Air compressor trips PPOB breaker

[gnikdaor]

Recently, I tried to run my portable air compressor using the 7.2 kw PPOB generator on my Powerboost. I read up on using PPOB in the owner's manual, and followed the procedure to put my truck in generator mode. I plugged in my air compressor, flipped the switch to turn on the compressor, and it started and stopped a few times before tripping the breaker. The compressor has a 115 volt, 15 amp motor. After resetting the breaker, I tried again. Same thing happened. I tried the second 120 volt outlet, just to rule out a problem with the first outlet. Still trips the breaker.

Now, I am not only a first time Powerboost owner, but electrical stuff in general is a serious weak point for me. As in, I don't know much about it. Mechanical stuff I understand, but not electrical/electronics. So, I don't know if 15 amps is too much of a load for the 120 volt outlets, which is rated 15 amps if I remember correctly. I will add, that on occasion, the air compressor will trip the 15 amp house breaker it is normally plugged into. Of course, that breaker also powers other outlets in both the garage and house as well, so it might just be something else was drawing off that house breaker when the compressor tripped it. I had nothing else plugged into the truck when it tripped.

I'm hoping that some of the electrically savvy people here might know what is wrong, or can point out something that I am doing wrong. Is the air compressor drawing too much of an initial load on the truck, causing the breaker to trip? Or could it be something wrong with the compressor itself?

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[JoeRedFly]

Your starting current is too high for the PPOB with that compressor. Which model is it? Unless it can be rewired for 240V it likely won't run off of the truck without adding a soft start module which would cost more than a smaller cheap compressor.

 

[Gros Ventre]

An electric motor has a starting surge of current. Commonly it is on the order of 1 1/2 to 2 1/2 times the running current. So what you're seeing is that the PPOB circuitry detects that surge and trips the breaker. Would be nice if Ford had planned for this... I have my house setup to be run by the PPOB (7.2kW). It operates fine except that the Hotwater heater (4,400 watts) trips the PPOB circuitry. Other smaller loads on the order of 1,000 watts or so don't cause a problem.

 

[Mszczewski]

The outlets in the truck's bed should be 20AMP outlets. It sounds like the inrush current on your compressor is high since it is tripping both your truck and your house circuits.

The truck measures wattage digitally, IE, it counts the watts drawn. The breaker trips if your load exceeds 3600 Watts on a leg. There is no forgiveness to 3601 Watts (per my understanding of the system).

(I understand that each outlet is rated for 20AMPS IE 2400 Watts (20AMPS*120Volts). I believe the truck isn't monitoring at the outlet level but at the leg/circuit level.)

Your typical breaker in a US home uses heat/resistance to determine when to trip. This means that if your inrush/surge current goes over the 3600 Watts for a moment but doesn't heat the breaker enough, you don't trip. There is some forgiveness in there.

I would check your compressor to see if there are any loose connections, anything that should be oiled, or the like since it sounds like it is drawing more than I would expect to get started.

 

[Gros Ventre]

The outlets in the truck's bed should be 20AMP outlets. It sounds like the inrush current on your compressor is high since it is tripping both your truck and your house circuits.

The truck measures wattage digitally, IE, it counts the watts drawn. The breaker trips if your load exceeds 3600 Watts on a leg. There is no forgiveness to 3601 Watts (per my understanding of the system).

(I understand that each outlet is rated for 20AMPS IE 2400 Watts (20AMPS*120Volts). I believe the truck isn't monitoring at the outlet level but at the leg/circuit level.)

Your typical breaker in a US home uses heat/resistance to determine when to trip. This means that if your inrush/surge current goes over the 3600 Watts for a moment but doesn't heat the breaker enough, you don't trip. There is some forgiveness in there.

I would check your compressor to see if there are any loose connections, anything that should be oiled, or the like since it sounds like it is drawing more than I would expect to get started.

