CEC Part I · Rule 12-012 & Table 53
CEC Direct Burial & Trench Depth Calculator
Calculate mandatory underground cable cover depths, approved Canadian cable types (NMWU / TECK90), and conduit protection rules for Ontario and Canada.
1. Trench & Site Parameters
2. CEC Rule Requirements
CEC Table 53MANDATORY TRENCH COVER DEPTH
600 mm (24 in)
Approved CEC Cables: NMWU (Non-Metallic Wet Underground) or TECK90 Armoured cable.
ESA Permit Required: Yes — pull an ESA permit before digging. Always call Ontario One Call (1-800-400-2255) for utility locates before placing a shovel in the ground.
Live Trench Cross-Section Preview
Mandatory CEC Trench Installation Rules (Rule 12-012)
- Locates First: Call 1-800-400-2255 (Ontario One Call) for free utility line locates before digging.
- Sand Bedding: Direct burial cable must be cushioned with a minimum of 75mm (3 in) of smooth sand on the bottom and top cover before backfilling to prevent sharp rock puncture.
- Warning Ribbon: Continuous yellow electrical warning tape must be buried half-way down the trench depth above direct-buried conductors.
- Canadian Approved Cable: Only use NMWU or TECK90. Never use US UF-B cable in Canada — it lacks CSA/CEC certification.
- ESA Permit: An Electrical Safety Authority permit is required for new underground feeders or branch circuits in Ontario.