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ABB S201-B20 — 1-Pole MCB (DIN Rail)

S201-B20 Miniature Circuit Breaker, 20 A, B-Curve, 1-Pole, 2

MPNS201-B20

ABB S200 series miniature circuit breaker, S201-B20, 20 A, B-curve, 1-pole, 277 VAC, 6 kA interrupting capacity, DIN rail mount, UL 1077 supplemental protection.

ABB S201-B20 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

S201-B20 — Specifications
ParameterValue
Amps20
TypeTrip Curve B
Poles1
MountingDIN Rail
Volts AC277
Breaking capacity6 kA

Product details

What the 20 A B-curve rating means on your panel

On a 277 VAC line, that 20 A rating protects branch circuits feeding lighting banks, control transformers, or small motor starters — not high-inrush loads like large compressors, where a C- or D-curve would be the right call. The 6 kA interrupting capacity at 277 VAC is enough for most commercial panelboards; if your fault current exceeds that, you need an upstream current-limiting breaker or fuse.

The 1-pole width leaves room for additional poles or a shunt trip in the same panel space.

Frequently asked questions

What are the key ratings for S201-B20?

The S201-B20 is a 20 A, 1-pole, B-curve miniature circuit breaker rated 277 VAC with a 6 kA interrupting capacity. It mounts on DIN rail and carries UL 1077 supplemental protection listing.

How does S201-B20 compare to S201MUC-K2?

The S201MUC-K2 is a 2 A, K-curve breaker with both AC and DC ratings (6 kA AC, 10 kA DC). The S201-B20 is a 20 A B-curve breaker for AC branch circuits only. They share the same 1-pole DIN-rail footprint and UL 1077 listing, but the trip curve and current rating are completely different — the K-curve is for motor or inductive loads; the B-curve is for lighting and resistive loads. They are not drop-in replacements for each other.

Where can I buy S201-B20 and get current pricing?

We source the S201-B20 to order against an RFQ through independent distribution. Submit a request for current pricing and availability — we confirm both at quote time. No stock counts or firm prices are published here.

What compliance documentation does ABB provide for S201-B20?

The S201-B20 is UL 1077 listed and CSA 22.2 certified as a supplemental protector. Standard ABB documentation includes the UL/CSA listing mark on the device and a declaration of conformity for CE-marked markets. RoHS and REACH compliance statements are available from ABB upon request.

MPN
S201-B20