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Choose Your DC MCB Model
DC Circuit Breaker 1P 250V | KYDB-63-1P
DC Circuit Breaker 2P 500V | KYDB-63-2P
DC Circuit Breaker 3P 750V 125A | KYDB-125-3P
DC Circuit Breaker 4P 1000V | KYDB-63-4P
DC Circuit Breaker 1P 250V 125A | KYDB-125-1P
DC Circuit Breaker 2P 500V 125A | KYDB-125-2P
DC Circuit Breaker 3P 750V | KYDB-63-3P
DC Circuit Breaker 4P 1000V 125A | KYDB-125-4P
KYDB Series Comparison
| Series | Rated Current | Voltage Options | Applications | Standards |
|---|---|---|---|---|
| KYDB-63 | Up to 63A | 250V / 500V / 750V / 1000V | Residential PV, small ESS, DC panels | IEC 60947-2, UL 489 |
| KYDB-125 | Up to 125A | 250V / 500V / 750V / 1000V | C&I solar, EV charging, industrial ESS | IEC 60947-2, UL 489 |
DC MCB Series Selection Guide
When selecting a DC MCB (Miniature Circuit Breaker) for solar PV, ESS, or EV charging projects, the current rating and installation scale are key factors. Kuangya offers two ranges optimized for different needs.
KYDB-63 Series — Designed for up to 63A, it is ideal for residential solar DC circuits and small-scale ESS racks. Compact and reliable, it ensures safe arc extinguishing at up to 1000VDC, making it a cost-effective choice for rooftops up to 10 kW.
KYDB-125 Series — Rated up to 125A, this model supports commercial PV systems, EV charging hubs, and industrial ESS containers. With higher breaking capacity, it guarantees compliance with both IEC 60947-2 and UL 489.
Kuangya DC MCBs integrate seamlessly with DC Fuse, DC SPD, DC Switch Disconnectors, and PV Combiner Boxes, ensuring complete protection coordination.
📌 Tip: Choose KYDB-63 for residential or small ESS, and KYDB-125 for commercial solar, EV charging, or large-scale ESS. For customized selection, reach out via our Enquiry Form.
All Kuangya DC MCBs are factory-tested under high-voltage DC conditions, ensuring consistent reliability and safety.
What is a DC MCB?
Why it matters
A DC MCB (Miniature Circuit Breaker) is essential in modern solar and ESS projects, protecting against overloads and short circuits. Unlike AC breakers, a solar DC MCB is engineered to extinguish persistent DC arcs, ensuring safety in rooftop arrays, battery systems, and EV charging. Compliance with IEC 60947-2 and UL 489 provides global reliability.
What’s inside
Kuangya DC MCBs feature arc extinguishing chambers, robust silver-alloy contacts, and modular poles from 1P to 4P. Rated up to 1000VDC / 125A, they handle the demands of high-power PV arrays and energy storage systems. Their precision design ensures stable breaking capacity, long service life, and consistent DC circuit protection under harsh operating conditions.
Where it’s used
DC MCBs are widely applied in residential solar rooftops, commercial PV plants, ESS racks, and EV charging hubs. They isolate faults before they damage inverters or batteries, ensuring uninterrupted operation. From small rooftop systems to large industrial ESS containers, Kuangya breakers deliver safe and bankable protection for every scale of project.
Install & service
All Kuangya DC breakers are DIN-rail mounted, compact, and designed for easy service. Their modular design allows field replacement without downtime, reducing O&M costs. With clear labeling, quick wiring, and robust housing, these DC distribution breakers ensure installer efficiency and long-term maintainability in demanding solar and ESS environments.
Applications & Use Cases
Kuangya DC MCB delivers reliable DC circuit protection for solar PV, ESS, and EV charging scenarios. It isolates faults, protects inverters/batteries, and coordinates with DC fuses, DC SPDs, and DC disconnectors inside PV combiner boxes.
Commercial & Industrial PV Arrays
High-current feeders protected by DC MCB 1000V for C&I rooftops and carports.
Ground-Mounted Solar Systems
Combiner arrays using miniature DC circuit breakers for safer maintenance.
ESS Battery Racks & Containers
Protection up to 125A; integrates with BMS and DC distribution.
EV Charging Hubs / Carports
Protects feeders in EV charging sites with upstream disconnects.
Microgrid & Off-Grid Systems
Rugged solar DC MCB ensures isolation for remote microgrids in harsh conditions.
Application Guidance
Not sure which DC MCB to choose? Use the quick guidance below. These pair well with DC Fuse, DC SPD, DC Switch Disconnectors and PV Combiner Boxes for a coordinated protection scheme.
63A
Residential Rooftop PV
Small PV arrays (up to ~10 kW), string protection
125A
Commercial & Industrial Rooftop
Multiple strings, higher feeder current
- Recommended: KYDB-125 (1P / 2P)
- Feeder & sub-array protection up to 125A
- Coordinate with upstream DC disconnectors
125A
Ground-Mounted / Utility PV & ESS
Large combiner outputs, DC bus & containerized ESS
- Recommended: KYDB-125 (3P / 4P)
- For 750 / 1000VDC mains, higher breaking capacity
- Integrates with PV combiner & DC distribution
125A
EV Charging Hubs / Carports
DC feeders & auxiliaries in EV charging sites
* Final sizing depends on IEC 60947-2 / UL 489 compliance, cable ampacity, fault level and system architecture. Need help? Talk to our engineers.
