Pro Power Max Current Output

[Sprint76]

Hello everyone, just picked up my 2023 Platinum and am loving it so far! I'm planning to use the truck to do power washing around various rental properties we have and I ran into an into an "issue" with a power washer I have. The tag on the motor of the pressure washer calls out 29A, so I was hoping I'd get lucky and the 30A outlet in the truck would power it. Plugging it in does not trip the breaker, but the power washer won't turn on, and almost sounds like it doesnt have enough power to fully spin up the motor on the pump.

All that said, is 29A too much to ask out of the truck? There are other washers available that I can go with but I'm trying to size it appropriately. I can get a 3,000 psi 3GPM with a 26A motor or a 1,500 psi 3GPM with a 12A motor. I don't want to go with the 26A and not be able to run it again like the 29A I have now.

Does anyone have any experience with a similar situation?

Thanks!

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[ThomasNC]

Do you have the ability to add a capacitor to the motor? I don't know if I would recommend it or not but it might get you over the hump.

 

[MontanaLightning]

You have a 9HP electric motor on that thing?

 

[Sprint76]

You have a 9HP electric motor on that thing?

On the pressure washer? I think its a 5 or 6hp based on the 240v/29amp calculation.

 

[MontanaLightning]

Sounds like you need to incorporate a VFD.

 

[Maquis]

If you can find a 240V pressure washer, it will draw half the amps for the same size washer.

There is a thread on here describing the use of a transformer to double the available amps. He was powering a 30A concrete mixer. Basically, if you connect a 240V to 120V step down transformer, you can get up to 60A at 120V. Transformer size must be 7.5 KVA.

 

[MontanaLightning]

He is already using a 240v motor.

 

[Sprint76]

If you can find a 240V pressure washer, it will draw half the amps for the same size washer.

There is a thread on here describing the use of a transformer to double the available amps. He was powering a 30A concrete mixer. Basically, if you connect a 240V to 120V step down transformer, you can get up to 60A at 120V. Transformer size must be 7.5 KVA.

Just found that thread, thanks for the recommendation. It looks like he's getting 30A of 110 using the 240, I need to just get the 30A out of the 240. I'm guessing it is giving 30A but that's not enough to kick over the 29A rated pressure washer. It is interesting that it didnt trip the breaker if it was trying to pull more though.

I guess my question really is does anyone know if the truck reliably outputs 30A at 240 that would be enough to drive a pressure washer or other equipment rated at 26A. At this point I'm guessing I'll just go with the 12A motor option to be safe. I think 1500psi and 3gpm is enough for my needs.

 

[Maquis]

Just found that thread, thanks for the recommendation. It looks like he's getting 30A of 110 using the 240, I need to just get the 30A out of the 240. I'm guessing it is giving 30A but that's not enough to kick over the 29A rated pressure washer. It is interesting that it didnt trip the breaker if it was trying to pull more though.

I guess my question really is does anyone know if the truck reliably outputs 30A at 240 that would be enough to drive a pressure washer or other equipment rated at 26A. At this point I'm guessing I'll just go with the 12A motor option to be safe. I think 1500psi and 3gpm is enough for my needs.

Didn’t realize your requirement was 30A 240V. I missed that.

 

[MontanaLightning]

You could also add a soft start.

 

[Sprint76]

Hello everyone, just an update on this in case anyone is referencing in the future. I was able to source a 6.5hp pressure washer, that is rated for 25 amps on the tag. The lightning faults for an overload when trying to start it even though it runs fine on a 30 amp circuit in our garage. What I found was that when connected to the garage panel, for a split second, the amps spikes to 70 on startup of the motor. It turns out this is typical for AC induction motors running on single phase and is called Inrush Current. I consulted some local motor shops on this and eventually found one that was very familiar with the situation where inverter style power supplies (pro power on board, solar installations, etc) will recognize the short duration current spike and trip, where a traditional breaker is less sensitive and not affected by it. He said there is no work around, not even a soft start, and that even downgrading to a 3 hp motor likely will not work either. Expect 3-4x the tagged amp draw on a motor when starting up, and the pro power on board will likely catch it.

My next step is a bit of a hail mary, but I'm going to attempt to get the motor rotating prior to flipping the switch on on the pressure washer. I plan to use a drill attached the motor drive to see if that eliminates the inrush current and therefore might work with the pro power. if that test works I have two ideas to make a permanent solution: use a smaller motor and another pulley/belt system to get the larger motor spinning prior to startup, or use a battery and car starter to do the same. I will update with results.

 

[P-38]

Have you tried a soft starter?

 

[MontanaLightning]

Use a VFD to soft start it and use a three phase motor.

 

[Sprint76]

Have you tried a soft starter?

I haven't. It's my understanding that soft starters wouldn't help a single phase induction motor based on the discussion with the people I spoke to today. Do you have a specific example of a soft start product that would be appropriate for a 240v/30a use case?

 

[Ragman]

Welcome to the bane of electronic breakers, your best example is A/C compressors on RVs. Soft starts are an option / add on to ease spike on compressor start to not trip breakers.

You can buy a soft start online best bet buy one and see.

I havent dug deep into this however past threads people with power tools with one Harbour Freight vs one “Dewalt” of equal amp rating - the brand name tool generally starts easier with less spiking.

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