Product Overview

The Schneider Electric NW20H1 MasterPact Circuit Breaker is a low-voltage air circuit breaker designed for high-capacity power distribution and electrical protection systems. It belongs to the MasterPact NW series, a product family developed for demanding industrial, commercial, and infrastructure power-distribution applications.

With a 2000 A rated current frame and a three-pole drawout configuration, the NW20H1 is intended for use in main distribution boards, power control centers, and large electrical switchboards. It provides a means of switching and isolating electrical circuits while supporting protection arrangements designed to manage overloads and short-circuit faults.

The H1 performance level provides a rated ultimate short-circuit breaking capacity of 65 kA at 440 V AC. The circuit breaker is also specified for a rated operational voltage of up to 690 V AC, subject to the applicable electrical ratings and installation conditions.

This product reference identifies a circuit breaker frame supplied without a trip unit. This distinction is important when planning a complete protection system. The trip unit is responsible for detecting specified abnormal electrical conditions and initiating the opening operation. Therefore, the correct compatible protection unit and accessories must be selected separately where they are not included in the supplied configuration.

The drawout design allows the circuit breaker to be withdrawn from its associated chassis for inspection, testing, and maintenance procedures. This arrangement is particularly useful in installations where maintenance access and equipment replacement are important operational considerations.

The NW20H1 is suited to power distribution systems where high current capacity, coordinated protection, and maintainable switchgear construction are required. Before installation or replacement, engineers should verify the complete catalog number, pole configuration, trip-unit requirements, chassis compatibility, and electrical ratings.

Technical Specifications

Note: The NW20H1 designation covers a product family with different configurations. Confirm the complete catalog number and nameplate before purchasing. The specifications above describe the referenced three-pole drawout frame without a trip unit.

Function and Working Principle

The NW20H1 is designed to switch and isolate high-current electrical circuits while forming part of a coordinated power-protection system. Its operation involves mechanical switching components, electrical contacts, and a compatible protection arrangement.

1. Normal Current Carrying

During normal operation, the circuit breaker remains closed and allows current to flow through its main contacts. The contact system is designed for the specified current rating and operating conditions.

For a 2000 A frame, correct conductor sizing, connection design, ventilation, and temperature management are important. The actual permitted current and operating performance must be evaluated against the complete switchgear assembly and its rated conditions.

2. Overload and Short-Circuit Protection

A circuit breaker protection system must detect abnormal current conditions and interrupt the circuit when the configured protection criteria are met.

The NW20H1 frame referenced here is supplied without a trip unit. A compatible protection unit must be selected and installed as required by the intended application. The protection settings should be coordinated with the upstream and downstream devices, conductor ratings, transformer characteristics, and system fault levels.

3. Arc Interruption

When the breaker opens under load or fault conditions, an electrical arc may form between the separating contacts. The air circuit breaker’s arc-control and interruption system is designed to extinguish this arc and interrupt the current.

The H1 performance level identifies the breaker’s specified short-circuit interruption capability. The rated breaking capacity must always be considered at the applicable system voltage and under the manufacturer’s stated test conditions.

4. Drawout Operation

The drawout construction allows the breaker to be moved between its operating and disconnected positions within a compatible chassis.

This design supports maintenance and inspection procedures without requiring the entire switchgear assembly to be dismantled. The correct racking procedure, interlocking arrangements, and electrical isolation steps must be followed to prevent unsafe operation.

5. Isolation and Switching

The NW20H1 is suitable for isolation according to the applicable EN/IEC 60947-2 requirements. Isolation is an important function in industrial distribution systems, where electrical equipment must be separated from the supply before maintenance.

Isolation procedures must still follow the installation’s safety rules, including verification of the de-energized condition and the use of appropriate lockout and tagging practices.

Role in Industrial Power Distribution Systems

The NW20H1 can serve as a main or feeder circuit breaker in a low-voltage distribution architecture. Its role depends on the system design, protection coordination, and the position of the breaker within the switchboard.

Main Incoming Protection

In a suitable distribution system, a high-capacity air circuit breaker may be installed at the incoming supply point. It provides switching and protection functions for the main distribution assembly.

The NW20H1’s 2000 A frame rating makes it relevant to systems with substantial current demand, provided that the actual load, fault level, and protection configuration are appropriate.

Feeder Circuit Protection

The breaker may also be used in a feeder arrangement supplying downstream distribution boards, motor control centers, or large industrial loads.

Protection settings must be coordinated with downstream breakers and the characteristics of the connected equipment. This helps ensure that faults are cleared by the appropriate protective device wherever the system design permits.

Power Control Center Integration

Large industrial facilities often use centralized switchgear to distribute electrical power to production equipment, utilities, and auxiliary systems.

A MasterPact NW circuit breaker can form part of this arrangement, providing a switching and isolation point for a high-capacity circuit.

Electrical Maintenance and Equipment Isolation

The drawout construction supports maintenance planning by allowing the breaker to be withdrawn from its chassis under the required safe conditions.

