EATON NZMH3-A400 3-Pole 400A Electronic Circuit Breaker, 50kA Breaking Capacity, Adjustable Protection

With a rated ultimate short-circuit breaking capacity of 50 kA at 400/415 V AC, the EATON NZMH3-A400 circuit breaker delivers uncompromising protection for demanding industrial power distribution. This 3-pole device handles 400 A nominal current with an electronic release that offers precise, adjustable overload and short-circuit protection.

Overview

Part of the NZM3 series, the NZMH3-A400 is engineered for fixed installation in low-voltage switchgear. It complies with IEC/EN 60947-2 and features a high switching capacity class (H). The breaker's electronic release (A-Release) allows fine-tuning of protection parameters to match specific load profiles, ensuring both safety and continuity of service.

What stands out

• Adjustable overload protection from 160 A to 400 A (0.4–1 × In)
• Short-time delayed short-circuit release adjustable from 240 A to 4000 A (1.5–10 × Ir)
• Instantaneous short-circuit release adjustable from 800 A to 4800 A (2–12 × In)
• High breaking capacity: 50 kA at 400/415 V AC, 25 kA at 690 V AC
• Rated insulation voltage up to 1000 V and impulse withstand voltage 8 kV

Technical details

• Number of poles: 3
• Rated current (In): 400 A
• Rated operational voltage (Ue): 690 V AC
• Rated ultimate short-circuit breaking capacity (Icu) at 400/415 V AC: 50 kA
• Rated ultimate short-circuit breaking capacity (Icu) at 690 V AC: 25 kA
• Rated service short-circuit breaking capacity (Ics): 100% of Icu
• Release type: Electronic (A-Release)
• Mounting type: Fixed installation
• Connection type: Screw terminals

Our verdict

The EATON NZMH3-A400 is a robust and flexible circuit breaker for industrial applications, offering high breaking capacity and precise adjustable protection to ensure reliable power distribution.