Terminal Wire Gauge

[usher42]

is 16 or 18 gause wires good for running trains and accesories, which gauge is best

[Nathan]

The answer has to do with how much current do you need.  #16 is better, but if your wire runs are short and the current draw is small the #18 will work.

The other thing to do is run a #16 main feeder and the do a drop, or connection with #18 if what you are connecting has small terminals or the wire will be where it would be seen on the layout and you want it easy to hide.

You do not say what scale you are working in.  In large scale (G) you may want your main feeders to be even larger if your wire length is long.

[r.cprmier]

You want some advice from an electrician?
 
Good.  Use a MINIMUM size of #14 wire, and #12 is even better.  Want some more?  Use stranded, with THHN, THWN, THNN, MTW, as an insulating jacket.

I wouldn't use #16 for a main buss on a bet!  The smaller size won't be as good as the larger aforementioned.  Also, you didn't specify if you are using DC or DCC, so I am assuming DC.  This would make a larger size even more important, especially if your layout is of any great size.

Rich

[usher42]

Its for n scale layout