Pronto Energy 
KNB2-63S6Z DC Miniature Circuit Breaker (DC MCB)
The KNB2-63S6Z 1P 6-25A DC miniature circuit breaker provides overload and short-circuit protection for DC circuits up to 250V. Its arc-extinguishing design handles DC current without sustained arcing, making it suitable for photovoltaic, telecom and DC power distribution applications.
Applications & circuit protection
The KNB2-63S6Z DC MCB is built for DC distribution circuits requiring reliable protection. It is widely used in photovoltaic systems, DC power supplies, telecom cabinets and industrial DC panels.
- Photovoltaic DC strings and combiner circuits
- Telecom and data-centre DC distribution
- DC power supplies and industrial DC panels
- Battery and energy-storage systems
Construction & operating reliability
The KNB2-63S6Z uses a dedicated DC arc-extinguishing system that interrupts DC arcs reliably, with high-conductivity contacts and a durable housing for long service life in DC applications.
- Dedicated DC arc-extinguishing design
- High-conductivity silver contacts
- Flame-retardant housing with IP20 protection
- Clear ON/OFF status indication
Wiring Diagram
Technical Parameter
| Parameter | Value |
| Model | KNB2-63S6Z |
| Compliant with standards | IEC/EN 60947-2 |
| Application | Photovoltaic and DC distribution circuits (overload and short-circuit protection) |
| Number of product poles | 1P |
| Rated working voltage | 250 V DC |
| Rated working current | 6–25 A |
| Breaking capacity | 15 kA |
| Tripping characteristic | Instantaneous magnetic ≈10 × In |
| Mechanical life | 20,000 operations |
| Electrical life | 1,500 operations |
| Terminal screw torque | 3.0 N·m |
| Protection level | IP20 |
| Installation method | 35 mm DIN rail |
| Certifications | CB, CE, SEMKO |
Standards & certifications
The KNB2-63S6Z is designed in accordance with IEC/EN 60947-2 and is available with CB, CE, SEMKO certifications. Certification documentation can be provided according to project and destination-market requirements.
- Standard: IEC/EN 60947-2.
- Certifications: CB, CE, SEMKO.
- Protection level: IP20 (where applicable).
OEM & B2B supply support
KORLEN supports distributors, OEM manufacturers, electrical contractors and project buyers with product selection, samples, technical documentation and commercial quotations.
If the KNB2-63S6Z configuration does not match your project, send us the required specifications, quantity and destination market. Our team can help identify a suitable configuration.
- Samples available for product evaluation.
- Flexible quantities for project and B2B purchasing.
- OEM and ODM support for suitable projects.
- Technical documentation and certification support available.
Frequently Asked Questions
The KNB2-63S6Z DC miniature circuit breaker protects DC circuits against overload and short circuit, including photovoltaic, telecom and DC power applications.
The KNB2-63S6Z is rated for 250V DC operation, with a breaking capacity of 15kA.
DC current does not self-extinguish like AC. The KNB2-63S6Z uses a dedicated arc-quenching design to interrupt DC arcs reliably and safely.
It mounts on standard 35mm DIN rail inside DC distribution boards or combiner enclosures.
