21 Powerboost generator issue?

[Sentinel1201]

Hello,

Picked up a 21 PB last weekend and have it out at the track this weekend. Running a Dometic overhead AC in the trailer (connected to the 240V 4 prong) and a set of tire warmers (connected to one of the 120V outlets). Here is my issue:

1. AC compressor will cut out frequently when running the warmers concurrently. AC is still powered up, just the compressor will not run so the trailer will not cool.
2. If I turn off the AC for a few minutes and start over, compressor kicks back on and runs fine.
3. I ran just the AC (no warmers) all night last night and it ran like a top, never once cut out. Which means the issue is only because during the day I am running the tire warmers concurrently.
4. In monitoring the power draw in the car, it is barely drawing 1500 watts for the AC and barely 700 watts for the tire warmers when its steady state.

Any ideas what could be going on? No breakers are being tripped, just AC compressor does not like the power output from truck when its also powering warmers. Would a soft start outlet help my issue or not really?

(Ignore the Honda generator in the pic, I brought it just as backup)

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[xtraman122]

Others were reporting soft start devices were helping with some other issues, so I bet it would help. Definitely worth trying.

 

[BLoflin]

Hard to tell from the pic, but my first guess is extension cords are too small for the length and current needed during compressor start up.

A soft start for compressor could help, but easiest is to buy the heaviest duty extension cord (10 gauge if you can) and shortest distance needed. Primarily for the trailer/air-conditioning connection, but wouldn't hurt for the other one running back to the tire warmers.

Depending on the A/C size you can pull 30+ amps momentarily while compressor starts.

So with a skinny extension cord at 25 or 50 feet, and when pulling max current at compressor start, you could be dropping enough voltage across the length of the cord, to be below minimum voltage at compressor to start.

Note: you will never see the momentary power draw on the PowerBoost display, it happens too fast. The 1500W you see is steady state after the compressor starts and is running.

 

[Sentinel1201]

Hard to tell from the pic, but my first guess is extension cords are too small for the length and current needed during compressor start up.

A soft start for compressor could help, but easiest is to buy the heaviest duty extension cord (10 gauge if you can) and shortest distance needed. Primarily for the trailer/air-conditioning connection, but wouldn't hurt for the other one running back to the tire warmers.

Depending on the A/C size you can pull 30+ amps momentarily while compressor starts.

So with a skinny extension cord at 25 or 50 feet, and when pulling max current at compressor start, you could be dropping enough voltage across the length of the cord, to be below minimum voltage at compressor to start.

Note: you will never see the momentary power draw on the PowerBoost display, it happens too fast. The 1500W you see is steady state after the compressor starts and is running.

Thank you for your suggestions.

The longer extension cord you see is running out to the motorcycle for warmers which has a low draw out of the 110V outlet in the bed. The AC is plugged in via a 12 gauge 10 foot 15 amp extension cord.

I like your suggestion of uprating the extension cord for the AC. Can you please link me to the right extension cord I need to get? With outlet type, amps and length there seem to be so many options and its a little confusing.

 

[Wslinky]

Thank you for your suggestions.

The longer extension cord you see is running out to the motorcycle for warmers which has a low draw out of the 110V outlet in the bed. The AC is plugged in via a 12 gauge 10 foot 15 amp extension cord.

I like your suggestion of uprating the extension cord for the AC. Can you please link me to the right extension cord I need to get? With outlet type, amps and length there seem to be so many options and its a little confusing.

You could also try switching which set of outlets your tire warmer is connected to. The 220v outlet uses both legs on the generator, since the trailer is only 110v it will only draw from one, I believe the 2 20a plugs are on opposite legs. So if the trailer is drawing from leg one plug the tire warmer in to leg two. Hopefully, that makes sense. The way you could check this is looking at the gauges, you should have power being drawn on each gauge instead of all on one.

 

[BLoflin]

Thank you for your suggestions.

The longer extension cord you see is running out to the motorcycle for warmers which has a low draw out of the 110V outlet in the bed. The AC is plugged in via a 12 gauge 10 foot 15 amp extension cord.

I like your suggestion of uprating the extension cord for the AC. Can you please link me to the right extension cord I need to get? With outlet type, amps and length there seem to be so many options and its a little confusing.

Well if your sure the cord you're using for the trailer connection is 12 gauge and just 10 foot, then that probably isn't the issue. There are 10 gauge cords avail everywhere, but not sure that would solve it.

How are you connecting your current 12g 10ft cord to the 240V plug in the truck?

Also as the other poster said, make sure your tire warmers and your trailer on different generator circuits (i.e. one on A side and other on B side). Easiest way to tell is watch the Sync 4 display and make sure you are pulling from both sides.

 

[Sentinel1201]

Well if your sure the cord you're using for the trailer connection is 12 gauge and just 10 foot, then that probably isn't the issue. There are 10 gauge cords avail everywhere, but not sure that would solve it.

How are you connecting your current 12g 10ft cord to the 240V plug in the truck?

Also as the other poster said, make sure your tire warmers and your trailer on different generator circuits (i.e. one on A side and other on B side). Easiest way to tell is watch the Sync 4 display and make sure you are pulling from both sides.

I did split the tire warmer and AC across the two circuits, and verified the draw on both meters in the truck's screen.

I am using this on the truck's 240V receptacle and then connecting my 12 gauge / 10 foot to one of the two ends for the trailer shore power:

Amazon.com: Cable Matters LED-Lit 4 Prong 30 Amp to 15 Amp Adapter for Generator (30 AMP to 110 Adapter Splitter) 30 Inches - NEMA L14-30P to 2X 5-20R: Garden & Outdoor

Now, I have both of the items below and can use that instead, if that would be better for the trailer AC?

