Introduction to the Functions of Temporary Electricity Secondary Distribution Box

The secondary distribution box is a distribution box in the power distribution system. The secondary box for temporary electricity must have a rainproof structure, and the leakage protection function is crucial. It further distributes the electricity allocated by the primary distribution box to 下级 electrical equipment and circuits. The secondary distribution box is a key link in the power supply network that connects the preceding and the following. It receives electricity from the primary general distribution box and is responsible for redistributing power to multiple tertiary boxes (terminal switch boxes) or medium-sized electrical equipment within its jurisdiction.

Expand Power Supply Range: As an intermediate hub for power coverage, it expands one main power source into multiple branch circuits, enabling electricity to effectively extend to various floors of buildings, different work sections in workshops, or various areas of construction sites. It forms a selective protection system with the primary box and tertiary boxes. When a fault occurs at the terminal, the switch closest to the fault point (usually on the branch of the tertiary box or secondary box) operates first, minimizing the affected range and avoiding large-scale power outages.
Power Source Disconnection and Isolation: Equipped with a main isolation switch or main circuit breaker, it is used to connect, carry, and break normal current. It can also provide an obvious electrical break point during line maintenance to ensure safety.
Overload Protection: Both the main circuit breaker and each branch circuit breaker have overload protection functions. When the current continuously exceeds the set value, they will operate with a time delay to cut off the power source, preventing the line from overheating and being damaged or causing a fire. Short-Circuit Protection: All circuit breakers have instantaneous short-circuit protection functions. When a short-circuit fault occurs in the line, they can trip quickly to cut off the huge short-circuit current and protect the power distribution system and equipment.
Leakage Protection (Necessary in Many Scenarios): Leakage protectors are often installed on the main circuit or branch circuits. When line leakage (which may cause electric shock accidents) is detected, they can cut off the power source immediately to ensure personal safety.
Measurement and Monitoring (Optional): Voltmeters, ammeters, electricity meters, etc., can be installed to monitor the voltage stability, current magnitude, and electricity consumption in this area in real time. Status Indication: It is usually equipped with indicator lights (such as power indicator lights, operation indicator lights) to visually display the power-on and operation status of the box.

Advantages

Improve Power Supply Reliability: Achieve "localized faults" through graded protection. A fault in one branch will not affect the entire system, only the local area. Faults are quickly located, and power supply is restored rapidly. Facilitate Management and Maintenance: The structure is clear, and responsibilities are well-defined. Each secondary box manages a specific area, enabling quick location of power usage issues and greatly simplifying operation and maintenance work.
Enhance Operational Safety: The main isolation switch ensures that the entire area can be safely powered off, facilitating maintenance and repair. The box itself also has a certain protection class, capable of withstanding the influence of the external environment.
Flexible Layout and Expandability: Space or circuits can be reserved inside the box according to the development of regional load, making it convenient to add new branch circuits on the existing circuits, adapting to changes in future power demand.
Economical and Efficient: Optimize cable routing, avoiding the direct laying of a large number of cables from the general distribution box to each terminal device, saving cable costs and construction workload.

Application Scenarios (Main Usage Occasions)

Secondary distribution boxes are widely used in medium and large-scale electricity-consuming venues, medium and large buildings, industrial parks, office buildings, and other places that require hierarchical power distribution. They are used to distribute the power from primary distribution boxes to various areas. They must be of rainproof structure and mainly serve the construction of national-level large construction sites, industrial factories and workshops, commercial and public buildings, residential communities, etc.