Prefabricated House Circuit

The renovation, reservation, and embedding of circuits in prefabricated houses must adhere to scientific standards to ensure the unity of safety and functionality. Specific operations should be handled differently based on the type of house (prefabricated panel houses or assembled prefabricated houses). The core points are as follows:

I. Wiring Specifications for Circuit Renovation in Prefabricated Panel Houses

1. Ceiling Wiring
   If the house has a ceiling structure, the space inside the ceiling can be utilized to arrange electrical wires. It is essential to ensure that the wire conduits are firmly fixed to prevent detachment due to vibration or gravity. The insulation performance of the wires must comply with national standards to prevent the risk of electric leakage. This method does not require damaging the walls and is suitable for local renovations in already decorated houses.

2. Wall Chasing Wiring
   Before chasing walls, it is crucial to confirm the type of wall structure:

   • Non-load-bearing walls: Chasing is allowed, but the depth must be controlled (generally not exceeding one-third of the wall thickness) to avoid compromising structural stability.
   • Load-bearing walls or the connection parts between prefabricated floor slabs and walls: Chasing is strictly prohibited, as it may weaken the house's seismic performance or cause cracks.
     After chasing, the slots should be promptly filled, and the wall surface should be repaired with cement mortar to ensure flatness. Chasing in the positions of prefabricated floor slabs is strictly prohibited, as their hollow structure is prone to breakage due to chasing, posing serious safety hazards.

II. Reservation and Embedding Techniques for Circuits in Assembled Prefabricated Houses

1. BIM Model Collaborative Design
   During the design phase, BIM technology should be used to accurately locate equipment pipelines and generate three-dimensional models in synchronization with civil engineering components, which are then provided to prefabricated component factories. Prefabrication personnel follow the drawing standards to reserve positions for wire conduits, wire boxes, and cabinets in prefabricated panels and walls, ensuring seamless integration with subsequent decoration.

2. Requirements for Reserving Wire Conduits

   • Prefabricated walls: Wire conduits and wire boxes are cast into the structural body in one piece at the factory, reducing on-site wet work.
   • Composite floor slabs: Horizontal wire conduits are laid within the cast-in-situ composite layer. The thickness of the cast-in-situ layer should be determined based on the crossing situation of the pipelines:
     • Without crossings, the thickness must meet structural safety requirements.
     • With crossings, the thickness should be at least 80mm to avoid damage from pipeline compression.
       By optimizing pipeline layout (e.g., reducing crossings and adopting parallel wiring), the layer thickness can be reduced, saving costs.

3. Standardization of Point Reservation

   • Cabinets and wire boxes: They must adhere to the module of prefabricated components and be accurately positioned on the components. For example, sockets, switches, and weak current equipment use standard 86-type wire boxes for easy installation later.
   • Equipment on composite floor slabs: Lighting fixtures and fire detectors should reserve deep-type wire boxes, with depths matching the thickness of the cast-in-situ layer to ensure reliable pipeline connections. The positions of wire boxes are initially located by electrical professionals and finally reviewed by structural professionals to avoid errors.

III. Key Considerations

• Safety First: During renovation or reservation, load-bearing structures should be avoided to prevent compromising the overall stability of the house.
• Compliance: All operations must comply with the "Construction Specifications for Residential Decoration and Renovation Engineering" and local electrical installation standards.
• Acceptance Inspection: After renovation, insulation resistance tests and power-on tests should be conducted to ensure no short circuits or electric leakage in the circuit.

Through scientific planning and standardized construction, the circuit system in prefabricated houses can balance safety, functionality, and economy, providing reliable protection for occupants.