Electrical Systems

Electrical Systems

Electrical systems are the nervous system of modern buildings, providing power for lighting, appliances, HVAC, and auxiliary systems. The design must adhere to the Philippine Electrical Code (PEC).

Power Distribution System

Service Entrance

The point where the utility company's lines connect to the building's system.

• Service Drop: Overhead connection.
• Service Lateral: Underground connection.

Panelboards

Distribution centers that divide the electrical power feed into subsidiary circuits.

• Main Breaker: Disconnects power to the entire panel.
• Circuit Breakers: Protect individual circuits from overcurrent/short circuits.

Wires and Cables

• Conductors: Usually Copper (Cu) or Aluminum (Al).
• Insulation: THHN (Thermoplastic High Heat-resistant Nylon-coated) is common.
• Sizes: Measured in AWG (American Wire Gauge) or $mm^2$.
  • 3.5 $mm^2$ (#12 AWG): Standard for outlets.
  • 2.0 $mm^2$ (#14 AWG): