Distribution Box Specifications Table

Distribution boxes are specified by type, material, dimensions, protection rating, mounting, and internal components to ensure safe and reliable low-voltage power distribution.

Key Specifications

1. Material and Construction

• Metal Boxes: High-strength Q195 cold-rolled steel, full metal construction for durability, corrosion resistance, and mechanical strength. Anti-rust treatment applied for long-term use .
• Plastic Boxes: Suitable for residential areas, supporting surface-mounted or flush-mounted installation, compliant with IEC 60439-3 .
• Outdoor Boxes: Fabricated from 2 mm GI sheet steel with reinforced channels, slanting roof with overhang, and Godrej-type 3-position locking system for security . 2. Protection and Safety
• IP Ratings: Indoor metal boxes typically IP30; outdoor LT distribution boxes IP55 for dust and water protection .
• Earthing: Solid earthing points on either side for safety .
• Internal Barriers: Metallic or heat-resistant insulating barriers between MCCBs to prevent overheating . 3. Dimensions and Capacity
• Ways: Distribution boxes range from 1-way to 36-ways depending on model (TOP-TS, TOP-TF, TOP-LS, TOP-PS, TOP-PF, TOP-S), .
• Busbars: Copper flat busbars (e.g., 25x4 mm) with color-coded insulation or paint for phases; provision for one busbar arrangement with MCCB and outgoing feeders .
• Cable Glands: Heavy-duty, double compression type for incoming and outgoing cables .
• Tolerance: Dimensions may vary ±10% over specified values . 4. Mounting and Installation
• Indoor Boxes: Surface-mounted or flush-mounted; DIN rail support on left and right sides for modular components .
• Outdoor Boxes: Provision for lighting inside, slanting roof for water runoff, and reinforced structure for mechanical stability .
• Front Cover: Hinged with screws behind the door for safety; PC window or metal cover options . 5. Compliance and Standards
• IEC 60439-3: For low-voltage switchgear and controlgear assemblies accessible to unskilled persons .
• IS 13947 (Part 2/1993): For MCCB and neutral unbalance protection .
• Type Testing: Certificates from CPRI or government-approved laboratories required for IP rating and material quality . 6. Internal Components
• MCBs, RCDs, RCCBs: Modular devices accommodated on DIN rails .
• Terminals and Screws: Brass terminal blocks, M4x4 screws, round M-shape screws, and plastic strips for secure connections .
• Busbar Insulation: Phase-colored insulation tubing or paint for safety and identification . This specification table provides a comprehensive overview for selecting distribution boxes based on application, environment, and safety requirements, ensuring compliance with international and national standards while supporting reliable electrical distribution.