Amazon.com: Camco Heavy Duty 12" 30 Amp Locking 4-Prong Male / 30Amp Standard Female PowerGrip Generator Adapter (55382): Automotive

Leisure Cords 30 Amp Male to 15 Amp Female Dogbone Adapter RV Electrical Converter Cord Cable (30A Male - 15A Female) - - Amazon.com

 

[xtraman122]

It won't really matter which adapter you use, because if the AC is 120v, there's no way any of those plugs can actually spit the load between the two legs. All those adapters are doing is splitting the two hot legs off of that L14-30P into each of those two NEMA 5-20Rs (Regular household plug). It's effectively no different than just plugging directly into one of the regular outlets in the back of the truck, because it's all coming from the same place.

You have 2 120v hot legs of power, each supplying 30A. One leg goes to the A bank of outlets and one pin on that L14-30R twist lock connector, the other goes to the B bank of outlets and the other hot pin on that twist lock. So whether you're pulling from the regular outlets or the 240v twist lock outlet, it's all coming from the same place. The only way to actually have something properly pull power from both legs is to have it be a native 240v device that'll draw from both hot pins of that L14-30 connector.

So I would say you're probably just hitting a quick surge that the pro-power doesn't like. There have been some issues with people getting saws to start up correctly as well. Doesn't trip the actual breaker on the truck, the pro power will just shut off on them. Your AC, even though it's on that adapter, is only pulling all its power from one single leg of power if it's a 120v device; the same as just plugging it into one of the regular outlets. I would either try switching it to the other leg of power than it's on now if they're not quite perfectly balanced (Try watching the pro power meter when the AC is off, but everything else is on, whichever has the lower draw, try plugging into that side). If that doesn't make it happy, I'd definitely try a soft start device, I bet it would help here.

 

[Wolf Man]

I don't have the pro power, in fact don't even have my truck yet. However if I understand correctly what I've been reading from this and other posts, seems like to watch what the current draw among other things for the pro power is you have to see the screen on the dash. I don't how practical it would be but seems like in future model years or even nextgen Ford should add some kind of screen or readout device at those outlets so you can see the info you need right there.

 

[xtraman122]

You can also check it from FordPass so you don’t need to be in the truck.

My truck is off, but you get the idea.

 

[Wolf Man]

Okay, cool never even thought of that.

 

[BLoflin]

It won't really matter which adapter you use, because if the AC is 120v, there's no way any of those plugs can actually spit the load between the two legs. All those adapters are doing is splitting the two hot legs off of that L14-30P into each of those two NEMA 5-20Rs (Regular household plug). It's effectively no different than just plugging directly into one of the regular outlets in the back of the truck, because it's all coming from the same place.

You have 2 120v hot legs of power, each supplying 30A. One leg goes to the A bank of outlets and one pin on that L14-30R twist lock connector, the other goes to the B bank of outlets and the other hot pin on that twist lock. So whether you're pulling from the regular outlets or the 240v twist lock outlet, it's all coming from the same place. The only way to actually have something properly pull power from both legs is to have it be a native 240v device that'll draw from both hot pins of that L14-30 connector.

So I would say you're probably just hitting a quick surge that the pro-power doesn't like. There have been some issues with people getting saws to start up correctly as well. Doesn't trip the actual breaker on the truck, the pro power will just shut off on them. Your AC, even though it's on that adapter, is only pulling all its power from one single leg of power if it's a 120v device; the same as just plugging it into one of the regular outlets. I would either try switching it to the other leg of power than it's on now if they're not quite perfectly balanced (Try watching the pro power meter when the AC is off, but everything else is on, whichever has the lower draw, try plugging into that side). If that doesn't make it happy, I'd definitely try a soft start device, I bet it would help here.

 

[BLoflin]

All good info, except maybe the first paragraph stating pulling 120V current from the big connector vs from the household plugs below is the same. I don't know for sure, but the big connector (i.e the 4 pin 240V) is rated for 30 amps (when using each 120V leg it's 30 amp on each side). The household plugs are rated at 20 Amps, so depending on how smart ProPower is, it should allow 30 amps at 120V say on Gen Side A (i.e. 3600Watts), but if pulling it just out of the household 120 plugs only allow 20A (i.e 2400Watts). I don't know if it is that smart.

In other words, you may (should?) be able to pull more Watts out of each side of the 240 plug than out of each side of the 120 outlets.

If anyone's tested this, let us know.

 

[xtraman122]

All good info, except maybe the first paragraph stating pulling 120V current from the big connector vs from the household plugs below is the same. I don't know for sure, but the big connector (i.e the 4 pin 240V) is rated for 30 amps (when using each 120V leg it's 30 amp on each side). The household plugs are rated at 20 Amps, so depending on how smart ProPower is, it should allow 30 amps at 120V say on Gen Side A (i.e. 3600Watts), but if pulling it just out of the household 120 plugs only allow 20A (i.e 2400Watts). I don't know if it is that smart.

In other words, you may (should?) be able to pull more Watts out of each side of the 240 plug than out of each side of the 120 outlets.

If anyone's tested this, let us know.

Good point, I didn't think of that. You must be right too, I think those do have their own circuit breaker on them and it would probably be against whatever electrical code autos have to follow to allow a 20A outlet pull 30A. I would hope so anyway. So it's coming from the place, but may have a 10A higher breaking point.

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