The ABB S204-D10 is a 4-pole miniature circuit breaker from the System pro M compact series, rated 10 A with a Trip Curve D characteristic. It mounts on a standard DIN rail and carries a 10 kA interrupting rating at 277 VAC — enough for most distribution panel fault levels.
What the ratings mean for fit
The D-curve (10–20× In magnetic trip) is the key spec here — it's designed for loads with high inrush current like small motors, transformers, or solenoid banks. A C-curve breaker would nuisance-trip on the same startup surge; the D-curve holds through it. The 10 A rating governs the continuous load: sized for circuits drawing up to 10 A steady, with the D-curve handling the momentary peak. Four poles means it switches all three phases plus neutral in a 3-phase 4-wire system (e.g., 480Y/277 V wye). The 10 kA interrupting rating at 277 VAC tells you it can safely clear a fault up to that level without welding contacts or cascading upstream — standard for branch-circuit protection in commercial and light industrial panels.
Where it goes in a panel
Snaps onto a 35 mm DIN rail inside a distribution board or sub-panel. The 4-pole width occupies four modular spaces (4 × 17.5 mm). Standard busbar comb connects the line side; load terminals accept up to 25 mm² conductor. No special tooling needed — it's a drop-in swap for any 4-pole MCB in the same footprint.