Options for small 240V portable generators?

[gamp945]

Hi all,

I'm looking for a small portable generator that has a 240V output. I will be using this for whole-home power during outages.

By "small" I mean about 3500W. This should cover all my needs (small home).

I know that there are lots of generators that have 240V in larger sizes (5KW+), but I don't need that much capacity. The main issue is that those larger sizes use more fuel. I want to be able to use as little fuel as possible so that I can deal with long power outages (week or more) more easily.

So far I've only found one unit smaller than about 5KW with 240V: Generac GP 3300 at Lowes.

Are you aware of any other options? Thanks for your advice.

 

[TractorJeff]

Why do you need 240 output?
A/C? Well Pump?

 

[Millwrong]

Honda makes a 4000W with a 240V output, and a great runtime of "up to" 16 hours.

https://powerequipment.honda.com/generators/models/em4000



If your main concern truly is runtime, and you don't live where its often -30°, have a look at the small diesel powered units. For instance, the Generac 5000W with the Yanmar will supposedly run for 32.4 hours at half load....


https://www.electricgeneratorsdirect.com/Generac-6864-Portable-Generator/p50700.html

 

[theoldwizard1]

Why do you need 240 output?
A/C? Well Pump?

Very good questions ! The most common answer would be a well pump.

I would get a 120V 3000W inverter generator, or possibly TWO 2000W generators that you can connect in parallel and then use a transformer to make 240V.

 

[gamp945]

Thanks for the replies.

I need 240 output for 2 reasons: first, so that I can properly plug into my load center and switch the interlock to generator mode. Second, to operate the HVAC system.

@Millwrong: I probably should have stated in the OP that one other reason for a small generator is that they are less expensive That diesel genny looks great, but too pricey for what I'm trying to accomplish. Thanks for the reference all the same.

 

[TractorJeff]

Well?
Typical conversations on here about home generators is the "Start Up Kick" that A/C needs that a lot of smaller generators just don't have in them! Especially if there are a bunch of other loads plugged in.

 

[alfredeneuman]

Very good questions ! The most common answer would be a well pump.

or possibly TWO 2000W generators that you can connect in parallel and then use a transformer to make 240V.

That would require the two generator to be EXACTLY in sync with one another.
If the aren't synchronized, the you run the risk of ruining one or both of the generators

 

[gamp945]

Well?
Typical conversations on here about home generators is the "Start Up Kick" that A/C needs that a lot of smaller generators just don't have in them! Especially if there are a bunch of other loads plugged in.

No well here.

From the calculations I've done on my HVAC, a genny rated at about 3500W constant (and about 4000 startup) will probably be enough. I'll have to hook it up and try it to know for sure.

The 3300W Generac that I linked to in the OP is rated at 3750 starting watts.

 

[mike93lx]

No well here.

From the calculations I've done on my HVAC, a genny rated at about 3500W constant (and about 4000 startup) will probably be enough. I'll have to hook it up and try it to know for sure.

The 3300W Generac that I linked to in the OP is rated at 3750 starting watts.

How big is the a/c? Remember that you will have other stuff plugged in when the a/c starts and your fridge could kick on at the same time.

I wouldn't go less than 5kw if you want a/c. Thanks that out and the 3.5kw one is probably fine

 

[gamp945]

Different HVAC systems have very different power requirements. From the calculations I've done using the manufacturer's extended performance data, a genny rated at 3500 constant / 4000 startup should work fine for my home. I won't know for sure until I actually try it, but I don't want to purchase larger than I need.

Bigger is not better in this case. My constant load will be no more than 2000W constant for the entire home under an emergency scenario.

 

[ForceFed70]

As you've found - You're going to be hard pressed to find a 240V 3500W generator. Seems you have to step up to 5000W before 240V is an option. 5000W is still only 20A at 240V, I wouldn't go smaller.

If fuel consumption is a concern, make sure it's an inverter style. As they're way more efficient. Consider options for turning the generator on/off if you're concerned with fuel supply. Shouldn't need it overnight for example.

 

[gamp945]

@ForceFed70: I've found 2 nearly identical generac units rated at about 3300W continuous and have 240V output. I also saw a unit Costco had last year on their website that was bout 4000W with 240V output, but they no longer sell it.

I'd love an inverter generator, but the ones that are large enough to power a home are way too expensive for me.

I do need to run the generator overnight for humidity control - another reason I need long run times.

 

[EOC_Jason]

That would require the two generator to be EXACTLY in sync with one another.
If the aren't synchronized, the you run the risk of ruining one or both of the generators

Some companies that sell the inverter generators (like Honda) sell parallel kits specifically for the purpose of increasing capacity and 240v capability...


