That's a narrow window — good for resistive loads and long cable runs where the inrush is modest, but not for motor feeders or transformer primaries that need a C or D curve to ride through the start surge. At 25 A it's sized for a 5.5 kW resistive load on a 400 V three-phase system or a 7.5 kW load on 230/400 V. The DIN-rail footprint matches the standard 18 mm per pole width, so three poles take 54 mm of rail — plan your enclosure fill factor accordingly.
S203-B25 Miniature Circuit Breaker, 3P, 25A, Curve B
MPNS203-B25
ABB, System pro M compact, Miniature Circuit Breaker, S203-B25, 3-pole, 25 A, Trip Curve B, 277 VAC, 10 kA interrupting rating, DIN rail mount.
$22.23Ref. 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) | 25 |
| 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-B25?
Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time.
Will S203-B25 drop into a panel that was specified around S203-C10 without rewiring?
Yes — both share the same 3-pole DIN-rail footprint, 277 VAC rating, and 10 kA interrupting rating. The only difference is the trip curve: B (3–5x In) vs C (5–10x In). If the original design called for a C curve to handle moderate inrush, swapping to a B curve may cause nuisance tripping on startup.
What compliance documentation does ABB provide for S203-B25?
The S203-B25 carries the standard ABB declaration of performance and CE marking for the Low Voltage Directive. RoHS and REACH compliance are covered by the manufacturer's declaration. UL/CSA listing is not confirmed in the available records.
MPN
S203-B25