5 wire wye

[pearlpass]

Read with interest the 5 wire wye with ? a parallel neutral, but all references refer to the usual four wire wye with a ground rather than two neutrals. Where can I find a diagram of a 5 wire intended to minimize heat and odd triplens? TNX, Dick

 

[charlie b]

Re: 5 wire wye

Haven't read anything about this myself. But I can say that if you add a second neutral, it would do nothing to minimize harmonic currents. What it may do is permit the harmonic currents to flow without overheating the (normal, single-sized) neutral. As to a diagram, I suppose you just draw the 4-wire and draw a parallel neutral.

 

[infinity]

Re: 5 wire wye

Also keep in mind that a parallel neutral would have to be #1/0 or larger {310.4}. Depending on the size of the feeder it may be better to install a single neutral rated at 200% of the feeder ampacity. For example if you were feeding a 100 amp panel with #3 THHN then your neutral could not be two parallel #3's. You could however use a single #3/0 to bring the neutral up to 200%.

 

[jtester]

Re: 5 wire wye

One of Mike Holt's recent e-mails on stray voltage mentioned that EPRI is doing some experimental installations in New York. You might turn to them.

Jim T