Excessive Neutral Current
Excessive Neutral Current
(OP)
All,
Is there a standard or reference out there describing neutral current or voltage/current imbalance limits (three phase 4.16kV wye overhead, United States)? I'm working on a study and am finding imbalance as much as 30% which I know is high, but I'd like to be able to point to a standard.
Thank you
Is there a standard or reference out there describing neutral current or voltage/current imbalance limits (three phase 4.16kV wye overhead, United States)? I'm working on a study and am finding imbalance as much as 30% which I know is high, but I'd like to be able to point to a standard.
Thank you






RE: Excessive Neutral Current
RE: Excessive Neutral Current
RE: Excessive Neutral Current
We have used a criteria of 15% maximum current imbalance in studies. We have recommended shifting loads to achieve 10% if the imbalance is more than 15%. This is based on the practicality of shifting loads, however, not on an industry standard.
One problem with studies is that records of what phase transformers are connected to are often not accurate.
RE: Excessive Neutral Current
RE: Excessive Neutral Current
Although we are attempting to achieve this goal, there are some feeders where phases have variations in daily or seasonal loading (i.e. phase A is always high in the summer/day but phase C is high during the winter/night). We also have a number that are reasonably balanced on normal load days, but are dramatically more unbalanced during extreme temperature.