Grounding & Bonding
Grounding electrode conductors, equipment bonding jumpers, neutral-ground bonds, ground fault current paths, and grounding conductor sizing.
- Explain the purpose of bonding in an electrical system
- Identify the correct color codes for grounding and neutral conductors in Canada
- Describe the function of the grounding electrode conductor
- Determine the minimum equipment grounding conductor size for various circuit ratings
- Explain the CEC Rule 10-210 single-point grounding requirement for solidly grounded AC systems
Lección 1
Grounding Fundamentals & Conductor Colors
Why Grounding Matters
Grounding is one of the most critical safety aspects of any electrical installation. A properly grounded system provides:
- Personal safety - ensures fault current flows through a low-impedance path to trip protective devices quickly
- Equipment protection - prevents dangerous voltage buildup on metal enclosures
- Fire prevention - ensures faults are cleared before excessive heating occurs
- Lightning protection - provides a path to earth for lightning-induced surges
The CEC addresses grounding and bonding in Section 10. Every electrician must understand the difference between grounding (connection to earth) and bonding (connection between conductive parts).
Grounding
Purpose: Connect the system to earth
Via: Grounding electrode conductor to electrode
Reason: Stabilize voltage, dissipate surges
Conductor: Green or bare copper
Bonding
Purpose: Connect metal parts together
Via: Bonding jumpers and conductors
Reason: Ensure fault current path for trip
Conductor: Green or bare copper
Conductor Color Codes
The CEC mandates specific colors for conductors to ensure consistency and safety:
- Grounding conductor: Green or bare copper - CEC Rule 4-036. This is the safety grounding conductor (also called the equipment grounding conductor).
- Neutral (identified) conductor: White or grey - CEC Rule 4-028. This is the grounded conductor that carries the return current.
- Hot (ungrounded) conductors: Black, red, blue, and other colors except white, grey, green, or bare.
The grounding conductor in Canada is green or bare. The neutral (identified) conductor is white or grey. Grounding connects the system to earth for voltage stabilization, while bonding connects metal parts together to ensure fault current can flow and trip protective devices.