Dimensions (Width × Height, unit: mm): (1) Height 50 Series: 100×50, 150×50, 200×50, 300×50, 400×50 (2) Height 100 Series: 100×100, 150×100, 200×100, 300×100, 400×100, 500×100, 600×100, 800×100 (3) Height 150 Series: 200×150, 300×150, 400×150, 500×150, 600×150, 800×150, 1000×150 (4) Height 200 Series: 300×200, 400×200, 500×200, 600×200, 800×200, 1000×200, 1200×200 (5) Extra‑long Span / Special Widened Cable Tray for Power Plants: 1000×100, 1000×150, 1000×200, 1200×200 Plate Thickness (unit: mm): 1.0/1.2/1.5/2.0/2.5/3.0/3.5 Ⅰ. Product Definition: Hot-dip galvanized large-span cable trays, with the national standard model of DJ series, are divided into three major categories: DJ-T ladder type, DJ-P tray type, and DJ-C channel type. The base material is Q235B thickened high-strength steel plate, with double-layer rolled side plates and multiple longitudinal reinforcing ribs on the bottom plate to enhance bending resistance. All trays, bends, and complete sets of accessories undergo hot-dip galvanizing for corrosion protection after being processed and molded. Core distinguishing criteria: Standard cable tray: single section 2m, support span 1.5~2m; large span cable tray: standard single section 6m, conventional support span 3m/6m, heavy-duty reinforced version can achieve 9~12m; standardized full-load deflection ≤ span L/200, safety factor ≥1.5, specifically designed to solve long-distance heavy-duty wiring in high-altitude, open factories, across roads, and across equipment. II. Forming and Hot-Dip Galvanizing Anti-Corrosion Process 1. Enhanced Forming Process: Standard Thickening of Plates: The basic thickness is 2.0/2.5mm. For widths exceeding 600mm and spans exceeding 6m, 3.0~4.0mm thickened steel plates are used. Structural Reinforcement: Double-layer bending and thickening of side plates with rolled edges, and integrated stamping of multiple continuous longitudinal reinforcement ribs on the bottom plate. The ladder-type model features denser rungs (150mm spacing) to enhance load-bearing capacity. Ultra-long Integrated Forming: The 6m-long plate is formed without segmentation, with prefabricated lifting holes, grounding holes, and connection holes. It is equipped with 6m-long bends, tees, reducers, and other special-shaped components. Riveting/Full Welding Process: The overall structure is free of weak breakpoints, and its resistance to twisting and sagging is significantly better than that of ordinary trays. 2. Hot-dip galvanizing heavy-duty corrosion protection process (in accordance with GB/T13912): degreasing and degreasing → thorough acid pickling to remove rust → plating activation aid → soaking in zinc liquid at 450~480℃ for 3~5min → centrifugal zinc removal → water cooling and passivation. Inspection of zinc coating indicators: average zinc coating thickness for thin plates ≥65μm, for thick plates ≥86μm, and zinc coating adhesion ≥610g/㎡; metallurgical bonding of the coating, resistant to peeling due to knocks and cuts, with sacrificial anode self-repair protection; neutral salt spray test for over 3000 hours; service life of 20~30 years in outdoor coastal and chemical environments; on-site cut sections must be coated with zinc-rich repair paint for sealing and rust prevention. III. Three Major Structural Classifications and Their Applications 1. DJ-T hot-dip galvanized large-span ladder-type hollow rungs, with optimal heat dissipation and light self-weight, are suitable for laying a large number of high-voltage, large-section power cables in power plants, substations, and utility tunnels; 2. DJ-P hot-dip galvanized large-span tray-type base plates with heat dissipation punching holes, which support cables in one piece and allow for separate laying of strong and weak electricity, are commonly used for integrated wiring in factories and new energy plant areas; 3. DJ-C hot-dip galvanized large-span trough-type fully enclosed trough body + supporting 6m long galvanized cover plate, with good shielding, dustproof, and waterproof effects, are dedicated for central control DCS, communication, and optical fiber weak electricity trunk lines. IV. Complete set of supporting hot-dip galvanized thickened accessories: 1. All components are synchronously and integrally hot-dip galvanized to prevent electrochemical corrosion of dissimilar metals; 2. Straight-through components: extended and thickened connecting pieces, Grade 8.8 high-strength hot-dip galvanized bolts, grounding jumper wires; 3. Special-shaped components: 6m horizontal bends, vertical up and down bends, tees, crosses, reducers