

The CHINT NB1-63DC is a DC Miniature Circuit Breaker (MCB) designed to provide reliable protection for DC electrical circuits. It automatically disconnects the circuit in the event of an overload or short circuit, ensuring safety and preventing damage to connected components. This MCB is widely used in renewable energy systems, industrial automation, and other DC power applications.








| Parameter | Specification |
|---|---|
| Manufacturer | CHINT |
| Part Number | NB1-63DC |
| Rated Voltage | 250V DC (1-pole), 500V DC (2-pole) |
| Rated Current | 1A to 63A (varies by model) |
| Breaking Capacity | 10kA |
| Number of Poles | 1P, 2P |
| Tripping Curve | C curve |
| Operating Temperature Range | -30°C to +70°C |
| Mounting Type | DIN rail (35mm) |
| Standards Compliance | IEC/EN 60947-2, GB/T 14048.2 |
The CHINT NB1-63DC has screw terminals for input and output connections. Below is the terminal configuration:
| Terminal Label | Description |
|---|---|
| L+ | Positive input terminal (Line) |
| L- | Negative input terminal (Line) |
| T+ | Positive output terminal (Load) |
| T- | Negative output terminal (Load) |
Note: For 2-pole models, the terminals are duplicated for both poles.
In a solar PV system, the NB1-63DC can be used to protect the DC circuit between the solar panels and the charge controller. Below is a simplified connection diagram:
Solar Panel (+) ----> L+ (MCB Input)
Solar Panel (-) ----> L- (MCB Input)
T+ (MCB Output) ----> Charge Controller (+)
T- (MCB Output) ----> Charge Controller (-)
| Issue | Possible Cause | Solution |
|---|---|---|
| MCB does not trip during a fault | Fault current is below the trip threshold | Verify the fault current and ensure it exceeds the MCB's rated trip current. |
| MCB trips frequently | Overloaded circuit or short circuit | Check the circuit for overloads or shorts. Reduce the load or fix the fault. |
| MCB does not power on | Loose or incorrect wiring | Verify all connections and ensure proper polarity. |
| MCB overheats during operation | Poor ventilation or excessive current | Ensure adequate ventilation and verify the current does not exceed the MCB's rating. |
Q1: Can the NB1-63DC be used in AC circuits?
A1: No, the NB1-63DC is specifically designed for DC circuits. For AC applications, use an AC-rated MCB.
Q2: How do I select the correct tripping curve?
A2: The NB1-63DC uses a C curve, which is suitable for most general-purpose DC applications. For specialized applications, consult CHINT's technical support.
Q3: Can I use the NB1-63DC in a high-altitude environment?
A3: Yes, but the breaking capacity may be reduced at altitudes above 2000 meters. Refer to the manufacturer's guidelines for derating information.
Q4: How often should I test the MCB?
A4: It is recommended to test the MCB at least once a year to ensure proper functionality.
By following this documentation, users can safely and effectively integrate the CHINT NB1-63DC into their DC circuits.