When you protect a 1.5kW single-phase motor with a standard B or C curve breaker, the starting current (typically 6–8 times full load) often trips the magnetic release. The ABB S201-K16 solves this by raising the magnetic trip threshold to 128A (8 × 16A). The motor starts without nuisance tripping, yet the breaker still provides reliable overload and short-circuit protection.

What 16A K Curve Covers
This rating suits motors up to about 2.2kW (depending on efficiency and starting method), small refrigeration compressors, water pumps, fans, exhausters, and solenoid-operated equipment. It also works for control transformers with high inrush (e.g., for PLC power supplies) and certain lighting circuits where electronic ballasts produce high inrush currents.

Electrical and Mechanical Specifications
The S201-K16 is a 1-pole, 17.5mm wide MCB rated for 230/400V AC and 72V DC. Breaking capacity is 6kA (Icn per EN 60898-1). Thermal overload follows the K-curve time-current characteristic; magnetic trip operates between 128A and 160A (8–10×In, typical 8×In). Terminals accept solid conductors up to 25mm², stranded up to 16mm², torque 2.8 Nm. Operating temperature –25°C to +55°C. Mechanical and electrical endurance: 20,000 cycles each.

K vs. C vs. D
C curve (5–10×In) would trip at 80–160A, which may still be too low for some motor starts. D curve (10–20×In, 160–320A) is often unnecessarily high, reducing short-circuit protection sensitivity. K curve sits in the middle with a defined 8×In threshold, specifically designed for motor protection per DIN VDE 0660. If the motor data sheet specifies a "K characteristic" breaker, this is the one.

Installation and Coordination
Mounts on 35mm DIN rail per EN 60715. For motor circuits, the breaker should be selected with a full-load current (FLC) at or slightly above the motor nameplate rating. The upstream protection (fuse or main breaker) must have sufficient breaking capacity. The S201-K16 can be used as a manual motor starter for small motors, but for frequent starting, add a contactor.

Compliance and Origin
Manufactured in Germany. Meets IEC/EN 60898-1 and IEC/EN 60947-2. RoHS compliant, SVHC-free. EAN is 4016779496124.