Okay, but..... RV's don't use receptacles that are used in building construction, and therein lies a problem. I know this thread is going a little sideways, but I thought I would add/clarify something.
Also, I sure hope the OP gets a good answer in this thread somewhere!
RVs use a receptacle (and switch) designated "self contained device" that are specifically for RVs and manufactured homes. See this Pass & Seymour manufacturer info.:
http://tinyurl.com/self-contained-devices. Residential, commercial, hospital, or any other grade of receptacle used in building construction cannot be used in the exterior wall of an RV because the walls are not thick enough to install an outlet box these receptacles. To install a non-SCD type of recept. in an RV exterior wall is inviting disaster. "Ordinary" receptacles must be installed in an outlet box so that there are no exposed terminals. SCD receptacles have a cover on the rear that covers the connections/terminals. You *could* install a non-SCD receptacle on an interior wall or mounted on a cabinet as long as you install an outlet box.
Secondly, a significant problem is that too often, wiring on an SCD receptacle has not been done properly. I have found this on our own TT on the first recept. I pulled out (to relocate up a bit). Rather scary IMO. SCD receptacles have two prongs (or stabs) for each wire to be pushed on to. The wire MUST be pushed onto both prongs or the termination can overheat. There is a proper tool for terminating the wire on SCD receptacles, but if one is very careful, you can push the wire in with a screwdriver.
SCD designated receptacles are not "crap" as I have often read. They are designed to meet Code and safety standards and there is no problem as long as they are installed properly. Too many times I have read that someone is gonna take the POS receptacle out and install a "proper" one.
I know from reading RV forums here and elsewhere that overheating and failed receptacles happen. If you have a 1500W heater running continuously or nearly continuously, there is a risk of fire if the recept. is not properly installed or the wrong one is in there. I wonder how many fires have been caused by improperly terminated wires at a recept.?
I think it would be smart to at least spot check some recepts. in your camper. And/or maybe it would be good to check all terminations on the circuit that is supplying a heater. And if you bought a used RV, I would also suggest checking to see if non-SCD receptacles have been installed. In view of the numerous manufacturing issues that we constantly hear about, I have to wonder how many RVs leave plants with improperly wired receptacles.
Please excuse the verbosity herein, but as an elec. eng. I couldn't resist....