China Exterior Electric Meter Box Suppliers & Factories

Sheet Molding Compound (SMC) is an unsaturated polyester composite reinforced with chopped glass fibers (typically 25%-30% content). Unlike steel, SMC is an electrical insulator (Class II protection), eliminating shock hazards caused by loose internal cables touching the outer shell. It never rusts, resists chemical attack, absorbs physical impacts without denting, and allows wireless smart meter signals to pass freely.

Factory type testing adheres strictly to IEC 60529. First, an automated vacuum chamber evaluates dust ingress (Talcom powder test, category 1 enclosure). Next, high-pressure water jets (100 kPa at 12.5 liters/min for IP65; 100 kPa at 100 liters/min for IP66) target all door seams, lock cylinders, and cable gland penetrations for a minimum of 3 minutes. Zero water penetration must occur on internal live conductors.

Yes. Automotive and utility-grade SMC formulations blend hindered amine light stabilizers (HALS), benzotriazole UV absorbers, and titanium dioxide pigments directly into the liquid resin matrix prior to molding. Accelerated weathering tests (ISO 4892-2 xenon-arc lamp exposure for 1000+ hours) demonstrate color retention (Delta E < 3.0) with no surface chalking or loss of mechanical tensile strength.

From final approval of 3D CAD step files, mold fabrication in our dedicated CNC tooling facility takes 30 to 45 business days depending on mold complexity and slider mechanisms. Initial T1 prototype samples are pressed, measured via CMM (Coordinate Measuring Machine) for dimensional tolerance, and air-freighted to clients for mechanical validation prior to mass production clearance.

Our exterior enclosures feature multiple tamper-evident security layers: internal hidden hinges inaccessible from the exterior, dedicated utility seal lugs for wire/padlock crimping, custom triangular or penta-head security drive bolts, and distinct internal partitions separating the main metering chamber from consumer-accessible MCB switches.

Three-phase models (such as our TY-SXS and CT-operated series) are engineered for main busbar nominal ratings from 10 A to 250 A, with rated insulation voltages up to 690 V / 1000 V AC. Busbar arrangements are supported by glass-reinforced DMC insulators rated for short-time withstand currents (Icw) of up to 30 kA for 1 second, guaranteeing physical containment during severe line faults.