NOARK’s Ex9BP-N DC MCBs avoid nuisance trips while still providing reliable fault protection.
When selecting MCB’s to help protect an expensive PV system, it’s important to consider more than just correct current and voltage rating. NOARK Ex9BP-N DC miniature circuit breakers are designed for direct current applications. Thanks to their polarity independency they are suitable for photovoltaic applications, but something often overlooked is their tripping characteristic.
PV circuits operate at high voltages, faults behave differently, and connected equipment such as inverters and DC/DC converters can generate short-duration current peaks. Noark’s Ex9BP-N DC MCBs address these challenges with a K-curve tripping characteristic, which allows transient currents to pass without nuisance trips while still providing reliable fault protection, making them an ideal choice for PV solar installations. Noark Electric has over 20 years of experience in industrial circuit protection and electrical components. Their products are widely used in switchboards, control panels, and renewable energy systems worldwide. Known for quality manufacturing and international compliance, Noark breakers are tested to IEC/EN standards and trusted for reliable operation in demanding industrial environments including photovoltaic systems.
Transient Currents in PV Systems can be challenging.
PV circuits often supply inverters, DC/DC converters, and other power electronics that create short-duration inrush currents during start-up or switching. A standard breaker may trip unnecessarily during these brief peaks, causing downtime, or react too slowly during a genuine fault. The K-curve characteristic of the Ex9BP-N series allows these transient currents to pass without nuisance trips, while still interrupting overloads and short-circuit faults immediately, protecting cables, connectors, and expensive PV equipment and keeping the system operating safely and efficiently.
Key Features of NOARK Ex9BP-N DC MCBs
The Ex9BP-N series combines K-curve protection with features that make it highly suitable for PV applications:
- Non-polarised design: can be installed without worrying about DC polarity.
- Tested to IEC/EN 60947-2: ensures international compliance and reliability.
- Short-circuit breaking capacity of 6 kA: provides dependable interruption under fault conditions.
- Rated operating voltage of 180 V DC per pole (up to 720 V DC): compatible with most string and combiner circuits.
- Rated current up to 63 A: protects individual PV strings or DC feeders.
- Compact modular design: available in 2- and 4-module widths for efficient panel layouts.
Flexible Integration with Accessories
The Ex9BP-N series supports a wide range of accessories, making it simple to integrate into monitoring or control schemes.
(Installers can combine up to three auxiliary/alarm modules and two release units, allowing tailored protection for complex PV systems.)
- Auxiliary contacts
- Alarm or signal contacts
- Shunt trip releases
- Undervoltage releases
Typical Applications in PV Systems
The Ex9BP-N K-curve DC MCB is commonly used in:
- PV string protection within combiner boxes
- DC distribution circuits feeding inverters
- DC loads in switchboards and control panels
Using a Noark Ex9BP-N DC MCBs ensure that transient currents from equipment start-up pass without nuisance trips, while genuine overloads or short-circuit faults are cleared immediately. Thanks to their DC-specific design, polarity independency, K-curve protection, and flexible accessory options, they deliver safe, reliable protection for photovoltaic circuits, minimising downtime and keeping solar systems operating efficiently.
Explore our full range of NOARK DC MCBs for photovoltaic systems, or contact the ECS team for assistance with your PV circuit protection solution.