Before any wiring work begins, the entire interior of the explosion-proof cabinet must be cleared of all loose metal shavings, leftover wire scraps, and small particulate debris that could compromise the sealing structure. All cable entry points should be checked against the approved construction drawing to confirm their position, opening size, and corresponding sealing fitting specifications match the designated hazardous area classification. Technicians must verify that the cabinet’s housing shows no visible cracks, deformation, or paint damage that could reduce its structural integrity under internal pressure fluctuations. Every unused opening on the cabinet shell must be pre-fitted with a certified sealing plug that matches the thread pitch and material rating of the original cabinet design.

Cable preparation before entry into the cabinet
Each cable that passes through the cabinet wall must be stripped carefully to avoid nicking or scratching the outer protective jacket, as any damage to this layer can create gaps that allow flammable gas to seep into the cabinet interior. The portion of the cable that sits inside the sealing fitting must retain its full outer jacket, and no bare conductors or exposed inner shielding layers should be positioned within the sealing path. The outer surface of the cable jacket should be wiped clean of all dust, grease, and residual cutting fluid before installation, to ensure a tight, contamination-free bond with the sealing compound inside the gland.

Sealing fitting installation and compression process
Feed the prepared cable through the sealing fitting in a straight, steady motion, and avoid twisting or pulling the cable at an angle that could misalign the internal sealing components. Tighten each compression nut gradually and evenly, moving in a rotational sequence across multiple partial turns instead of cranking one side fully tight at once. This uniform compression ensures the sealing material wraps completely around the cable jacket without creating uneven gaps or localized points of excessive stress that could crack the fitting housing. After tightening, technicians should pull the cable gently from both inside and outside the cabinet to confirm it cannot shift or rotate freely under normal applied force.

Internal wiring layout for explosion-proof safety
All conductors inside the cabinet must be arranged with sufficient clearance to prevent physical contact between high-power loops and low-signal PLC module wiring, which reduces the risk of accidental short circuits that could generate excessive heat. No excess cable length should be coiled tightly inside the cabinet, as dense loops can trap heat and create unintended electromagnetic coupling that interferes with PLC signal stability. Every terminal connection point for PLC modules must be secured with the specified torque value, and no loose wire strands are allowed to extend outside the terminal clamp where they could come into contact with adjacent conductive parts. All wiring paths must avoid blocking the cabinet’s internal flameproof gaps, so any internal pressure surge caused by an electrical fault can be dissipated safely through the designated pressure relief structure instead of building up to rupture the cabinet housing.