Key Specifications (Parameters) Standard: IEC 62271-100 Rated Voltage (Ur): 12 kV Rated Insulation Level: Power Frequency Withstand Voltage (1 min): 28 kV (rms) Lightning Impulse Withstand Voltage (Up): 75 kV (peak) Rated Current (Ir): 1250 A (The "12" in the current position denotes 1250A) Rated Frequency (fr): 50/60 Hz Rated Short-Circuit Breaking Current (Isc): 31.5 kA (The "31" in the model denotes 31.5kA breaking capacity) Rated Short-Circuit Making Capacity: 80 kA (peak) (standard for 31.5kA class) Rated Short-Time Withstand Current (Icw): 31.5 kA / 3 s Rated Operating Sequence: O - 0.3s - CO - 15s - CO (Standard auto-reclosing sequence) Rated Cable Charging Breaking Current (Ic): 31.5 A (per IEC for 31.5kA class) Mechanical Endurance: Class M2 (up to 10,000 operations) Electrical Endurance: Class E2 (for extended electrical endurance) Capacitor Bank Switching: Class C1 Mounting Type: Truck-mounted (drawout) - Designated by "-E" suffix Pole Center Distance: 210 mm Control Voltage (Designation "210"): Typically 220V DC / 240V AC (50/60 Hz) for spring charging motor and shunt trips Operating Mechanism: Stored energy spring mechanism (motor charged standard) Number of Poles: 3 Interrupter: Vacuum interrupters rated for 31.5kA breaking capacity Approximate Dimensions (W x H): 650 mm x 622 mm