and adapters; 4. Functional components: 6m long galvanized cover plates, metal divider plates, fireproof dividers; 5. Support system: thickened load-bearing brackets, extended columns, seismic support and hangers (mandatory for industrial, tunnel, and substation applications). V. Five Core Advantages 1. Ultra-large support span, significantly reducing the overall cost of supports. Compared to a conventional 6m span with supports only at both ends, the amount of support arms and columns is reduced by more than 60% compared to a 2m ordinary bridge frame, reducing wall/steel structure drilling, lifting labor, and overall construction cost by more than 30%. In areas where equipment spans or roads cross the factory building, there is no need for intermediate columns, which does not obstruct the equipment passage. 2. With ultra-high load-bearing capacity, long-term resistance to deflection and deformation, double-layer crimping, and a multi-reinforcement mechanical structure, the rated uniform load for a 6m span is 300-1000kg/m, and the full-load sag is strictly controlled within the specified limits. It can support multiple heavy-duty high-voltage cables, ensuring no twisting or permanent deformation under long-term heavy loads. 3. Long-lasting heavy-duty corrosion protection through hot-dip galvanizing, with a thick zinc coating suitable for all indoor and outdoor scenarios, resistant to rainwater, high salt spray, mild acids and alkalis, and high humidity. It is suitable for long-term outdoor use in coastal docks, offshore wind power, chemical industries, sewage plants, and open-air utility tunnels, requiring almost no maintenance in the later stages. 4. With a super-long single section of 6m, construction efficiency is significantly improved. The single-piece integrated molding reduces splicing joints by 2/3, lowering the risks of grounding discontinuities and water infiltration through gaps. The speed of high-altitude lifting and long-distance through-construction is increased by 50%, effectively shortening the construction period. 5. With strong structural rigidity and excellent seismic performance, the overall bending and torsional stiffness is much higher than that of ordinary cable trays. When paired with seismic supports and hangers, it meets the seismic specifications for tunnels, substations, and large factories, avoiding the risk of vibration-induced detachment. VI. Preferred Scenarios 1. Large steel structure factories and logistics warehouses: open roofs without columns, dense and heavy-duty cables; 2. Chemical plants, oil refineries, wastewater treatment plants, coastal power plants, offshore wind power platforms (high salt spray corrosion environment); 3. Urban utility tunnels, tunnels, high-speed cable trenches, overhead main cables crossing roads in factory areas; 4. Substations, photovoltaic/wind farms, metallurgical blast furnace areas, with a large number of 10kV high-voltage cables laid centrally; 5. Airports, high-speed rail stations, large venues, with high-altitude long-distance main cables above 8m in height; 6. Equipment-intensive factory areas, with cross-equipment areas where support columns cannot be added in the middle. Ⅶ Key points of construction and installation specifications: 1. Support arms, columns, and connecting bolts must all be equipped with thickened hot-dip galvanized parts, and the mixed use of ordinary thin galvanized accessories is prohibited; 2. For the high-altitude lifting of six-meter-long trays, two-point synchronous lifting shall be adopted to prevent unilateral twisting; for spans > 6m, intermediate load-bearing supports must be added; 3. Grounding jumper wires shall be installed on each section of the tray along the entire line, and repeated grounding shall be added for chemical and substation projects to ensure continuous equipotential conduction; 4. When laying strong and weak electrical cables on the same tray/trough, metal dividers must be installed for complete isolation; 6m-long galvanized cover plates must be provided throughout the process in open and dusty environments; 5. For spans of six meters and above, as well as high-voltage main lines, seismic support hangers shall be installed according to specifications; 6. Immediately apply zinc-rich repair paint to the cut and drilled sections on site to repair damaged zinc layers; 7. After installation, the full-load deflection of the tray shall be rechecked, and the sagging amount shall not exceed 1/200 of the span. If the standard is exceeded, support points shall be densified.