This calculation is used to calculate rectifier and ground bed sizing to protect large underground piping systems such as pump/compressor stations and large transmission piping systems.
These systems are not practical for 1 amp or less with low driving voltages. In addition, impressed current system require an AC power source to operate a rectifier to convert AC to DC power.
R — Total ground bed to earth resistance(0hms)
r — Resistance to earth of one installed anode (0hm/ cm)
ρ — Actual soil resitivity (0hm / cm)
K — Correction factor for anode grouping
N — Number of anodes