Chint NCH8-20/20 AC contactor

Chint **NCH8-20/20** is an AC contactor specifically designed for household and small commercial scenarios, suitable for controlling low-inductance loads or electric motors. The following is an in-depth analysis based on the latest manufacturer's data and industry regulations:

 I. Analysis of Core Parameters and Functions

 1. **Model Coding Rules**

- **NCH8**:  

  It is the code name for Chint's household contactor series. Adopting a modular design, it supports rail mounting and is suitable for dense wiring requirements in distribution boxes.

- **20/20**:  

  - **First 20**: The **rated operating current of the main contact is 20A**, which can drive electrical appliances of approximately 4.6kW under 230V (such as high-power water heaters, small air conditioners).  

  - **Second 20**: The contact combination is **2 poles (2P) + 2 normally open contacts (2NO)**. There are no auxiliary normally closed contacts, making it suitable for simple on-off control (such as lighting circuits, single-speed motors).  

2. **Electrical Performance Indicators**

- **Rated Voltage**:  

  The main circuit supports **230V/400V AC** (50/60Hz), and the control coil voltage can be **24V DC** or **220/230V AC** (to be confirmed by model suffix or manual).

- **Breaking Capacity**:  

  In the AC-7a (household load) category, it can break **6 times the rated current** (i.e., 120A), meeting the daily overload protection requirements.

- **Life Parameters**:  

  - **Mechanical Life**: ≥1,000,000 times (contact action without load).  

  - **Electrical Life**: ≥100,000 times (on-off under full load), suitable for frequent operation scenarios.  

 3. **Safety and Certification**

- **Protection Class**: IP20 (prevents the intrusion of solids with a diameter >12mm), and must be installed in a closed distribution box.

- **Certification Standards**:  

  - Chinese market: Passed **CCC certification** (certificate number: 2020980304000201), in line with GB/T 17885 standard.  

  - International market: Complies with **IEC/EN 61095** standard, applicable to European and some Southeast Asian countries, but does not explicitly mark UL certification (for the US market, please consult local distributors).  

 II. Typical Application Scenarios

 1. **Home Automation Control**

- **Lighting Systems**:  

  Cooperate with smart switches or sensors to realize multi-area lighting linkage (such as timing/induction control of corridor and garage lighting).

- **Appliance Control**:  

  Drive high-power appliances such as washing machines and dryers, replacing traditional mechanical switches to extend the service life of equipment.  

2. **Small Commercial Scenarios**

- **HVAC Systems**:  

  Control air conditioning fans and floor heating thermostatic valves, supporting centralized management of multiple devices.

- **Charging Pile Control**:  

  Cooperate with electric vehicle charging piles to realize charging power adjustment and safe power-off.  

3. **Industrial Auxiliary Applications**

- **Small Motor Control**:  

  Drive single-phase motors with power ≤4kW (such as water pumps, ventilators), which need to be matched with short-circuit protection circuit breakers.

- **Automated Production Lines**:  

  Serve as the start-stop controller for auxiliary equipment in production lines (such as conveyor belts, detection devices).  

 III. Selection and Usage Suggestions

 1. **Key Matching Parameters**

- **Load Current**:  

  It is necessary to ensure that the actual load current is ≤20A. Long-term overload may cause contact welding. For example, the maximum power of resistive loads (such as electric heaters) under 230V is **4.6kW**, and inductive loads (such as motors) need to be derated to **below 3kW**.

- **Coil Voltage**:  

  If a 220/230V AC coil is selected, it is necessary to confirm the voltage stability of the control circuit in the distribution box. Fluctuations exceeding ±15% may cause misoperation.  

 2. **Installation and Maintenance Points**

- **Rail Mounting**:  

  Adopt TH35-7.5mm standard rails. During installation, a heat dissipation gap of at least 18mm must be reserved to avoid overheating caused by dense installation of multiple contactors.

- **Wiring Specifications**:  

  - Cross-sectional area of main circuit wires: ≥2.5mm² (copper core) to ensure low-impedance connection.  

  - It is recommended to use 0.75mm² shielded wires for control wires to reduce electromagnetic interference.

- **Regular Maintenance**:  

  Check the contact wear every six months. If the thickness of the silver alloy contacts is <0.5mm, they need to be replaced; clean the iron core attraction surface to prevent noise increase caused by dust.  

 3. **Alternative Solutions and Compatibility**

- **International Market Adaptation**:  

  If UL certification is required, you can consider Chint **NCH8G series** (compatible with IEC/EN 61095 standard) or Schneider **LC1D series** (20A model).

- **Function Expansion**:  

  To realize interlocking or status feedback, **AX auxiliary contacts** (such as AX-11 type, 1NO+1NC) can be added, which are quickly connected through the side card slot.  

IV. Purchase and Technical Support

 1. **Channels and Prices**

- **International Market**:  

  European users can purchase through distributors via Whatsapp: 0086-13811255435 (approximately 30 Euros per unit). For the US market, please contact **Chint Power** via Whatsapp: 0086-13811255435 to confirm inventory.  

 2. **Obtaining Technical Documents**

- **Official Information**:  

  Chint's official website provides the *NCH8 Series Product Manual*, which contains detailed wiring diagrams, dimension diagrams, and certification documents (such as CQC certificates).

- **Installation Videos**:  

  Platforms such as Bilibili have tutorials like "NCH8 Contactor Wiring Demonstration", which demonstrate practical steps such as rail installation and contact testing.  

3. **After-Sales Service**

- **Warranty Period**:  

  36 months from the date of leaving the factory. Non-human damage can be replaced free of charge.

- **Troubleshooting**:  

  If the contactor fails to pull in, first check whether the coil voltage is normal; if the contacts are stuck, the power must be cut off immediately and the components replaced.  

 V. Comparative Advantages with Competitors

 VI. Notes

1. **Environmental Restrictions**:  

   - Operating temperature: -5℃~+40℃. When humidity >90%, moisture-proof measures must be added.  

   - At an altitude >2000m, the rated current needs to be derated by 10%.

2. **Regulatory Compliance**:  

   - The Chinese market needs to be matched with circuit breakers conforming to GB 10963 standard (such as Chint NB1 series).  

   - The EU market needs to pass CE certification (NCH8 series has self-declared compliance).

3. **Safe Operation**:  

   - Before maintenance, disconnect the main circuit and control power supply, and use insulated tools for operation.  

   - It is prohibited to use in flammable and explosive environments, as contact arcs may cause danger.  

Through the above analysis, Chint NCH8-20/20 has high cost performance and reliable performance in household and small commercial scenarios. Users can choose the appropriate voltage specifications and expansion modules according to specific needs, and contact the manufacturer for customized solutions if necessary.