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ABB S201-B40 — 1-Pole MCB (DIN Rail)

ABB S201-B40 MCB, 1P B-Curve 40A 277VAC, 6kA

MPNS201-B40

ABB S201-B40, 1-pole miniature circuit breaker, Trip Curve B, 40 A, 277 VAC, 6 kA interrupting rating, DIN rail mount.

ABB S201-B40 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

S201-B40 — Specifications
ParameterValue
Amps40
TypeTrip Curve B
Poles1
MountingDIN Rail
Volts AC277
Breaking capacity6 kA

Product details

The ABB S201-B40 is a 1-pole miniature circuit breaker rated 40 A with a Trip Curve B characteristic, designed for 277 VAC circuits and a 6 kA interrupting capacity.

The 40 A rating and Trip Curve B mean this breaker trips between 3x and 5x rated current (120 A to 200 A magnetic trip threshold), which is the standard choice for resistive loads, lighting circuits, and general-purpose outlets where inrush is low. The 1-pole form factor occupies a single 18 mm module on the DIN rail, so it replaces an existing B-curve 40 A breaker in the same slot without re-busing.

Frequently asked questions

What is S201-B40's listed amps and trip curve?

The S201-B40 is rated 40 A with a Trip Curve B characteristic, meaning it trips magnetically between 3x and 5x rated current.

Where can I buy the S201-B40?

The S201-B40 is sourced and quoted to order against an RFQ through independent distribution, with availability and current pricing confirmed at quote time.

Will S201-B40 drop into a panel specified around S201MUC-K2 without rewiring?

No — the S201MUC-K2 is a Trip Curve K breaker (magnetic trip at 8x to 12x rated current) and is rated for DC circuits, while the S201-B40 is Curve B for AC circuits only. Both mount on DIN rail and share the same 1-pole 18 mm footprint, but the trip curve difference means they are not drop-in substitutes without verifying coordination and load type.

MPN
S201-B40