What Size Wire Do I Need To Feed A 45 KVA Transformer? For a 45kVA transformer, 54A×1.25=68A, so use a 4 AWG conductor rated 85A at 75°C, per Table 310.16. What size breaker do I need for a 45 kva transformer? A 45 KVA transformer protected on the supply side with a 70-ampere circuit breaker
How Do You Calculate Cable Size? Divide the voltage running through the cable by your target current. If, for instance, 120 volts will act on the cable, and you want 30 amps to run through it: 120 / 30 = 4. This is your target resistance, measured in ohms. 30,000 x 1.724 x 10^-8 =
What Is The Formula For Calculating Cable Size? Divide the voltage running through the cable by your target current. If, for instance, 120 volts will act on the cable, and you want 30 amps to run through it: 120 / 30 = 4. This is your target resistance, measured in ohms. 30,000 x 1.724 x