Voltage used in the distribution box

Low-voltage distribution boxes are typically rated up to 1000V, with common industrial voltages ranging from 380V to 660V, while primary distribution boxes handle higher voltages from 4 kV to 35 kV.Low-Voltage Distribution Boxes

Low-voltage distribution boxes are designed for residential, commercial, and industrial applications where the voltage does not exceed 1000 volts. Most industrial systems use voltages up to 600V, while common models include:

• GGD series: Rated at 380V AC, 50Hz, used in power plants and substations .
• GCK series: Rated around 660V AC, 60Hz, suitable for motor control and lighting equipment .
• GCS series: Rated 400V AC, 50Hz, used in high-consumption areas like buildings and factories . These boxes must match the expected load to prevent overheating, voltage drop, or equipment failure. Proper short-circuit protection, grounding, and adherence to standards like NEC and IEC are essential for safety .

Primary Distribution Boxes

For higher-voltage applications, such as utility distribution networks, primary distribution boxes handle voltages between 4 kV and 35 kV. Common voltage classes include 5 kV, 15 kV, 25 kV, and 35 kV, with the 15 kV class (e.g., 12.47 kV line-to-line) being widely used in North America . These boxes are designed for equipment rated to the voltage class, including insulators, transformers, and surge arresters.

Key Considerations

• Voltage Rating: Always select a box rated for the system voltage to avoid overheating or failure .
• Load Matching: Ensure the box can handle the maximum expected current and peak loads .
• Safety Standards: Follow IEC 61439 and local electrical codes for short-circuit withstand, grounding, and protective devices .
• Environmental Factors: Choose materials and enclosures suitable for indoor or outdoor use, considering dust, moisture, and temperature . In summary, for typical low-voltage applications, 380V to 660V is suitable, while primary distribution systems require 4–35 kV-rated boxes. Always verify the voltage and current ratings, protection devices, and compliance with safety standards before installation.