Installation of armored incoming line in explosion-proof distribution box

Armored incoming lines must be securely connected, properly grounded, and sealed to maintain explosion-proof integrity in hazardous areas.

Cable Entry and Routing

The incoming armored cable should enter the distribution box from the bottom, avoiding top, side, back, or door entries to reduce exposure to environmental hazards and maintain safety . The cable must be sheathed and bundled, with waterproof bending to prevent moisture ingress. The conductor bundle should not contact the inlet or outlet directly, and it is strictly forbidden to connect the power cord to the switch box using bolts . Rubber-insulated cables are recommended for mobile or switch boxes .

Connection and Grounding

Inside the box, the armored cable should be connected to the terminals using insulated wires, ensuring that joints are tight and no live parts are exposed . The grounding wire must be connected to a dedicated grounding screw and extended to the armored cable or conduit, providing an uninterrupted grounding path . The protective earth (PE) and neutral (N) lines should be connected through separate terminal boards, not spliced, and sized according to the largest load conductor .

Material and Sealing

The distribution box should be made of stainless steel (grade 304 or higher) or aluminum with a minimum wall thickness of 4 mm . Threaded connections alone are insufficient for sealing; use certified sealing compounds or fittings to prevent explosive gas ingress . Regular inspection of seals is necessary, especially in high-moisture or vibration-prone environments .

Compliance and Safety Standards

All components, including armored cables, must comply with ATEX or equivalent safety certifications and installation must follow EN 60079-14 standards for hazardous areas . Minimize the number of electrical components and cable runs in the hazardous zone to reduce ignition risk . Only qualified personnel with proper certification should perform the installation .

Installation Environment

Install the distribution box in ventilated, dry, and normal temperature locations, avoiding areas with gas, smoke, steam, liquids, or excessive vibration . Ensure sufficient space for maintenance and operation, allowing at least two people to work safely around the box .

Summary

Proper installation of armored incoming lines in explosion-proof distribution boxes requires careful attention to entry location, cable sheathing, grounding, sealing, material selection, and compliance with safety standards. Following these practices ensures the system maintains its explosion-proof integrity and operates safely in hazardous environments .