beemerphile1 wrote:
smkettner wrote:
Using a standard adapter to plug a 30 amp RV into a 50 amp pedestal is perfectly safe in all conditions...
I have to disagree with the "safe in all conditions". Some RVs especially some pop ups do not have a main breaker! Most RVs do have a main breaker which would be either 30 amp or tandem 50 amp.
If the RV has a 30 amp main breaker the only thing exposed to 50 amp would be the cord. Even then it would only receive 50 amp if there was a dead short like cutting with a lawn mower or something.
However without a main breaker the panel in the RV could potentially be subjected to the full 50 amps and could smoke things if the panel was only rated for 30.
It is crazy that some manufacturers don't use a main breaker, but it is true.
Even if the panel was only rated for 30, the odds of having some fault that creates an exact 50 amp load are very slim. A direct short circuit, which is far more likely, would trip a 50 amp breaker quickly. Besides, 6000 watts has this way of creating something very hot very quickly, and the power dissipated in the electrical panel which is only rated for 30 amps will be tiny fraction of that. In other words, something else will be smoking long before the panel would. Even if you had a 50 amp panel something would still be going up in smoke and flames.
My popup only has two breakers, one 20 amp for the air conditioning and one 15 amp for the converter and the AC outlets. I would have no qualms about plugging it into a 50 amp outlet if that's all that's available because if there was going to be a 50 amp fault, it would have to happen between the pedestal and the electric panel.
Even if I plugged into a 30 amp pedestal and had a 30 amp fault in the panel, I would still have a major problem. Whether I'm dissipating 3600 watts in a fault in the electric panel or 6000 watts in the electrical panel won't make much difference, something's going to be burning up rapidly.
Even at 50 amps the 10 AWG shore power cord is only dissipating about 100 watts. Oh, it will be getting noticeably warm all right, but I'm more worried about where the other 5900 watts are going.:)
