EATON NZMH3-A320 3-Pole 320A Electronic Circuit Breaker

With a rated short-circuit breaking capacity of 50 kA at 400/415V AC, the EATON NZMH3-A320 delivers uncompromising protection for demanding industrial power distribution. This 3-pole circuit breaker, rated at 320 A, combines robust construction with precise electronic trip technology to safeguard your electrical infrastructure.

Overview

Engineered for reliability, the NZMH3-A320 is a fixed-mount circuit breaker featuring screw terminals and compliance with IEC/EN 60947-2. Its electronic release offers adjustable overload and short-circuit protection, ensuring adaptability to varied load profiles. The unit is designed for operation up to 690 V AC, with an insulation voltage of 1000 V and impulse withstand of 8 kV, making it suitable for harsh electrical environments.

What stands out

• High breaking capacity: 50 kA at 400/415V AC, 30 kA at 690V AC.
• Adjustable overload protection (Ir) from 128 A to 320 A (0.4–1×In).
• Short-circuit delay (Isd) adjustable from 2 to 10×Ir.
• Instantaneous short-circuit protection (Ii) adjustable from 2 to 10×In.
• Full service breaking capacity (Ics = 100% Icu) for repeated fault interruptions.
• Robust design with rated impulse withstand voltage of 8 kV.

Technical details

• Series: NZMH3
• Number of poles: 3
• Rated current (In): 320 A
• Release type: Electronic
• Rated operational voltage (Ue): 690 V AC
• Rated insulation voltage (Ui): 1000 V
• Rated impulse withstand voltage (Uimp): 8 kV
• Rated short-circuit breaking capacity (Icu) at 400/415V AC: 50 kA
• Rated short-circuit breaking capacity (Icu) at 690V AC: 30 kA
• Rated short-circuit service breaking capacity (Ics): 100% Icu
• Overload protection adjustment range (Ir): 128 - 320 A (0.4 - 1 x In)
• Short-circuit delay protection adjustment range (Isd): 2 - 10 x Ir
• Short-circuit instantaneous protection adjustment range (Ii): 2 - 10 x In
• Mounting type: Fixed installation
• Connection type: Screw terminals
• Standard compliance: IEC/EN 60947-2
• Protection function: Overload, short-circuit

Our verdict

A high-performance industrial circuit breaker that offers precise electronic protection and exceptional breaking capacity, making it a dependable choice for critical power distribution systems.