1. Current draw:
- Estimate the maximum current your layout will draw: This includes locomotives, lights, sound decoders, and any other accessories. Consider peak loads when multiple locomotives are running simultaneously.
- Consult your DCC system’s manual: It should indicate the maximum current it can handle. Choose a wire size capable of carrying at least that amount.
2. Wire length:
- Longer wires have higher resistance: This means more voltage drop, leading to inconsistent performance. Choose a larger wire size for longer runs to minimize voltage drop.
3. Layout size and complexity:
- Larger layouts: May require thicker wires to maintain consistent voltage across the entire track.
- Complex layouts with many branches: Might benefit from multiple bus wires or thicker gauges for specific sections.
Here are some general guidelines:
Oddly the current runs on the outside of the wire, so a multi-stranded wire will allow more current than a solid piece of copper. I always recommend stranded copper wire.
- Rule of thumb for OO scale: 32/0.2 stranded copper wire
- Smaller layouts: 24/0.2 stranded copper wire
- Larger layouts or high current situations: 32/0.2 stranded copper wire
- Feeder wires: 16/0.2 stranded copper wire.
Additional tips:
- Always use good quality copper wire: Avoid aluminum.
- Consider future expansion: Choose a wire size that can accommodate your layout’s potential growth.
- Consult online resources and forums: Many model railroading communities offer specific advice based on your layout details.
Remember: It’s better to err on the side of caution and choose a thicker wire than you think you need. This will ensure adequate power delivery and prevent voltage drop issues.