Portuguese low-voltage distribution boxes are designed for indoor and outdoor use, with rated voltages up to 400–1,000V, modular enclosures, and protection levels ranging from IP30 to IP55 depending on type.

Indoor LV Distribution Boxes (GGD Type)

The GGD-type AC low-voltage distribution panels are widely used in Portugal for industrial and commercial applications. Key specifications include:

• Rated Voltage: 400V AC, 50Hz
• Rated Current: GGD1 – 1000A, GGD2 – 1600A, GGD3 – 3150A
• Protection Level: IP30
• Standards Compliance: GB7251.1-2023 (Low-voltage Switchgear and Controlgear Assemblies)
• Operating Environment: Indoor installation, ambient temperature -5°C to +40°C, altitude ≤ 2000m, relative humidity ≤ 50% at 40°C (higher at lower temperatures)
• Design Features: Modular construction, flexible electrical schemes, strong breaking capacity, excellent thermal and dynamic stability, inclination from vertical ≤ 5° These panels are suitable for power plants, substations, factories, and enterprises, providing reliable power distribution, control, and protection .

Outdoor LV Distribution Boxes (ADU Type)

For outdoor applications, ADU-type LV distribution boards are used in public areas and for grid connections:

• Mounting: Floor-mounted on a base
• Enclosure Types: PNT, DIN, and concrete
• Protection Level: Typically IP55 for weather resistance
• Features: Incoming/outgoing connections to the grid and end customers, metallic grounding sheet, and secure locking systems
• Construction: Reinforced 2 mm GI sheet steel, slanted roof with overhang, concealed hinges, and solid earthing points

General LV Switchgear Features

Modern Painel de distribuição de baixa tensão integrates:

• Circuit breakers, contactors, relays, fuses, and monitoring devices
• Modular and scalable design for different power requirements
• Compliance with IEC 61439 and ANSI/NEMA standards
• Smart monitoring systems for real-time diagnostics, remote control, and predictive maintenance
• Applications: industrial plants, commercial buildings, residential complexes, data centers, hospitals, and transportation networks

Dimensions and Customization

While exact dimensions vary by manufacturer and rated current, typical LV distribution boxes are modular enclosures allowing customization for:

• Number of outgoing feeders
• Bus bar arrangements (single or multiple)
• Integration of MCCBs and fuse switches
• Expansion for future power requirements Outdoor boxes often include slanted roofs, reinforced panels, and IP55 protection, whereas indoor GGD panels prioritize compact modularity and IP30 protection .

Summary

Portuguese LV distribution boxes are engineered for safety, reliability, and flexibility, with indoor GGD panels suited for high-current industrial applications and outdoor ADU panels designed for public and grid-facing installations. They comply with national and international standards, offer modularity for expansion, and provide protection levels appropriate to their environment.