Maintenance personnel can inspect the breaker and associated connections according to the manufacturer’s procedures without treating the complete switchboard as a single inseparable assembly.

Industrial Applications

The MasterPact NW20H1 is intended for high-capacity low-voltage power distribution applications. Its suitability depends on the available fault current, system voltage, rated current, and the protection design.

1. Industrial Manufacturing Facilities

Manufacturing plants often contain large electrical distribution systems supplying production lines, process equipment, motors, and auxiliary services.

A high-capacity circuit breaker can be used in the main distribution or feeder section to support controlled switching and electrical protection.

2. Power Distribution Switchboards

Main distribution switchboards require circuit breakers capable of carrying substantial current and interrupting specified fault levels.

The NW20H1’s 2000 A frame and H1 interruption performance make it relevant to appropriately engineered low-voltage distribution assemblies.

3. Commercial and Infrastructure Buildings

Large commercial buildings, transportation facilities, and infrastructure installations may use high-capacity low-voltage switchgear to distribute power to multiple sections of a facility.

A compatible MasterPact NW circuit breaker can provide a switching and protection point within the distribution architecture.

4. Data Centers and Critical Facilities

Data centers require carefully coordinated power distribution systems to supply server rooms, cooling equipment, UPS systems, and auxiliary infrastructure.

High-capacity circuit breakers may be used in main or feeder distribution sections. Selection must consider system redundancy, fault levels, selectivity, and the required continuity of service.

5. Utility and Industrial Substations

Low-voltage distribution sections within substations may use air circuit breakers to control and protect outgoing feeders and auxiliary power systems.

The NW20H1 can be considered where its voltage, current, breaking capacity, and mounting configuration match the electrical design.

Installation and System Integration

Installation of a 2000 A air circuit breaker requires detailed engineering and strict compliance with the manufacturer’s instructions. The work should be carried out by qualified electrical personnel.

1. Verify Electrical Ratings

Before installation, confirm the system voltage, rated operating current, prospective short-circuit current, and required breaking capacity.

The NW20H1 H1 configuration is specified for 65 kA at 440 V AC. The actual installation must remain within the applicable voltage and fault-interruption ratings.

Do not select a breaker based only on the 2000 A frame rating. The protection design must also account for load current, conductor capacity, system grounding, and fault-clearing requirements.

2. Confirm Trip Unit Compatibility

The referenced configuration is supplied without a trip unit. A suitable compatible trip unit must be identified according to the intended protection functions and the breaker configuration.

Protection requirements may include long-time, short-time, instantaneous, and ground-fault protection, depending on the selected unit and system design.

Do not assume that a trip unit from another MasterPact model is compatible. Confirm the manufacturer’s approved combinations and installation instructions.

3. Check Drawout Chassis Compatibility

The breaker must be installed in a compatible drawout chassis and switchboard arrangement.

Before installation, verify the frame size, pole arrangement, connection system, racking mechanism, interlocks, and auxiliary connections. A breaker that looks similar may not fit or operate correctly in a different chassis configuration.

4. Prepare the Switchgear Compartment

The supplied dimensions are 439 × 441 × 395 mm. Confirm the exact mechanical drawing and required installation clearances before preparing the switchgear compartment.

Consider the space needed for:

• Breaker insertion and withdrawal.
• Primary and secondary connections.
• Racking access.
• Cable bending and termination.
• Inspection and maintenance.
• Heat dissipation and ventilation.

The IP30 protection rating should also be considered when evaluating the overall switchgear enclosure and installation environment.

5. Connect Power and Auxiliary Circuits

Power connections must be designed for the rated current and installation conditions. Use appropriate conductors, busbars, connection hardware, and tightening procedures.

Auxiliary wiring may include indication, control, interlocking, and trip-related circuits, depending on the installed accessories. Follow the applicable wiring diagrams rather than relying on terminal appearance.

6. Commissioning and Functional Testing

Before energizing the equipment, inspect the mechanical installation, electrical connections, grounding, and auxiliary wiring.

Verify the correct operation of the racking mechanism, mechanical interlocks, opening and closing functions, indication circuits, and the installed protection unit. Protection testing should follow the approved commissioning procedure.

All testing and commissioning should be performed by qualified personnel using suitable equipment and established electrical safety procedures.

Compatible System Components

The NW20H1 operates as part of a complete switchgear assembly. The following components may be required depending on the application and supplied configuration.

The components listed above are not necessarily included with the NW20H1 frame. Confirm the actual bill of materials and accessory configuration before procurement.

Alternative Models and Replacement Considerations

The NW20H1 belongs to the MasterPact NW family. Replacement selection must account for frame rating, voltage, short-circuit performance, pole configuration, mounting arrangement, and trip-unit compatibility.

Before selecting a replacement, compare:

• Rated current and frame size.
• Rated operational voltage.
• Ultimate and service short-circuit breaking capacity.
• Short-time withstand current.
• Number of poles.
• Fixed or drawout mounting.
• Trip-unit type and protection functions.
• Control and auxiliary accessory configuration.
• Chassis and connection compatibility.
• Mechanical dimensions and installation clearances.

