My
Target Voltage method, based on NEC 110.10 & 110.3(B), uses either table data or field measurements for the same variables.
1) One advantage of choosing your impedance here, lets you control the fault clearance STD used by
IEEE 1100 (The Emerald Book). Even if you don't care about ASCC (Available Short-Circuit Current) and OCPD trip times, you have control of it in this calc..
That formula would be,
ASCC = E/Z, line voltage(E) over line impedance(Z). According to Mike Holt, 120vac / 4.8 ohms = 25A, and 500 Seconds, or 8+ minutes to trip the breaker.
2) This calc includes a
Power Factor for proper motor FLA in Tbl 430-150. Motor power-factor adjustment is critical for proper wire size.
NEC Table 430-150 said:
For 90 and 80 percent power factor, the figures shall be multiplied by 1.1 and 1.25 respectively.
3) This Target Voltage method shows
Choked Power and Choked Amps, so meeting equip. power needs, or lighting effects (Choked Watts / Watts)x100, is known before the install.
4) That link includes a proof for using any source voltage to match wire sizes by either the
Volts Dropped or the
Iimpedance results shown, using different NEC Tbl.8 wire Size and Length variables. But, the same calc. results could also be matched to Tbl.9 wire Size and Z. values.
5) Plugging the variables of that proof into a spreadsheet would be faster, but I believe getting familiar with the seperate table and field-measurement formulas for Power factor, Choked Power, Choked Amps, and Z, brings more skill-set leverage to my service ability, and more wage / renewal leverage to the bargaining table.