transformer phasing

[Anonymous]

Hi, I'm new to model railroading and am helping a friend wire up his train set. I was wondering if I properly phased all the transformers if I could attach one leg from each transformer together as a common ground for the whole system? Then when it comes to insulating the track for blocks can we just insulate the center rail? A common ground would save a lot of extra wire if I could just tap off the outside rail wherever I needed. I have 2 train transformers and 2 constant transformers for lighting and turn-outs (I've already rewired the turnouts so they aren't powered by the track) I'd appreciate any advice you can offer. Thanks!

[Hudsonmike]

Yes but it will not save you much wire.
Run telephone wire around the complete layout so you can put track connectors on about every ten or twelve feet or so. So you will always have good connections.
Track pins become loose over time and lose their conductivity.
Also watch your polarity some Engine horns will not work when its in correct.
Mike

[nfmisso]

QUOTE: Originally posted by Hudsonmike

Run telephone wire around the complete layout .....

Do NOT use telephone wire for track power, it is not intended to carry that much current. Use 12 guage wire, house wire if you like solid conductor, speaker cable if you prefer stranded.

Telephone wire is 28 guage; which has 71 ohms per 1000 feet. 12 guage has 1.65 ohms per 1000 feet.

Common rail can be done, it is quite common in two rail model railroading, don't know about three rail, You might want to take your question over to one of the Classic Toy Train forums.

[BR60103]

Coty, if you're using 3-rail, you usually use the common rail approach and insulate the center rail. You would only insulate the outside rail for operating accessories or non-derailing switches.
Lionel's instruction manual used to have directions for phasing transformers.
Start with 2 transformers. Connect the common posts to the outside rail. Connect the variable post to the center rail of different blocks (adjacent). Run a loco from one block to the other. If it shorts out, reverse the plug on one transformer and try again.
This only works if the transformer has a non-polarized plug.
OK guys, how out of date am I?

[Anonymous]

not out of date as far as i'm concerned, that's exactly what i'm dealing with. i thought i had the phasing part under control but i just got back from my friends house where i was tried putting theory to practice and came up with a problem. i connected the two commons of his train transformers (1033 and rw 110) and got them in phase with each other. than i took one of my 12 volt accessory transformers and put one of its legs on the common leg, and checked my voltages and it showed in phase with one transformer, but out of phase with the other. i'm an electrician by trade, i don't really see how this is possible. i'm going to talk to some of the guys at work tonight, maybe i'm missing something here.

anyhow, since we're on the topic... is the "U" tap the common or the hotrail? i saw a picture in a lionel book showing it as the outside rail, but my friend has it as the hot rail. when i was testing the phasing i did try switching this both ways and came up with the same problem.