Section 62 “Fixed electric heating systems” • Code File, September 2017
September 15, 2017 — In addition to a number of changes in 2012, CE Code Section 62 “Fixed electric heating systems” underwent a fairly substantial rewrite in 2015. So what’s changed?
The first thing of note is the title was changed to encompass more fixed electric heating systems. This eliminates anything portable (which involves an approval agency label) and allows for the inclusion of new technology as it evolves without having to be specifically identified.
Next is the addition of Rule 62-112, which deals with the temperature of adjacent combustible materials. After all, who hasn’t seen a hotel bathroom door with charred or peeling paint due to being left partially open under a heat lamp? This situation was partially addressed by Rule 62-118 which required a timer for the lamp, but the new Rule requires the relocation of either the fixture or the door.
Ground fault protection has been required for a couple of code cycles; however, ground fault requirements where taken out of the individual clauses in the 2015 code and put into one Rule (62-116) with two exemptions:
The first is for industrial establishments with maintenance and supervision provided by qualified persons servicing the installation to use ground fault detection. The second is for heating cable and panel sets connected to an ungrounded Class 1 extra-low-voltage power circuit supplied from the secondary of an isolating transformer, supplied by not more than 150V-to-ground.
The next new addition to Section 62 was the creation of Table 67 “Clearance requirements of installed heating systems”. While the rules and clearances existed in the previous code, they were cumbersome to read and, at times, difficult to understand. In conjunction with Diagrams B62-1 to B62-5, Table 67 clarifies what those rules mean, and how different types of heating fixtures are to be installed.
Appendix B also provides a table based on the proposed maximum temperatures table for CSA C22.2 No.130 (which forms the basis for the creation of Table 67). This table provides guidance on the maximum temperatures of the different materials, and lists the sources for this information.
New Rule 62-314 was created to cover requirements for skin effect heat tracing—a new method of surface heating using a ferromagnetic envelope (heat tube) that produces heat through the I2R losses of return current. This is why the conductor does not meet Table 19 or 4-004 rules for conductor sizing, as these losses are part of the approved functionality of the equipment.
It is important to note the heat tube will often be approved separately from the isolation transformer and control equipment feeding it. Each are manufactured for a specific job and may require special coatings for corrosion or other forms of protection depending on the location. Appendix B and Diagram B62-6 go into what to look for when installing a skin effect heating system.
Lastly, bare element water heaters, infrared drying lamps, storage tank water heaters and induction and dielectric heating equipment were taken out of Section 26 and dropped into Section 62. This resulted in a 4th section, “Other heating systems”, which brings together heating cables and panels within pipes and ducts, as well as pipeline impedance heating rules (pipeline resistance heating).
Now, nowhere in the code does it say heating equipment should be installed during the summer and fall, but it’s sure nice to have it in place when the cold snap hits! I always hated installing heat trace and heaters when it was minus 35 and customers were looking over my shoulder because their lines were freezing up, so now is the time to get those systems installed, tested and working.
* This article also appears in the September issue of Electrical Business Magazine.
EPEC 2017: IEEE Canada Electrical Power & Energy Conference
October 22-25, 2017
Electrical Safety in Construction Workshop
October 25-26, 2017