Small trailers are often 15/20 amp
15 amp looks like a standard household plug, in fact that is exactly what it is
20 amp is alot like that save the neutral pin is turned sideways like this - |
Larger trailers, and small Motor homes may have a 30 amp plug. This looks like a old 3-prong dryer plug, Two flat blades and a single round pin. In fact it can plug into some of the old dryer/air compressor style outltes DO NOT DO THIS!!!!!!!!!!!!!
Many electricians when installing a TT-30 recpitical fail to read the 125 volt rating on the outlet and hook it up for 220 and wind up destroying all the electrical/electronic stuff in the customer's trailer.. Thus making him a CUSS SOME MORE.
Larger Trailers and Motor homes have a FIFTY AMP plug, this has 3 flat blades and one that is either round or "U" or "D" shaped (Dpending on the manufacturer and how you look at it.
All 3 deliver 120 volt to the MH, the last delivers either 120 volt or 240 volt depending on what you plug into as well, However very very very few RV's have anything in them that eats 240 volt with the exception of an Energery Management System.. These test for 240 volt (They do not eat it, just look for it) and that's how they know you are on 50 amps.
When pluging into one of those 30 amp (3-wire) outlets that look like an old dryer type outlet.. If you are not sure TEST IT FIRST with a proper volt meter.
Proper meter, as low as 10 bucks or less at Harbor Freeight and other places, Heck, I've seen 'em in dollar stores.
New electronics for your motor home.. start adding zeros to that, 2 or 3 at least.
Home is where I park it!