50 amp to 30 amp

In theory there is no difference between theory and practice. In practice there is. Yogi Berra

pianotuna wrote:
hohenwald48,

I find low voltage to be endemic in the summer time if it is hot enough to wish to run the roof air conditioner.

Endemic (confined to a specific area) is definitely a possibility.

Probably just a difference in where we travel and where we camp. I've never seen low voltage as a problem in real life. I suppose if you frequent some of the older campgrounds it might be an issue but everywhere I've gone (we average over 100 nights a year for nearly 20 years) things have been just fine. Your mileage may differ.

CaperGuy3 wrote:
Is there any danger in plugging in a 30 amp TT to a 50 amp pedestal assuming I have the correct adapter?

No, that is our preferred method. Most campgrounds 50amp receptacles are in much better shape than the the 30amp. Just keep in mind that doing that does not give you more electricity to use and your trailer still has its' own 30amp breaker.
Barney

Is there any danger in plugging in a 30 amp TT to a 50 amp pedestal assuming I have the correct adapter?

hohenwald48,

I find low voltage to be endemic in the summer time if it is hot enough to wish to run the roof air conditioner.

In nearly 20 years of RV'ing I have never used a surge protector. Only 1 time have I had an issue with low voltage. Also, I have had 2 RV's with 50 amp service for a total of over 5 years and probably haven't had to use a 30/50 adapter more than two or three times. I've never had a problem finding 50 amp sites and I don't go looking for them. Just finished a 4 week trip from Nashville to Wyoming. No reservation anywhere and 50 amp every night. If you stay in state or national parks that might be different. Like most things on web forums, the theoretical problems are usually much more severe than the real life problems.

capsfloyd wrote:
We are looking at a 50 amp TT.

It may help to know that it can be really hard to find 50 amp pedestals due to the min. NEC electrical requirements. RV manufacturers will entice folks to buy a 50 amp RV so you can run multiple AC units and also have more power for other loads, but they never tell you how hard it can be to find 50 amps.

In the 2005 edition of the NEC, 20 percent of an "RV park" (as the NEC calls them) were required to be 50 amps, and in prior to that edition, only 5 percent was required. Some private and some gov't CGs *may* have gone above the min. code requirement and provided more 50 amp pedestals and some may have done an upgrade to their wiring system. You might be able to be more selective in choosing a CG by researching in advance, but if you're on a road trip you may not have much of a choice.

We've stayed in several casino RV parks and all pedestals had 30 & 50 amp receptacles. Have been in some older CGs with no 50 amp pedestals at all. I've seen countless numbers of 50 amp RVs plugged into 30 amps with an adapter in many of the CGs we've been to. A 50 amp RV may sound great, but it would be good to be prepared to only find 30 amps in many CGs.

In addition, due to the way the NEC provides for min. "demand factors" and the required min. wiring size to a run of pedestals on the same feeder cable, voltage drop in a CG can be mild to severe due to demand factor allowances. If you have a 50 amp RV, there's not much you can do except for perhaps trying to be closer to the source of power (either a transformer or distribution panel).

Low voltage is simply very common out there and it's not normally a CG's fault. Having an autoformer is a really good idea. AC units especially are susceptible to low voltage (below 105 volts).

Interestingly, I just came across this statement from those responsible for NEC rule changes for 2005: Text revised to increase the number of 50A, 125/250V receptacle recreational vehicle sites from 5 percent to 20 percent. This change was based on a survey of 500 campgrounds involving 45,000 recreational vehicle sites, which showed that an average of 18 percent of the sites provide 50A 125/250V receptacles. Seems to me that they should have assessed the numbers of 50 amp RVs being purchased at that time and projections for the future.

No problem using a 30 to 50 adapter.

You may be better served by an autoformer than by just a surge device.

Use a 50/30 adapter and your existing surge protector.
All works fine together.

We have used a 50A surge guard on our 50A trailer for years. We use a 30A male to 50A female adapter at 30 amp sites and it works great.
Brian