LMB1-125DC 1000V DC Breaker | 125A MCB for PV & Energy Storage

LMB1-125DC 1000V DC Breaker | 125A MCB for PV & Energy Storage

Engineered for DC power systems and solar PV applications, the LMB1-125DC series DC MCB from LVMA delivers robust 6kA short-circuit protection up to 1000V DC and 125A. With 1P through 4P pole options, DIN rail mounting and IEC 60947-2 compliance, it is a dependable, cost-effective protection solution for DC combiner boxes, storage systems and industrial DC circuits.

Engineered for DC power systems and solar PV applications, the LMB1-125DC series DC MCB from LVMA delivers robust 6kA short-circuit protection up to 1000V DC and 125A. With 1P through 4P pole options, DIN rail mounting and IEC 60947-2 compliance, it is a dependable, cost-effective protection solution for DC combiner boxes, storage systems and industrial DC circuits.

Product Overview

The LMB1-125DC is a professional DC-rated miniature circuit breaker (DC MCB) designed and manufactured by LVMA for overload and short-circuit protection in low-voltage DC power systems. Optimized for the fast-growing solar photovoltaic and battery energy storage markets, this breaker supports a rated voltage up to 1000V DC and a rated current up to 125A, with 1-pole, 2-pole, 3-pole and 4-pole configurations to match diverse system architectures.
Built with a dedicated DC arc-quenching chamber and magnetic blowout structure, the LMB1-125DC safely extinguishes DC arcs that occur during fault interruption — a critical performance difference from standard AC-only MCBs. With a 6kA ultimate and service short-circuit breaking capacity, Category A operation and full compliance with IEC 60947-2, it provides reliable circuit protection for DC distribution panels, solar combiner boxes, battery energy storage systems and industrial DC control circuits.
Featuring standard 35mm DIN rail mounting, clearly engraved polarity markings and a visible green status indicator, this DC MCB is easy to install, operate and maintain. Its flame-retardant housing and high-quality internal components ensure long service life even in demanding DC power environments.

Core Features & Advantages

  • DC-specific arc extinguishing system: Optimized arc chute with magnetic blowout design for reliable DC arc interruption, preventing arc restrike and ensuring safe, complete fault clearing.
  • Wide voltage & current rating: 1000V DC rated voltage, 125A maximum rated current, covering most residential, commercial and industrial DC power applications.
  • Full pole configuration range: Available in 1P, 2P, 3P and 4P versions to suit single-pole protection, dual-pole positive/negative disconnection and multi-pole DC system requirements.
  • 6kA high breaking capacity: 6kA ultimate short-circuit breaking capacity (Icu) and 6kA service breaking capacity (Ics), Category A operation, providing robust fault protection for DC circuits.
  • Clear polarity indication: Clearly marked positive (+) and negative (-) terminals to prevent reverse wiring errors that would compromise protection performance.
  • Visual ON/OFF indicator: Integrated green indicator window for at-a-glance confirmation of breaker operating status.
  • Standard DIN rail mounting: Fits universal 35mm DIN rails, compatible with most distribution enclosures for quick new installation and retrofit replacement.
  • Premium flame-retardant housing: High-temperature resistant, flame-retardant engineering plastic casing with excellent electrical insulation and mechanical strength.
  • Global compliance: Fully compliant with IEC 60947-2 international standard and CE certified, suitable for international projects and cross-border export requirements.

Detailed Technical Specifications

ParameterSpecification Details
ModelLMB1-125DC
BrandLVMA
Product TypeDC Miniature Circuit Breaker (DC MCB)
Available Pole Configurations1 Pole (1P), 2 Pole (2P), 3 Pole (3P), 4 Pole (4P)
Rated Operational Voltage (Ue)DC 1000V
Rated Current (In)125A
Ultimate Short-Circuit Breaking Capacity (Icu)6kA
Service Short-Circuit Breaking Capacity (Ics)6kA
Trip CategoryCategory A
Trip CharacteristicC curve (standard for DC power & solar PV applications)
Applicable StandardIEC 60947-2
CertificationCE
Mounting Method35mm standard DIN rail mounting
Housing MaterialFlame-retardant engineering plastic
Terminal TypeScrew clamp terminals
Operating Temperature Range-25°C ~ +60°C
Storage Temperature Range-40°C ~ +70°C
Mechanical Endurance≥ 20,000 operations
Electrical Endurance≥ 10,000 operations
Degree of Protection (front)IP20

Pole Configuration Selection Guide

  • 1P (Single Pole): Protects and disconnects one pole of the DC circuit. Suitable for low-voltage DC control loops, auxiliary DC circuits and small DC loads.
  • 2P (Double Pole): Simultaneously disconnects both positive and negative poles of the DC circuit. The most widely used configuration for solar PV strings, battery bank circuits and DC feeders, providing complete electrical isolation and maximum safety.
  • 3P (Three Pole): Used for three-wire DC systems, multi-string DC combiner circuits and industrial DC control systems requiring three-pole simultaneous protection and synchronized disconnection.
  • 4P (Four Pole): Designed for four-wire DC systems, multi-channel DC distribution and large-scale solar combiner boxes requiring four-pole synchronized switching and full-circuit protection.

Application Scenarios

  • Solar PV power systems: String protection and main DC side protection in photovoltaic combiner boxes, DC distribution cabinets and inverter input circuits.
  • Battery energy storage systems (BESS): Battery bank protection, charge/discharge circuit protection and DC distribution for residential and commercial energy storage installations.
  • DC power distribution panels: Main and branch circuit protection for industrial and commercial DC power distribution systems.
  • EV charging infrastructure: DC side protection for DC fast charging stations and charging pile power distribution units.
  • Telecom & data center power: 48V and other DC power system protection for communication base stations and data center DC power systems.
  • Industrial DC control systems: Protection for DC motor circuits, PLC power supplies and industrial automation DC control loops.
  • Off-grid renewable systems: DC circuit protection for off-grid solar, wind and hybrid renewable energy power systems.

Installation & Operation Notes

  1. Strict polarity compliance: Always connect the circuit according to the clearly marked positive (+) and negative (-) terminal markings. Reverse polarity will severely reduce breaking performance and may cause permanent damage.
  2. De-energized installation: All installation and wiring work must be performed with the DC circuit fully de-energized, and carried out by qualified electrical personnel.
  3. Proper wire sizing: Select appropriate cable cross-section according to the 125A rated current, and tighten terminal screws to specified torque to ensure reliable contact and prevent overheating.
  4. Mounting instruction: Snap the breaker firmly onto a standard 35mm DIN rail; ensure proper clearance between adjacent devices for heat dissipation and operation.
  5. AC use prohibition: This is a DC-dedicated circuit breaker and must NOT be used in AC circuits.
  6. Regular maintenance: Periodically inspect terminal connections, operating mechanism and insulation condition to maintain long-term reliable performance.
  7. After fault tripping: Identify and fully resolve the cause of overload or short circuit before resetting the breaker.

Packaging & Ordering Information

  • Standard packaging: Individual color box with product instruction manual and quality certificate
  • Customization: OEM logo printing and custom current rating options available for volume orders
  • Sample policy: Sample orders accepted for quality evaluation and field testing
  • Lead time: 3–7 working days for standard stock models; 10–15 working days for OEM and custom specifications
  • Pricing: Tiered volume pricing available for wholesale, EPC project and OEM orders

Frequently Asked Questions (FAQ)

Q: Can this DC MCB be used in AC circuits?

A: No. The LMB1-125DC is specially designed, tested and calibrated for DC circuits only. Using it in AC circuits will result in incorrect protection performance and create serious safety risks.

Q: What is the main difference between 1P and 2P DC MCBs?

A: A 1P breaker protects and disconnects only one line of the DC circuit, while a 2P breaker simultaneously disconnects both the positive and negative poles, providing full electrical isolation. 2P configuration is the standard choice for solar PV and battery systems for maximum safety.

Q: What is the short-circuit breaking capacity of this breaker?

A: Both the ultimate breaking capacity (Icu) and service breaking capacity (Ics) are rated at 6kA, which fully meets the protection requirements of most distributed solar PV and industrial DC systems.

Q: What international standard does this DC MCB comply with?

A: The LMB1-125DC complies with the IEC 60947-2 international standard for low-voltage switchgear and controlgear, and carries valid CE certification.

Q: Is this breaker suitable for 1000V solar PV systems?

