Appendix B Rule 12-100

Table 19 indicates the maximum allowable conductor temperature for various types of building insulated conductors and cables. Where the surface temperature and/or the temperature on the insulation of conductors, cables, or raceway systems exceeds 90 °C, such assemblies are a potential fire hazard if installed adjacent to combustible material and, in such cases, the assemblies should be relocated or supported in a manner to remove this potential hazard.

The low temperature marking on insulated conductors and cables indicates compliance with a test at that temperature, as specified in the product Standard, but does not guarantee safe installation at that temperature.

Care should be taken when installing insulated conductors and cables at low temperatures. Measures to consider include preconditioning at higher temperatures prior to installation, and avoidance of mechanical shock from dropping the insulated conductors or cable, unreeling the insulated conductors or cable too quickly, or bending sharply or quickly at bends. Manufacturers should be consulted when further information is desired.

Source: Appendix B Rule 12-100, CSA C22.1:21, Canadian Electrical Code, Part 1 (25th Edition), Safety Standard for Electrical Installations. © 2021 Canadian Standards Association. Please visit