Chint NXA20N/4 Air Circuit Breaker

Chint NXA20N/4 is an air circuit breaker belonging to the Chint NXA series.

Basic Information

Pole Number: 4P

Frame Current: 2000A

Breaking Capacity: Classified as N series, with a breaking capacity of 80kA

Mounting Method: Drawer-type as standard, facilitating installation and maintenance

Control Circuit Voltage: 220VAC

Product Features

Safety and Reliability: Allows setting of 2 independent earth fault protection curves to ensure personal and equipment safety. Core components such as the operating mechanism and controller are self-manufactured, ensuring high compatibility between parts and the finished product.

Independent Innovation: Adopts a patented key-lock mechanical interlocking design, enabling 0-second interlocking installation for client-side systems. The mid-mounted mechanism design improves the contact synchronization during closing and opening operations.

Interconnectivity: Equipped with dual configurations for local and remote communication to meet networking requirements in different scenarios. It can also realize early warning of current faults through handheld test devices.

Rated Voltage: The rated operational voltage covers AC380/400/415V, AC440V/525V/690V

Pricing Information: Taking the price on the Chint Electric official mall as an example, the promotional price is ¥16,032 per unit, and the market price is ¥40,080 per unit. The specific price may vary depending on the purchase channel, order quantity, and other factors.

The operating mechanism of the Chint NXA20N/4 air circuit breaker has the following core characteristics, elaborated in terms of structural design, interlocking function, energy storage and control, etc.:

1. Core Structural Design Features
2.  Mid-mounted Mechanism Design

Adopts an innovative mid-mounted layout, which improves the contact synchronization by 50% during closing and opening, significantly reducing the risk of phase-to-phase arc interference and contact wear

Optimizes the transmission path, reduces mechanical loss, and improves operational efficiency and reliability

2.  Self-manufactured Key Components

Core components of the operating mechanism (such as energy storage devices and latching systems) are independently developed and produced by Chint, increasing the compatibility between parts and the finished product by 20%

Core processes are automated, ensuring 100% consistency of products off the production line and reducing fault risks caused by batch differences

2. Safety Interlocking System
3.  Key-lock Mechanical Interlocking

The patented key-lock interlocking solution enables 0-second completion of interlocking installation for client-side systems without additional adjustments

Supports multiple interlocking logics such as three-lock two-key to prevent misoperation and meet the safety isolation requirements of complex power distribution systems

Drawer-type models can lock the chassis and the main body with padlocks in the “Open” position to prevent accidental insertion of the crank handle to change the position

2.  Multi-level Misoperation Prevention Design

Interlocks between energy storage and closing operations to avoid closing in an uncharged state

Features an opening-priority mechanism, allowing the opening command to be executed immediately regardless of the current state

Drawer-type models are equipped with position locking function, enabling corresponding operations only when in the correct position (Connected/Test/Disconnected)

3. Energy Storage and Operation Methods

4. Performance and Reliability
5.  Automatic Energy Storage Mechanism

The motorized operating mechanism automatically completes energy storage after closing, ensuring readiness for the next closing operation and shortening fault recovery time

The energy storage status is clearly indicated mechanically, facilitating on-site personnel to quickly judge the equipment status

2.  High Mechanical Service Life

Mechanical operation life reaches more than 10,000 cycles (compliant with IEC 60947-2 standard)

Energy storage springs are made of high-quality alloy materials with excellent fatigue resistance, minimizing performance degradation during long-term use

3.  Modular Design

The operating mechanism and the circuit breaker main body adopt modular assembly, facilitating maintenance and replacement and reducing downtime

Supports seamless integration with intelligent controllers to achieve real-time monitoring of operating status and fault diagnosis

5. Adaptability and Expandability
6.  Compatible with Multiple Mounting Methods

Compatible with both drawer-type and fixed-type mounting methods to meet the requirements of different cabinet types and spaces

Drawer-type models have three working positions (Connected/Test/Disconnected) for safe maintenance

2.  Intelligent Control Interface

Supports mainstream communication protocols such as Modbus-RTU, which can be connected to upper computer systems to realize remote monitoring and control of the operating mechanism

Cooperates with intelligent controllers to record key data such as operation times and energy storage status, supporting predictive maintenance

6. Operating Mechanism Configuration Description

Standard Configuration: Motorized Operating Mechanism (MO) + Closing Coil (CC) + Shunt Trip Coil + Manual Energy Storage Handle

Optional Accessories: Zone Selective Interlocking Module, Auxiliary Contact Block (2DI/2DO or 4DO), Position Indicator Switch, etc.

