INPUTS
Booster & district sizing
Simultaneous, not total roster
Running average; starts/stalls spike higher
Lit cars, powered frogs, etc. on the same bus
Command station / booster output rating
Circuit-breaker segmentation
Should trip below the booster rating so the booster stays up
Bus wire voltage drop
One-way length of the bus run
Worst-case load drawn through this bus
RESULTS
Boosters / power districts
—
—
Total current demand—
Usable per booster (with headroom)—
Locos one booster can run—
Circuit-breaker segmentation
—
—
Load per section (even split)—
Bus voltage drop
—
—
Voltage drop—
As % of bus voltage—
Max length within 3% at this load—
Sizing leaves ~20% booster headroom for inrush and simultaneous starts. Voltage drop is round-trip (Vdrop = 2 × length × ohms/ft × current) against a ~14.5 V HO bus; keep it under ~3% for crisp DCC. Splitting a long bus with extra feeder drops (each feeder halves the effective run) is the usual fix. Figures are planning estimates — confirm against your command station’s specs.