Wiring & Installation Guide
Practical notes for installing DC MCB in solar PV, ESS and EV charging systems. Coordinate the breaker with DC fuses, DC SPDs, DC disconnectors and PV combiner boxes.
Wiring Accessories
- MC4 leads / ring or fork lugs for PV strings and feeders.
- Comb busbar (phase combs) or Cu links for multi-pole bridges.
- DIN-rail EN 60715 mounting; allow air gaps for heat dissipation.
- Use the correct torque for terminals (see datasheet); re-check after 24–48 h.
Cabling & Protection
- Size cables by continuous current + temperature derating.
- Keep feeder runs short and avoid tight bundles to reduce temperature rise.
- For strings: MCB provides isolation; coordinate with a gPV fuse.
- Add upstream SPD and main disconnector.
Polarity & Labeling
- Clearly label + / −, pole count and VDC rating at the device.
- Use handle-tie kits when poles must trip together (2P/3P/4P).
- Keep minimum bend radius; route away from sharp edges and hot surfaces.
- Record settings, torque and test results in the O&M log.
Typical DC Voltage by Pole Configuration
Values below reflect common system groupings for Kuangya KYDB series; always verify the exact rating on the product label and the datasheet (IEC 60947-2 / UL 489).
Pole option
Typical VDC
Typical application
1P
250 V DC
Small DC panels, auxiliaries, single-pole isolation
2P
500 V DC
PV strings (±), EV auxiliaries, balanced two-wire feeders
3P
750 V DC
ESS rack segments, higher-voltage sub-arrays
4P
1000 V DC
PV combiner outputs, containerized ESS / DC distribution
Why does the allowable DC voltage increase with more poles?
Multi-pole DC MCBs place poles in series so the total arc distance is increased and the voltage stress is divided across internal arc chambers. For example, 2P ≈ 500 VDC and 4P ≈ 1000 VDC for the KYDB series. Note that breaking capacity still follows the device rating—adding poles does not multiply the short-circuit rating. Always use the manufacturer’s approved pole kits so the poles trip together.
Can I wire poles in parallel to increase current?
Parallel poles are not recommended unless explicitly stated by the manufacturer. Unequal impedance causes current imbalance and nuisance tripping. Choose the correct frame (e.g. KYDB-125) and size cables per derating instead.
Why Choose Kuangya for DC MCBs
Factory-tested DC miniature circuit breakers engineered for solar PV, ESS and EV charging. Certified to IEC 60947-2 / UL 489, with rapid delivery and OEM options.
Factory-Direct & Certified
Own manufacturing with ISO 9001 QA. Batch test against IEC 60947-2 / UL 489.
Visit our factory →High-Voltage Type Testing
Arc-quenching tests for 1000VDC / 125A. Routine inspection & traceability reports.
See quality program →Fast Lead Time
Stock on key poles. Typical delivery 7–15 days. Global shipping support.
Check availability →OEM / ODM Ready
Private label, custom poles, voltage markings & packaging to match your line.
Explore OEM options →Global Project Experience
Deployed in PV farms, C&I rooftops, ESS containers & EV hubs across 30+ regions.
View case studies →DC MCB FAQ
Frequently asked questions about DC MCB applications in solar PV, ESS and EV charging. Covering voltage, breaking capacity, fuse coordination, SPD protection, switch disconnectors, and compliance with IEC 60947-2 / UL 489.
1. What is a DC MCB and how does it work?
A DC MCB (Miniature Circuit Breaker) provides overcurrent and short-circuit protection in direct current systems such as solar PV, ESS, and EV charging. It interrupts the DC arc safely to protect equipment and cables.
2. What are the typical applications of a DC MCB?
They are used in solar rooftops, ground-mounted PV arrays, ESS battery racks, and EV charging hubs to ensure reliable circuit protection.
3. How is the rated voltage defined?
The rated voltage increases with the number of poles: 1P=250VDC, 2P=500VDC, 3P=750VDC, 4P=1000VDC. This enables flexible design for different PV and ESS voltages.
4. Can DC MCBs be used in parallel?
Not recommended unless approved by the manufacturer. Parallel poles may cause current imbalance. Instead, select the correct frame size such as KYDB-125 and follow IEC 60947-2 guidelines.
5. How to size a DC MCB for PV strings?
Choose a current rating above the PV string short-circuit current (Isc). Check breaking capacity, coordination with DC fuses, and compliance with UL 489 / IEC 60947-2 standards.
6. What is the breaking capacity of Kuangya DC MCBs?
Kuangya breakers are rated up to 6kA at 1000VDC, ensuring safe disconnection under fault conditions for both residential and utility-scale PV systems.
7. What are the installation requirements?
DIN-rail mounted per EN 60715. Use proper torque for terminals, MC4 leads or busbars for secure wiring, and maintain clear polarity labeling (+/−).
8. Are DC MCBs compliant with global standards?
Yes. They comply with IEC 60947-2 and UL 489, meeting global certification requirements.
9. Can DC MCBs be combined with other protective devices?
Yes, they are often coordinated with SPDs, fuses, and switch disconnectors inside PV combiner boxes to form a complete protection stack.
