Snaps onto standard DIN rail — the 3-pole footprint occupies three module widths (roughly 54 mm). Rated 277 VAC phase-to-neutral, so it suits single-phase branch circuits in North American 277/480 V lighting panels or three-phase 480 V delta systems where each pole protects a line-to-neutral load. The 4 A rating is a tight fit for a 0.75 kW motor at 400 V three-phase (about 1.8 A FLA) or a 1 kVA control transformer; verify the full-load amps on your load before committing the BOM line.
S203-D4 Miniature Circuit Breaker, 3P, 4A, Curve D, 10 kA
MPNS203-D4
ABB S203-D4, Miniature Circuit Breaker, 3 Pole, 4 Amp, Trip Curve D, 277 VAC, 10 kA Interrupting Rating, DIN Rail Mount.
$17.49Ref. price · indicative, final on quote
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) | 4 |
| Parameter | Value |
|---|---|
| Interrupting rating (AC) | 10 kA |
| Parameter | Value |
|---|---|
| Mounting type | DIN Rail |
| Parameter | Value |
|---|---|
| Type | Trip Curve D |
Product details
Frequently asked questions
Will S203-D4 drop into a panel specified for S203M-C50?
Yes, both share the same DIN-rail footprint and 277 VAC voltage rating, so physical fit is identical. But the S203-D4 is 4 A Curve D versus the S203M-C50's 50 A Curve C — never substitute without recalculating the branch circuit protection.
MPN
S203-D4