Key Specifications Brand: Schneider Electric Product Series: Masterpact MT Product Type: Low-voltage power circuit breaker (Air circuit breaker - ACB) Model Reference: MT08 H1B Number of Poles: 3P (3 Poles) Mounting Mode: Fixed (F) Protection Unit: Micrologic 2.0 (Basic electronic trip unit) Frame Size: 800A frame (MT08) Rated Current (In): 400 A (Adjustable setting on 800A frame) Electrical Parameters Rated Operational Voltage (Ue): 690 V AC (50/60 Hz) Rated Insulation Voltage (Ui): 750 V DC / 800 V AC Rated Impulse Withstand Voltage (Uimp): 8 kV Breaking Capacity (Icu) at 440 V: H1B (High Performance): 85 kA RMS at 440V (typical for H1B rating) At 415V: 85-100 kA (typical) At 380V: 100-125 kA (typical) At 220V: 125-150 kA (typical) Breaking Capacity (Icu) at 690V: 40-50 kA (typical for H1B) Utilization Category: Category B (Selective protection) Service Breaking Capacity (Ics) at 440V: 75% of Icu (typically 64 kA) Short-time Withstand Current (Icw) at 440V: 85 kA for 1 second (typical for Category B with H1B rating) Making Capacity (Icm) at 440V: 187 kA peak (typical) Operational Voltage Range: 200-690 V AC Frequency: 50/60 Hz Power Loss: Approximately 80-100W at 400A load (estimated)