HO DCC Bus-Wire & Voltage-Drop Guide
FREE
HO scale DCC wiring reference: the longest bus run that stays within 3% voltage drop for each wire gauge and load, plus loco current and feeders. Free PDF.
- Secure checkout Handled by PayPal
- Instant download Issued when payment clears
- Re-download anytime Within your active window
Details
A long DCC track bus loses voltage to the resistance of the wire, and the far end of the layout ends up running weaker than the near end — sluggish locos, flaky sound, unreliable decoders. The fix is sizing the wire so the round-trip drop stays under about 3% of bus voltage. This free one-page reference tells you when you're within that budget.
The main table gives the longest bus run that stays under 3% for each common wire gauge (10 through 22 AWG) at 2, 3, and 5 amps, so you can pick a gauge and know your reach at a glance. It includes a typical HO loco current table to size your load, the drop formula itself, and the feeder strategy for when a run is simply too long — a heavy bus with short feeders soldered to the rail every few feet.
The figures assume solid copper at room temperature on a 14.5-volt bus; stranded wire, connectors, and warm rooms add a little, so treat the lengths as a ceiling — shorter is always safer.
Sizing boosters, breakers, and bus for a whole layout? The RailForge Power District & Wiring Planner does the full job.
Make it real. Make it RailForge.
Specifications
- Scale: HO (1:87.1)
- Standard: DCC, ~14.5 V bus
- Covers: 10-22 AWG, 3% voltage-drop limit
- Includes: Max run by gauge/load, loco current, booster sizing, feeders
- Format: Printable PDF (US Letter)
- Price: Free download
Customer reviews
No reviews yet
Own this one? Be the first to review it.
Reviews will appear here once approved.