Minimum conductor size formula
Minimum conductor size formula
(OP)
All of you are probably familiar with the formula S = I x sqrt(t)/k used to determine the minimum conductor size in mm2. What factor do you put in to get it in American size (AWG/kcmil)?
I tried looking at the NEC but couldn't find anything, and the only way I can think of is to use a metric/American conversion table. Hope someone can shed some light into this. Cheers.
I tried looking at the NEC but couldn't find anything, and the only way I can think of is to use a metric/American conversion table. Hope someone can shed some light into this. Cheers.






RE: Minimum conductor size formula
To convert in² to kcmil, multiply by 4000/pi
To convert in² to AWG is a bit more complicated:
AWG = 36 - ln(400·sqrt(A/pi))·39/ln(92)
where A is area in in² and AWG is the AWG# for positive results, #1/0 for a result of zero, #2/0 for a result of -1, #3/0 for a result of -2, etc.
RE: Minimum conductor size formula
RE: Minimum conductor size formula