hello Sir, Excellent documents on this subjects - " Harmonic Currents in the Data Center: A Case Study "

cheers

I will agree that the level of current harmonics and their voltage distortion effects in data center circuits have been reduced over the pase few years. I also agree that the tripplin harmonics that cause neutral overloading is not as severe as it once was. That being said, I will continue to recommend against the use of multi phase branch circuits that rely on a common neutral. My recommendation is to always use a dedicated neutral for each 120 volt single phase brance circuit There are several reasons for this. One is for ease of maintenance and maninuplation of circuits as data center equipment is changed. upgraded etc. Another is to reduce the chance of any interfearance on one circuit affecting another. Another is that a loose connection on one neutral conductor will not affect another.

Larry LeSueur

Thank you Mike,

For your continued interest in getting us the best information available.

Best Regards;

Carlos Gil, PE

This is a 15 year old subject and was addressed buy NEC some years ago.. In data centers neutral conductors must be teh same size as teh load conductors which must be oversized to accomidate teh Peak curents. Today vertualy all computer power supplies are power factor corrected and reflect a 0.9 to 0.95 PF. In leu of the 0.7 that was in the OLD days. The artical is good but the subject is old.

Very informative article, well woth the time and effort. Thanks.

Thanks for the information. I work at a University and will be passing this on to the data people. My job centers around fire protection, but Harmonics are definitely a consideration in a 20,000 student campus.