Agreed as to the "no forgiveness" issue. That digital monitoring of the current does that. One solution is to get an Auto-transformer and use it to start the compressor. When you do that the inrush current is limited as you raise the setting of the auto-transformer to full.

 

[v8440]

Do you mean a variable transformer? Edit: I see that variable transformers are generally autotransformers.

 

[Gros Ventre]

Auto-transformer is the more formal name. It allows you to start something at a very low voltage and ramp up the voltage. Thus sidestepping the starting surge. I looked into one for my hotwater heater but they don't come that big at a reasonable price.

 

[v8440]

I THINK all variable transformers are autotransformers, but I know not all autotransformers are variable. Some are made without extra taps for voltage selection, though many if not most do in fact have selectable taps.

 

[PBXL]

A free thing you can try first is to make sure the gas engine in the truck is running when you turn on the compressor. This has helped me make it over the initial surge on some items before. You can put it in tow haul mode or something like that so that the engine stays running while you turn on the compressor.

 

[travisN000]

Depending on its draw, something like this might help:

https://www.amazon.com/Exqutoo-Starter-Electric-Max-1800W-Activate/dp/B0C8MC7RK8/


reviews are 50/50 on amazon, worked for some, but not for others.

A more expensive and highter rated one:

https://www.amazon.com/dp/B07VQDMFZD/

 

[gnikdaor]

Your starting current is too high for the PPOB with that compressor. Which model is it? Unless it can be rewired for 240V it likely won't run off of the truck without adding a soft start module which would cost more than a smaller cheap compressor.

I don't know the model, it is an old compressor I got from my father. But the motor is a 2 HP Dayton, capacitor start, 60 hz. It appears that it can be wired for 230 volt, giving it a working current of 7.5 amps versus 15 amps with the 115 volt setup, according to the label.

I noticed the plug itself has a split on one of the two "blades" that plug into the outlet. Maybe that is the issue, the truck senses a short from the plug. That could explain why it also occasionally trips the house breaker.

It looks like I should buy a new plug for it. The switch housing cover is removable, making it easy to access the terminals to wire in a new plug.

 

[gnikdaor]

The outlets in the truck's bed should be 20AMP outlets. It sounds like the inrush current on your compressor is high since it is tripping both your truck and your house circuits.

The truck measures wattage digitally, IE, it counts the watts drawn. The breaker trips if your load exceeds 3600 Watts on a leg. There is no forgiveness to 3601 Watts (per my understanding of the system).

(I understand that each outlet is rated for 20AMPS IE 2400 Watts (20AMPS*120Volts). I believe the truck isn't monitoring at the outlet level but at the leg/circuit level.)

Your typical breaker in a US home uses heat/resistance to determine when to trip. This means that if your inrush/surge current goes over the 3600 Watts for a moment but doesn't heat the breaker enough, you don't trip. There is some forgiveness in there.

I would check your compressor to see if there are any loose connections, anything that should be oiled, or the like since it sounds like it is drawing more than I would expect to get started.

You are correct, it is 20 amps, I was just going off memory (a bad idea for me!)

 

[HammaMan]

If it's occasionally tripping a house breaker, it needs to be wired for 240v operation. It takes quite a bit of energy to trip a traditional style house breaker (not to be confused with AFI breakers, those trip if you just have the wrong thought when plugging in some devices).

 

[gnikdaor]

If it's occasionally tripping a house breaker, it needs to be wired for 240v operation. It takes quite a bit of energy to trip a traditional style house breaker (not to be confused with AFI breakers, those trip if you just have the wrong thought when plugging in some devices).

The lights in the garage do blink for a split second when it fires up. I think it can be wired for 230 volts according to the label on the motor. However, I don't have the requisite outlet in the garage for that.

I guess I would then just run the compressor off the truck at that point.

 

[v8440]

Weird thought, could you set it up with a plug for 230 and a plug for 110, and just tape up the unused plug? That may not be possible, I'd have to see the wiring diagram for the motor. Would neatly solve the problems though!

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