UL approval is, IM0, self-serving. UL exists on funds receivable from companies requesting UL approval, ie: a company pays to obtain UL approval by funding all testing.
For Alternating Current, no mfgr. uses stranded wires bundled together, instead solid-core wire is used because it is much cheaper to buy, and because outlets and terminals are cheaper to make.
Direct Current wiring, however is always stranded wire.
The RVIA is the equivalent of the NEC for recreational vehicles, and governs electrical wiring.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"