Power station distribution boxes are modular, robust enclosures designed for safe power distribution, typically made of steel with IP54–IP55 protection, and include high-voltage, transformer, and low-voltage compartments.Construction and Materials
Distribution boxes are generally fabricated from cold-rolled or galvanized steel sheets with thickness ranging from 1.5 mm to 3 mm, providing mechanical rigidity and corrosion resistance for indoor or outdoor use . Outdoor boxes often feature a slanted roof with overhangs to prevent water ingress and a waterproof awning for additional protection . Doors are typically concealed hinged, with dual-door designs separating live and non-live parts for safety, and can open up to 110° for outer doors and 90° for inner doors . Locking mechanisms may include Godrej-type 3-position locks or padlocks for security .
Compartments and Layout
A standard box-type substation is divided into three main compartments :
- High-voltage compartment: Contains switchgear, busbars, fuses, and protection devices for 10kV–35kV connections.
- Transformer compartment: Houses oil-immersed or dry-type transformers, with temperature control systems such as automatic cooling fans.
- Low-voltage compartment: Integrates low-voltage distribution cabinets, reactive power compensation devices, metering, and intelligent monitoring systems. Busbars are typically copper flat bars (e.g., 25x4 mm), with adequate clearance from the enclosure to meet safety standards . Cable entry is facilitated via heavy-duty, double compression cable glands, and removable flanges allow top or bottom entry .
Protection and Standards
Distribution boxes are designed to meet IP54–IP55 protection ratings, ensuring dust and water resistance . They comply with standards such as IEC60439, GB7251.3, GB17467, NEN-60439, and IS 13947, depending on the region . Optional features include ground fault interrupters, circuit breakers, and thermal protection .
Dimensions and Mounting
Dimensions vary depending on capacity and manufacturer, but typical tolerances allow ±10% over specified dimensions . Enclosures can be wall-mounted, floor-mounted, or embedded, with flanges positioned accordingly. Modular designs allow for standardized production and easy expansion, supporting currents up to 630A in low-voltage panels .
Additional Features
- Internal lighting for maintenance and inspection .
- Transparent impact-resistant covers for protection of internal components .
- Modular and standardized design for rapid deployment and ease of wiring .
- Temperature and humidity tolerance: up to +70°C for short periods and 90% humidity at lower temperatures . These specifications ensure that power station distribution boxes are safe, durable, and adaptable for urban, industrial, and construction site applications.
