DC Circuit Breaker
DC circuit breakers are essential protection devices designed to safely interrupt direct current in solar PV, battery storage, and DC power systems. Compared with AC protection, DC current requires faster arc extinguishing and higher reliability.
At Moreday, we provide a full range of DC circuit breaker solutions covering low voltage to high voltage applications, including 600V, 1000V, and 1500V systems. Whether you need protection for photovoltaic installations, battery systems, or industrial DC distribution, our products ensure stable and safe operation.
Our DC Circuit Breaker Range
We offer a complete portfolio of DC protection devices to meet different system requirements:
A compact design engineered specifically for low-voltage systems, suitable for the protection of PV strings and battery circuits. It offers a wide range of rated current specifications from 1A to 125A, with optional configurations available in 1P, 2P, 3P, and 4P.
MDB1Z-63H DC Circuit Breaker
- Poles: 1P, 2P, 3P, 4P
- Rated Current: 10A-63A
- Breaking Capacity: 10kA, 6kA
- Rated Voltage: 1P:250V, 2P:600V, 3P:750V, 4P:1000V
- Curve Code: B, C
- Mechanical Durability: 10,000 cycles
- Electrical Durability: 2,000 cycles
- Protection Degree: IP40; Wiring port IP20
MDB1Z-63 DC Circuit Breaker
- Poles: 1P, 2P, 3P, 4P
- Rated Current: 1A-63A
- Breaking Capacity: 6kA (In ≤ 6A to 40A), 4.5kA (In 50A, 63A)
- Rated Voltage: 1P:250V, 2P:600V, 3P:750V, 4P:1000V
- Curve Code: B, C
- Mechanical Durability: 10,000 cycles
- Electrical Durability: 1,500 cycles
- Protection Degree: IP40; Wiring port IP20
MDB1Z-63S DC Circuit Breaker
- Poles: 1P, 2P, 4P
- Rated Current: 10A-63A
- Breaking Capacity: 6kA (In ≤ 6A to 40A), 4.5kA (In 50A, 63A)
- Rated Voltage: 1P:250V, 2P:600V, 3P:750V, 4P:1000V
- Curve Code: B, C
- Mechanical Durability: 10,000 cycles
- Electrical Durability: 1,500 cycles
- Protection Degree: IP40; Wiring port IP20
MDB2Z-63 DC Circuit Breaker
- Poles: 2P
- Rated Current: 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A
- Breaking Capacity: 6kA
- Rated Voltage: 800V/1000V~
- Curve Code: B, C
- Mechanical Durability: 15,000 cycles
- Electrical Durability: 1,500 cycles
- Protection Degree: IP40; Wiring port IP20
MDB1Z(NC)-125 DC Circuit Breaker
- Poles: 1P, 2P, 3P, 4P
- Rated Current: 80A, 100A, 125A
- Breaking Capacity: 6kA (In ≤ 100A), 4.5kA (In 125A)
- Rated Voltage: 1P:250V, 2P:600V, 3P:750V, 4P:1000V
- Curve Code: B, C
- Mechanical Durability: 10,000 cycles
- Electrical Durability: 1,500 cycles
- Protection Degree: IP40; Wiring port IP20
Why Choose MOREDAY DC Circuit Breaker?
MOREDAY is a professional DC Circuit Breaker manufacturer with over 18 years of experience in designing, producing, and exporting miniature circuit breakers. Located in Yueqing – China’s “Electric Device Metropolis” – we serve distributors, contractors, and electrical engineers across 30+ countries with high-quality, IEC/CE/RoHS certified circuit protection solutions.
- Industry-Leading Quality: Every DC MCB undergoes rigorous testing to ensure consistent performance and safety
- Innovative Design: Our R&D team continuously improves our products to meet evolving industry standards
- Comprehensive Support: From selection guidance to after-sales service, we're with you at every step
- Global Compliance: All MOREDAY MCBs meet international safety standards, including IEC, RoHS, CE, and more
- Competitive Pricing: Premium quality without the premium price tag
Precision Engineering - Inside MOREDAY DC Circuit Breaker Technology
At MOREDAY, we believe that true quality is revealed in the details. Our DC Circuit Breaker manufacturing philosophy centers on “Sublime Micro-Engineering Narratives” – where every component, from the smallest spring to the largest contact assembly, represents surgical precision and artistic interpretation of technical excellence.
- Fire-Retardant Casing: The shell is made of PA66 nylon material, offering V0-grade flame retardancy and high impact resistance.
- Silver Alloy Contacts: We use premium silver-graphite contacts to ensure low contact resistance and prevent welding during short circuits.
- Arc Extinguishing Chamber: An optimized 13-plate grid design rapidly cools and extinguishes arcs, extending the electrical life of the dc breaker.
- Visual Indicator: Clear Red/Green window indicates contact position for safe maintenance.
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How to Select the Right DC Circuit Breaker for Your Application
Proper MCB selection requires considering multiple factors. Use this comprehensive guide to specify the correct DC Circuit Breaker for your installation.
