Chint NXC-75/220V AC contactor

Product description

The Chint NXC-75/220V AC contactor is a commonly used industrial-grade control device suitable for controlling three-phase loads with a rated current of 75A and a coil voltage of 220V. Below is a detailed analysis of this contactor model:

*I. Basic Parameters and Specifications*Schneider LC1DN3210 and Chint NXC32 contactors*

1. **Rated Parameters*Chint DC Contactor NC1-5011-36V*

- **Model Meaning**: NXC-75 (design series)/220V (coil voltage)

- **Rated Current**: 75A (can control 37kW three-phase motors under AC-3 usage category)

- **Coil Voltage**: 220V AC (50/60Hz)

- **Pole Configuration**: 3 poles (main contacts) + 2 normally open (NO) + 2 normally closed (NC) auxiliary contacts

- **Mechanical Life**: 10 million operations

- **Electrical Life**: 1 million operations (AC-3 category)

2. **Application Scenarios*Wiring of Delixi AC Contactor*

- Start, stop, and forward/reverse control of three-phase motors

- On/off control of electric heating equipment and lighting circuits

- Combined with thermal relays to form motor protection circuits

*II. Core Structure and Terminal Description*CHINT AC contactor CJX2*

*1. Appearance and Components**

![Chint NXC-75 Contactor Appearance](https://picsum.photos/600/400?random=1)

*(Schematic diagram; actual product may vary)*

*2. Terminal Layout**

Terminal Type	Identification/Number	Function Description
Main Contacts	L1/T1, L2/T2, L3/T3	Three-phase power input/output (L1-L3 for power supply, T1-T3 for load)
Coil Terminals	A1, A2	220V coil power supply (A1 to live wire, A2 to neutral wire)
Auxiliary Contacts	13/14 (NO), 21/22 (NC)	Control circuit signal feedback (NO/NC)
Thermal Relay Interface	95/96, 97/98	Connect to thermal relay for overload protection

*III. Typical Application Wiring Diagrams**

*Scenario 1: Direct Start Control of Three-Phase Motor**

```

┌─────────────────────────────────┐

│ Circuit Breaker (Q) │

│ ┌───┐ ┌───┐ │

│ L1 ──────┤ │───┤ ├───┬─────┘

│ │ │ │ │ │

│ L2 ──────┤ │───┤ ├───┼─────┐

│ └───┘ └───┘ │ │

│ │ │

│ ┌───┐ ┌───┐ │ │

│ L3 ──────┤ │───┤ ├───┴─────┘

│ └───┘ └───┘

│ │ │

│ ┌──────┴───────┴──────┐

│ │ Contactor Main Contacts │

│ │ (L1/T1-L3/T3) │

│ └──────┬───────┬──────┘

│ │ │

│ ┌───┐ ┌───┐

│ T1 ──────┤ │ │ │──── Motor U Phase

│ │ │ │ │

│ T2 ──────┤ │ │ │──── Motor V Phase

│ │ │ │ │

│ T3 ──────┤ │ │ │──── Motor W Phase

│ └───┘ └───┘

│

│ ┌───────────────┐

│ │ Control Circuit │

│ │ │

│ │ ┌───┐ ┌───┐ │

│ └──┤SB1├──┤KM ├──┘

│ │ │ │

└───┘ └───┘

Stop Coil A1

│

└───────────┐

│

┌───┐

│ │

└───┘

│

└──── Neutral Wire N

```

**Explanation**:

- Circuit Breaker (Q): Protects the circuit from overloads and short circuits

- Contactor (KM): Main contacts control motor power supply; coil A1/A2 connected to 220V

- Start Button (SB1): When pressed, the coil is energized, main contacts close, and the motor starts

*Scenario 2: Motor Control with Overload Protection**

```

┌─────────────────────────────────┐

│ Circuit Breaker (Q) │

│ ┌───┐ ┌───┐ │

│ L1 ──────┤ │───┤ ├───┬─────┘

│ │ │ │ │ │

│ L2 ──────┤ │───┤ ├───┼─────┐

│ └───┘ └───┘ │ │

│ │ │

│ ┌───┐ ┌───┐ │ │

│ L3 ──────┤ │───┤ ├───┴─────┘

│ └───┘ └───┘

│ │ │

│ ┌──────┴───────┴──────┐

│ │ Contactor Main Contacts │

│ │ (L1/T1-L3/T3) │

│ └──────┬───────┬──────┘

│ │ │

│ ┌───┐ ┌───┐

│ T1 ──────┤ │ │ │──── Thermal Relay (FR)─┐

│ │ │ │ │ │

│ T2 ──────┤ │ │ │ │

│ │ │ │ │ │

│ T3 ──────┤ │ │ │ │

│ └───┘ └───┘ │

│ │

│ ┌──────────┴──────────┐

│ │ Motor │

│ └────────────────────┘

│

│ ┌──────────────────────────────────┐

│ │ Control Circuit │

│ │ │

│ │ ┌───┐ ┌───┐ ┌─────┐ ┌───┐ │

│ └──┤SB1├──┤SB2├──┤FR NC├──┤KM ├──┘

│ │ │ │ │ │ │ │

└───┘ └───┘ └─────┘ └───┘

Stop Start Overload Protection Coil A1

│

└───────────┐

│

┌───┐

│ │

└───┘

│

└──── Neutral Wire N

```

**Explanation**:

- Thermal Relay (FR): Connected to the main circuit via terminals 95/96; NC contacts 97/98 are wired in series in the control circuit

- During overload, the bimetallic strip in FR heats and bends, opening the NC contacts, de-energizing the contactor coil, and stopping the motor

*IV. Installation and Usage Precautions**

1. **Environmental Requirements**

- Temperature Range: -5°C ~ +40°C

- Humidity: ≤95%RH (no condensation)

- Altitude: ≤2000 meters

2. **Installation Steps**

- Install vertically to maintain heat dissipation space

- Use M8 bolts for main circuit terminals, tightening torque 8-10N·m

- Use 0.75-2.5mm² wires for control circuits to ensure good contact

3. **Maintenance Key Points**

- Regularly clean oxide layers on contact surfaces

- Check for loose bolts (at least once a year)

- Coil temperature rise should not exceed 65K (at 40°C ambient temperature)

*V. Common Faults and Solutions**

Fault Phenomenon	Possible Causes	Solutions
Coil not energizing	Power not connected, coil burned out, mechanical jamming	Check voltage, replace coil, clean components
Contact overheating	Poor contact, excessive load, contact oxidation	Tighten terminals, reduce load, polish contacts
Not releasing after power-off	Residual magnetism in core, contact adhesion	Replace core, clean or replace contacts
Excessive noise	Broken core short-circuit ring, voltage fluctuations	Replace core, stabilize power supply voltage

*VI. Selection Alternatives**

If NXC-75 is out of stock, consider the following alternative models:

- **Schneider LC1-D75**: Same specifications, strong compatibility

- **Siemens 3TF52**: Higher reliability, suitable for critical applications

- **ABB A9-40/75**: Modular design, easy to expand

**Note**: When replacing, confirm that coil voltage, contact capacity, and installation dimensions are consistent.

Summary**

The Chint NXC-75/220V AC contactor is a reliable industrial control component that can effectively manage three-phase loads through proper wiring and maintenance. Before use, verify power supply compatibility and prioritize control circuits with overload protection to extend equipment life and ensure safety.