Automatic Production Line MCCB Circuit Breaker Wcm6 (E) L CE/CCC 22ka-50ka 3p/4p

The WCM6(E)L is Westhomes' mid-range moulded case circuit breaker series, available in both thermal-magnetic (WCM6) and electronic-trip (WCM6E) versions, with leakage-protection variants (WCM6L). It covers rated currents from ~100A to 630A and breaking capacities from 22kA to 50kA. The "L" suffix indicates an integrated residual-current (earth-leakage) protection module, making the unit suitable for wet areas, construction sites, and personnel-safety-sensitive installations.

The WCM6(E)L is built on Westhomes' automated assembly and testing line, which ensures consistent torque, contact alignment, and trip-unit calibration across every unit. Automated production reduces human-assembly variation and supports full traceability, so that each breaker meets the same rated performance whether it is unit number 1 or unit number 10,000. This is a key reason the series is competitive for large-volume tenders and OEM projects.

The WCM6 uses a thermal-magnetic release: a bimetal strip bends under sustained overload current to trip after an inverse-time delay (I²t), while a solenoid coil trips instantaneously when a severe short-circuit current is detected. The thermal element protects against overloads, and the magnetic element protects against short circuits. It is simple, reliable, and requires no external power supply.

The WCM6E uses current transformers or shunts to sense each phase current, feeding an electronic trip unit (ETU) that compares the measured values against user-adjustable thresholds. The ETU provides precisely adjustable long-time (overload), short-time, and instantaneous protection, with better accuracy and coordination than a thermal-magnetic unit. It requires a small auxiliary supply or is self-powered from the circuit being protected.

A 3P breaker switches only the three phase conductors (L1/L2/L3) and is used in three-phase three-wire systems or where the neutral is not switched. A 4P breaker additionally switches the neutral conductor, used in three-phase four-wire systems, main incomers, and applications requiring neutral isolation. The WCM6(E)L is offered in both 3P and 4P so it can be matched to the earthing arrangement (TN, TT, IT) of the installation.

The electronic trip unit typically offers: Ir (long-time pickup, adjustable 0.4–1.0 × In) for overload protection with an inverse-time curve; Isd (short-time pickup, adjustable 1.5–10 × Ir) with a selectable short-time delay (tsd) for selectivity; and Ii (instantaneous pickup, adjustable or fixed) for severe short circuits. On WCM6L versions, an additional residual-current setting IΔn and delay Δt are provided for earth-leakage protection.

Ir sets the long-time (overload) pickup current as a fraction of the breaker's rated current In. For example, a 250A breaker set to Ir = 0.8 will begin its inverse-time overload trip at 200A. This lets you coordinate the breaker with the actual cable ampacity and load profile rather than tripping at the full 250A, reducing nuisance trips while still protecting the conductors from thermal damage.

Isd (short-time pickup) introduces a deliberate short delay before tripping for moderate short circuits, so that a downstream breaker can clear a fault on its own branch — a principle called selectivity (discrimination). Ii (instantaneous pickup) trips without any delay for very severe faults, protecting the breaker and switchgear from the highest currents. Setting Ii at least 1.5× Isd ensures the two stages do not overlap.

Yes. The WCM6(E)L series is both CE-marked and CCC-certified, and is type-tested to IEC 60947-2 (and IEC 60947-2 Annex B / GB 14048.2 for CCC). This means it can be deployed in European, Chinese, and most international projects that reference IEC standards. The WCM6L leakage variant additionally complies with the residual-current requirements of IEC 60947-2 annex for RCCB-type protection.

Choose the WCM6 thermal-magnetic version for simple, cost-effective feeder or motor protection where fixed trip curves are acceptable and no external auxiliary supply is available. Choose the WCM6E electronic version when you need adjustable Ir/Isd/Ii for coordination, better accuracy, or remote signaling. Choose WCM6L when personnel protection against earth leakage (e.g., in construction, agriculture, or wet locations) is required.