Convert Electric Pressure Washer to Gasoline

[Xoloski]

Has anyone converted an Electric Pressure Washer to operate on Gasoline power?

I acquired a Landa PHW4-22024A pressure washer that is 3 phase 460 Volt, 20 Amp, 6.3 HP electric powered pump motor and a Diesel Fired water heater.
I do not have 3 Phase power to my home shop, only single phase 240 Volt.
New this 3-phase unit list for around $10K, plus mine has the accessories of hose reel with new hose and flat-free tires.

I brought the pressure washer to the local Landa dealer that both sold and maintained the machine. After looking up the serial number in their database, they said the pump was rebuilt in 2018 and otherwise the unit received regular maintenance. The dealer’s maintenance team tested the machine and said it could stand to have the coils cleaned but otherwise was in good condition with 650 hours on the meter.

My purpose was to trade my 3 phase machine for a single phase unit for my use in my home garage. The dealer offered me $`1250 in trade toward a new Landa from him. There was no offer of cash nor trade for used equipment. The least expensive piece of equipment I could get was a single phase 110 Volt unit and then I would have to provide $3200 +tax to get that marginal pressure washer. The way I view the offer is, after receiving $1250 trade value toward a new piece of his equipment, I am paying the dealers 40% markup on his equipment and really only realize a $500 value of my pressure washer. I do accept that this dealer is in business to make money but, wow $500 for a $10K machine?

My options then are:

1. Sell/Trade the Landa myself to an individual or business.
2. Buy and install a Roto-Phaser, which I don’t really want to do.
3. Buy a 3 Phase generator for a power source.
4. Convert the 3 Phase motor to single phase which I understand is excessively difficult.
5. Use the pump and heater components of the pressure washer to create a gasoline powered pressure washer.

I do have a 18hp Onan B34G engine that I restored last year.
I also have an older Landa Pressure washer that was Gasoline powered to use as a frame/chassis donor.

I believe that converting my Landa to gasoline is the best option, short of selling/trading.

My questions to the forum are
1) Has anyone does this,
2) what do I need to consider before I attempt this action, and
3) do you see any other options?

Thank you!

 

[danski0224]

If the pump is direct drive, the interface will be different.

You will also have to watch the RPM of the pump and the engine vs an electric motor.

An equivalent single phase motor will likely draw around 60 amps.

There are pressure washer websites galore. You will probably want a belt drive motor and pump. It will likely be easier to get a matched engine and pump package and then reassemble your unit on another cart.

 

[Xoloski]

Thanks for your reply. I should have mentioned that the 3 Phase Landa is belt driven. I'll be able to set the pump RPM to Onan engine RPM ratio without issue.

 

[MileHighRover]

What are the specs of your machine? Find out how much horsepower you'll need to drive the pump to match the current specs. The rest will be easy.

 

[strutaeng]

Years ago I "built" cold water pressure washer with a 5 HP TEFC Baldor motor I wanted to put to use. I bought a belt driven CAT pump and ordered the right sheave for the desired GPM & psi. There are equations from the pump manufacturers for sizing motors/rpm and such.

Landa can probably give you the spec for an equivalent single phase motor if you had the power supply to run it. Maybe a 7.5 HP? That's probably the cheapest/easiest option. May need to change the magnetic contactor?

Or they can do the same for a gas motor. They likely use the same pumps for both applications.

 

[Xoloski]

What are the specs of your machine? Find out how much horsepower you'll need to drive the pump to match the current specs. The rest will be easy.

Roger that, I read that I would need the gas engine to be 2x the rated horsepower of the electric motor. The motor spec is 6.3 HP so I'd need 12.6 HP in the gas. The Onan I have is 18 HP and has electric start. My concerns are some kind of pump unloader or engine idle control that would idle the gas engine when the pressure washer wand is off.

 

[mike93lx]

I feel like tagging @fatfillup in pressure washer threads is my new calling

 

[danski0224]

My concerns are some kind of pump unloader or engine idle control that would idle the gas engine when the pressure washer wand is off.

You can buy unloaders from any of the pressure washer sites online.

They go in the pump discharge line before the flexible high pressure wand hose connection and the bypass is fed into the pump inlet (hose feed water connection). The unloader is not part of the pump, at least on typical consumer type pressure pumps.

You would have to do some digging on the existing high pressure pump to see how the unloader is configured, There is something there, at least some sort of switch to kill the motor when the wand trigger is released.

