Equipment Grounding Conductor
Is an EGC the same as a grounded conductor?
No. A grounded conductor is the circuit conductor intentionally connected to ground and normally carries load current; the EGC is part of the effective ground-fault current path and does not carry normal operating current.
What performance characteristic matters most for an EGC?
Low impedance and adequate ampacity so fault current is high enough to trip overcurrent protection quickly.
Can metallic conduit or cable armor serve as an EGC?
Yes, in some code-compliant installations metallic raceways, conduit, or cable sheathing can serve as part of the EGC path when permitted by the applicable electrical code and installed continuously and correctly.
An equipment grounding conductor (EGC) is the conductive path connecting normally non-current-carrying metal parts of electrical equipment to the system grounded conductor or grounding electrode conductor, providing a low-impedance path for fault current to trip protective devices quickly. It does not carry normal load current, only during ground faults, and is typically green or bare in cords, raceways, or enclosures.
On a manufacturing floor, the EGC is the green or bare bonding path built into cords, cables, raceways, conduit, or metal enclosures that ties exposed metal parts of tools, machines, panels, and frames back to the grounding system. Its job is not to carry normal load current; it carries current only during a ground-fault condition, when a live conductor contacts exposed metal and the fault current needs a rapid return path to operate the breaker or fuse. In practice, this means verifying that portable tools, extension cords, machine feeders, control panels, and receptacles have a continuous grounding path, and that the path is not interrupted by damage, incorrect adapters, missing pins, loose terminations, paint, corrosion, or unauthorized rewiring. On construction sites under OSHA, employers must also maintain an assured equipment grounding conductor program for cord sets, non-building receptacles, and cord-and-plug equipment used by employees.
Open or discontinuous grounding path: a broken ground wire, damaged cord, loose lug, or missing equipment grounding pin leaves exposed metal unprotected and prevents fault-current clearing.
Misuse of the EGC as a current-carrying or neutral conductor: the EGC is part of the fault-current path, not the normal return path; using it incorrectly can defeat protection and create shock hazards.
Improper bonding/grounding of portable or fixed equipment: using unapproved cords, non-grounded receptacles, incorrect adapters, or failing to bond enclosures, raceways, and frames can leave non-current-carrying metal energized during a fault.