A: Yes. With a 1000V DC rated voltage and dedicated DC arc extinguishing structure, it is specifically designed for mainstream 1000V-class photovoltaic systems and is widely used in PV combiner boxes and DC distribution cabinets.

Q: What mounting standard does this breaker use?

A: It adopts universal 35mm DIN rail mounting, which is compatible with almost all standard electrical distribution enclosures and switchgear panels on the market.

Product Overview

The LMB1-125DC is a professional DC-rated miniature circuit breaker (DC MCB) designed and manufactured by LVMA for overload and short-circuit protection in low-voltage DC power systems. Optimized for the fast-growing solar photovoltaic and battery energy storage markets, this breaker supports a rated voltage up to 1000V DC and a rated current up to 125A, with 1-pole, 2-pole, 3-pole and 4-pole configurations to match diverse system architectures.
Built with a dedicated DC arc-quenching chamber and magnetic blowout structure, the LMB1-125DC safely extinguishes DC arcs that occur during fault interruption — a critical performance difference from standard AC-only MCBs. With a 6kA ultimate and service short-circuit breaking capacity, Category A operation and full compliance with IEC 60947-2, it provides reliable circuit protection for DC distribution panels, solar combiner boxes, battery energy storage systems and industrial DC control circuits.
Featuring standard 35mm DIN rail mounting, clearly engraved polarity markings and a visible green status indicator, this DC MCB is easy to install, operate and maintain. Its flame-retardant housing and high-quality internal components ensure long service life even in demanding DC power environments.

Core Features & Advantages

  • DC-specific arc extinguishing system: Optimized arc chute with magnetic blowout design for reliable DC arc interruption, preventing arc restrike and ensuring safe, complete fault clearing.
  • Wide voltage & current rating: 1000V DC rated voltage, 125A maximum rated current, covering most residential, commercial and industrial DC power applications.
  • Full pole configuration range: Available in 1P, 2P, 3P and 4P versions to suit single-pole protection, dual-pole positive/negative disconnection and multi-pole DC system requirements.
  • 6kA high breaking capacity: 6kA ultimate short-circuit breaking capacity (Icu) and 6kA service breaking capacity (Ics), Category A operation, providing robust fault protection for DC circuits.
  • Clear polarity indication: Clearly marked positive (+) and negative (-) terminals to prevent reverse wiring errors that would compromise protection performance.
  • Visual ON/OFF indicator: Integrated green indicator window for at-a-glance confirmation of breaker operating status.
  • Standard DIN rail mounting: Fits universal 35mm DIN rails, compatible with most distribution enclosures for quick new installation and retrofit replacement.
  • Premium flame-retardant housing: High-temperature resistant, flame-retardant engineering plastic casing with excellent electrical insulation and mechanical strength.
  • Global compliance: Fully compliant with IEC 60947-2 international standard and CE certified, suitable for international projects and cross-border export requirements.

Detailed Technical Specifications

ParameterSpecification Details
ModelLMB1-125DC
BrandLVMA
Product TypeDC Miniature Circuit Breaker (DC MCB)
Available Pole Configurations1 Pole (1P), 2 Pole (2P), 3 Pole (3P), 4 Pole (4P)
Rated Operational Voltage (Ue)DC 1000V
Rated Current (In)125A
Ultimate Short-Circuit Breaking Capacity (Icu)6kA
Service Short-Circuit Breaking Capacity (Ics)6kA
Trip CategoryCategory A
Trip CharacteristicC curve (standard for DC power & solar PV applications)
Applicable StandardIEC 60947-2
CertificationCE
Mounting Method35mm standard DIN rail mounting
Housing MaterialFlame-retardant engineering plastic
Terminal TypeScrew clamp terminals
Operating Temperature Range-25°C ~ +60°C
Storage Temperature Range-40°C ~ +70°C
Mechanical Endurance≥ 20,000 operations
Electrical Endurance≥ 10,000 operations
Degree of Protection (front)IP20

Pole Configuration Selection Guide

  • 1P (Single Pole): Protects and disconnects one pole of the DC circuit. Suitable for low-voltage DC control loops, auxiliary DC circuits and small DC loads.
  • 2P (Double Pole): Simultaneously disconnects both positive and negative poles of the DC circuit. The most widely used configuration for solar PV strings, battery bank circuits and DC feeders, providing complete electrical isolation and maximum safety.
  • 3P (Three Pole): Used for three-wire DC systems, multi-string DC combiner circuits and industrial DC control systems requiring three-pole simultaneous protection and synchronized disconnection.
  • 4P (Four Pole): Designed for four-wire DC systems, multi-channel DC distribution and large-scale solar combiner boxes requiring four-pole synchronized switching and full-circuit protection.

