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ABB S203-K20 — 3-Pole MCB (DIN Rail)

S203-K20 Miniature Circuit Breaker, 3P, 20A, Curve K

MPNS203-K20

ABB S203-K20, 3-pole miniature circuit breaker, 20 A, Trip Curve K, 277 VAC, 10 kA interrupting rating, DIN rail mount.

$20.32Ref. price · indicative, final on quote
ABB S203-K20 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

S203-K20 — Identification
ParameterValue
Number of poles3
S203-K20 — Electrical
ParameterValue
Voltage (AC)277
Current (A)20
S203-K20 — Protection
ParameterValue
Interrupting rating (AC)10 kA
S203-K20 — Mechanical
ParameterValue
Mounting typeDIN Rail
S203-K20 — Other specifications
ParameterValue
TypeTrip Curve K

Product details

20 A, Curve K, 3-pole MCB for motor and transformer branch circuits

The K curve provides a higher magnetic trip threshold (typically 8–12× In) than a C curve (5–10× In), making it suitable for loads with moderate inrush — motor starters, transformer primaries, and solenoid banks — where nuisance tripping on a C curve would be a problem. The 20 A continuous rating and 10 kA interrupting capacity at 277 VAC cover most light-industrial and commercial branch circuits.

The 3-pole footprint matches the common 3-module width (52.5 mm) of ABB's S200 series. Busbar comb and accessory terminals (auxiliary contacts, shunt trip, undervoltage release) are shared across the S200 family, so a panel already built around S203-C10 or S203M-C50 accepts the S203-K20 without rewiring the busbar or reordering accessories.

The S203-K20 carries a current lifecycle stage. No official successor has been announced; the S200 series remains the active platform.

Frequently asked questions

Where can I buy S203-K20 and how is it quoted?

Sourced through independent distribution. Submit an RFQ for current availability and pricing — confirmed at quote time, no stock or price figures on this page.

What is the closest functional second-source to S203-K20?

The S203-C10 shares the same 3-pole DIN-rail footprint and 10 kA interrupting rating but uses a C curve (5–10× In) instead of K (8–12× In). If the branch circuit feeds a motor or transformer, the K curve is the better fit; for general-purpose resistive or lighting loads, the C curve works. Both use the same accessories and busbar.

Will S203-K20 drop into a panel specified around S203-C10 without rewiring?

Yes — same 3-pole width, same DIN-rail mount, same busbar comb pattern. No rewiring needed; just swap the MCB.

MPN
S203-K20