Installation of Bridge Racks for Container Houses

The installation of bridge racks for container houses should adhere to the following specifications and key points:

I. Basic Requirements for Bridge Rack Installation

1. Installation Method
   Bridge racks should be installed horizontally and vertically, with smooth transitions at bends to avoid sharp angles. When installed in layers, combination racks should be prioritized to ensure structural stability. The spacing between supports should comply with regulations: horizontal installation spacing should be between 1.5 and 3 meters, and vertical installation spacing should not exceed 2 meters. Additionally, support fixing points should not be installed on connecting plates.

2. Materials and Corrosion Protection
   Bridge racks and supports should be made of galvanized or spray-painted corrosion-resistant materials. In outdoor or corrosive environments (such as coastal areas), special corrosion-resistant materials that are moisture-resistant and impact-resistant should be selected. Before installation, check the bridge rack's certificate of conformity and quality documentation to ensure the materials meet design requirements.

II. Grounding and Cross-Connection Specifications

1. Grounding Requirements
   Metal bridge racks and their supports should be connected to the grounding (PE) or neutral (PEN) main line at least twice along their entire length. Non-galvanized bridge racks should be cross-connected using copper flexible conductors with a cross-sectional area of no less than 4mm². The bending angle of the cross-connection wire should be 135°, and both the starting and ending points should be reliably grounded. When the total length exceeds 30 meters, additional grounding connection points should be added every 20-30 meters.

2. Details of Cross-Connection Wiring
   When connecting cross-connection wires, use grip washers, flat washers, or remove the spray-painted layer of the bridge rack before fixing to ensure good contact. For galvanized bridge racks, the ends of the connecting plates may not require cross-connection grounding wires, but they should be fixed with no fewer than two anti-loose nuts or washers. When fixing bolts, pay attention to the order and exposed length to avoid omissions or loosening.

III. Handling of Special Scenarios

1. Expansion Joints and Compensation Devices
   Steel bridge racks exceeding 30 meters in length, and aluminum alloy or plastic bridge racks exceeding 15 meters, should be equipped with expansion joints. When crossing building deformation joints (such as expansion joints or settlement joints), the bridge rack body should be disconnected and a 50mm gap should be reserved. Both sides should be connected using "expansion connection plates," with bolt fixing holes elongated to accommodate expansion needs.

2. Fireproof Sealing and Waterproof Measures
   Fireproof sealing or fireproof packs should be added inside the bridge rack. When crossing floors or equipment, it should be fixed with steel mesh and painted with fire-retardant coating. The installation height of outdoor bridge racks should be higher than the height of snow accumulation and water accumulation. Waterproof covers should be selected, and drainage holes should be provided. When the bridge rack crosses water pipes, the bridge rack should be located above; if unavoidable, a water baffle should be installed above the bridge rack.

IV. Construction Details and Acceptance Criteria

1. Bolt and Nut Installation
   The nuts on the bridge rack connecting plates should be located on the outside, with no missing or loose fixing bolts. Supports at bends should be added according to the bend radius to ensure that the cable bending radius meets requirements.

2. Acceptance Points
   After installation, check the horizontal deviation of the bridge rack (not exceeding 10mm), the tightness of seams, and the consistency of support orientation. The grounding resistance test should meet design requirements, and cross-connection points should be clearly marked.