There is no idle control. I have a gas PW, and the engine runs at the same RPM, pumping or not. Obviously it changes a bit under load. There is a manual throttle lever, and that can be changed a bit.

 

[Bert_]

First thing I would do is pull some panels off that thing and see what's in it. I would think it would be belt driven. Also look at the motor nameplate to see what it really is. It probably uses a standard 5hp motor and 6.3 is a made-up number. But you don't know any of this until you look at it.

 

[Xoloski]

Years ago I "built" cold water pressure washer with a 5 HP TEFC Baldor motor I wanted to put to use. I bought a belt driven CAT pump and ordered the right sheave for the desired GPM & psi. There are equations from the pump manufacturers for sizing motors/rpm and such.

Landa can probably give you the spec for an equivalent single phase motor if you had the power supply to run it. Maybe a 7.5 HP? That's probably the cheapest/easiest option. May need to change the magnetic contactor?

Or they can do the same for a gas motor. They likely use the same pumps for both applications.

I spoke with my local Landa dealer and he told me the controls are all 3 phase and there was no viable way to go to single from 3 phase.
A pump is a pump, how it is driven shouldn't matter, only that it turns at the correct RPM which is 1025. I just need to match the pulleys so the pump is that RPM.
The Onan B43G engine is rated for optimal cooling air flow, torque, and engine life at 3600 RPM. So I'll need to change one of the two pulleys to slow the Engine RPM by 28.5% to meet the required Pump RPM.
Should have a lot of torque...

If my Onan drive pulley is 3", I would need a 10.54" driven pulley to be spot on.
I'll see what exists and get the least expensive of the two pulleys to achieve the correct ratio.

 

[mike93lx]

It probably uses a standard 5hp motor and 6.3 is a made-up number.

Feels a lot like it's a converted number from the kw rating of an 80% efficient 5hp motor. 5/.0.8=6.25

Nameplate on the 5hp motor is probably about 4.7kw, divide by 746w =6.3hp

 

[blazemaster83]

Put the word out that you want to trade for a gas powered unit. I have 3 phase at my shop and would love an electrical unit like you have. I use one at work for cleaning boat hulls and it is so nice to just walk up and hit the start button vs dealing with a gas engine. Batteries, fuel, fuel storage, carb issues, starting issues, etc...

 

[Bert_]

The controls WILL be single phase. They might even run on 120v through a control transformer. There will be a contactor that is too small to run a same size single phase motor but that would be easily replaced.

If it were me I would try to keep it electric. I think they are much nicer than gas

 

[strutaeng]

I spoke with my local Landa dealer and he told me the controls are all 3 phase and there was no viable way to go to single from 3 phase.
A pump is a pump, how it is driven shouldn't matter, only that it turns at the correct RPM which is 1025. I just need to match the pulleys so the pump is that RPM.
The Onan B43G engine is rated for optimal cooling air flow, torque, and engine life at 3600 RPM. So I'll need to change one of the two pulleys to slow the Engine RPM by 28.5% to meet the required Pump RPM.
Should have a lot of torque...

If my Onan drive pulley is 3", I would need a 10.54" driven pulley to be spot on.
I'll see what exists and get the least expensive of the two pulleys to achieve the correct ratio.

I think you have a good plan. I just re-read and missed you already HAD the engine. So that's a no-brainer now that I think about it.

Gas would also be portable if that's ever a need. How heavy is a machine like that anyways? It looks like a miniature tank, LoL.

I could see myself having a use for a hot pressure washer. I've seen them used and very effective on heavy caked on gunk.

I've pressure washed aluminum transmission cases with mine and it's decent; hot water pressure would undoubtedly be better.

Please keep us posted on your motor swap.

 

[fatfillup]

To switch from 3 phase to single phase you need to swap to a single phase motor, 7.5 hp if you can't find a 6Hp and you likely won't find a 6 outside of the pressure washer industry. You will also need to switch to a heavier contactor, 40 amp min, replace incoming power lead to 8 gauge and run 8 gauge wire to the motor also. Then you may need to address rewiring the step down transformer that will power the burner as it will be single phase 220 or 110 volt. Doable but fair amount of work. You can use a 5 hp and sacrifice some performance and might not have to change wiring or contactor.

As to selling it, your market is limited to folks that have 3 phase power and want a used washer. I almost never sell a used 3 phase machine, they normally get parted out.

As to powering it with your engine. More then enough power to run the pump. Next question comes in, how do you power the burner. A factory built gas engine machine would either have a 12 volt burner or belt driven generator to power the burner. You can certainly plug in the wall once you determine what voltage the burner is. Likely 220 volt but could be 110volt

As to cost of the machine, list for 10k or so but I would sell similar unit depending on options for 7 to 8.5 and make good money and be happy.

