The Canadian Electrical Code and the Cable Bus Systems
Electrical Cable Sizing in Canada
The Cable Bus System is a way to lay cables in Cable Trays; the difference is that each cable keeps a distance of at least one diameter from all other cables in the Tray. The reference standard is C22.2 NO. 273-14 - Cablebus.
Compared with the NEC, the CE Code has higher de-rating factors for cables running in parallel and close to each other. The reason is the reduced capacity of dissipating heat.
That is one of the reasons why in Canada the use of Cable Buses is so widespread. That allows the use of Ampacity form Tale 1 of the CE Code without any correction for the number of cables (Table 5C). However, table 5A for temperature correction should be applied appropiately for ambient temperatures different then 30°C.