All three are ABX loop boxes but with different materials, protection ratings, and installation methods: (1) ABX-T — cold-rolled steel enclosure, IP40, surface or flush mounting, designed for indoor use with a multi-layer protective shield. The most economical indoor option. (2) ABX-T-2 — PC/ABS alloy or stainless steel, IP54/IP65, underground pit or ground-mounted outdoor, 180° upward-opening door, concealed screws. Designed for harsh underground/exposed outdoor use. (3) ABX-S (this product) — PC/ABS alloy plastic, IP54/IP65, wall-mounted for indoor or sheltered outdoor, three-layer structure (panel + breaker rack + bottom box), expandable slots with blank cards, double-ring knock-outs. The ABX-S is the wall-mount plastic counterpart: lighter than steel, easier to install on walls, with the expandable blank-card design for future circuit growth. Choose ABX-S for wall-mounted indoor/sheltered outdoor distribution where a corrosion-proof plastic enclosure and future expandability are valued; choose ABX-T for indoor steel; choose ABX-T-2 for underground or exposed outdoor.

The ABX-S loop box is designed with pre-formed expansion positions on the mounting base. During initial installation, not all positions may be needed — the unused positions are covered with matching blank cards (plastic filler plates) that fit flush with the active device positions, maintaining a uniform appearance and the enclosure's IP rating. When additional circuits are required in the future, the blank card is simply removed and a new DIN-rail device (MCB, RCBO, etc.) is installed in its place. This eliminates the need to drill new holes, cut new knock-outs, or replace the enclosure — making the ABX-S a future-proof solution for installations where load growth is expected. The blank cards are color-matched to the enclosure and sit flush, so the box looks complete and professional even when not fully populated.

The ABX-S is rated IP54 (standard) or IP65 (optional) and is designed for indoor installation or sheltered outdoor locations. "Sheltered outdoor" means locations where the enclosure is protected from direct rain, snow, and prolonged UV exposure — such as under eaves, in covered walkways, inside equipment kiosks, or in well-ventilated pump houses. It is NOT recommended for fully exposed outdoor installation subject to direct rain, water jets, flooding, or intense direct sunlight, as even the IP65 rating does not provide protection against prolonged immersion or the full UV intensity of unshaded sunlight, which can degrade the plastic over many years. For exposed outdoor or underground installation, the ABX-T-2 (IP54/IP65, underground/ground mount) or the JP series outdoor distribution box is more suitable. When installing the ABX-S in a sheltered outdoor location, ensure good ventilation to prevent condensation and mount it out of direct sunlight if possible.

The three-layer structure means the ABX-S enclosure is composed of three independently separable components: (1) the front panel (door), (2) the circuit breaker mounting rack (the DIN-rail and component mounting plate), and (3) the bottom box (the wall-mounted base that contains the cable entries and grounding bar). The key benefit is that the middle layer — the component rack — can be removed from the box and pre-wired on a workbench, then installed as a complete assembly. This modular approach reduces on-site installation time, improves wiring quality (bench assembly allows better access and quality control), and simplifies maintenance — if a major component fails, the entire rack can be swapped out quickly rather than working inside the wall-mounted box. The three-layer design also makes it easier to access cable entries at the back of the box during installation, since the front two layers can be removed to expose the bottom box.

The double-ring knock-out system consists of two concentric circular knock-out rings at each cable entry position. The installer removes only the ring(s) needed for the cable diameter being used: (1) For smaller cables — remove only the inner ring, leaving the outer ring intact, creating a smaller opening that matches the cable gland or conduit size. (2) For larger cables — remove both the inner and outer rings, creating a larger opening. This eliminates the need for separate cable gland plates or adapters for different cable sizes, and ensures that unused entries remain sealed (the knock-out is not removed), preserving the IP rating. The knock-outs are typically scored and can be removed with a punch or screwdriver. Always ensure that the cable gland or conduit used matches the opening diameter to maintain the IP54/IP65 rating — a loose-fitting cable entry will compromise the weatherproof seal.

The PC/ABS alloy plastic enclosure is electrically non-conductive, which provides an inherent safety advantage over steel enclosures — the external surface cannot become energized in the event of an internal fault, reducing the risk of electric shock to persons touching the enclosure. However, grounding is STILL required for the ABX-S for two reasons: (1) Cable armor/sheath bonding — if armored cable is used, the metallic armor must be bonded to earth for safety and to manage induced voltages. (2) Internal metallic components — the DIN rail, busbars, any metallic cable glands, and the devices themselves must be properly earthed via the integrated copper grounding terminal bar. The grounding bar provides a centralized earthing point that is connected to the system PE conductor, ensuring all conductive parts inside the enclosure are at earth potential. The plastic enclosure itself does not need to be grounded (it is non-conductive), but all internal metallic parts and cable armor must be. Always verify grounding continuity during commissioning.