Pro Power Onboard - B side never takes power

[hturnerfamily]

... some campgrounds are wired this way, because many 50A RV's only need 120V. So they bring only 120V to the pedestal and wire it to both sides of the receptacle...

no, a NEMA 14-50 4-prong outlet is not 'wired with only 120v', it is 240v, with two hot wires, a neutral, and a ground. Campgrounds don't wire it differently 'just because' all RVs don't need 240v, because some DO. Motorhomes and large fifth-wheels, and actually even some towables use 50amp 240v power. The pedestal they plug into IS 240v. The outlet is wired to a double-pole 50amp BREAKER, for 240v power.
Where the difference between your Home's panel and most 50amp RVs is simply that the RVs might not have 240v appliances, and the RV's breaker panel doesn't use any 240v breakers, but it still has 240v power coming into it.
The difference is that RV panels can be designed to use both '120v sides' of the power, separately, ultimately providing up to 100amps at 120v, so that running two overhead air conditioners, the microwave, and everything else at the same time is accommodated by that amount of power.

The more common 30amp RV outlet IS only 120v, and therefore doesn't support many of the larger RVs that we see today.

Like FORD, the RV industry started accepting the NEMA 14-50 240v outlet as the standard many years ago, whether for large RVs, or EVSE equipment.

Otherwise, yes, 240v service is 240v service, whether from your utility, or the campground outlet.
If it's a 240v outlet, it's 240v power.

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[FlasherZ]

no, a NEMA 14-50 4-prong outlet is not 'wired with only 120v', it is 240v, with two hot wires, a neutral, and a ground. Campgrounds don't wire it differently 'just because' all RVs don't need 240v, because some DO. Motorhomes and large fifth-wheels, and actually even some towables use 50amp 240v power. The pedestal they plug into IS 240v. The outlet is wired to a double-pole 50amp BREAKER, for 240v power.
Where the difference between your Home's panel and most 50amp RVs is simply that the RV doesn't have 240v appliances, and the RV's breaker panel doesn't have any 240v breakers. It uses both sides of the 120v power, ultimately 100amps at 120v, so that running two overhead air conditioners, the microwave, and everything else at the same time is accommodated by that amount of power.
The more common 30amp RV outlet is only 120v, and therefore doesn't support many of the larger RVs that we see today. Like FORD, the RV industry started accepting the NEMA 14-50 240v outlet as the standard many years ago, whether for large RVs, or EVSE equipment.

Otherwise, 240v service is 240v service, whether from your utility, or the campground outlet. If it's a 240v outlet, it's 240v power.

I stand by my comments. I have seen many campgrounds wired such that a single 120V hot single phase is wired to both ungrounded poles of the 14-50 receptacle. This is because many RVs use 120V AC units on one side and all other 120V loads on the other side.

I agree with you that it SHOULDN'T be that way, but at many campgrounds, that is indeed the case.

Measure between A-B and you'll get 0V because it's the same wire.

Measure between A-N and B-N and you'll get 120V on each.

And many RVs will work just fine this way, but EV's will not charge.

But this is off-topic, I mentioned it because it xould be happening in this case - OP needs to make sure his didn't get wired like this... so check that 240V loads work, then test receptacles from adjacent breakers on the same side of your panel.

 

[Yellow Buddy]

I stand by my comments. I have seen many campgrounds wired such that a single 120V hot single phase is wired to both ungrounded poles of the 14-50 receptacle. This is because many RVs use 120V AC units on one side and all other 120V loads on the other side.

I agree with you that it SHOULDN'T be that way, but at many campgrounds, that is indeed the case.

Measure between A-B and you'll get 0V because it's the same wire.

Measure between A-N and B-N and you'll get 120V on each.

And many RVs will work just fine this way, but EV's will not charge.

But this is off-topic, I mentioned it because it xould be happening in this case - OP needs to make sure his didn't get wired like this... so check that 240V loads work, then test receptacles from adjacent breakers on the same side of your panel.

If the panel was wired in single / non-split phase method, wouldn't that mean 240V appliances won't work regardless of the truck? To your point it would just take the line of least resistance and end up with only 120V.

