Common to Track or Transformer?

You might get a voltage drop, or lack of crisp operation, using the rails as a common return bus. In the long run (sorry) it doesn't take any more labor, and a very small increase in cost of copper, to run a separate return to each accessory.

For a temporary small layout, you're probably OK with your method.

@Arthur P. Bloom posted:

You might get a voltage drop, or lack of crisp operation, using the rails as a common return bus. In the long run (sorry) it doesn't take any more labor, and a very small increase in cost of copper, to run a separate return to each accessory.

For a temporary small layout, you're probably OK with your method.

Thanks Arthur - Appreciate the insight!

I think running a common wire is always better.

Thanks for everyone’s replies. I’m considering getting this wire so I can keep my hot and common straight for accessories  

Is a 16/2 like this (photo attached) appropriate, or overkill for a seasonal layout with about 10 accessories? I might also use it to run an extra power drop to the opposite side of my track  

I’ll be running this all back to a terminal strip with jumpers so I only need to run one hot/common back to transformer.

The layout is only about 8’ in total diameter.

That’s Cupper Clad Aluminum. It’s about 2 gauges smaller effectively electrically than pure copper. So if you really want 16 ga copper, then buy 12 ga CCA

All electronics has copper,

https://www.allelectronics.com...auto-zip-wire/1.html

@cjack posted:

All electronics has copper,

https://www.allelectronics.com...auto-zip-wire/1.html

Thanks Chuck - that looks to be a good option. Is 16g too much for general purpose use, or a good all around gauge?

I think it's a good size for a run back to an assortment of accessories. You don't usually run them all at the same time, but a 16 ga cu zip cord wire carrying 10 amps drops about 0.8 volts in a 10 foot run. 18 ga drops about 1.2 volts in a 10 foot run. You'll have more consistency in the voltage with the 16 ga when running an accessory and simultaneously turning on another one. Some accessories are fairly sensitive to the voltage applied.

@cjack posted:

I think it's a good size for a run back to an assortment of accessories. You don't usually run them all at the same time, but a 16 ga cu zip cord wire carrying 10 amps drops about 0.8 volts in a 10 foot run. 18 ga drops about 1.2 volts in a 10 foot run. You'll have more consistency in the voltage with the 16 ga when running an accessory and simultaneously turning on another one. Some accessories are fairly sensitive to the voltage applied.

16/2 it is. Thanks again!

Aluminum wire is outlawed for line voltage applications (120/240) because it makes houses burn down. It is not dangerous at our low voltages. but I would beware of it in any application, on principle.

I think one of the issues with aluminum for house wiring is that it loosened up mechanically with heating and cooling. The power companies still use it for the drop to the house though.

That was THE issue, and yes, it is allowed for large feeder wires. The connections have to be torqued properly and an anti-oxidant chemical applied to the connections.

So I got the 16/2 zip wire and it seems quite a bit beefier than I expected. Is thermostat or doorbell wire sufficient to run to accessories? That seems more the size of other accessory wires I’ve seen. Thoughts?

The beef is the thickness of the insulation, which is required by NEC to provide a robust product for consumers. (600 Volt breakdown, for instance.)

Yes, you can use other wire, with thinner insulation.

Door bell wire is usually solid conductor. I’d use stranded. The 16 ga is good for running the accessory power to the general area of the accessories and then go with the lighter ga to each accessory…if you don’t need a different voltage for each accessory.

Thanks everyone! The 16/2 will come in useful for some speakers I have to connect for another project