Equivalent Models of Chint NXA20N/4 from Other Brands

Core parameters of Chint NXA20N/4: 2000A frame current, 4-pole, N-series breaking capacity (80kA), drawer-type mounting. It is suitable for use as the main switch or protection switch for important branches in low-voltage power distribution systems. The following are equivalent models from mainstream brands and key points for replacement:

1. Core Parameter Matching Table

2. Detailed Description of Equivalent Models from Various Brands

2.1 Schneider Electric

Classic Model: MT20N2 4P D/O MIC5.0 (Drawer-type, equipped with MIC5.0 intelligent trip unit)

New-generation Model: MTZ2 20N2 4P D/O (Masterpact MTZ2 series, replacement for MT series)

Breaking Capacity: N2 series has a breaking capacity of 80kA at 400V, fully matching NXA20N/4

Operating Mechanism: Motorized energy storage + manual energy storage, compatible with the operation mode of NXA

2.2 ABB

Emax 2 Series: E2.2N-A 2000 Ekip Dip LSIG 4P WMP

Breaking Capacity: E2N series has a breaking capacity of 80kA at 415V, meeting replacement requirements

Mounting Method: WMP stands for withdrawable (drawer-type), consistent with the mounting method of NXA

Trip Unit: Ekip Dip LSIG provides overload, short-circuit, and earth fault protection, with functions equivalent to the NXA controller

2.3 Siemens

3WL Series: 3WL1220-3FG42-4GA2 (4P, 2000A, 80kA, drawer-type)

3WA Series (New-generation): 3WA2220-3HB42-1FA0 (replacement for 3WL with improved performance)

Breaking Capacity: Size II specification has a breaking capacity of 80kA at 500V, suitable for the application scenarios of NXA20N/4

Note: The 3WL series has been announced as discontinued; the 3WA series is recommended for new projects

2.4 Changshu Switch

CW1 Series: CW1-2000M/4P Drawer-type (Type M has a breaking capacity of 80kA)

CW1-2000H/4P: Type H has a higher breaking capacity (100kA), which can be downwardly compatible for replacement

Intelligent Controller: Supports L, M, H-type controllers, with protection functions consistent with NXA

2.5 Equivalent Models from Other Brands

3. Key Points for Replacement
4.  Breaking Capacity Matching

Ensure that the rated ultimate short-circuit breaking capacity (Icu) of the replacement model is ≥80kA at 400V system voltage

Prioritize selecting models with the same breaking class (N series) to avoid safety risks caused by insufficient breaking capacity

2.  Mounting Dimension Verification

For drawer-type circuit breakers, verify that the drawer rail dimensions, body width, and depth are compatible with the original cabinet

The position and dimensions of the main circuit terminals should be consistent with NXA20N/4 to avoid re-drilling

3.  Control Circuit Adaptation

The control voltage (AC220V/DC220V) must match that of NXA20N/4

The number of auxiliary contacts, parameters of the shunt trip coil and closing coil should be consistent with the original system

Communication protocols (such as Modbus-RTU) must be compatible to ensure the normal operation of intelligent monitoring functions

4.  Trip Unit Function Matching

The replacement model should be equipped with LSIG (Long-time, Short-time, Instantaneous, Ground Fault) protection functions

The protection curves need to be coordinated with the original system to avoid selective protection failure

5.  Operating Mechanism Compatibility

Ensure that the energy storage method (motorized/manual) and interlocking functions are consistent with the original operating habits

Drawer-type models must have a three-position locking function (Connected/Test/Disconnected) to prevent misoperation

4. Recommended Replacement Solutions
5.  Cost-effective Choice: Changshu Switch CW1-2000M/4P Drawer-type or Delixi CDW3-2000N/4P, domestic alternatives with moderate prices and matching performance
6.  International Brand Replacement: Schneider MTZ2 20N2 4P or ABB Emax 2 E2N 2000 4P, with reliable quality, suitable for important projects
7.  Upgrade Replacement: Siemens 3WA2220-3HB42-1FA0 or Eaton IZMX40N4-A20W, new-generation products with higher intelligence level