A replacement should never be approved solely because it carries the same 2000 A rating. The protection coordination and complete switchgear design must be reviewed.

Key Advantages

High Current Capacity

The 2000 A frame rating makes the NW20H1 relevant to large low-voltage distribution systems that require substantial current-carrying capability.

H1 Short-Circuit Performance

The H1 performance level provides a specified 65 kA short-circuit breaking capacity at 440 V AC, subject to the manufacturer’s rating conditions.

Drawout Construction

The drawout design supports inspection, maintenance, and replacement procedures within a compatible switchgear assembly.

Three-Pole Configuration

The three-pole arrangement is designed for three-phase power distribution applications where the specified configuration is appropriate.

Isolation Capability

The breaker is suitable for isolation according to the applicable EN/IEC 60947-2 requirements.

Integration with Industrial Switchgear

The MasterPact NW family is designed for integration into low-voltage distribution assemblies used in industrial and infrastructure environments.

Maintainability

The drawout arrangement and availability of compatible accessories support planned maintenance and equipment lifecycle management.

Technical FAQs

1. What is the Schneider Electric NW20H1?

The NW20H1 is a MasterPact NW low-voltage air circuit breaker designed for high-capacity power distribution protection. The referenced configuration is a 2000 A, three-pole drawout frame supplied without a trip unit.

2. What is the rated current of the NW20H1?

The rated current frame is 2000 A at the specified operating conditions. The actual protection settings and permitted current depend on the installed trip unit and complete system configuration.

3. What is the short-circuit breaking capacity?

The H1 performance level is rated at 65 kA at 440 V AC. The applicable breaking capacity must be checked against the system voltage and the manufacturer’s technical documentation.

4. Does the NW20H1 include a trip unit?

The referenced configuration is specified without a trip unit. A compatible protection unit must be selected separately if required for the installation.

5. Is the NW20H1 a fixed or drawout breaker?

The referenced product configuration is drawout. It is designed for use with a compatible chassis and racking arrangement.

6. What is the maximum rated operational voltage?

The published rated operational voltage is up to 690 V AC at 50/60 Hz. The short-circuit performance and other ratings vary according to the operating voltage.

7. What are the dimensions and weight?

The supplied dimensions are 439 × 441 × 395 mm, and the net weight is approximately 90 kg.

8. Can the NW20H1 be used as a main incoming breaker?

It may be used in a main incoming position when the system voltage, current, fault level, protection coordination, and switchgear design are appropriate. A qualified electrical engineer should verify the complete installation.

9. Is the NW20H1 still available as a current production model?

The referenced product documentation identifies a planned discontinuation at the end of 2025 and lists LV948287 as its replacement reference. Availability should be confirmed with Schneider Electric or an authorized supplier.

10. What should be checked before purchasing a replacement?

Confirm the complete catalog number, pole configuration, drawout arrangement, trip-unit requirements, breaking capacity, chassis compatibility, auxiliary accessories, and physical condition. Also verify whether the quoted item includes the trip unit and associated mounting components.

Procurement and Maintenance Recommendations

When purchasing the Schneider Electric NW20H1, begin by confirming the exact catalog number and configuration. The product name alone does not establish whether the breaker includes a trip unit, chassis, auxiliary contacts, or other accessories.

For replacement projects, compare the original equipment nameplate with the proposed replacement documentation. Pay particular attention to the three-pole drawout arrangement, 2000 A frame rating, H1 performance level, and 65 kA breaking capacity at 440 V AC.

For new-old-stock or used equipment, request clear photographs of the nameplate, front panel, terminals, racking mechanism, and accessory positions. Confirm whether the breaker has been inspected or tested and establish the condition of the main contacts and mechanical operating mechanism.

Because the unit weighs approximately 90 kg, transportation and handling require suitable lifting equipment and an appropriate handling plan. Protect the breaker against impact, moisture, and contamination during storage and shipment.

Maintenance should follow the manufacturer’s procedures and the facility’s electrical safety program. Inspection may include mechanical operation, contact condition, connection integrity, auxiliary circuits, interlocks, and protection-unit testing where applicable.

For critical power systems, protection settings and coordination should be reviewed whenever a breaker is replaced or modified. A physically compatible breaker is not necessarily electrically equivalent.

Conclusion

The Schneider Electric NW20H1 MasterPact Circuit Breaker is a 2000 A, three-pole drawout air circuit breaker designed for high-capacity low-voltage power distribution. Its H1 performance level provides a 65 kA rated short-circuit breaking capacity at 440 V AC, while the drawout construction supports maintenance and equipment replacement in compatible switchgear assemblies.

The referenced configuration is supplied without a trip unit, so the required protection unit and accessories must be verified separately. With dimensions of 439 × 441 × 395 mm and a weight of approximately 90 kg, the NW20H1 is intended for substantial industrial and infrastructure switchgear installations.

For maintenance and replacement projects, confirm the full catalog number, electrical ratings, trip-unit requirements, and chassis compatibility before procurement or installation.