Originally Posted by jimh
even though the rv 50 amp is considered to be two 110v circuits; the neutral wire is the same size as each of the "hot" 110v wires. the main throws both circuits if one is thrown. the wire size alone would tell u that they are actually wanting the voltage to be 220 volts leg to leg (110v each leg to neutral).
if it were 110 volt same phase, it could over load the neutral w/o throwing a breaker (the neutral could be asked to carry up to 100a which is too much).
if u plug into a 50 amp rv connection w/ an adapter to 30a, u will be fine; they only use one "hot" leg of the 50 amp.
This is very true and Jim is certainly the expert on this stuff.
The "Hot" alternates every 1/60th of a second (60 cycle) between the two circuits so that the Neutral sees return current that never exceeds the 50 amp rating of the RV service. Measuring between the two hots will show 220 VAC, but unless something in the camper actually requires 220 (rare); the dual circuits are utilized as two 110 lines.
It is difficult to explain the concept in terms that most people who are non-electricians (like me) can understand and make the explanation "technically correct" for those that do this for a living (like Jim).
We are very lucky to have subject matter experts here to keep us on the straight and narrow!
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW