Product Overview

The Schneider Electric NW25H1 MasterPact NW Circuit Breaker is a high-capacity air circuit breaker designed for low-voltage power distribution and electrical protection in industrial and commercial installations. As part of the MasterPact NW family, it is intended for applications where reliable switching, high short-circuit interruption capability, and coordinated electrical protection are essential.

The NW25H1 has a rated current of 2500 A at 40°C and belongs to the H1 performance class, with a rated short-circuit breaking capacity of 65 kA at 440 V AC. Its rated operational voltage is up to 690 V AC at 50/60 Hz. These characteristics make it suitable for use in appropriately engineered main distribution boards, large electrical switchboards, and industrial power systems.

This product is associated with the MasterPact NW25H1 three-pole drawout circuit-breaker configuration. The referenced configuration is supplied without a trip unit, meaning the required protection and control unit must be selected separately according to the electrical system design.

The drawout construction allows the breaker to be moved between defined operating and disconnected positions within a compatible switchboard installation. This arrangement can simplify inspection, maintenance, and replacement compared with permanently fixed equipment, provided that the correct cradle and interlocking accessories are installed.

The NW25H1 is designed to protect electrical distribution circuits against fault conditions when equipped with the appropriate protection system. It can also be used for controlled switching and isolation in accordance with its ratings and the applicable installation standards.

Since the exact configuration of a MasterPact NW circuit breaker can vary, buyers should verify the pole count, mounting arrangement, trip unit, cradle, auxiliary contacts, operating mechanism, and accessory requirements before ordering.

Technical Specifications

Important: NW25H1 identifies a breaker performance and frame configuration, not every detail of a complete assembly. Confirm the full product reference and accessories before purchase. The dimensions and weight above correspond to the supplied listing information and the referenced three-pole drawout configuration.

Function and Working Principle

The NW25H1 is designed to provide switching and protection functions in low-voltage electrical distribution systems. It connects and disconnects power circuits under specified operating conditions and works with a suitable protection unit to detect and respond to electrical faults.

1. Overcurrent Protection

Overcurrent can occur when a circuit carries more current than its intended operating limit. Common causes include excessive load, equipment malfunction, and abnormal operating conditions.

When fitted with a compatible trip unit, the circuit breaker can monitor current and initiate a trip when the configured protection thresholds are exceeded. The selected trip unit determines the available protection functions and settings.

Because the referenced configuration is supplied without a control unit, the required trip unit must be specified separately. The breaker frame alone should not be treated as a complete protection solution.

2. Short-Circuit Interruption

A short circuit can produce extremely high current within a very short period. If not interrupted correctly, the resulting thermal and electromagnetic forces can damage conductors, busbars, switchgear, and connected equipment.

The NW25H1 H1 performance class provides a rated ultimate short-circuit breaking capacity of 65 kA at 440 V AC. This rating indicates the breaker’s tested fault-interruption capability under specified conditions.

The actual suitability of the breaker depends on the prospective fault current at the installation point, the system voltage, coordination requirements, and the applicable electrical standards.

3. Switching and Isolation

The circuit breaker can be used to connect or disconnect a power circuit as part of a properly designed distribution system.

Its drawout construction allows the breaker to be withdrawn from a compatible cradle for maintenance or replacement. This arrangement can support maintenance planning and reduce the need to remove the entire switchboard assembly.

Isolation procedures must always follow the manufacturer’s instructions and applicable safety regulations. A drawout mechanism does not eliminate the need for electrical isolation, lockout, and verification of safe working conditions.

4. Short-Time Current Withstand

The NW25H1 specification includes a short-time withstand current rating of 65 kA for 1 second and 3 seconds under the stated conditions.

This capability is important in electrical distribution systems where selective coordination is required. It allows a suitable upstream or downstream protection arrangement to be designed so that the intended circuit breaker operates during a fault.

Protection coordination must be calculated for the complete installation rather than determined from the breaker rating alone.

5. Electrical System Coordination

In a large distribution network, multiple protective devices operate together. The main breaker, feeder breakers, transformers, busbars, and downstream loads must be coordinated to achieve the required protection and continuity of service.

The NW25H1 can form part of such an arrangement when its ratings, trip-unit settings, and accessories are selected according to the system study.

Role in Industrial Power Distribution Systems

The MasterPact NW25H1 is intended for high-current distribution applications. It is typically installed in a main or secondary switchboard where substantial electrical loads require controlled switching and fault protection.

Main Incoming Power Protection

In a main distribution board, the circuit breaker can serve as an incoming protective device between the supply source and the downstream busbar system.

Its 2500 A rating makes it relevant to installations with substantial current requirements. The final selection must account for the transformer’s capacity, busbar rating, available fault current, and required protection settings.

Transformer Secondary Protection

A transformer secondary circuit may require a high-capacity circuit breaker to protect the downstream distribution system.

The NW25H1 can be considered for an appropriately rated transformer installation when its voltage, current, breaking capacity, and trip-unit configuration meet the system design requirements.

