ABB S273-K20 Circuit Breaker – 3-Pole, 20 A, K-Curve

The ABB S273-K20 is a high-quality miniature circuit breaker designed for industrial and commercial applications requiring dependable overcurrent protection. With its K-curve trip characteristic, it’s ideal for protecting circuits with higher inrush currents, such as motors, transformers, and inductive loads, while still offering fast tripping under short-circuit conditions.

Key Specifications

• Model: S273-K20

• Manufacturer: ABB (Asea Brown Boveri) – SACE Series

• Poles: 3 (three-phase)

• Current Rating: 20 A

• Voltage Rating:

  • 277 V AC (single-phase)

  • 480 V AC (three-phase)

• Trip Curve: K-curve – suited for high inrush current loads

• Interrupting Capacity: 10 kA @ 480 V AC

• Mounting Type: DIN-rail (quick and secure installation)

• Protection Rating: IP20 – protection against accidental contact

• Weight: Approx. 1 lb

Features & Benefits

• Reliable Overcurrent Protection – Protects equipment and wiring from overloads and short circuits.

• K-Curve Performance – Handles 8–12 times the rated current during inrush without nuisance tripping, perfect for inductive loads.

• Compact DIN-Rail Mounting – Saves panel space and allows easy integration into existing systems.

• Safety-Focused Design – Finger-safe terminals and IP20 housing for safer installation and operation.

• Durable Construction – Built with ABB’s industrial-grade materials for long service life in demanding environments.

Typical Applications

• Motor control circuits

• Transformers and inductive load protection

• HVAC equipment

• Lighting control systems with high start-up surges

• Industrial machinery and automation panels

Why Choose ABB’s S273 Series

ABB’s S273 series breakers are engineered to deliver consistent, reliable performance, meeting strict IEC and UL standards. The combination of compact design, robust build quality, and application-specific trip curves ensures long-term protection for mission-critical electrical systems.