#10 stranded wire and receptacles...

[kayakrguy]

Brian,

The houses we lived in in Manitoba had plastic switch plates. Now, I am not gonna say that was the norm in CA, 'cause I honestly don't know...

One of the saner things about CA is that, on the whole, there is less variation in lots of stuff--food, hardware etc. What I mean is, for example, if you go down supermarket store cereal aisle in the US you find 405 varieations on cereal, most of it sugar laden crap. In a Canadian market there might only be 75 choices of sugar laden crap<g>

[rustyelectrician]

#10 is way overkill. #12 (20 amps) is mechanically stronger than #14 and not much more expensive. I doubt that you will need more than 20 amps for your trailer.

Stranded cable (and the more strands the better) is best for automotive, marine or trailer applications. Vibration and huge ambient temperature variations are the enemy here and properly installed stranded is more resistant to breaking.

As far as "protection" is concerned, romex (loomex in the west) or wire molding will not stand up to screws or nails, ergo wise placement of the cabling is your main defense. I doubt you will be subject to an official inspection. Your concern ought to be fire prevention.

Stranded under a screw head is awkward but not illegal in Canada. (The CEC and the US NEC are closely related) A good tip is to strip 3/4" or so for your connection, unravel the strands and re-twist the strands in the opposite direction (left-twist). If done smoothly, the screw head will then tend to pull the strands under the head.