I assume your thinking was to mount the pump on a separate frame with your engine and using the Landa as a heater past the pump it will work fine but be cumbersome. You just have to figure out how to power the burner and make sure you have a flow switch or pressure switch in the right place to turn the burner off when the trigger is shut off. Very important

 

[fatfillup]

First thing I would do is pull some panels off that thing and see what's in it. I would think it would be belt driven. Also look at the motor nameplate to see what it really is. It probably uses a standard 5hp motor and 6.3 is a made-up number. But you don't know any of this until you look at it.

I won't argue that. It started back in the 90's to get a marketing advantage over competitors.

I do think the motors are a bit beefier then a standard 5 hp but I may be fooling myself. Amp draw is everything. Keep it at or under the full load amps on the motor and you will be fine. Note, every motor that I see on new equipment is rated 1.15 service factor and continuous duty. Can't say for certain what that means but we don't have many motor issues and they are run balls to the walls from the factory and many run hours everyday.

 

[fatfillup]

I feel like tagging @fatfillup in pressure washer threads is my new calling

Keep it up or I'll never see the threads

Happy to help

 

[Xoloski]

Put the word out that you want to trade for a gas powered unit. I have 3 phase at my shop and would love an electrical unit like you have. I use one at work for cleaning boat hulls and it is so nice to just walk up and hit the start button vs dealing with a gas engine. Batteries, fuel, fuel storage, carb issues, starting issues, etc...

Where do I put this word out at? I would love to trade for a single phase unit of similar performance.

Sidebar: My son lives in Poulsbo, WA. He is the owner of Great Northern Electric there.

 

[Xoloski]

To switch from 3 phase to single phase you need to swap to a single phase motor, 7.5 hp if you can't find a 6Hp and you likely won't find a 6 outside of the pressure washer industry. You will also need to switch to a heavier contactor, 40 amp min, replace incoming power lead to 8 gauge and run 8 gauge wire to the motor also. Then you may need to address rewiring the step down transformer that will power the burner as it will be single phase 220 or 110 volt. Doable but fair amount of work. You can use a 5 hp and sacrifice some performance and might not have to change wiring or contactor.

As to selling it, your market is limited to folks that have 3 phase power and want a used washer. I almost never sell a used 3 phase machine, they normally get parted out.

As to powering it with your engine. More then enough power to run the pump. Next question comes in, how do you power the burner. A factory built gas engine machine would either have a 12 volt burner or belt driven generator to power the burner. You can certainly plug in the wall once you determine what voltage the burner is. Likely 220 volt but could be 110volt

As to cost of the machine, list for 10k or so but I would sell similar unit depending on options for 7 to 8.5 and make good money and be happy.

I assume your thinking was to mount the pump on a separate frame with your engine and using the Landa as a heater past the pump it will work fine but be cumbersome. You just have to figure out how to power the burner and make sure you have a flow switch or pressure switch in the right place to turn the burner off when the trigger is shut off. Very important

Great information, thank you.
My burner is 110 volt. I would likely plug into the wall.
I have this older Landa that was gas powered. Originally had a 15 HP Honda then the previous owner replaced it with a 8 HP Honda. When that wouldn't work, he sold it.
I was going to simply replace the engine until I discovered that someone had welded the pulley to the pump shaft, and crooked at that. I'll likely use the old unit frame and incorporate the components of the 3 phase unit into it.

 

[tarmy]

Funny part of this is that here in Commiefornia the overlords are outlawing ICE engines for smaller things like this starting in January. There is a lot of discussion on some forums that this specific conversion to “illegal” pressure washers will be common as the electrics have some limitations.

 

[fatfillup]

Great information, thank you.
My burner is 110 volt. I would likely plug into the wall.
I have this older Landa that was gas powered. Originally had a 15 HP Honda then the previous owner replaced it with a 8 HP Honda. When that wouldn't work, he sold it.
I was going to simply replace the engine until I discovered that someone had welded the pulley to the pump shaft, and crooked at that. I'll likely use the old unit frame and incorporate the components of the 3 phase unit into it.

good plan, will make a nice project

The draw backs to gas engine are:

Pain to drag outside and hook up (especially if your electric can run in place)
Noise
Have to have gasoline
Twice the maintenance

Pros:

can run anywhere
don't need 240 current

Good luck