Welding Requirements: Welded joints between conductors must be free from slag inclusions, undercut, porosity, and incomplete penetration. For lap welding of flat steel strips, the overlap length must be at least twice the strip width, and welding must be performed on three sides; for rebar lap joints, the overlap length must be at least six times the diameter, and welding must be performed on both sides. For flat steel lap joints, the overlap length should be at least twice the width (welded on three sides); for round steel lap joints, the overlap length should be at least six times the diameter (welded on both sides); for connections between round steel and flat steel, the overlap length should be at least six times the round steel diameter (welded on both sides). Welded joints require anti-corrosion treatment (except for joints embedded in concrete).
Contact Area and Conductivity: Connections between metal conductors must provide sufficient contact area and ensure good electrical conductivity across the contact surfaces.
Connection Conductor Requirements: Bare copper wire must not be used for underground connections; steel conductors with anti-corrosion treatment are required, and welded joints must receive two coats of anti-corrosion coating. Bolted clamping connections between conductors are strictly prohibited.
Terminal Board Installation: Equipotential bonding terminal boards must be securely fastened, and contact surfaces must be free of rust. Terminal boards should be connected via bolts to facilitate disassembly for periodic testing. When using BV-10 to 25 mm² conductors, the wire ends must be tinned and crimped with copper terminals before connecting to the equipotential terminal board; for BV-6 mm² or smaller conductors, the wire end may be formed into a loop for direct connection to the terminal board, secured with a flat washer and a spring washer (lock washer), ensuring the bolt tightening direction matches the direction of the wire loop.
Auxiliary Equipotential Box Connection: When connecting an auxiliary equipotential box to piping, if the pipeline contains plastic fittings, a bonding jumper must be installed across them.
Bathroom Local Equipotential Bonding: The local equipotential bonding system in a bathroom must not be connected to the PE (protective earth) line outside the bathroom. The equipotential terminal box is installed inside the bathroom, typically embedded within the tiled wall surface; regarding wiring, conductors laid within walls or underground must be protected by plastic conduit. If bathroom renovations require moving internal walls, the equipotential bonding system must also be reconfigured.
Material Inspection and Construction Preparation: Before construction begins, designate a material storage area based on the project's planned quantities, then select and measure materials according to the daily work schedule. Cut samples of the required size and type-adhering to specifications-and submit them to a qualified testing agency for physical and chemical property analysis; only materials that pass inspection may be used.
Positioning, Layout, and Conduit Embedding: During the civil engineering foundation phase, mark locations according to the blueprints and position the selected materials precisely as designed. Embed conduits and steel pipes concurrently with the civil construction progress, ensuring proper placement for all lines passing through concrete slabs or beams based on the layout of the main equipotential bonding box. Determine the depth and width of wall chases based on the diameter of the equipotential bonding conductors; the chase depth should generally be 1–1.5 cm below the finished wall surface. Align conduit chases vertically with the center of the box and avoid diagonal or horizontal cutting within the wall; horizontal protective conduits should ideally be embedded within the cast-in-place concrete.
Box Installation: Locate the main equipotential bonding box as close as possible to the grounding device to ensure a short, direct connection. For local equipotential bonding boxes, balance functionality with aesthetic considerations; in bathrooms, these boxes may be installed within the suspended ceiling. The cross-sectional area of the equipotential bonding terminal block must meet mechanical strength requirements and must not be smaller than the cross-section of the largest connected bonding conductor. If all bonding conductors are copper, the terminal block must be copper; if steel conductors are included, the terminal block should be made of galvanized flat steel.