Schneider NW20 ACB Frame Unit

Module Feature

NW20 is the 2000A frame size of Schneider MasterPact NW air circuit breaker series.

It supports fixed or withdrawable drawer type installation, available in 3-pole or 4-pole configuration. It needs to be equipped with Micrologic electronic trip unit to realize configurable protection functions. It adopts stored-energy spring operating mechanism, supports motor charging and electric closing/tripping. It has built-in arc extinguishing chamber and high short-circuit breaking capacity, suitable for main incoming, bus tie and large motor feeder loop. It is widely stocked as maintenance spare for industrial plant, power station and data center low voltage distribution cabinet.

Working principle

Current transformers collect three-phase and neutral current signals and send them to Micrologic trip unit.

Electronic protection unit executes long-time overload, short-time delay short-circuit, instantaneous and earth fault logic judgment. Once fault condition is satisfied, the trip coil releases the stored spring energy to separate main contacts and cut off fault current rapidly. It records trip events, operation count and fault waveform, and uploads data via communication module to SCADA system.

Onboard components

Main contact set, arc extinguishing chamber, spring energy storage mechanism, closing/trip coil, CT group, auxiliary contact block, drawer base (drawout version), front operation handle, status indicator window and metal insulated frame.

LED indicators

Front indicators show breaker ON, breaker OFF, spring charged, fault trip and FTA communication status.

Hardware self‑diagnosis

Dependent on matched Micrologic trip unit. It monitors trip circuit continuity, internal power supply, CT signal loss and hardware anomaly. Fault information can be read by EcoStruxure Power Commission software.

Programming software

EcoStruxure Power Commission, used for protection curve setting, communication parameter configuration, event log query and firmware upgrade.

Electrical & Process Parameters

Model:NW20 Brand:Schneider Electric Device type:MasterPact NW 2000A air circuit breaker frame Function:Overload, short circuit and earth fault protection for low voltage main power distribution system

Mechanical & Structure

Mounting:Switchgear cabinet fixed or withdrawable drawer mounting Protection class:IP30 front panel, IP20 terminal compartment Housing:Heavy-duty reinforced insulated ACB frame

Environmental

Operating temperature:-10℃ ~ +55℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE, IEC 60947 Status:Original Schneider distribution spare

Installation

Isolate upstream high voltage before replacement.

Check primary copper bar and secondary control wiring, confirm pole number and trip unit type, test spring charge, closing/tripping action and protection function after commissioning.

Interface

Primary copper bar terminal, secondary screw terminal block for auxiliary contact, trip coil and communication FTA.

Diagnostic

Cannot charge spring: Charging motor fault, mechanical jam or limit switch damage. Trip circuit supervision alarm: Trip coil open, fuse blown or loose wiring. Protection refusal to trip: Trip unit damaged, CT wiring reversed or contact burnout.

Product Brief

Schneider NW20 air circuit breaker frame, MasterPact NW 2000A spare for low voltage main incoming distribution cabinet replacement.