For the electrical gurus. Getting 50 Amp off two outlets?

[ov10mech]

I am considering buying a 5th wheel that has two air conditioning units with 50 amp service. The location where it will be placed permanently only has 30 AMP service, so I will not be able to run both at once. However, there is a standard outlet about 20 feet away from the camper that could technically give me the juice needed to un that 2nd AC when I need to. The question is - is it possible to somehow combine these two power sources into a single 50 AMP input? Its a bit easier on a boat because there are two separate input plugs.

[wnjj]

ScottG wrote:
To the OP, as usual, a conversation regarding electrical questions has been taken down a long path with many detours and there are many wrong statements and frankly bizarre theory's bouncing around that's it's just not worth reading anymore.

Bottom line is just try it.
If it works, it works. if it doesn't, it doesn't (probably because of a GFCI).
As a career EE I can tell you there will be no harm either way.

As a career EE, you should know that "if it works, it works" is bad advice for electrical things. Working and working safely are too different things entirely. You didn't address the legitimate open neutral concern. Granted, the odds of a molded cord like the one in the link failing in that way is slim.

[ScottG]

To the OP, as usual, a conversation regarding electrical questions has been taken down a long path with many detours and there are many wrong statements and frankly bizarre theory's bouncing around that's it's just not worth reading anymore.

Bottom line is just try it.
If it works, it works. if it doesn't, it doesn't (probably because of a GFCI).
As a career EE I can tell you there will be no harm either way.

[TakingThe5th]

Have you considered something like this?

Automatic Energy Select Switch

This is a 20 amp version. It might not allow you to run both air conditioners at the same time but it does help manage what is available.

[MEXICOWANDERER]

I would tend to want to do my homework before doing any connect. A transformer twin offering a yet ungrounded neutral can cause more than raised eyebrows.

Line to Line: Preferably 120 vac different breakers.

Line to Line 240 volts: Risk of potential open neutral gremlin

Here is a standard Delta connected 3-phase transformer used in larger service drops...



Chances are you are dealing with a single, simple 2H 3X service drop transformer. But "Know Before You Blow" is a quirk of mine.

[AllegroD]

So what is your set up? Is this all on your site and included. If not, what does the park management think of you paying for 30 amp and using 50 amp? Have you asked them?

[wnjj]

DrewE wrote:
In theory, it can be done. If the 20A outlet (or the 30A one, for that matter) has a GFCI, it will trip due to the other neutral providing a second return path for the current...and rightly so.

In practice, I would strongly recommend against it. Particularly in some fault conditions, this can be a dangerous setup. If the neutral on the 30A circuit were to open and the two are on the same phase, you can have 50A flowing through the 20A circuit's neutral connection without a breaker tripping. That's a significant overload, enough to be reasonably worried about fire.

Putting the air conditioner on an isolated circuit that connects to the 20A outlet is a safer and IMHO better approach.

X2 on the open neutral concern.

Edited my brain fart.

[DrewE]

In theory, it can be done. If the 20A outlet (or the 30A one, for that matter) has a GFCI, it will trip due to the other neutral providing a second return path for the current...and rightly so.

In practice, I would strongly recommend against it. Particularly in some fault conditions, this can be a dangerous setup. If the neutral on the 30A circuit were to open and the two are on the same phase, you can have 50A flowing through the 20A circuit's neutral connection without a breaker tripping. That's a significant overload, enough to be reasonably worried about fire.

Putting the air conditioner on an isolated circuit that connects to the 20A outlet is a safer and IMHO better approach.

[Lwiddis]

Where? Just the location I’m looking for...two ACs needed.

[BB_TX]

That adapter should do what you want, provided;
- the "standard" outlet is not a GFCI protected outlet (will trip a GFCI)
- the two A/Cs are wired to the two different hot legs in your distribution panel
- the standard outlet is a 20 amp outlet (15 amp probably not enough)
- if the 20 amp connection ends up going to one of your hot buses that also is connected to some other high current devices, it will probably trip the breaker when operating that A/C and some other device.

You can get up to 50 amps, but not the 100 amps capability you get from true 50 amp service.

[SoundGuy]

Bill.Satellite wrote:
The combiners do work but please understand that 50amp services provides you with 5 separate 50 amp legs or a total of 100 amps of service.

Surely a typo - you must mean "2 separate 50 amps legs".

[Big_Katuna]

You don’t need two 50A legs. I have mine breakered with 30A breakers which will let you run two ACs and the fridge just fine.

Maybe just run one more 120 wire to your existing 30A recep and replace your 30A recep with a 50A.

It would be cleaner.

Cheaper too as the wire is smaller. No need for #6.

[time2roll]

You are not going to combine power. Best shot is to break out the dedicated A/C branch circuit, remove it from the breaker panel and tie it to an inlet. Use an extension cord from the inlet to the second power source.

Search '5-15 inlet' on amazon

[Bill_Satellite]

The combiners do work but please understand that 50amp services provides you with 2 separate 50 amp legs or a total of 100 amps of service.
The combiners send 30 amps to each leg (or in your case 30 amps to one leg and 20 amps to the other) for a total of 60 (or 50) amps. That's still way better than only 30 amps but you have to keep your eye on what things are on which leg of service to ensure you don't trip on breaker or the other.
I should also add that if the 2nd connection has a GFCI plug or there is a GFCI in the circuit then the combiners will NOT work.

[ov10mech]

Just looking for enough to run the 2nd A/C unit.

[ScottG]

Retired EE here, if I really needed it and could not get true 50A to the trailer, I'd probably try it.
I see no danger in it.
JMHO.

Scott