cpal said:
Harmonic currents are generated within the utilization eq. and cycle at frequencies higher than 60 hertz. These freq, are generally multiples of 60 and called triplins. 60 X 3= 180 and so on.
High freq current tends to send the electrons to the outer circumfrence of the conductor which accounts for less conductive material for the current to follow. Less conductor CMA the higher the resistance per foot causing a higher I sq R loss.
I'm not sure that this is a problem with the smaller BC conductors but it is an argument used when considering the larger neutral Vs individaul neutrals
Charlie
Ummm... Saturday, day off, brain dead temporarily...
CMA is...?
BC is...?
I'm well aware of harmonics and skin-effect, but consider this:
Using an individual branch circuit neutral, the current with all harmonics generated have to travel the entire length of the circuit.
In a multiwire branch circuit using an oversized neutral, only the uncancelled harmonics and the unbalanced portion of current travel the neutral. Voltage drop on the circuit is essentially halved (balanced load), I?R loss is decreased, less required conductors, less conduit, less man-hours, etc.