NXB-63H Miniature Circuit Breaker

The NXB-63H is a miniature circuit breaker designed to protect low-voltage distribution circuits and electrical equipment against overload and short-circuit faults. It is suitable for AC 50Hz systems and is available with rated currents of 1A, 2A, 3A, 4A, 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A and 63A. The rated operational voltage is 230V AC for 1P and 1P+N versions, and 400V AC for 2P, 3P, 3P+N and 4P versions. The rated insulation voltage is 500V. The product is available with B, C and D instantaneous tripping characteristics, allowing selection according to the circuit type, load starting current and actual operating conditions. Pole configurations include 1P, 1P+N, 2P, 3P, 3P+N and 4P, making the product suitable for different single-phase and multiphase distribution systems. The rated short-circuit breaking capacity Icn is 10,000A, while the service short-circuit breaking capacity Ics is 7,500A. The rated impulse withstand voltage is 4kV. Mechanical endurance is 20,000 operating cycles, and electrical endurance is 10,000 operating cycles. When several devices are installed side by side or when the product is used at high altitude, the rated current should be adjusted according to the number of adjacent devices and the installation altitude. The recommended correction factors are for reference only; final selection should also consider ambient temperature, installation conditions, load characteristics and actual operating conditions.