Einführung
Proper grounding is essential for electrical safety. Equipment grounding conductors (EGC) must be sized correctly to safely carry fault currents.
Types of Grounding Conductors
Different grounding conductors serve different purposes:
- Equipment Grounding Conductor (EGC): Connects equipment to ground
- Grounding Electrode Conductor (GEC): Connects system to earth
- Main Bonding Jumper: Bonds neutral to ground at service
- Each has specific sizing requirements
EGC Sizing per NEC Table 250.122
Equipment grounding conductor size based on overcurrent device:
- 15A circuit: Minimum 14 AWG copper
- 20A circuit: Minimum 12 AWG copper
- 30A circuit: Minimum 10 AWG copper
When to Upsize Ground Wire
Ground wire may need to be larger in certain situations.
Tipp
When ungrounded conductors are increased in size for voltage drop, the EGC must be proportionally increased.
Grounding Electrode Conductor Sizing
GEC sizing is based on service entrance conductor size per NEC Table 250.66:
- For copper service conductors up to 2 AWG: 8 AWG copper GEC
- For larger services: Proportionally larger GEC
- Different requirements for aluminum GEC
- Local codes may require larger sizes
Ground Wire Installation
Proper installation ensures effective grounding protection.
Wichtig
Never reduce ground wire size below NEC minimums. Undersized ground wires can fail during fault conditions, creating dangerous situations.
Fazit
Proper ground wire sizing is critical for electrical safety. Always follow NEC requirements and upsize when necessary for long runs or increased phase conductors.
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