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Grounding Electrode Calculator

Calculate grounding electrode conductor sizes and requirements per NEC 250.52 and 250.66.

Quick Presets

NEC References

250.52 - Grounding Electrodes
250.66 - GEC Sizing
250.68 - Connection
250.104 - Bonding

Service Configuration

Grounding Electrode Type

Ground Rods (Driven Electrodes)
Standard driven ground rods - most common residential electrode
NEC 250.52(A)(5)
Requirements:
  • •Minimum 8 feet in length
  • •Minimum 5/8 inch diameter for steel
  • •Copper-clad, galvanized, or stainless steel
  • •Driven to full length unless bedrock encountered
  • •Two rods required if resistance >25 ohms
  • •Minimum 6 feet apart if multiple rods

Soil Conditions

Clay/Loam Soil
Good conductivity when moist
Ground Rod Requirements: Single 8ft rod typically sufficient

Compliance Status

Code Compliant

Grounding Requirements

Grounding Electrode Conductor
#4 Copper
Per NEC 250.66 for 200A service
Ground Rods Required
1 Rod
Test first rod - if >25Ω install second
Electrode Specifications
Minimum Length: 8 feet
Minimum Diameter: 0.625 inches
NEC 250.52(A)(5)

Bonding Requirements

Required Bonding (NEC 250.104):
•Metal water piping system (if ≥10 ft underground)
•Gas piping system (bonding jumper only)
•Structural metal frame (if present)
•Metal objects likely to become energized
Important Notes:
• Use same size conductor as GEC for bonding jumpers
• Bond around water meters and insulating fittings
• Gas pipe bonding: jumper only (not electrode)