Anyhow, unless it is a window unit, a 3500w generator isn't going to be able to start your A/C unit's compressor... They have a huge initial surge demand. And even if by some chance the breaker on the generator doesn't trip, the marginal power is not going to be good for the unit and will more than likely shorten its lifespan.

If you want to run things on a generator for extended periods quite often, you don't want a generator that is 'just big enough'.. You want one that is at best only running at half load with your intended average usage...

 

[JOE.G]

Would the Generac one listed above run a well pump if that was only thing connected?

 

[rlitman]

Some companies that sell the inverter generators (like Honda) sell parallel kits specifically for the purpose of increasing capacity and 240v capability...

Not that I am aware of. The smallest Honda 120/240V inverter generator is the EU7000i, and that unit is not parallel capable.

The paralleling kits allow you to increase the load capacity of the smaller inverters, but do not get you 240V.

 

[gamp945]

Thanks, Jason. I mentioned in another post that my load will be no more than 2000W at one time. Most of the time about half that. I think a genny rated at ~3500W constant is the correct size.

As I've mentioned a couple times now, you can calculate the starting wattage of your HVAC if you have extended data chart from the manufacturer. I have calculated this and 4000W startup should be enough. Constant wattage for my HVAC is no more than 1000W. It is comparable to a window unit in power consumption.

What I'm really hoping to hear from people is actual make/models of generators that are around 3500W and have 240V output. I've already got the wattage requirements figured out using hard data.

 

[EOC_Jason]

The paralleling kits allow you to increase the load capacity of the smaller inverters, but do not get you 240V.

My bad you are correct, I didn't pay close enough attention and didn't realize it was just a 120v 30A RV style plug and a 120v 30A twist-lock...

 

[rlitman]

My bad you are correct, I didn't pay close enough attention and didn't realize it was just a 120v 30A RV style plug and a 120v 30A twist-lock...

Yeah. Wouldn't it be awesome if that were possible...

But that's not necessarily a deal breaker.

First off, you're completely right in that anybody can easily and safely parallel inverter generators. The same cannot be said about other types of generators.

Second, the 120V parallel output can be applied to an interlock on both phases. 240V loads will get no power, and any MWBC runs the risk of overpowering the neutral (so you can't have that), but otherwise you CAN use a 120V generator to power your house panel's 120V loads.

 

[theoldwizard1]

From the calculations I've done on my HVAC, a genny rated at about 3500W constant (and about 4000 startup) will probably be enough. I'll have to hook it up and try it to know for sure.

All AC units specify something called "locked rotor amp" (LRA) This is the MAXIMUM starting current they will draw before their internal protection will shut them down. This can be SEVERAL TIMES more than the normal running current/breaker size.

If you want to run your AC, you are likely going to need a generator that can handle 10KW starting loads.

 

[theoldwizard1]

I'd love an inverter generator, but the ones that are large enough to power a home are way too expensive for me.

An inverter generator in the 3000W range can run a whole house minus and 240V load. You can even plug it in to the typical exterior connection (L14-20 or L14-30) and connect the two hot legs together.

I do need to run the generator overnight for humidity control - another reason I need long run times.

If that means an air conditioner, you are going to half to go BIG !

 

[wyliesdiesels]

Thanks, Jason. I mentioned in another post that my load will be no more than 2000W at one time. Most of the time about half that. I think a genny rated at ~3500W constant is the correct size.

As I've mentioned a couple times now, you can calculate the starting wattage of your HVAC if you have extended data chart from the manufacturer. I have calculated this and 4000W startup should be enough. Constant wattage for my HVAC is no more than 1000W. It is comparable to a window unit in power consumption.

What I'm really hoping to hear from people is actual make/models of generators that are around 3500W and have 240V output. I've already got the wattage requirements figured out using hard data.

Post a picture of the nameplate of the unit(s). Is this a split system with large compressor? Inverter ductless mini-split? OR? As said above, the LRA is important here.

My 3 ton central HVAC compressor draws 100a in-rush during startup for about 200ms as measured by a Fluke 381 RMS clamp meter. Those small generators no way no hell would start that.

 

[nadogail]

IMHO, the amount of fuel required to run a 3 KW gen set a full load is about equal to what it will take to run a 6 KW gen set at 50% load.

 

[ForceFed70]

If you have your heart set on a 3500W, look at the Champion brand. They have one that has a 30A 240 Plug. I use one for the horse trailer when we are camping.

Are you sure? Your typical "trailer plug/circuit" is 120V 30A and I really doubt you'll find a 240V outlet on a champion brand 3500W generator.

