In most residential situations, you should not run electrical power wire and Ethernet cable through the same hole in framing. The Ontario Electrical Safety Code and standard wiring practice require separation between Class 1 power wiring and Class 2 low-voltage signal cables. Running them together creates interference problems and potential code violations, depending on the cable types and how they are routed.
Power and low-voltage cables can cross each other (at 90 degrees) without issue. They can also run parallel at a distance if the power cable is rated or shielded appropriately. Shielded Ethernet (STP or SFTP) is more resistant to interference than unshielded (UTP). Running both cables through the same drilled hole in a stud where they would be bundled together is generally not compliant and not recommended even where technically arguable.
If you need both to run in the same general area, use separate conduits or dedicated holes. Metal conduit around the power wire provides shielding and physical separation. This is the cleanest solution where both types of cabling must follow the same path through a wall or floor.
EZSMART runs new circuits and low-voltage rough-ins across Ontario. Contact us for proper separation and code-compliant installation of both power and data infrastructure.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp