Neutral conductor dimensioning
Neutral conductor dimensioning
(OP)
"Preferred neutral conductor options include 50% or 100% of the phase conductor. In limited cases, it is also possible
to select a conductor rating up to 200%."
The above lines were stated in the ABB- MNS panels documents.
Why is the neutral conductor dimensioned sometimes lesser than the phase conductors.
to select a conductor rating up to 200%."
The above lines were stated in the ABB- MNS panels documents.
Why is the neutral conductor dimensioned sometimes lesser than the phase conductors.






RE: Neutral conductor dimensioning
However, with the increased use of non-linear loads, the neutral can carry a substantial harmonic current, primarily third harmonic currents in addition to the imbalance current. For many applications, such as office buildings, high tech facilities etc, it has become common to oversize the neutral to 200% to account for the harmonic (triplen) currents.
RE: Neutral conductor dimensioning
Those office buildings dpc is talking about are mostly lighting and electronic loads. As you probably know, their power supply are made of capacitors charging only on top of the voltage sinewave, creating high current inrushes for only very short amounts of time. If you look on a 3phase plot, you`ll see that very short bursts of currents on peak of each phase will add up instead of cancel with each other.