Wire size for 12v LED-accessory bus line

@BenLMaggi posted:

All of the structures on my layout are powered with 12v LED lights that I install myself. They are operated at 10 volts from the DC output of a train transformer, which hopefully will prolong their life a bit. For bus lines that will need to run no more than 20 feet or so, is 18g copper wire sufficient?

Thanks.

Maybe.  Besides max voltage, length and temperature, Copper wire size guidelines are also dependent on the maximum current in Amps that will be flowing through it.  So, the answer depends on the total wattage of all the LEDs.  How many LEDs will be connected to this bus and what are their individual wattages?

Another way this question could be answered is to wire up all of the LEDs on a test bench and measure the current flowing through the circuit. For simplicity, check the amps flowing through a main wire at one output terminal of the DC power pack.

For the difference in price, 16g is probably a wise choice.

Thanks. I will go with 16g.

@BenLMaggi posted:

All of the structures on my layout are powered with 12v LED lights that I install myself. They are operated at 10 volts from the DC output of a train transformer, which hopefully will prolong their life a bit. For bus lines that will need to run no more than 20 feet or so, is 18g copper wire sufficient?

Thanks.

Hi Ben,

16 awg is a good choice.  Below are my wiring conventions for non-track power.

Hope that helps.

George

#18 AWG is sufficient if you are only powering LED lighting.  Otherwise, larger wires are appropriate.  On our Club's S and O gauge travel layouts #14 AWG is used for the 10V and 14V accessory buses.  Don't use the track common (outer rail wiring) for the accessory return - run a dedicated one with the 10V.