what gauge wire is best to use for a bus wire

[cozyp]

hi there guys what size wire would be the best for a bus wire,im tempted to use flat copper bus wire on sale in my local shop but it would mean soldering underneath the board for the diffrent feeds around the layout.but using normal wire i think i can

get away without getting the soldering iron out

[stevecamden]

I don't know what gauge it is, but I just use ordinary electrical lighting wiring cable - cheap and cheerful from B&Q

Steve

[Drpepper]

stevecamden said:

I don't know what gauge it is, but I just use ordinary electrical lighting wiring cable - cheap and cheerful from B&Q

Steve

This site has been invaluable in negotiating me through the minefield

of sorting out power bus, droppers etc:-

http://www.brian-lambert.co.uk/DCC.htm

James.

[Phil_Spiegel.]

I, as well as any others, have produced booklets/notes/web pages giving guidance for this subject: The 'problem' with a 'specific' answer is that it HAS to make ASSUMPTIONS about Scale/Gauge, Size of Layout, AND the MAXIMUM OUTPUT of the Cotroller Used!

This

is because it musr meet 2 essential requirements (which luckily come to a simialr answer) ...

1/ Adequate Power in Use at the most distant part of a layout - not forgetting that once you have gone digital, this COULD be more thn 1 loco, and might include

many carriges with lighting, and an increasing number of locos with sound.
The BUS is helping overcome the resistanc eof passing the current through the TRACK (which might be BRASS or Nickel Silver or Steel (Brass is the better conductor ... ad copper wire

better still). You do not want more than a 1-2Volt drop 'under load' at the most distant part. (This drop is caused becauser ALL wiring has resistance).

2/ SHORT CIRCUIT PROTECTION: THIS varies with the Controller,as to the MAXIMUM CURRENT which should

be able to flow NORMALLY ... and the short circuit current to operate the safety trip should be just aboove that!. A starter-controller with 1A output will MAYBE allow 2A to flow before it trips (as an easy discussion example) - so the wiring loop must have

a resistance low enough for that to flow V=IR 16= 2 x R.. R<=8 ohms
BUT with a LARGER RATING CONTROLLER eg 8A MAX the WIRE LOOP resisitance must be <=2 ohms or the controller would NEVER TRIP.

THE COIN TEST - onthe track at the furthest location

- does it trip? is a good test.
For 00/H0 indoor layouts <10m bus length, I use '6A' flex - with 2-4 Amp limits on each section. For OUTDOORS in G Scale I use several parallel busses of 15A AUDIO FLEX ... but ALWAYS CHECK with the 'coin test' ... esecially

when you upgrade controller.