Earth rod configurations for 220kV substations are designed for high fault current handling and enhanced safety requirements.

High-Voltage Considerations

• •Fault current: Designed for 40kA or higher
• •Step voltage: Limited by grid design
• •Touch voltage: Equipment grounding critical
• •GPR: Ground potential rise management

Design Features

• •Multiple rod electrodes in grid pattern
• •Heavy-gauge conductor connections
• •Exothermic welded joints
• •Concrete inspection chambers

Standards Compliance

• •IEEE 80 for grounding design
• •IEC 61936 for installation requirements
• •IS 3043 for Indian installations

Testing Requirements

• •Fall-of-potential method
• •Step and touch voltage measurements
• •Current injection testing
• •Annual resistance verification