Busbar and Feeder Protection

Industrial switchboards distribute power to multiple feeders and equipment groups. The breaker can be used in a coordinated distribution arrangement to provide switching and protection for a main busbar section or a high-current feeder.

The trip-unit settings and coordination with downstream devices should be determined through an engineering protection study.

Maintenance and Equipment Replacement

The drawout configuration is useful in installations where maintenance access and breaker replacement are important operational considerations.

A compatible drawout cradle and the correct mechanical and electrical interlocks are essential. The breaker must not be treated as interchangeable with a fixed-mounted or four-pole version without checking the complete assembly.

Industrial Applications

1. Manufacturing Facilities

Large manufacturing plants use substantial electrical power for production machinery, motors, heating equipment, and automated production lines.

The NW25H1 may be used in a main or secondary distribution board to protect high-current circuits supplying these systems. Its suitability depends on the installation’s load profile and fault-current calculations.

2. Power Distribution Rooms

Industrial power distribution rooms contain switchboards that distribute electrical energy from transformers or incoming supplies to different facility areas.

A 2500 A circuit breaker can be used in an appropriately rated distribution assembly to provide switching and protection for major electrical circuits.

3. Data Centers

Data centers require carefully coordinated electrical distribution systems to support servers, cooling equipment, UPS systems, and auxiliary infrastructure.

A high-capacity air circuit breaker may be used in a main or secondary distribution board where its ratings and protection functions match the electrical design. The complete protection arrangement must be evaluated for redundancy, selectivity, and fault interruption.

4. Infrastructure and Utility Facilities

Large infrastructure installations may use high-current circuit breakers in electrical distribution systems serving pumps, ventilation equipment, auxiliary machinery, and facility services.

The NW25H1 may be considered where the voltage, current, fault level, and installation configuration meet the project requirements.

5. Commercial and Industrial Buildings

Large commercial buildings and industrial complexes often require main switchboards capable of handling substantial electrical loads.

The MasterPact NW family provides circuit-breaker solutions for such distribution systems. The NW25H1’s 2500 A rating makes it relevant to selected high-current applications.

Installation and System Integration

Correct installation is essential for the safety and performance of a high-capacity air circuit breaker. Installation should be performed by qualified electrical personnel using the manufacturer’s documentation and the applicable electrical standards.

1. Verify the Complete Breaker Configuration

Before installation, confirm whether the breaker is three-pole or four-pole, fixed or drawout, and whether a trip unit is included.

For the referenced configuration, the breaker is three-pole, drawout, and supplied without a control unit. The required trip unit and associated accessories must be identified before commissioning.

2. Check Electrical Ratings

Confirm that the installation’s rated voltage, operating current, and prospective short-circuit current are within the breaker’s permitted ratings.

The 2500 A rated current is specified at 40°C. Ambient temperature, enclosure conditions, connection arrangements, and other installation factors must be considered during system design.

3. Inspect the Drawout Cradle

A drawout breaker must be installed in a compatible cradle or chassis. Verify the mechanical dimensions, primary disconnect connections, secondary connections, position indicators, and interlocking arrangements.

Never force the breaker into the cradle if the alignment or mechanical engagement is incorrect.

4. Install the Correct Trip Unit

The trip unit is an essential part of the protection system. Select a compatible unit with the required protection functions and current rating.

Configure protection settings according to the system coordination study. Do not use arbitrary settings based only on the breaker’s 2500 A frame rating.

5. Verify Busbar and Cable Connections

The primary connections must be suitable for the installation’s current and fault withstand requirements.

Inspect contact surfaces, connection hardware, clearances, insulation, and mechanical support. Tightening procedures and torque values must follow the manufacturer’s instructions.

6. Check Mechanical and Electrical Interlocks

Interlocks help prevent unsafe operating sequences and inappropriate breaker positioning.

Before energization, verify the correct operation of the drawout mechanism, position indicators, closing and opening functions, and any installed electrical interlocks.

7. Commissioning and Functional Testing

Before returning the system to service, qualified personnel should perform the required inspection and testing procedures.

These may include checking trip-unit settings, verifying auxiliary circuits, testing mechanical operation, confirming protection coordination, and completing the commissioning records.

Compatible System Components

The NW25H1 operates as part of a complete low-voltage distribution assembly. The following components may be required depending on the switchboard design and selected configuration.

The components listed above are not necessarily included with the breaker. Confirm the supplied bill of materials and full catalog reference before ordering.

Alternative Models and Replacement Considerations

The MasterPact NW range includes different current ratings, performance classes, pole configurations, and mounting arrangements. Replacement selection should be based on the electrical system and the complete breaker configuration.

Before selecting a replacement, compare:

• Rated operational voltage.
• Rated current and temperature conditions.
• Ultimate and service short-circuit breaking capacity.
• Short-time withstand current.
• Number of poles.
• Fixed or drawout mounting.
• Trip-unit type and protection functions.
• Cradle and primary connection arrangement.
• Auxiliary contacts and operating accessories.
• Switchboard dimensions and installation clearances.
• Protection coordination and commissioning requirements.