Selection Factor | What to Check | MOREDAY Recommendation |
|---|---|---|
Current Rating (In) |
Rated current should exceed normal load current by 15–25% safety margin. |
1–63A for residential & light commercial 63–125A for industrial & distribution panels |
Breaking Capacity (Icn) |
Must exceed maximum prospective short-circuit current at installation point. |
6kA for residential 10kA for commercial 15kA+ for industrial projects |
Trip Curve Type |
Match breaker sensitivity with load type and inrush current characteristics. |
Type B – Lighting & resistive loads Type C – General commercial use (recommended for 80% applications) Type D – Motors, transformers, high inrush equipment |
Number of Poles |
Select according to system phase configuration. |
1P / 2P – Single-phase systems 3P – Three-phase 4P – Three-phase + Neutral (recommended for industrial distribution) |
Voltage Rating |
Rated voltage must be equal or higher than system voltage. |
Up to 400/415V AC standard Higher voltage models available upon request |
Installation Environment |
Consider temperature, dust, humidity, and enclosure protection. |
Operating temperature: -25°C to +60°C IP20 standard, higher IP with enclosure |
Certification & Compliance |
Must comply with international and local standards. |
CE / CB / TÜV certified Compliant with IEC standards |
Special Application (Solar & DC Systems) |
DC systems require specially designed arc-extinguishing structure. |
Use MOREDAY DC MCB for PV combiner boxes and battery storage systems. |
DC Circuit Breaker Trip Curve Guide: How to Choose B, C or D for Your Application
Choosing the wrong trip curve may cause nuisance tripping or insufficient short-circuit protection. Understanding load characteristics is critical for system safety and reliability.
Curve Type | Magnetic Trip Range | Best For | Inrush Tolerance | Typical Buyers | MOREDAY Supply |
|---|---|---|---|---|---|
Type B |
3–5 × In |
Lighting circuits, heating elements, residential panels |
Low |
Residential installers, small contractors |
Available in 1P–4P, CE/CB certified |
Type C |
5–10 × In |
Distribution panels, small motors, office buildings |
Medium (industry standard) |
Recommended for 80% of commercial applications |
Default production curve |
Type D |
10–20 × In |
Motors, transformers, compressors, EV charging equipment |
High |
Prevents nuisance tripping in high starting current equipment |
Available upon project request |
Type K |
8–14 × In |
High inrush machinery, X-ray systems, heavy equipment |
MOQ applies for customization | ||
- If your load is mainly lighting → Choose Type B
- If your load includes motors under 3kW → Choose Type C
- If your system includes large motors or compressors → Choose Type D
- If you have any questions, please contact the MOREDAY engineering team.
- What happens if I use Type B for a motor? It may trip instantly during startup due to high inrush current.
- Can Type D replace Type C? Yes, but it may reduce sensitivity and not be suitable for light loads.
DC Circuit Breaker Manufacturing Process - From Raw Materials to Certified Products
Our Production Workflow As a vertically integrated MCB manufacturer, we control every stage:
1. Raw Material Inspection
- Imported silver alloy contacts
- High-purity electrolytic copper terminals
- PA66 flame-retardant housing (UL94 V0)
- Bimetallic strips from certified suppliers
2. Automated Assembly
- Robotic contact assembly (±0.01mm precision)
- Arc chamber installation & testing
- Thermal & magnetic element calibration
- Final assembly in Class 10,000 cleanroom
3. 100% Quality Testing
- Automatic electrical testing station
- Temperature rise measurement
- Dielectric strength testing
- Mechanical operation testing (20+ cycles)
4. Certification & Packaging
- Batch traceability labeling
- IEC/CE compliance documentation
- Anti-static packaging
- Custom branding (OEM orders)
Applications
Electrical Solutions for Every Need
As a trusted electrical equipment manufacturer, MOREDAY delivers high-performance electrical solutions designed for residential, commercial, industrial, and renewable energy applications—providing cost savings, operational efficiency, and reliability across diverse industries worldwide.
Solar & Energy Systems
The solar sector relies on specialized DC components for safe high-voltage management and surge protection in photovoltaic systems.
Industrial Manufacturing
Industrial manufacturing requires robust electrical controls for heavy machinery and automation systems.
Commercial & Residential
Buildings need electrical solutions prioritizing safety and efficiency while meeting codes.
Marine & Offshore Industries
Marine applications require components withstanding saltwater, humidity, and vibration.
DC Breaker Factory Image
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More Than Just a DC Circuit Breaker Manufacturer
At MOREDAY, we go beyond manufacturing DC Circuit Breaker by offering a suite of value-added services tailored to meet your project needs. Our commitment to excellence ensures that every customer receives personalized attention, expert guidance, and seamless support throughout their journey with us.
Technical Consultation
Our engineering team provides professional DC protection design support for solar PV systems. From breaker selection to full combiner box configuration, we help you ensure safety, compliance, and long-term reliability.
OEM & Custom Solutions
We support logo printing, customized voltage ratings, special tripping curves, and private label packaging. MOREDAY helps distributors and project contractors build competitive branded products for local markets.
Certified Quality Assurance
Our MCB products comply with CE, CB, and TÜV standards. Each unit undergoes strict testing for breaking capacity, temperature rise, and durability to meet international project requirements.
Global Project Experience
MOREDAY products are widely used in solar power plants, energy storage systems, EV charging stations, and industrial applications across Europe, Asia, and Africa.
Frequently Asked Questions
A DC circuit breaker is a protection device designed to interrupt direct current in case of overload or short circuit, ensuring system safety.
- Can an AC circuit breaker be used for DC?
No. AC circuit breakers are not designed for DC arc suppression and may fail to interrupt the current safely.
DC breakers are designed to handle continuous current without zero crossing, requiring stronger arc extinguishing capability.
- Where are DC breakers used?
They are commonly used in solar systems, battery storage, DC distribution panels, and industrial DC applications.
- How do I choose the correct DC breaker rating?
It depends on system voltage, load current, and application requirements. Always select a breaker with appropriate voltage and current margins.
Get Your DC Circuit Breaker Quote Today !
We provide samples for free, you just need to tell us what you need