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:
- Basic Parameters and SpecificationsSchneider LC1DN3210 and Chint NXC32 contactors
- Rated ParametersChint 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)
- Application ScenariosWiring 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
- Core Structure and Terminal DescriptionCHINT AC contactor CJX2
- Appearance and Components
(Schematic diagram; actual product may vary)
- 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
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
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
- Installation and Usage Precautions
- Environmental Requirements
– Temperature Range: -5°C ~ +40°C
– Humidity: ≤95%RH (no condensation)
– Altitude: ≤2000 meters
- 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
- 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)
- 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 |
- 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.
