Remote Neutral Bus: Voltage Drop Minimization

One disadvantage is from the viewpoint of fault finding.

To me it's better if all feeds from a panel have there corresponding neutral along side them in the main terminal chamber.

Fred-

1010-0100 and Thanks!

My work is noted for meeting and wining and dining the local code and regulations. I am particularly interested in the history of and reasons for why distribution is done as it is, a bit of an enthusiast concerning the whys and why-nots.

I worked in a plant where I found the 3-phase 4-wire supply conductors for a bussbar system were run 2 phases in one pipe, phase and a neutral in another. Drove me crazy, they wouldn't correct it. Inspected and passed as installed by a local contractor. They just didn't know that you must not do that, unless you are intent on heating things up.

I'm currently refurbishing a 100 kVA resistance welder that has 480/3/60 primary and a half-wave rectified secondary that runs at 20,000 amps, so I am right in the middle of heating things up! That rascal is braced for some serious current stresses, is liquid cooled, and I'm paying attention to Micro-Ohms.

I appreciate Tony's input about being able to lift a neutral for fault finding, at the point of circuit origination. In the remote neutral bus scenario, that need would still be met, albeit a bit less conveniently.

I would most certainly chat up a local inspector before proceeding. I find that departures from the norm can be challenging to a regulatory mindset, so I thought I'd solicit input here before proceeding.

Again, the intent would be to cut the voltage drop in half for a given wire size, by relocating the neutral bus.

Thanks again

Robert

I've seen neutrals shared

and I've seen it work well

and I've seen some nasty things happen

and I've learned never to do that just because of one word - harmonics

taught me some very very good lessons

Stub

Stub-

After reading your post, I went off on a quest for understanding harmonics, and found-

"The main problems associated with harmonic currents are:

- Overloading of neutrals is caused because 3rd (and any triple-N) harmonics do not have 120° Phase shifts and so add instead of cancelling in the neutral".

( http://www.rose-hulman.edu/class/ee/HTML/ECE471/PDFs/Lect15.pdf )

(Might want to read 180° for the single-phase center-tapped system I am looking at)

Give a man a fish, he'll have a meal. Teach a man to fish... Thanks for the lesson!

Considering harmonics, I'll stand down on this exercise.

RK