 

[jclem40c]

I have a Champion 3500 watt purchased at Tractor Supply. Spec plate on the generator states, and I quote,


Model 46598
60 HZ
single phase
Power Ratio 1.0
120/240 volts
amps 29.2/14.6
AC watts 3500

 

[ForceFed70]

I have a Champion 3500 watt purchased at Tractor Supply. Spec plate on the generator states, and I quote,


Model 46598
60 HZ
single phase
Power Ratio 1.0
120/240 volts
amps 29.2/14.6
AC watts 3500

OK, I stand corrected. I spent a lot of time looking at champion generators recently and never saw a 240V model less than 5000W.

Seems this particular model is a bit of a unicorn. Quick google search can't find any examples of one for sale new, couple of used ones on ebay tho.

 

[finn]

I bought a cheap 240 capable generator from Menards on Black Friday for $187. That generator is in the Menards hot deals section of this site on clearance for $220 now.

It’s something like 4050w starting power though. That would be pretty marginal for an a/c system, but rill start my well pump, if just barely.

Nice thing about the spendy inverter units is the ability to idle down in low load conditions t save fuel.

 

[TheEquineFencer]

I give up...I was wrong, it has a (NEMA TT-30R) 120V 30A RV plug AND a (NEMA L14-30R) 120/240V plug.... Look at Page #6 of the PDF below...

https://y79961nbs4u2hvbnwronx9zx-wp...-content/uploads/2017/08/46598-om-english.pdf

 

[tyme2par4]

IMHO, the amount of fuel required to run a 3 KW gen set a full load is about equal to what it will take to run a 6 KW gen set at 50% load.

I think this is the key thing that no one else has mentioned. Just because it's a larger generator, doesn't mean it's going to burn more fuel at the same power output.

You're going to be hard pressed to find a generator less than 5kW with a 240V outlet. The simple reason is because a 3500W generator would only put out 14.5A at 240V. That's not enough to run most 240V appliances.
The few that you do find are marketed towards the RV crowd. Many RVs have A/C units that run on 240V but only require about 10A.

Just step up to a 5000W generator, and find one with a bit larger fuel tank. I have a Troy-bilt XP7000 with a 8.5 gallon tank. That will run 11 hours at 50% load. At 35% load, it would probably run 14-15 hours.

 

[theoldwizard1]

I do need to run the generator overnight for humidity control - another reason I need long run times.

Time to "think outside the box" !

Your "average" home can run quite comfortably on 2000-3000 watts WITH NO 240V LOADS ! (Okay, is would not try to run the toaster, microwave and coffee pot at the same time, but you can stagger those.)

OP did not state why humidity control was important, but maybe it is for some person who is in poor health (or someone who needs a good night sleep so that they can work the next day). The simple solution is to rig up one bedroom with a window air conditioner ! There are a lot of inexpensive, low power, 120V window AC units that will easily run on a 2000-3000W inverter generator. Worst case is, you might need 2. One for the window air conditioner and one for the rest of the house.

A problem with small inverter generators is that the have small fuel tanks. Most of the external fuel tank aftermarket kits require you to plumb in a vacuum operated fuel pump. While do-able, it is a very tight fit inside those housings. The simple solution is a siphon feed from a gas ca that is higher than the generator carburetor !

Put a "T" in the fuel line from the internal tank to the carburetor. Add a piece of hose from the third connection over to a fuel shutoff. From the fuel shutoff run a hose to you large external fuel supply. Assuming you do NOT have an external fuel tank with a bottom connection for gravity feed (which would be perfect), you will need to run the hose into the tank from the top.

Three ways to start a siphon. A jiggle siphon pump. An outboard primer bulb. Stick a second hose into the tank and seal the opening up as best you can with wet rags. Blow into his hose. Using clear fuel line well let you see when the fuel is flowing.

 

[ttpete]

Time to "think outside the box" !

Your "average" home can run quite comfortably on 2000-3000 watts WITH NO 240V LOADS ! (Okay, is would not try to run the toaster, microwave and coffee pot at the same time, but you can stagger those.)

OP did not state why humidity control was important, but maybe it is for some person who is in poor health (or someone who needs a good night sleep so that they can work the next day). The simple solution is to rig up one bedroom with a window air conditioner ! There are a lot of inexpensive, low power, 120V window AC units that will easily run on a 2000-3000W inverter generator. Worst case is, you might need 2. One for the window air conditioner and one for the rest of the house.

A problem with small inverter generators is that the have small fuel tanks. Most of the external fuel tank aftermarket kits require you to plumb in a vacuum operated fuel pump. While do-able, it is a very tight fit inside those housings. The simple solution is a siphon feed from a gas ca that is higher than the generator carburetor !

Put a "T" in the fuel line from the internal tank to the carburetor. Add a piece of hose from the third connection over to a fuel shutoff. From the fuel shutoff run a hose to you large external fuel supply. Assuming you do NOT have an external fuel tank with a bottom connection for gravity feed (which would be perfect), you will need to run the hose into the tank from the top.

