Parallel Conductor Ampacity Calculator

Inputs

View results
Ampacity of one conductor before correction/adjustment factors. Enter the adopted table, listing or schedule value.
A
Maximum ampacity allowed for one conductor by the terminal, equipment or temperature-rating limit.
A
Number of same-phase conductors sharing current in parallel. Use 2 for two parallel paths per phase.
paths
Actual expected line current before applying the load multiplier.
A
Use 100% for a direct load screen or a higher multiplier when your design method requires it.
%
Correction factor for ambient temperature from the adopted code or manufacturer data.
Adjustment factor for current-carrying conductors in the same raceway, cable or bundle.
Optional extra multiplier for project-specific derating. Use 1.00 when none applies.
Use 100% when the parallel paths are intended to share evenly. Lower this as a conservative allowance for uneven current sharing concerns.
%

Results

Default result
Edit inputs
Usable total ampacity(I_use_total)
167.4A
Pass

2 parallel paths x usable per-conductor ampacity

Also computed

Design load current(I_design)Pass162.5A

125% of entered load current

Total ampacity margin(I_margin)Pass4.94A

Usable parallel ampacity meets the multiplied design load.

Utilization(U)Pass97.05%

Usable per-conductor ampacity(I_use_each)83.72A

derated conductor ampacity controls before sharing allowance

Terminal-limited per conductor(I_term_lim_each)83.72A

Adjusted per conductor before cap(I_adj_each)83.72A

Method notes 3 notes
  • Adjusted per-conductor ampacity = base ampacity per conductor x ambient correction x conductor-count adjustment x other derating factor.
  • Usable total ampacity = min(adjusted per-conductor ampacity, terminal cap per conductor) x current-sharing allowance x parallel paths.
  • This does not verify whether the conductors may be paralleled, choose a conductor size, select an overcurrent device or approve the installation. Use the adopted code edition, listed equipment instructions and qualified review for final work.

Powered by MachineCalcs ↗