Wiring methods — Underground

1) Wiring underground shall be run

a) in rigid steel or rigid aluminum conduit;
b) in non-metallic underground conduit;
c) as mineral-insulated cable, aluminum-sheathed cable, or copper-sheathed cable; or
d) as cable suitable for direct earth burial as selected in accordance with Rule 12-102 3) or, where a deviation has been allowed in accordance with Rule 2-030, for service entrance below ground as selected in accordance with Rule 12-102 3).

2) Insulated conductors in conduit shall be of types selected in accordance with Rule 12-102 3) as being suitable for use in wet locations.

3) Cables buried directly in the earth shall be installed in accordance with Rule 12-012.

4) Suitable corrosion-resistant protection shall be provided for aluminum conduit, and for aluminum sheathed cable, copper-sheathed cable, and also for mineral-insulated cable if used where materials coming in contact with the cable may have a deteriorating effect on the sheath.

Source: Rule 30-1004, CSA C22.1:21, Canadian Electrical Code, Part 1 (25th Edition), Safety Standard for Electrical Installations. © 2021 Canadian Standards Association. Please visit store.csagroup.org