Eaton NZMH2-A40-BT-NA 3-Pole 40A Thermomagnetic Circuit Breaker 107800

Protecting three-phase circuits from overload and short-circuit damage demands a breaker that combines reliable thermal-magnetic tripping with high breaking capacity. The Eaton NZMH2-A40-BT-NA answers this need with a 40 A rated current and 50 kA breaking capacity at 400/415 V AC, making it suitable for industrial distribution boards where fault currents can be substantial.

Who is it for

This circuit breaker is intended for panel builders, maintenance engineers, and industrial electricians who need a fixed-mount, screw-terminal protection device for motor feeders, distribution circuits, or as a main switch in sub-distribution boards. Its 3-pole configuration suits three-phase systems up to 690 V AC.

Main features

• Thermomagnetic release (BT) provides both overload protection (adjustable 32–40 A) and short-circuit protection (fixed 240–400 A, 6–10 × In).
• High breaking capacity: 50 kA at 400/415 V AC, 65 kA at 230/240 V AC, ensuring safety under severe fault conditions.
• Rated operational voltage up to 690 V AC, insulation voltage 690 V, impulse withstand 6 kV.
• Frame size NZM2, compact design for DIN rail or screw mounting.
• Complies with IEC/EN 60947-2, suitable for global industrial applications.

Specifications

• Number of poles: 3
• Rated current: 40 A
• Overload release setting range: 32–40 A
• Short-circuit release setting: 240–400 A (6–10 × In)
• Rated operational voltage: up to 690 V AC
• Rated insulation voltage: 690 V
• Rated impulse withstand voltage: 6 kV
• Breaking capacity at 400/415 V AC: 50 kA
• Breaking capacity at 230/240 V AC: 65 kA
• Standard: IEC/EN 60947-2
• Mounting type: fixed, screw mounting
• Connection type: screw terminals
• Switching capacity class: H (high)

Tips

When selecting a circuit breaker, verify that the short-circuit current at the installation point does not exceed the breaker's Icu. For motor circuits, consider the inrush current and adjust the instantaneous release if necessary. Always follow local wiring regulations and ensure proper torque on screw terminals.