The S203-B50 is a 3-pole miniature circuit breaker rated 50 A with Trip Curve B, meaning it trips at 3 to 5 times rated current — built for resistive and light inductive loads like heaters, lighting circuits, and small transformers where inrush is modest. Snaps onto standard DIN rail, so it integrates into any 35 mm rail enclosure without extra brackets. Three poles let you protect a three-phase circuit or three independent single-phase legs from one unit.
S203-B50 Miniature Circuit Breaker, 3-Pole, 50A Curve B, 277
MPNS203-B50
ABB S203-B50, 3-pole miniature circuit breaker, 50 A, Trip Curve B, 277 VAC, 10 kA interrupting capacity, DIN rail mount.
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026
Specifications
| Parameter | Value |
|---|---|
| Number of poles | 3 |
| Parameter | Value |
|---|---|
| Voltage (AC) | 277 |
| Current (A) | 50 |
| Parameter | Value |
|---|---|
| Interrupting rating (AC) | 10 kA |
| Parameter | Value |
|---|---|
| Mounting type | DIN Rail |
| Parameter | Value |
|---|---|
| Type | Trip Curve B |
Product details
Frequently asked questions
Where can I buy S203-B50 and how do I get a price?
The S203-B50 is sourced to order against an RFQ through independent distribution. Submit an RFQ for current availability and pricing — confirmed at quote time.
What is S203-B50's listed amps?
50 A continuous rating, with Trip Curve B meaning magnetic trip between 150 A and 250 A (3–5× In).
What compliance documentation does this brand provide for S203-B50?
Standard ABB miniature circuit breakers carry IEC/EN 60898-1 certification. Specific documentation (RoHS, REACH, UL) should be confirmed at quote time against the specific production batch.
MPN
S203-B50