Voltage drop under CSA C22.1
This page opens every generated report. It sets out why voltage drop is checked, and the formula this tool uses.
Why it's checked
Excess voltage drop starves connected equipment of the voltage it was designed for — motors run hot and lose torque, lighting dims, electronic loads misbehave, and heating elements under-perform. CSA C22.1 (the Canadian Electrical Code, Part I) addresses this through Rule 8-102 and the associated Appendix B note.
Because it sits in the Code's informative appendix, an authority having jurisdiction can apply stricter project-specific limits — always confirm the target percentage against the governing specification before relying on this tool's default.
The formula this tool applies
Voltage drop is calculated from conductor resistance (R) and reactance (X), current, one-way circuit length, and the load's power factor angle θ:
| System | Formula |
|---|---|
| DC | Vd = 2 × I × L × R |
| AC — single phase | Vd = 2 × I × L × (R·cosθ + X·sinθ) |
| AC — three phase | Vd = √3 × I × L × (R·cosθ + X·sinθ) |
Where I is load current (A), L is one-way conductor length (km), and R/X come from the conductor's resistance/reactance table for the chosen material and temperature rating (per the methodology of CSA C22.1 Appendix D, Table D3). Percentage drop is Vd ÷ Vsystem × 100.
Describe the electrical system
These choices set the resistance/reactance table and the drop formula used downstream.
System voltage
System type
Conductor material
Insulation temperature rating
What do you need to find?
Calculation inputs
Load & circuit
Cable reference database sample data — verify before use
Representative R/X and base ampacity values compiled per the CSA C22.1 Table D3 / Table 2 & 4 methodology, plus a few illustrative North American cable references. Not a substitute for a manufacturer datasheet.
Results
Export report
The report opens with the CSA reference page from Step 1, followed by your system setup and results.