WSB1-63 3P MCB 10kA 6–80A | CE Certified | AC230/400V

A 3P MCB switches and protects the three phase conductors (L1, L2, L3) together but does not break the neutral. It is used for balanced three-phase loads where the neutral is not switched, such as three-phase motors, heaters and three-phase distribution feeders. A 4P device additionally switches and protects the neutral, required when neutral isolation is needed for safety or code reasons.

A 10kA rating means the breaker can safely interrupt a prospective short-circuit current of up to 10,000 A at 230/400V AC. This is important in commercial or industrial panels that are fed close to a transformer, where available fault current can exceed the 6kA level typical of residential boards. Using a 10kA breaker where the fault level is higher prevents the device from failing to clear a fault or rupturing under fault.

The range includes 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A and 80A. The 80A rating extends the WSB1-63 platform to heavier branch circuits and small sub-mains, allowing a single family of breakers to cover lighting, sockets and larger three-phase loads without moving up to an MCCB. Always match In to the cable ampacity — an 80A breaker must sit behind conductors rated at least 80 A.

Overload protection comes from a bimetal strip that heats with sustained overcurrent and bends to trip the mechanism on an inverse-time curve. Short-circuit protection comes from an electromagnet that pulls the release instantly when current crosses the curve threshold. Both mechanisms act simultaneously across all three poles, so a fault on any phase disconnects the entire three-phase circuit.

For standard three-phase motors, pumps and compressors, choose a Curve C (5–10× In) for smaller motors, and Curve D (10–20× In) for larger motors, transformers or equipment with high starting inrush. Curve B (3–5× In) is generally too sensitive for motors and will nuisance-trip on start-up. Always check the motor's locked-rotor current so that starting current stays below the magnetic pickup level.

Yes. It is rated for AC 50/60 Hz at a rated operational voltage of up to 400V between phases (230V phase-to-neutral), which covers standard TN-S, TN-C-S and TT three-phase distribution systems. It is an AC-only device and must not be used on DC supplies; verify the voltage marking on the breaker before installation.

The CE marking indicates the product has been assessed and declared compliant with the applicable EU health, safety and environmental protection directives (typically the Low Voltage Directive and EMC Directive for MCBs). Combined with IEC 60898-1 type testing, CE allows the breaker to be sold and installed in EU/EEA member states; importers and contractors should retain the declaration of conformity and test certificates for their records.

Mount it by clipping the rear of the breaker onto a standard 35 mm DIN rail in the distribution enclosure. Connect the three incoming phases (L1, L2, L3) to the top terminals and the outgoing phases to the bottom terminals, using correctly sized copper conductors tightened to the specified torque. Because this is a 3P device, neutral is not switched through the breaker and should be terminated on a separate neutral bar.

If it trips the moment a motor or large load starts, the inrush current may be exceeding the magnetic pickup of a B or C curve; try a higher curve (C or D) sized correctly for the load. If it trips immediately even when the load is disconnected, treat it as a hard short circuit or earth fault and do not keep resetting. If it trips after minutes of running, it is likely an overload or overheating due to poor terminals, high ambient temperature or undersized cable.

Typical uses include protecting three-phase air-conditioning and heat-pump circuits, three-phase pumps and fans, machine-tool and workshop outlets, small industrial distribution boards, elevator and escalator circuits, and main protective devices in commercial buildings where a 10kA fault level is expected. The extended 80A rating also covers larger branch feeders that would otherwise require an MCCB.