50 to 30 amp service

[clayway]

I had an RV tech tell me I should not plug my 30 amp service motorhome into a 50 amp service.
Could this create a problem
Thanks in advance for your advice

[tropical36]

clayway wrote:
I had an RV tech tell me I should not plug my 30 amp service motorhome into a 50 amp service.
Could this create a problem
Thanks in advance for your advice

If the tech was being really technical, he was just stating that your AWG#10 30amp cord wouldn't be properly protected from where it plugs in to the 50/30amp cord and outlet converter at the pedestal to your main breaker box, but to have an overload on this cord to the point of melt down would be highly improbable to almost impossible. A common coach overload would trip it's own 30 main and a short circuit between the two points in question, would trip the 50amp main on the pedestal faster than you could say "trip it".

[J-Rooster]

enblethen wrote:
As long as your shore power cord is in good shape, you will have no problem.

X-2

[RoyB]

This is what a RV50AMP service to RV30A service ADAPTER looks like schematic wise. As you can see only one leg of the two 50AMP circuits is being used. Your 30AMP Trailer main breaker will allow you to only use up to 30AMPs of service...

RV50AMP Service


RV50A MALE to RV30A FEMALE ADAPTER


RV30AMP SERVICE


PLEASE NOTE: This only works for RV 50AMP service hookups. Connecting to a HOUSE Dryer 240AC circuit is a different story and will burn up a bunch of things in your 30AMP trailer system...

Roy Ken

[clayway]

Thanks for all the great information! It never fails to amaze me how many folks are ready to jump in & help.

Just a little more information, I moved from a Class A Coach 50 Amp service to a class C 30 Amp, I had an electrician install the 50 amp for the old coach & was hoping I could continue to use it. Looks like I can

Happy Thanksgiving To All

Dennis

[2oldman]

clayway wrote:
I had an RV tech tell me I should not plug my 30 amp service motorhome into a 50 amp service.

It's really hard on the plug when you try to bend the prongs.

Go back and tell that RV tech that's what you did.

[wa8yxm]

I have had some techs tell me several fantastic things.. Sometimes in areas where I happen to have more than a little bit of knowledge.. In one case this extended to a Medical Doctor talking about a condition I have done rather a lot of research in (So I hired someone who knows more than he does in case you are wondering how that turned out)

Plugging a 30 amp RV into a 50 amp outlet using an adapter will cause no problems and in fact may solve one or two.

Think like this, A Lamp with two old fashion 60 watt space heater,,,er, light bulbs in it, draws exactly 1 amp at 120 volt (Assuming the lamps average exactly 60 watts) but the outlet you plug it into may be a 15 or a 15/20 (20 amp capable).. And this is normal. Same with your RV, it can not draw more than the MAIN breaker is rated for.

Some folks will yammer "What if the cord shorts"

True, you can suck the full 50 amps down the 30 amp cord if it shorts, for about as 1/10th as long as it takes me to type THIS at close to 100wpm (not the paragraph, not the post, but the word THIS) (or if you like the blink of an eye) not nearly long enough to do secondary damage. A partial short that could draw enough to damage the cord, outside a lab, is not possible. The short would "Blow" before the cord was damaged.

[wolfe10]

Harvard wrote:

clayway wrote:
I had an RV tech tell me I should not plug my 30 amp service motorhome into a 50 amp service.
Could this create a problem
Thanks in advance for your advice

Maybe he was thinking the 240 VAC thingy that happens to 30 ampers on a regular basis, it seems.

But, not at a CG where 30 amp is ALWAYS one hot, one neutral and a ground.

Sure, a home dryer is 240 with two hots and a ground and looks similar to a 30 amp plug, but SURE IS NOT.

[dougrainer]

Harvard wrote:

clayway wrote:
I had an RV tech tell me I should not plug my 30 amp service motorhome into a 50 amp service.
Could this create a problem
Thanks in advance for your advice

Maybe he was thinking the 240 VAC thingy that happens to 30 ampers on a regular basis, it seems.

There is nothing that happens on a regular basis. The OP needs to find a new tech as his does not have the knowledge to be credible. When plugging into a 50 amp receptacle with a 50 to 30 dogbone, the adapter uses just one leg of the 2 HOT legs and uses the neutral and Ground. The SUPPLY to his 30 amp RV will be on a 50 amp breaker, but the RV internal breaker panel has a 30 amp breaker that is the gateway to all the circuits in the RV and will be the protecting breaker for the RV. Doug

[Bumpyroad]

DrewE wrote:
It's not really any different from a functionality point of view than many pedestals that have both 50A and 30A plugs, where the 30A plug is served by one of the two 50A phases.

I can't remember having a 30 amp outlet that is not controlled by a 30 amp breaker. yes, probably taken off one of the 50 amp sides however.
bumpy

[Harvard]

clayway wrote:
I had an RV tech tell me I should not plug my 30 amp service motorhome into a 50 amp service.
Could this create a problem
Thanks in advance for your advice

Maybe he was thinking the 240 VAC thingy that happens to 30 ampers on a regular basis, it seems.

[Jack_Diane_Free]

Have done it often with no problems.

[ScottG]

On a side note, the 50A receptacle is usually in much better shape (tighter) than the 30A. That comes in handy if your someplace hot and running your AC. My TT is 30A and I always use the 50A when it's available.

[Crazy_Ray]

Simple answer NO> NAC

[DrewE]

With an appropriate adapter, it should be okay, assuming of course the 50A service is wired properly. Ideally the adapter ought to have some sort of overcurrent protection (a fuse or circuit breaker) to protect the RV shore cord etc. Unfortunately, despite the seeming sketchiness, I don't believe many (or any) readily available adapters have any sort of overcurrent protection. Dogbone style adapters are generally much higher quality and more reliable than single-piece hocky puck style ones and therefore strongly preferable.

The adapter simply puts the 30A 120V service on one of the two legs of the 50A 120/240V service. It's not really any different from a functionality point of view than many pedestals that have both 50A and 30A plugs, where the 30A plug is served by one of the two 50A phases. You do not want to put 220V into your RV, regardless of amperage ratings. It's not unheard of for electricians to mistakenly wire 30A RV outlets for 220V because the connector is quite similar to a 220V connector. 50A RV outlets are probably less frequently miswired because they are identical to standard (4-wire) electric range connectors that electricians deal with regularly.

I doubt you'll often (or ever) come across a campsite with 50A service that doesn't also have 30A service. Obviously, it's silly to use an adapter when 30A service is available.

[ScottG]

Agreed, no problem but I suggest you plug everything in and then turn on the 50A breaker. Make sure the 50A plug is fully seated.