If the panel isn't wired correctly and A-B is getting 0V that would imply the truck itself is wired wrong and Inverter 1 is powering both legs of the outlet.

 

[FlasherZ]

If the panel was wired in single / non-split phase method, wouldn't that mean 240V appliances won't work regardless of the truck? To your point it would just take the line of least resistance and end up with only 120V.

If the panel isn't wired correctly and A-B is getting 0V that would imply the truck itself is wired wrong and Inverter 1 is powering both legs of the outlet.

Yes, I haven't seen any confirmation of 240V loads working, that's a first step.

If the truck's receptacle does that, then yes, inverter wired wrong. I'm making an assumption that it isn't the case.

It's more likely to be in how the power gets from the truck's receptacle to the panel. I can't rule out that an electrician wired it only for a handful of 120V loads.

But more information will tell us that.

 

[Maquis]

I stand by my comments. I have seen many campgrounds wired such that a single 120V hot single phase is wired to both ungrounded poles of the 14-50 receptacle. This is because many RVs use 120V AC units on one side and all other 120V loads on the other side.

I agree with you that it SHOULDN'T be that way, but at many campgrounds, that is indeed the case.

Measure between A-B and you'll get 0V because it's the same wire.

Measure between A-N and B-N and you'll get 120V on each.

And many RVs will work just fine this way, but EV's will not charge.

But this is off-topic, I mentioned it because it xould be happening in this case - OP needs to make sure his didn't get wired like this... so check that 240V loads work, then test receptacles from adjacent breakers on the same side of your panel.

I’ve also seen this wiring at campgrounds. RVs have never had 240V anything, so they wouldn’t know the difference.

Another relatively easy troubleshooting tactic would be to reverse A & B somewhere between the truck and the panel. See if the problem moves to the other circuit.

 

[hturnerfamily]

sorry, the camping world disagrees with you - go check your local campground's 50amp outlet and you'll see 240v.... it's as simple as that. And, yes there ARE motorhomes that use 240v power.

 

[Maquis]

sorry, the camping world disagrees with you - go check your local campground's 50amp outlet and you'll see 240v.... it's as simple as that. And, yes there ARE motorhomes that use 240v power.

I’m glad you represent the entire camping world.

 

[FlasherZ]

sorry, the camping world disagrees with you - go check your local campground's 50amp outlet and you'll see 240v.... it's as simple as that. And, yes there ARE motorhomes that use 240v power.

I don't understand why you insist on being so disagreeable. It's a fact, and I know you've seen my posts elsewhere, so it's not like I don't know what I'm talking about.

I've seen 4 campgrounds in the past year alone set up like this - one in northern AR, one near Lake of the Ozarks, one in Indiana, and one in Kentucky.

Measure hot-hot and you get 0V. Measure hotA-neutral and you get 120V Measure hotB-neutral and you get 120V.

My 50A RV doesn't use 240V. It places both rooftop 120V AC units on one leg and all other loads on the other leg. It works regardless of whether there is 240V available, or if it's wired like I describe using 120V-only.

It really is that way, as much as you are needing to be right. Again, though, that's now far off-topic.

Looking forward to the OP helping out - do 240V loads work? And if so, do loads on adjacent breakers (vertically) work?

 

[tls]

And if so, do loads on adjacent breakers (vertically) work?

Tsk tsk do we know OP isn't in Canada?

 

[Yellow Buddy]

Tsk tsk do we know OP isn't in Canada?

The opposite. The OP IS in Canada according to the profile.

https://homeinspectioninsider.com/orientation-electrical-panels-canada-us/

Electricity also flows counterclockwise up north.

 

[tls]

OK, he's going to have to turn the advice from @FlasherZ 90 degrees then.

 

[hturnerfamily]

I don't understand why you insist on being so disagreeable. It's a fact, and I know you've seen my posts elsewhere, so it's not like I don't know what I'm talking about.

I've seen 4 campgrounds in the past year alone set up like this - one in northern AR, one near Lake of the Ozarks, one in Indiana, and one in Kentucky.

Measure hot-hot and you get 0V. Measure hotA-neutral and you get 120V Measure hotB-neutral and you get 120V.

My 50A RV doesn't use 240V. It places both rooftop 120V AC units on one leg and all other loads on the other leg. It works regardless of whether there is 240V available, or if it's wired like I describe using 120V-only.

