NEC 2023 — Chapter 9, Tables 8 & 9 · K-Formula vs. AC Impedance · §210.19(A) / §215.2(A)(1)
NEC 210.19(A) / 215.2(A)
System Type
Conductor Material
NEC 210.19(A) · 215.2(A)(1)
One-Way Distance (ft)
Load Current (A)
Source Voltage (V)
NEC Chapter 9, Table 8 · Table 310.12
Conductor Size
Construction — Method 1 / Table 8
NEC Chapter 9, Table 9
Conduit Type
Power Factor — 0.85
Power Factor Type
Method 1 — K-Formula
Chapter 9, Table 8 · DC-resistance basis · Quick field estimates
Voltage Drop — Method 1
VD (V)
0.00 V
VD (%)
—%
Load Voltage
0.00V
Method 2 — Table 9 AC Impedance
Chapter 9, Table 9 · AC impedance basis · Preferred for large conductors & long runs
Voltage Drop — Method 2
VD (V)
0.00 V
VD (%)
—%
Load Voltage
0.00V
Additional Scenarios
Other Scenarios →Side-by-Side Comparison
| Method | VD (V) | VD (%) |
|---|---|---|
| Method 1 — DC-resistance basis (Table 8, solid/stranded) | 0.00 | —% |
| Method 2 — AC impedance basis (Ze to neutral, per Ω/kft) | 0.00 | —% |
| Δ (Table 9 − K-Formula) | 0.00 | —% |
Disclaimer — Important
NEC Chapter 9 Table 8 (conductor properties / circular mils) and Table 9 (AC resistance & reactance, 3-phase, 60 Hz, 75°C, three single conductors in conduit) reference data. Table 9 does not publish values above 1000 kcmil, or for 700/800/900 kcmil, or for 14 AWG aluminum — Method 2 shows “not available” for those combinations.
NEC §210.19(A) Informational Note & §215.2(A)(1) Informational Note: 3% branch circuit / 5% combined feeder + branch are recommendations, not requirements.
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