MDB7-100 is applied in a PV system; it can close automatically, the quality is excellent, and it can maintain the power transmission mode for a long time.


  • 6ka high-performance segmentation capability
  • Automatic reclosing function
  • Din Rail installation
  • Small and intelligent
  • Allow over and under voltage function
  • Excellent material


A PV reclosing breaker is a specialized type of electrical switch used in photovoltaic systems to protect electrical equipment from damage due to fault conditions. It is designed to automatically interrupt the flow of current when a fault is detected, isolating the affected part of the system to prevent further damage. After a predetermined time, the breaker recloses, restoring power to the system if the fault has cleared.

PV Reclosing Circuit Breaker MDB7-100


Interrupter: This is the part responsible for breaking the electrical connection during a fault.
Contacts: These conductive parts enable the flow of current when the breaker is closed.
Actuator: This is the mechanism that opens and closes the breaker.
Control Unit: This component monitors the system for faults and sends signals to the actuator.
Reclosing Relay: This device determines when to reclose the breaker after a fault has cleared.


When a fault occurs in the PV system, the control unit detects the abnormal current flow and sends a signal to the actuator. The actuator then opens the breaker, disconnecting the faulty section from the rest of the system. This interrupts the current flow and extinguishes the electrical arc.

After a predetermined time, the reclosing relay sends a signal to the actuator to close the breaker, reconnecting the previously isolated section. If the fault has cleared, power is restored to the system. However, if the fault persists, the breaker will open again, repeating the process until the fault is resolved or a pre-set limit of reclosing attempts is reached.


Model MDB7-100
Rated Current In
1p+n, Single Phase 3p+n, Three-phase Four-wire System
Rated Working Voltage Ue
1P+N/2P 230V AC/50Hz 3P+N/4P 400V AC/50Hz
Electrical Life
≥6000 times, cos=0.85~0.9
Mechanical Life
Automatic Reclosing Tc
Rated Impulse Withstand Voltage (uimp)
For mounting on
35mm DIN rails
Degree of protection


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Common Queries

Frequently Asked Questions

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A: A PV reclosing breaker is designed to protect electrical equipment in photovoltaic systems by interrupting the flow of current during fault conditions and automatically reclosing once the fault is resolved.

We have a scientific and perfect management process to ensure that each process is fully implemented in accordance with production standards, and we provide strict testing procedures.
The most important thing is that we want to ensure that customers have confidence in and recognition of Moreday products and can fully devote themselves to product sales without worrying about after-sales problems.

A: The main types of PV reclosing circuit breakers are vacuum circuit breakers, SF6 circuit breakers, and air circuit breakers. Each type has its own advantages and drawbacks in terms of performance, maintenance, and environmental impact.

A: PV-reclosing breakers increase system reliability by automatically isolating faults and restoring power after the issue has been resolved. This minimizes downtime and keeps the photovoltaic system operational.

A: When selecting a PV reclosing breaker, consider factors such as voltage and current ratings, type of circuit breaker, reclosing settings, and environmental factors like temperature, humidity, and altitude.

A: Common issues with PV reclosing circuit breakers include failure to open or close, inaccurate fault detection, and frequent reclosing. These issues can be addressed by ensuring proper installation, following the manufacturer’s guidelines, regularly inspecting and maintaining the breaker, and monitoring its performance to adjust settings as needed.

A: To maintain your PV reclosing circuit breaker for optimal performance, follow the manufacturer’s guidelines for installation, regularly inspect and clean the breaker contacts, monitor the breaker’s performance and adjust reclosing settings as needed, and perform routine maintenance, especially for SF6 circuit breakers, to address potential gas leakage.

A: Future trends in PV reclosing circuit breaker technology include the integration of advanced sensors and communication protocols for improved fault detection and remote monitoring, the development of eco-friendly alternatives to SF6 circuit breakers, and enhanced fault-clearing capabilities through faster-acting actuators and advanced arc-extinguishing methods.

A: A PV reclosing circuit breaker differs from a traditional circuit breaker in its ability to automatically reclose after a fault has been resolved. This feature enables continuous operation of the photovoltaic system and minimizes downtime.

A: Although PV reclosing circuit breakers are designed specifically for photovoltaic systems, they can be used in other applications with similar voltage and current requirements, as long as they meet the necessary safety standards and regulations.

A: Choosing the right reclosing settings for your PV reclosing circuit breaker is crucial to ensuring proper fault clearing and restoration of power. Incorrect settings may cause the breaker to reclose too quickly or too slowly, leading to further damage or prolonged downtime.

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