A replacement breaker should never be selected solely because it has the same nominal current rating. Its breaking capacity, mechanical dimensions, and protection characteristics must also meet the installation requirements.

Key Advantages

High Current Capacity

The 2500 A rated current makes the NW25H1 suitable for selected high-current low-voltage distribution applications.

High Short-Circuit Breaking Capacity

The H1 performance class provides a 65 kA ultimate breaking capacity at 440 V AC under the specified test conditions.

Drawout Construction

The drawout arrangement supports removal and maintenance in compatible switchboard systems, helping maintenance teams manage inspection and replacement activities.

Short-Time Withstand Capability

The specified short-time withstand rating supports the design of coordinated protection systems where selective operation is required.

Industrial Power Distribution Design

The MasterPact NW family is intended for demanding power distribution applications, including industrial and commercial switchboards.

Configurable Protection System

The breaker can be equipped with an appropriate trip unit and accessories to match the requirements of the electrical installation.

Isolation Suitability

The referenced configuration is suitable for isolation according to IEC 60947-2, subject to the manufacturer’s operating instructions and applicable safety procedures.

Technical FAQs

1. What is the Schneider Electric NW25H1?

The NW25H1 is a MasterPact NW air circuit breaker designed for high-current low-voltage power distribution protection. The referenced configuration is a 2500 A, three-pole, drawout model.

2. What is the rated current of the NW25H1?

Its rated current is 2500 A at an ambient reference temperature of 40°C. Actual application suitability depends on installation conditions and the complete electrical design.

3. What is the short-circuit breaking capacity?

The H1 performance class provides a rated ultimate short-circuit breaking capacity of 65 kA at 440 V AC. The applicable ratings should be checked at the system’s actual operating voltage.

4. What is the maximum rated operational voltage?

The referenced model has a rated operational voltage of up to 690 V AC at 50/60 Hz. The installation must comply with the manufacturer’s voltage and application requirements.

5. Is the NW25H1 a fixed or drawout circuit breaker?

The NW25H1 family includes different mounting configurations. The dimensions and weight supplied for this listing correspond to the three-pole drawout configuration described in the referenced product data.

6. Does this version include a trip unit?

The referenced three-pole drawout configuration is specified without a trip unit. A compatible protection unit must be selected separately to provide the required protection functions.

7. What is the purpose of the drawout design?

The drawout design allows the breaker to be moved between defined positions in a compatible cradle. This can make inspection, maintenance, and replacement more convenient when the switchboard is designed for this arrangement.

8. Can the NW25H1 replace another 2500 A circuit breaker?

Not automatically. Pole count, voltage, breaking capacity, mounting type, cradle, connection arrangement, trip-unit functions, and accessories must all be checked before replacement.

9. What should be inspected before purchasing a used NW25H1?

Verify the complete product reference, pole configuration, mounting type, trip-unit status, mechanical condition, primary contacts, secondary connections, operating mechanism, and included accessories. For critical installations, request appropriate inspection and test documentation.

10. What is the difference between the 2500 A rating and the 65 kA breaking capacity?

The 2500 A rating is the breaker’s rated continuous current under specified conditions. The 65 kA figure is its rated ultimate short-circuit breaking capacity at the specified voltage. These values describe different electrical characteristics and must both be considered during selection.

Procurement and Maintenance Recommendations

The NW25H1 is a high-capacity circuit breaker, so procurement should be based on the complete configuration rather than the family name alone.

Before placing an order, confirm the full catalog number, three-pole or four-pole arrangement, fixed or drawout construction, trip-unit status, cradle compatibility, and required accessories. For the referenced configuration, the trip unit is not included and must be considered separately.

For new, surplus, or refurbished equipment, request clear photographs of the nameplate, front panel, primary contacts, secondary terminals, and drawout mechanism. Confirm whether the breaker has been inspected or tested and establish the applicable warranty and return conditions.

During maintenance, follow the manufacturer’s procedures for inspecting contact surfaces, mechanical components, operating mechanisms, interlocks, and auxiliary circuits. Protection settings should be documented and reviewed by qualified personnel. Any maintenance or testing must be performed under appropriate electrical safety procedures.

For replacement projects, check the switchboard’s physical arrangement, busbar connections, cradle, control wiring, and protection coordination. A breaker with the same 2500 A rating may still require substantial modification if its configuration differs from the installed unit.

Conclusion

The Schneider Electric NW25H1 MasterPact NW Circuit Breaker is a high-capacity air circuit breaker designed for industrial and commercial low-voltage power distribution. The referenced three-pole drawout configuration has a rated current of 2500 A, an H1 short-circuit performance rating of 65 kA at 440 V AC, and a rated operational voltage of up to 690 V AC.

Its drawout construction supports maintenance in compatible switchboard systems, while the configurable protection arrangement allows the breaker to be integrated into appropriately engineered distribution networks. Since trip-unit and accessory configurations can vary, buyers should verify the complete product reference and supplied components before purchase or replacement.