I am looking for some advice from a Canadian electrical inspector.I have three parralel runs of cable with at least 100% distance between them,.These cables are run in a ventilated csble tray, and are used to form a single service. These cables will be exposed to an ambient temperature below 30 degrees celcius for 355 days of the year and a maximum of 10 day above 40 degrees celcius.
1. Do I have to derate using table 5-A if it is only a few days a year of 40 degree temperatures?
2. Do I have to derate using table 5-C. It says in section 12-2210-1(b)(In the 2002 CEC edition),that for multi conductor cables you use the number of conductors in each cable to determine the derating factor. If I have 3 parallel runs of tech cable to make a single service, and I do not count the neutral or ground conductor that leaves me with 9 conductors, 3 in each cable.If I counted all nine
I would have to derate my cable to 70%. This seems a bit extreme. I should be able to keep it at 100% ampacity due to only 3 conductors per cable.
Thanks for any help and code rules I can refer to
Camp Black Bear