The Chint NB1-63DC Series is a specialized Miniature Circuit Breaker (MCB) engineered specifically for the demanding requirements of Photovoltaic (PV) DC systems. In solar applications, DC currents pose a unique challenge because they do not have a natural "zero-crossing" point, making arcs significantly harder to extinguish than in AC systems.

The NB1-63DC features an integrated permanent magnet and high-efficiency arc-shute system that forces the DC arc into the cooling chamber rapidly. Whether used in residential rooftop arrays or commercial solar farms, this breaker provide essential protection against overloads and short circuits in DC string boxes, inverters, and battery energy storage systems (BESS).

• Optimized DC Arc Extinguishing: Equipped with specialized internal magnets that pull the DC arc away from the contacts, ensuring fast interruption and preventing damage to the breaker’s internal mechanism.

• High Voltage DC Rating: Available in various configurations to support system voltages: 1P (250V), 2P (500V), and 4P (1000V DC).

• Reliable Contact Indication: Features a clear green/red physical indicator window, providing a visible mechanical confirmation of the contact status regardless of the toggle position.

• Polarity Sensitivity: Designed for directional DC flow, ensuring maximum breaking capacity when wired according to the clearly marked (+) and (-) terminals.

• DIN Rail Compatibility: Standard 35mm DIN rail mounting allows for seamless integration into existing solar combiner boxes and DC distribution panels.

1. Solar Combiner Boxes: Protection for individual DC strings before they enter the manifold.

2. Solar Inverters: Serving as the primary DC disconnect and overcurrent protection at the inverter input.

3. Battery Storage (BESS): Managing DC circuits in off-grid or hybrid solar storage systems.

4. DC Electric Vehicle (EV) Chargers: Localized protection for DC charging infrastructure.

• Global Certification: Chint is a world leader in low-voltage electrical products. The NB1-63DC is fully compliant with IEC 60947-2, ensuring it meets the safety codes required by inspectors worldwide.

• Enhanced Safety Margin: Rated for an impulse withstand voltage (Uimp) of 4kV, providing extra protection against atmospheric surges commonly found in outdoor PV installations.

• Ambient Resilience: Engineered to operate in extreme temperatures ranging from -35°C to +70°C, essential for rooftop junction boxes exposed to direct sunlight.

• Silver-Alloy Contacts: Utilizes high-purity silver-based contacts to maintain low contact resistance and prevent overheating during continuous DC load cycles.

Q: Can I use a standard AC breaker for my solar DC strings?

A: No. Standard AC breakers are not designed to extinguish DC arcs. Using an AC breaker in a DC circuit can result in the breaker failing to trip or catching fire during a fault. Always use a dedicated DC MCB like the NB1-63DC.

Q: Does polarity matter when wiring this breaker?

A: Yes. The NB1-63DC is polarity-sensitive. You must connect the positive (+) and negative (-) wires to the corresponding marked terminals to ensure the magnetic arc-quenching feature works correctly.

Q: What is the difference between 1P, 2P, and 4P for DC?

A: The number of poles determines the maximum voltage the breaker can handle. Generally, 1P is for 250V, 2P for 500V, and 4P for 1000V DC systems by wiring the poles in series.