Here's the neat thing about answering questions on the forum:
I have to check my facts. I remember the "32 Amp" limitation in my (paper) user's manual, so surely I can get a PDF copy on the internet and show you, too...
So... do a web search on "Xantrex C40", but nowadays you find nothing but the brochures. No user's manuals out there. This shouldn't be a surprise, since Schneider Electric bought out Xantrex a couple of years ago, and subsequently they've hit the "random shuffle" button on the website. I can't find anything any more.
Expand the google search to include "Trace". Yes, once upon a time, Xantrex was actually Trace Engineering. They're the guys who invented this stuff!!!!
So eventually I found a TRACE C40 user's installation manual. Wow, that's been sitting around on a website for at least 10 years!
Here's the link:
http://itacanet.org/eng/elec/solar/c40cc.pdfSo in their wisdom, Xantrex re-wrote this manual, sometime in the early 2000's when Trace was bought. The manual produced was still readable, but the organization of the data and the sense of "intelligent judgement" in the Trace manual was lost. I can't recall how the section reads in the Xantrex manual, but this TRACE manual lays out the facts and the margins of safety you should be trying to achieve. The choices you have and decisions you must make are much more clear in this TRACE C40 manual.
I'm a strange person, I know - I read the manual. I do this for a living, BTW. Having thoroughly read the user's manual for my TRACE SW4024 Inverter, I can tell you that I really admire the technical writer in charge of those books. His work was a model of clarity and frankness, with intelligence expected on the part of the user. If you were to put a current Schneider Electric user's manual beside the old TRACE version (of the SAME machine) you would immediately pick up the difference.