Application Scenarios

  • Solar PV power systems: String protection and main DC side protection in photovoltaic combiner boxes, DC distribution cabinets and inverter input circuits.
  • Battery energy storage systems (BESS): Battery bank protection, charge/discharge circuit protection and DC distribution for residential and commercial energy storage installations.
  • DC power distribution panels: Main and branch circuit protection for industrial and commercial DC power distribution systems.
  • EV charging infrastructure: DC side protection for DC fast charging stations and charging pile power distribution units.
  • Telecom & data center power: 48V and other DC power system protection for communication base stations and data center DC power systems.
  • Industrial DC control systems: Protection for DC motor circuits, PLC power supplies and industrial automation DC control loops.
  • Off-grid renewable systems: DC circuit protection for off-grid solar, wind and hybrid renewable energy power systems.

Installation & Operation Notes

  1. Strict polarity compliance: Always connect the circuit according to the clearly marked positive (+) and negative (-) terminal markings. Reverse polarity will severely reduce breaking performance and may cause permanent damage.
  2. De-energized installation: All installation and wiring work must be performed with the DC circuit fully de-energized, and carried out by qualified electrical personnel.
  3. Proper wire sizing: Select appropriate cable cross-section according to the 125A rated current, and tighten terminal screws to specified torque to ensure reliable contact and prevent overheating.
  4. Mounting instruction: Snap the breaker firmly onto a standard 35mm DIN rail; ensure proper clearance between adjacent devices for heat dissipation and operation.
  5. AC use prohibition: This is a DC-dedicated circuit breaker and must NOT be used in AC circuits.
  6. Regular maintenance: Periodically inspect terminal connections, operating mechanism and insulation condition to maintain long-term reliable performance.
  7. After fault tripping: Identify and fully resolve the cause of overload or short circuit before resetting the breaker.

Packaging & Ordering Information

  • Standard packaging: Individual color box with product instruction manual and quality certificate
  • Customization: OEM logo printing and custom current rating options available for volume orders
  • Sample policy: Sample orders accepted for quality evaluation and field testing
  • Lead time: 3–7 working days for standard stock models; 10–15 working days for OEM and custom specifications
  • Pricing: Tiered volume pricing available for wholesale, EPC project and OEM orders

Frequently Asked Questions (FAQ)

Q: Can this DC MCB be used in AC circuits?

A: No. The LMB1-125DC is specially designed, tested and calibrated for DC circuits only. Using it in AC circuits will result in incorrect protection performance and create serious safety risks.

Q: What is the main difference between 1P and 2P DC MCBs?

A: A 1P breaker protects and disconnects only one line of the DC circuit, while a 2P breaker simultaneously disconnects both the positive and negative poles, providing full electrical isolation. 2P configuration is the standard choice for solar PV and battery systems for maximum safety.

Q: What is the short-circuit breaking capacity of this breaker?

A: Both the ultimate breaking capacity (Icu) and service breaking capacity (Ics) are rated at 6kA, which fully meets the protection requirements of most distributed solar PV and industrial DC systems.

Q: What international standard does this DC MCB comply with?

A: The LMB1-125DC complies with the IEC 60947-2 international standard for low-voltage switchgear and controlgear, and carries valid CE certification.

Q: Is this breaker suitable for 1000V solar PV systems?

A: Yes. With a 1000V DC rated voltage and dedicated DC arc extinguishing structure, it is specifically designed for mainstream 1000V-class photovoltaic systems and is widely used in PV combiner boxes and DC distribution cabinets.

Q: What mounting standard does this breaker use?

A: It adopts universal 35mm DIN rail mounting, which is compatible with almost all standard electrical distribution enclosures and switchgear panels on the market.

Data Download

LVMA low voltage selection manual

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