Specifications General Product Type: Motor Protection Circuit Breaker (MPCB) Series / Family: WATSN Model: WATSN125b/4A Number of Poles: 4 (three-phase + neutral) Rated Current (In): 125A Mounting Type: DIN-rail mountable Application: Protection of motors and electrical equipment in industrial and commercial systems Electrical Ratings Rated Operational Voltage (Ue): Typically 400V AC Rated Frequency: 50/60 Hz Rated Insulation Voltage (Ui): 690V AC Rated Impulse Withstand Voltage (Uimp): 8 kV Breaking Capacity (Icu): Typically 10 kA or higher (depending on configuration) Protection Characteristics Overload Protection: Thermal trip mechanism to protect against sustained overcurrent Short-Circuit Protection: Magnetic trip for instantaneous disconnection during high fault currents Under-Voltage Protection: To prevent damage due to insufficient voltage Tripping Characteristics: Thermal-magnetic for overload and short-circuit protection Mechanical & Environmental Housing: Compact, modular design suitable for industrial environments Degree of Protection: IP20 (front face) Terminal Connections: Screw or clamp terminals Operating Temperature Range: Standard range for electrical environments Mounting: Compatible with DIN-rail for easy installation Functional Features Four-pole protection for comprehensive coverage of three-phase and neutral Thermal-magnetic trip for motor and system protection Flexible mounting and easy installation into industrial panels and switchboards Reliable protection for both overload and short-circuit conditions in motor circuits