The **WMS2-63-R/K** is a specific model of a **Miniature Circuit Breaker (MCB)** typically used in modular electrical distribution systems. It is designed to protect electrical circuits from damage caused by excess current resulting from an overload or short circuit. --- ### 1. Technical Specifications The model name follows a standardized nomenclature used by many industrial manufacturers (like those following the IEC 60898-1 standard). | Feature | Specification | | :--- | :--- | | **Model Series** | WMS2 (Modular Circuit Breaker Series) | | **Rated Current ($I_n$)** | 63 Amperes | | **Number of Poles** | Usually 1P, 2P, 3P, or 4P (depending on the specific configuration) | | **Tripping Curve** | **K** (High Inrush/Sensitive Protection) | | **Mounting Type** | DIN Rail (35mm) | | **Application** | Protection of cables and motors | --- ### 2. Key Components and Electronic/Mechanical Parts While an MCB is primarily an electromechanical device, its internal "electronic" functionality is derived from these critical parts: #### A. Thermal Tripping Unit (Overload Protection) * **Bimetallic Strip:** Consists of two different metals bonded together. As current flows, it heats up. If the current exceeds 63A for a sustained period, the metals expand at different rates, causing the strip to bend and trigger the mechanical latch to open the contacts. #### B. Magnetic Tripping Unit (Short Circuit Protection) * **Electromagnetic Coil (Solenoid):** In the event of a short circuit (very high current), the magnetic field generated by this coil instantly pulls a plunger. This provides "instantaneous" tripping to prevent wire melting or fires. #### C. The "K" Curve Characteristics * The **K-type** tripping curve is specialized. It is designed to trip at **8 to 12 times** the rated current ($I_n$). * It is more sensitive than a D-curve but handles higher inrush currents than a B or C curve. It is ideal for **motors and transformers** where high startup surges are expected but sensitive protection is required. #### D. Arc Extinguishing System * **Arc Chute:** A series of parallel metal plates. When the contacts open under load, an electrical arc is formed. The arc chute pulls the arc away from the contacts, splits it into smaller segments, and cools it down to safely extinguish the energy. --- ### 3. Usage Context The **R/K** designation often indicates a specific variant: * **R:** Often refers to a "Red" indicator or a specific frame size/reset mechanism. * **K:** Specifically denotes the tripping characteristic, making it suitable for industrial inductive loads.