CSA C22.1:24 Table D3 K-value voltage drop calculation for copper and aluminum conductors. Calculate voltage drop for a known distance, or find the maximum circuit length for a target drop percentage.
Voltage Drop
—
V
Drop %
—
%
K Value
—
Ω·km
f Factor
—
Max Length
—
m
CSA C22.1:24 Reference
Table D3 — K values for calculating voltage drop
Formula: VD = K × f × I × L / 1000
Drop Level
CSA C22.1:24 Table D3 provides K values (ohms per circuit-kilometre) for calculating voltage drop in installations of 2, 3, or 4 insulated conductors in a cable or raceway, based on a conductor operating temperature of 75 °C. The voltage drop is calculated as:
VD = K × f × I × L / 1000
where K = table value (Ω/km), f = circuit factor, I = load current (A), L = circuit length (m)
The voltage drop factor f depends on the electrical system and circuit configuration: 1.0 for DC 2-wire, 1-phase AC 2-wire, and 3-phase 3-wire line-to-grounded circuits; 1.73 for 3-phase 3-wire or 4-wire line-to-line circuits.
For conductor operating temperatures other than 75 °C, multiply the K value by 0.95 for 60 °C or 1.05 for 90 °C (Note 3).
2024 Code Change: Table D4 (5% drop on 6 V systems) has been deleted in CSA C22.1:24. Table D3 now uses a K-value formula approach replacing the older distance-lookup format from the 2021 code. K values are based on IEC 60287-1-1:2006 and IEEE 141-1993.