ABB S201-Z20 — 1-pole MCB, Trip Curve Z, 20 A
The ABB S201-Z20 is a 1-pole miniature circuit breaker rated at 20 A with a Trip Curve Z characteristic, designed for DIN-rail mounting in distribution boards and control panels. The 6 kA interrupting capacity at 277 VAC covers standard branch-circuit fault levels in commercial and light industrial installations.
What the ratings mean for fit
Trip Curve Z is the key decision point here: it trips between 2.5× and 4× rated current, faster than Curve B or C. This makes the S201-Z20 suited for protecting semiconductor circuits, control transformers, and other loads where the inrush is minimal but short-circuit protection must clear quickly. The 20 A rating and 6 kA SCCR at 277 VAC mean it can handle a 20 A continuous load and safely interrupt a fault up to 6,000 A without upstream coordination issues in a typical 277/480 V panel.
Panel integration and deployment
Mounts on standard 35 mm DIN rail per EN 60715, occupying one module width (17.5 mm). The 1-pole form factor fits single-phase branch circuits or individual phase legs in multi-pole assemblies. Rated for 277 VAC line-to-neutral applications, common in North American commercial lighting and receptacle circuits.