Voltage Drop Recommendation Study
Resolve operating current from saved Load Flow or the Load List, evaluate individual and feeder-plus-branch paths, and review conductor recommendations.
Method & Standards
Voltage drop is calculated using the project AC resistance/reactance model and load power factor. Cable Schedule current and voltage take precedence; missing values can be resolved from a converged Load Flow result or the Load List.
VD₃φ = √3 × I × (R cosφ + X sinφ) × L VD₁φ = 2 × I × (R cosφ + X sinφ) × L
NEC recommendations (informational notes):
- NEC 215.2(A)(3): Feeder circuits — ≤ 3 % recommended
- NEC 210.19(A)(1): Branch circuits — ≤ 3 % recommended
- Combined feeder + branch — ≤ 5 % recommended
Feeder and branch results are also accumulated along connected cable paths for the combined 5% recommendation. Cables without length, load current, voltage, or conductor-size data are marked Not Evaluated but remain listed in the table. Circuit type (feeder/branch) is determined from the Circuit Type or Service Type field in the cable schedule.