30 amp vs. 50 amp?
- Thread starter 31qbss
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If your trailer is 30 AMP use 30 AMP We have a MH with 30 AMP and run 2 Air Cons With the 50 AMP you probably ran your 30 AMP with a 50 / 30 AMP adaptor. The 30 AMP plug is different from the 50 AMP and wouldn't fit. Some 50 AMP have 30 AMP nest to them and I reckon thats what you had. Dnag it I know what I said just didn't state it properly.
Gary RV_Wizard
Site Team
It is physically impossible to plug a 30A trailer plug into a 50A outlet with no adapter. The number and alignment of pins is not even close to the same. Either you had an adapter or it was a 30A outlet. Many power pedestals have both 30A (3 pin) and 50A (4 pin) outlets) on them.
Regardless, if your trailer is wired for 30A, that's all you can use, no matter what you are plugged into. You have exactly the same power available inside your RV on a 50A outlet (with adapter) as you do on a 30A outlet without one. Whatever you ran last trip will run next time on 30A power.
Looking back at what you said, I suspect your RV actually has 50A service and you were plugged to a 50A outlet with no adapter. Next time you camp you may have only a 30A outlet and will need an adapter and you will have less total power available and you will have to economize a bit. If that's the case, ask further questions here.
If your trailer is wired for 50A, it will have a 4 prong plug. If it is wired for 30A, it will have a three prong plug. Which is it?
Regardless, if your trailer is wired for 30A, that's all you can use, no matter what you are plugged into. You have exactly the same power available inside your RV on a 50A outlet (with adapter) as you do on a 30A outlet without one. Whatever you ran last trip will run next time on 30A power.
Looking back at what you said, I suspect your RV actually has 50A service and you were plugged to a 50A outlet with no adapter. Next time you camp you may have only a 30A outlet and will need an adapter and you will have less total power available and you will have to economize a bit. If that's the case, ask further questions here.
If your trailer is wired for 50A, it will have a 4 prong plug. If it is wired for 30A, it will have a three prong plug. Which is it?
At the campsite they had a 30 amp plug with a breaker - left for 50amp and right for 30amp .. hence no need for an adaptor. There is a big sign on the side of the RV at the electrical outlet saying '30 AMP'. At least I know that 30 will work now! Might explain why when we had several lights AND the TV on there was a buzzing humming sound - like some kind of motor started?? Created interference on the TV.
Sue
Sue
BernieD
Well-known member
Sue
The way the electronics work, you can't stuff 50 amp service into a 30 amp plug. 50A service provides 2 50A legs while 30A provides 1 30A leg. I have never seen a pedestal with a breaker switch for 50/30A service. Was there another receptacle that had 4 slots rather than the 3 on your 30A plug? By the way, the buzzing may have been because you had the switch in the 50A position.
The way the electronics work, you can't stuff 50 amp service into a 30 amp plug. 50A service provides 2 50A legs while 30A provides 1 30A leg. I have never seen a pedestal with a breaker switch for 50/30A service. Was there another receptacle that had 4 slots rather than the 3 on your 30A plug? By the way, the buzzing may have been because you had the switch in the 50A position.
If the pedestal has both 50A and 30A outlets, it will have 2 breakers, one for each outlet. The 50A breaker will be a ganged double breaker as 50A service is 2 legs of 50A each. The breaker does not select the service, it only protects its corresponding outlet.
31qbss said:
You normally use the 30 amp receptacle, but if the site only has 50 amps (Rock Crusher Canyon in FL is one) or if there is a problem with the 30 amp circuit, you can use the 50 amp receptacle if you have a 30-50 adapter. They're not expensive so it would be a good idea to carry one with you just in case. (If you don't have one at Rock Crusher, they'll be more than happy to rent you one.
).
Sue,
The answer to RV Roamer's question is the key to your question. If the plug on the end of your power cord has three prongs (two flat & one round) you have a 30 AMP RV. You can plug into a 50 AMP receptacle using a 30 to 50 amp adapter. It does not buy you a thing. The maximum amount of power you can use, in your trailer, will be controlled by the main circuit breaker(30 AMP) in your trailer. Their can be a drawback: if your main breaker(30 AMP) fails, the 50 AMP breaker in the shore power pedestal will not trip until you are using more than 50 AMPS. This is more than your equipment is rated for.
Green lights and soft breezes,
The answer to RV Roamer's question is the key to your question. If the plug on the end of your power cord has three prongs (two flat & one round) you have a 30 AMP RV. You can plug into a 50 AMP receptacle using a 30 to 50 amp adapter. It does not buy you a thing. The maximum amount of power you can use, in your trailer, will be controlled by the main circuit breaker(30 AMP) in your trailer. Their can be a drawback: if your main breaker(30 AMP) fails, the 50 AMP breaker in the shore power pedestal will not trip until you are using more than 50 AMPS. This is more than your equipment is rated for.
Green lights and soft breezes,
With regard to my 30A MH -- Does that mean when I have a choice between 30A and 50A on the park's pole, I should put on the adapter and go for the 50A? Does it give me more margin against tripping the circuit breaker on the park's pole?Ned said:
Tom
Administrator
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Frank I suppose the 50A breaker will be a little more tolerant than the 30A breaker if you're running close to or above 30A. Personally, I'd plug into 30A if my rig had a 30A cord and the CG had both 30A and 50A receptacles.
Ron
Moderator Emeritus
Its 50A instead of 30A. Unless of course the park has put 30A breakers on the 50A which we have seen. I don't really think most folks would even notice the difference,
Tom
Administrator
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I'd prefer to have a 30A breaker protecting a 30A cord.
Ron
Moderator Emeritus
Good point Tom.