Three ways to start a siphon. A jiggle siphon pump. An outboard primer bulb. Stick a second hose into the tank and seal the opening up as best you can with wet rags. Blow into his hose. Using clear fuel line well let you see when the fuel is flowing.

Personally, I'd install an electric fuel pump and change-over valve between the tank and carburetor, then use the extra port on the valve for a sucker hose. You just line the 5 gallon cans up and change over on the fly. I have this on my genset and when I shut it down, I pull the hose out of the can and let it run out of fuel.

 

[gamp945]

@jclem40c
@finn

Thanks for your help. I now have 2 more options thanks to you guys.

Tractor supply no longer sells the 46598, but they do sell Model 100216 for $299. 3650 watts with 4500 starting watts.

And the Wen 56400M at Menards is a steal at $229. This one even includes a wheel kit. 3500 watts with 4050 starting watts.

Thanks again.

 

[wyliesdiesels]

@jclem40c
@finn

Thanks for your help. I now have 2 more options thanks to you guys.

Tractor supply no longer sells the 46598, but they do sell Model 100216 for $299. 3650 watts with 4500 starting watts.

And the Wen 56400M at Menards is a steal at $229. This one even includes a wheel kit. 3500 watts with 4050 starting watts.

Thanks again.

You still havent listed the LRA or the type of AC system you have...

 

[gamp945]

You still havent listed the LRA or the type of AC system you have...

I didn't ask for help with that. Thanks all the same.

 

[TheEquineFencer]

I didn't ask for help with that. Thanks all the same.

Kinda cold response there...I feel a chill in the air...

I hope you do the math with the calcs for POWER FACTOR...But I guess you didn't ask for that either...

Either way, let us know what happens...This should be a good one...

 

[gamp945]

Sorry, I did not mean to come across as rude. No offense intended. I should have put a smiley I guess

 

[EOC_Jason]

gamp, for those two generators you listed, they both have the generic chinese engines. I have a similar 3500W model (old AC Delco brand I got cheap off CL). Anyhow, I *highly* suggest if you do buy a generator with one of those style engines (they all look the same, just different HP depending on generator size) go on eBay and order yourself a spare carburetor, I got mine for like $10 shipped.

After cleaning out the carb twice and it still not running right, swapping out the carb made it purr like a kitten. Anyhow, point being if you are ever in a situation when you need it to run and it doesn't, having a spare good carb sitting around for $10 is cheap insurance.

Also like someone else mentioned, even though a generator is rated for a certain wattage, check the manual for the actual breaker sizes for the 120V & 240v, mine are undersized and just those last few amps you are expecting but don't have could be an issue when something large is trying to start up.

 

[gamp945]

Jason, that's a great idea about getting a spare carb. I actually plan to do an immediate conversion to propane to avoid the carb fouling, plus storing propane is a lot easier for me than having fresh gas on hand for emergencies.

The 240V / 4000W model that Costco had last year was dual-fuel, so I'm a bit ticked that I didn't get it before it disappeared from the website. Maybe they'll get it back soon though.

 

[On-Wheel]

Champion had a 3750 with 240. I'm not sure if still made but I got one with a camper.

What ton is the AC? The compressors have a very high spike on start up.One thing that might help is to have the fan on first.
It takes 2 Honda 2000 to start a camper 13,500 btu unit but AC will run with one Honda .

 

[metlmunchr]

The OP obviously isn't interested in useful information, hence the top secret capacity of his A/C system which is the limiting factor on minimum generator size pretty much 100% of the time.

I've got a 4500 continuous / 5500 surge Generac, and starting the same 13,500 btu camper A/C unit like On-Wheel mentioned puts a noticeably heavy load on the generator. That's barely a 1 ton unit, and a far cry from what most anyone would consider an "HVAC system".

You can study and calculate all you like using extended performance data from whatever manufacturer, and it ain't gonna tell you a thing about what it takes to start a compressor. That's entirely a function of the Locked Rotor Amperage of the compressor itself as Wylie and several others have said.

Funny thing is, if you read the reviews on the generator at Lowe's site, they're horrible when they come from anyone who attempted to use it at near full capacity. One guy said it has a 14 amp breaker, and when he monitored the actual current draw, he got an instant trip at 14.5 amps. That alone says its unlikely to start anything bigger than a small window unit. Another one said he bought it for charging an off-grid battery bank. He could control the charge rate, and therefore the current draw on the generator, and he was getting consistent trips at 6 amps. Sounds like quality control ain't one of their strong points.

But they're cheap, and sometimes that's all that really matters

 

[TheEquineFencer]

Sorry, I did not mean to come across as rude. No offense intended. I should have put a smiley I guess