Small Complete Set of Power Distribution Boxes

Small Complete Set of Power Distribution Boxes integrates various electrical components according to a specific circuit scheme, installed within a small metal cabinet. Although small, it is a complete power system unit. Shangming is the supplier of this product, and we also provide various other types of distribution cabinets and boxes.

Product Composition

Shangming's Small Complete Set of Power Distribution Boxes features advanced design and reliable quality. Component-wise, this series is not simply a collection of multiple distribution boxes, but rather a modular unit collection scientifically configured based on electrical system logic, functional division, and installation coordination.

1. Box Support System

This part is responsible for the physical protection of the box.

Shell: Typically made of cold-rolled steel plate or stainless steel.

Mounting Rails: Standard metal rails arranged horizontally inside the box for quick mounting of circuit breakers and other components.

Panel: Equipped with a door; a customizable viewing window door is available, exposing only the circuit breaker operating handle to prevent accidental contact with live parts.

2. Primary Distribution System

The primary distribution system handles power distribution, providing control and protection.

Main Circuit Breaker: The main control switch for the entire box, used for emergency power outages or maintenance.

Miniature Circuit Breaker: Provides overload and short-circuit protection for each branch circuit.

Residual Current Device (RCD): Monitors current leakage and instantly cuts off power in case of electric shock risk.

Surge protector: Absorbs instantaneous high voltage generated by lightning strikes or power grid fluctuations, protecting downstream precision electrical appliances.

3. Auxiliary and Monitoring System

Indicator lights: Red for operation, green for stop, yellow for fault, displaying the current power status.

Metering instrument: Small DIN rail-mounted energy meter for monitoring voltage, current, or power consumption.

Terminal block: For neat connection of external load cables, facilitating future maintenance.

4. Electrical Connections and Accessories

Busbar: Comb-shaped or fork-shaped copper busbars, replacing messy jumpers, making connections between circuit breakers more compact and reducing heat generation.

Grounding and neutral busbar: Uses dedicated copper strips to centrally connect the neutral and ground wires of all circuits.

Internal wiring harness: Flame-retardant wires meeting current rating requirements, routed through cable trays with clear wire number markings.

How to Choose the Right Complete Distribution Box?

Before starting a project, it's crucial to correctly identify the complete distribution box configuration. Inappropriate selection can lead to functional redundancy, wasted costs, installation difficulties, or limited future expansion.

Step 1: Define the Application Scenarios and Load Characteristics

Please confirm the following questions:

1. Where will it be used?

Indoor drying workshop → IP40 is sufficient

Outdoor/pump room/seaside → Requires IP54/IP65, stainless steel material

2. What equipment will it power?

Lighting/sockets: Single-phase, low current (≤32A)

Motors/welding machines: Three-phase, high current (≥32A), requires thermal relays/contaminators

Smart devices: Requires 24V DC, communication interface

3. Is automated control required?

Manual Start/Stop → Basic Power Box

Automatic Logic/Remote Monitoring → Requires PLC/HMI Box

Step 2: Calculate Electrical Parameters and Determine Capacity

1. Total Load Estimation

List the power (kW) and operating voltage of all electrical equipment. If you have difficulty, Shangming's technical team can help you confirm.

Calculate the total current, considering a simultaneity factor Kx = 0.7–0.9;

Example:

3 x 5.5kW motors (380V) → Single motor current ≈ 11A, total current ≈ 3 × 11 × 0.8 = 26.4A;

Lighting 5kW (220V) → Current ≈ 23A;

Main incoming line recommended ≥63A.

2. Branch Circuit Planning

Each type of load should have an independent circuit to avoid interference. Single circuit current ≤ 80% of the circuit breaker's rated value.

Important equipment is recommended to have a separate circuit + UPS.

Step 3: Determine the number and combination of enclosures

Simple scenario: 1 integrated enclosure

Medium-complex scenario: 2–3 enclosures

High complexity and high security requirements: 3–6 enclosures

Step 4: Select protection level and material

Shangming's products offer protection levels from IP30 to IP66, and materials include cold-rolled steel and stainless steel.

If you have safety and intelligence requirements, and need to improve the convenience of future maintenance based on the specific installation location, please communicate with us. Shangming will review the feasibility and provide a quotation and samples within 1-2 working days based on the drawings and technical requirements.

FAQ

Q: Why choose a Small Complete Set of Power Distribution Boxes instead of a single large cabinet?

A: Small, complete distribution boxes can be flexibly combined with different functional enclosures according to actual needs. Some cables and components are pre-integrated at the factory, making on-site installation simpler and faster, and suitable for confined or irregular spaces. During maintenance, functional zoning is clearly defined, facilitating troubleshooting and repair.

Q: How to perform daily maintenance and inspection?

A: Check the operating status of all circuit breakers and contactors quarterly to ensure there is no overheating or loosening.

Regularly clean dust accumulated inside the enclosure, especially the cooling fan and filters. Check the door frame seals for aging and cracking, and replace them if necessary.

Record the inspection results and corrective actions after each maintenance for traceability.

About Us

Shangming Electric is located in Yueqing, Wenzhou, China, the "Electrical Capital of China." Leveraging the well-developed industrial chain of Yueqing's electrical industry cluster, we have established a rigorous and efficient production and quality control system. Our factory is equipped with over 5 automated production lines, with a monthly production capacity of over 3,000 units.

We have obtained ISO9001 quality management system certification, as well as CE, CQC, and other relevant product certifications. We have successfully cooperated with customers in over 50 countries and regions worldwide. In addition to products, we also provide technical consultation and on-site installation guidance.