It really is that way, as much as you are needing to be right. Again, though, that's now far off-topic.

Looking forward to the OP helping out - do 240V loads work? And if so, do loads on adjacent breakers (vertically) work?

nope, wrong again, no matter how many times you say it doesn't make it true, you don't even know how your own 50amp 240v RV works. I worked in the RVing industry, I know. I own a 50amp 240v motorhome, I know. I've also advised campgrounds on how to correctly wire for larger motorhomes with 50amp 240v service if they only currently have 30amp 120v outlets.

no, both of your roof air conditioners are not on the same 'side', they are on separate 20amp circuits, with one on side A, and one on side B of the incoming 240V power. While your breaker panel in the RV might not use the combined sides for any 240v needs, it is still 240v power coming in. If you use a voltmeter and touch both the A and B hot legs, you'll see 240v, if not, you are not measuring it correctly. There's no reason for any 'campground' to install a 50amp 240v outlet if it is NOT 240v.

 

[FlasherZ]

nope, wrong again, no matter how many times you say it doesn't make it true, you don't even know how your own 50amp 240v RV works. I worked in the RVing industry, I know. I own a 50amp 240v motorhome, I know. I've also advised campgrounds on how to correctly wire for larger motorhomes with 50amp 240v service if they only currently have 30amp 120v outlets.

no, both of your roof air conditioners are not on the same 'side', they are on separate 20amp circuits, with one on side A, and one on side B of the incoming 240V power. While your breaker panel in the RV might not use the combined sides for any 240v needs, it is still 240v power coming in. If you use a voltmeter and touch both the A and B hot legs, you'll see 240v, if not, you are not measuring it correctly. There's no reason for any 'campground' to install a 50amp 240v outlet if it is NOT 240v.

Zero volts, I'm an electrician and know how to use a meter. But it's pretty easy - take a hot wire and put both probes on that wire, set it to volts, and you'll get 0V. There is no differential. You are spreading crazy misinformation and need to stop. You absolutely have not worked on electrical infrastructure if you have no idea how this works.

Several posters have told you that they have had the same experiences. But yet you persist. And if you insist on remaining on an ignorant world, I wish you the best.

My AC units are indeed both on the same leg, with everything else on the other. But other configurations do exist...

From just one of a few sites that describe how it REALLY works:

In a typical 50A RV, L2 will have the
water heater (12 amps), rear a/c (13
amps) and washer/dryer (11 amps)
on L2, with everything else on L1. You
may have a convenience outlet wired
to L2 as well, but that is not very
common due to inverter configuration.

I will say it one final time: my RV, along with MANY others, does NOT use 240V and the service provided at a number of campgrounds is NOT 240v service. Again, off topic...

Now do us all a favor and stop with the misinformation. And have a great day.

 

[PungoteagueDave]

too much misinformation and doublespeak here. 50-amp RV service is a standard 120/240-amp 3-pole with 4 prongs. It requires a 50-AMP breaker to wire it up - hence 240 volts. Yes, it is split. But it supplies a total of 240 volts at the outlet if the receiving device uses it accordingly.

 

[FlasherZ]

too much misinformation and doublespeak here. 50-amp RV service is a standard 120/240-amp 3-pole with 4 prongs. It requires a 50-AMP breaker to wire it up - hence 240 volts. Yes, it is split. But it supplies a total of 240 volts at the outlet if the receiving device uses it accordingly.

This is not always true, as I mentioned above. Several campgrounds take a 100A single ungrounded conductor to BOTH hots in the pedestal. This is not 240V but rather only 120V. In the past year alone I've encountered this four times.

Most RVs will still work because you have 120V A-N and B-N but 0V A-B. And yes, MANY campgrounds are wired this way and you CANNOT get 240V from them!

You will get 0V if trying to charge an EV on these receptacles, because the same hot goes to A and B. I have had this happen many times to me when using campgrounds to charge during the past decade.

Would it be ideal to use 240V to feed it? Yes! But since most 50A RVs have only 120V loads, it's not necessary to provide 240Vand some campgrounds did not go that direction. 2 current carrying conductors (admittedly larger) compared to 3.

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