I excitedly cracked open my shiny, new Canadian Electrical Code to see what the future might bring. I found it full of surprises, most of them good, some others not so much. Here are a few thoughts.
Section 4 – Conductors and Section 12 – Wiring Methods have received lots of attention.
The allowable wiring ampacities provided in Tables 1 to 4 as well as the correction factors contained in Tables 5A to 5D have been revised upward to better harmonize with the U.S.National Electrical Code. You will find that the allowable ampacities of many wire sizes have increased significantly, resulting in smaller wire sizes.
Some first-class changes have come about:
Rule 10-814(2) – Bonding Conductor Size now makes it a requirement that bonding conductors in parallel cables or conduit also be paralleled. This was previously permitted. But as you know, the lowest impedance fault path is always closest to the circuit conductors that supply the fault.
Rule 32-208(1) – Transfer Switches now clarifies that each fire pump must have its own transfer switch. This earlier requirement was not as clearly stated in earlier versions of the book.
Rule 46-204 – Protection of Electrical Conductors will require that emergency power supply conductors and associated communication conductors be protected against fire exposure. This requirement is similar to the present requirement for fire pump wiring.
Rule 18-154 – Sealing Class I, Zone 2 simplifies the requirement for cable seals for non-explosion-proof equipment in hazardous locations.
There are also some notable new rules:
Rule 18-052 – Marking provides some new IEC designations for Class I hazardous location equipment, protection levels Ga, Gb and Gc.
Rule 4-006(1) – Temperature Limitations now requires that where electrical equipment maximum termination temperatures are marked, the maximum allowable ampacities of conductors must be based on the corresponding temperature columns from Tables 1 to 4.
There is a brand new Section 64 – Renewable Energy System.
There is also a new Table 12E – Allowable Ampacities for Type DLO Cables in a Permanent Installation. The new table applies to portable power cables.
As usual, there are a few head scratchers:
The disparity of Rule 14-100(d) – Overcurrent Protection of Conductors with the remainder of the rule has not been addressed.
Rule 10-212(1) – Grounding Conductors for Equipment in an Ungrounded System says there must be no connection between the grounding conductor and the system neutral. That seems to overstate the point. It should be obvious.
Rule 32-102(1) – Wiring Methods no longer requires concrete encasement for fire alarm system wiring in non-metallic conduit and non-metallic tubing. This move is in the wrong direction.
Rule 46-108(2)(c) – Wiring Methods now permits emergency power supply conductors in rigid non-metallic conduit without concrete encasement. The requirement still stands for non-metallic tubing. Granted, new Rule 46-204 and Appendix B do require a 1 hour fire rating for emergency power wiring but the change is bound to cause some initial confusion.
Rule 14-104 (2) seems to provide exceptions to the easements provided by Table 13 for wire sizes 14 to 10 AWG. However, Table 13 references the rule without any qualifications and the table does not appear to acknowledge the changes.
Rule 4-004(21) addresses allowable ampacities for bare or covered conductors with reference to a new Table 66. However, it is only when we turn to Table 66 that it becomes obvious that the table only applies to overhead wiring.
I’m sure you will derive much enjoyment, finding your way through the new book. As with previous articles, you should always consult with the electrical inspection authority in each province or territory as applicable for a more precise interpretation of any of the above.