Schneider Electric NW40 H1 MasterPact Air Circuit Breaker Unit

Module Feature

NW40 H1 is Schneider MasterPact series high-current air circuit breaker frame. The H1 code represents 65kA breaking capacity grade, rated current 4000A.

It adopts modular structure, supports fixed and withdrawable mounting form, can be equipped with different Micrologic protection control units to realize overload, short circuit, earth fault and power quality monitoring functions. It has mechanical interlock and electrical interlock function, suitable for heavy load continuous power supply occasions. Widely used for main incoming cabinet and bus tie cabinet in large distribution system.

Working principle

When the circuit has normal load current, the breaker conducts and supplies power steadily.

Once overload, short circuit or earth fault occurs, the trip unit detects abnormal current signal and sends trip command to release mechanism, the main contact separates rapidly to cut off fault circuit. Mechanical interlock prevents misoperation during maintenance. Communication option can upload electric parameters and alarm information to upper energy management system.

Onboard components

Main contact and arc extinguishing chamber, operating spring mechanism, mechanical interlock assembly, current transformer group, control unit socket, secondary terminal block, front manual operation handle.

LED indicators

Front panel LEDs indicate power on, breaker closed, fault trip and ready status.

Hardware self‑diagnosis

Self-check covers trip unit power supply, CT abnormality, communication circuit fault and internal mechanism exception. Fault records and electrical data can be read through local display or EcoStruxure software.

Programming software

EcoStruxure Power software for protection curve setting, power data recording, alarm configuration and firmware upgrade of Micrologic trip unit.

Electrical & Process Parameters

Model:NW40 H1 Brand:Schneider Electric Device type:Air Circuit Breaker Frame In:4000A Icu:65kA @440V AC Pole:3P / 4P optional Installation:Fixed / withdrawable Function:High current main circuit protection and power distribution control

Mechanical & Structure

Mounting:Installed in low voltage distribution cabinet Protection class:IP30 for cabinet assembly Housing:Metal reinforced breaker frame

Environmental

Operating temperature:-5℃ ~ +60℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:IEC60947-2, CE compliant Status:Schneider Electric original MasterPact spare

Installation

Install the breaker in distribution cabinet according to specified clearance. Connect main busbar and secondary control wiring.

Select matching Micrologic trip unit and set protection parameters. Test closing, opening and emergency trip function before power transmission. Regularly check arc extinguishing chamber and mechanism lubrication.

Interface

Main busbar connecting terminals, secondary signal terminals, communication port, trip unit socket.

Diagnostic

Cannot close: Under-voltage coil abnormal, interlock locked or energy storage incomplete.

Trip without load: CT wiring fault, false protection parameter setting.

High temperature alarm: Busbar connection overheating, poor contact.

Product BriefSchneider Electric NW40 H1 MasterPact air circuit breaker frame, 4000A rated, 65kA breaking capacity, fixed or withdrawable type, used for large low-voltage main distribution protection.