provide the power a well pump starting up will need with out messing up the motor.

 

[HEC]

I recently bought a 1500 watt gen. from tractor supply to just run my now coal boiler . It is not to loud , doesn't use to much fuel and did a good job of runing the coal boiler during this power outage we just had .The coal boiler doesn't use much power but does use some sensitive equipment . I am quite confident it would run an oil boiler also not sure about a furnace with the blower and all .

 

[Tig]

Nice set up Jim.
Based on the following estimate I found online, I think you could get away with a 3500W (running) inverter generator.
Well pump 1/3 HP, 750W running and 1500 startup.
Refrigerator, 700W running and 2200W startup.

Edit: 4000W would be preferable, but I've not seen that size in a portable inverter generator for a reasonable price.

 

[IXLR8]

Tig- Thanks for the input, I am considering one of these two. As far as I am conserned, no inverter generator is reasonably priced.

Yamaha EF4500iSE - 4000 Watt Electric Start Inverter Generator. $3100
OOP's- This Yamaha is only 120vac, I need 220vac for the well pump so
I will have to look at this one.
Yamaha EF6300iSDE - 5500 Watt Electric Start Inverter Generator. $3700

Honda EM5000iS - 4500 Watt Electric Start Portable Inverter Generator. $3700

 

[Ford850]

Take a look at this EU series Honda, EU6500iS
Honda Generator Model EU6500 - Mayberrys.com

or this 7000 unit:
Honda Generator Model EU7000 - Mayberrys.com

 

[CobyRupert]

What is the size of your well pump? What is the surge capacity of the inverter generator you're looking at? Those might be 2 numbers you want to look at.

 

[boggen]

honda 3000watt i think 3000eu or 3000ei is model number. super quiet, have it right outside the door/window on cabin, with screens open, and tv directly on opposite wall and you can not tell that it is there. well there is a hum and some vibration that is felt (enter cabin sets up off the ground on some posts including deck generator is setting on, so the entire flooring kinda absorbs and sends some of the vibration through the cabin. but really not that noticeable.

over-protection / surge / generic fuse...
this genny has a over load protection circuit/switch. that i have had to use a few different times, a window a/c unit, and microwave, are the biggest culprits of one running and then the other tries to start up / gets turned on. power tools (drill, chop saw, table saw, replicating saw, vacuum cleaner), using a couple tools at one time i have also had to hit the "over load protection" switch. due to tripping it

the biggest issue is "brown outs" not enough power and electronic stuff. (cell phones, tablets, laptops, desk top computers, a fancy microwave with electronics), all these electronics can be damaged via "brown outs" not enough power coming in. and the electronics start getting errors to point of damaging them.

window or central a/c compressor, fridge a/c compressor, freeze a/c compressor, compressors do not like being turned off and then suddenly turned back on. the gas can get an "air lock" going which requires extra pressure to get the air lock to resolve itself. . brown outs can also cause a compressor to goto a sudden stop (to much torque / not enough power to keep it turning). so ya gotta be careful there with what is currently connected to genny.

220v motors (example nearly all well pumps out there exception 12v ones). you need to be careful with the two hots (110v legs), have had issue of not a good balance of power on both legs. example... running a toaster, some lights, some fans all on one 110v leg (call it red cable), if well pump kicks on, it will want to pull from both (black and red cables), but the red cable just not going to have power due to other stuff running, and motor may not start up and if it does it may stutter to point it stops. how ever, if i balanced out the load on both red/back cables (toaster,lights,fans), better chance motor will start up and stay running and not cause overheating problems of the 220v well pump motor.

there are better inventors / genney combos out there, but not enough specs to general buyer that is offered. to help balance out loads automatically in the 2 legs (red/black cables), and normally you should just attempt to balance the loads of what you have on and when.

 

[Threepoint]

This is exactly what I am afraid of.... will an idling inverter generator be able provide the power a well pump starting up will need with out messing up the motor.

If you will be powering much of anything in addition to the well pump, are you sure the auto-idle feature will even come into play between pump cycles? It takes a very small load to throttle up a portable generator with auto-idle, e.g., even just a few lights would do it. Perhaps the models you're looking at are different, but from my own personal experience, and input from a couple of gen. manufacturer's techs, auto-idle rarely will activate as long as any load is present, so is best left turned off on a portable back-up generator in a power outage situation. I'm curious to know if others have had a contrary experience.

 

[brain55]

Not exactly true. It may depend on the generator. I have had a Honda EU3000is and a EU6500is, both would run four 4' two bulb fluorescent lights and my solvent tank without coming off idle.

Brian

 

[boggen]

auto idler / economy mode for the honda 3000watt unit i have... if it is going to be large loads on the unit, manual suggests... turning genny off, turn off the auto idler, then start the genny again.

there is a noticeable difference between auto idler on and off. if window a/c unit for cabin is turned on. or running some larger power tools.
--there is a "delay" with auto idler. that gives a brown out effect (low power). and then almost a surge (to much power), the genny will run at a higher RPM's for a few seconds before idling back down for given load on it.
--auto idler off, the genny perks up some momentarily and keeps on going, there is a little bit of a brown out, but not as much as when auto idler is on.

for running some lights, tv, a computer, a fan, or other small power stuff, auto idler is awesome! less noise, less fuel used, and is very responsive with no noticeable brown outs. it is only with the larger power hungry stuff, auto idler is ugly at.

 

[IXLR8]

3pt- I think that is the difference between a generator with "auto-idle" and an inverter generator. From what I know, an "auto-idle" generator has basically two modes, idle and full speed. An inverter generator runs the full rpm range between idle and full speed directly dependent on load.

 

[zzvyb6]

I have a Honda EU6500IS. The 'IS' designates the inverter generator model(s). Mine has a battery providing electric start. If you throw a motor startup onto the load line, the Honda IS makes use of the battery supply to get the startup power needed to roll the motors. That means well pump, garage door openers, washing machine, and furnace.

During a crisis, I tend to keep the garages open, the clothes dirty and the toilets and furnaces on point.

I also have a Costco supplied 3000IS "Something-Tools" generator that is part of my JLG T350 Boom Lift (battery version). It can service my Stihl electric pressure washer, small air compressor or my Wagner Power Painter.

Same deal.

Meanwhile, you can switch off the throttle down feature and run it at full conventional rpm if you so desire.

 

[Threepoint]

3pt- I think that is the difference between a generator with "auto-idle" and an inverter generator. From what I know, an "auto-idle" generator has basically two modes, idle and full speed. An inverter generator runs the full rpm range between idle and full speed directly dependent on load.

Ah, thanks for this. That's a big difference in the inverter sets that I was not aware of.

 

[BobRip]

I would recommend that you get a guarantee from the supplier that if it does not work you can return it. I had trouble running my 1.25 hp well pump on an 8 kW generator. I just increased the wire size in the well from 12 gauge to 10 gauge and it ran fine on a 5 kW generator. There are too many variables to know what will work.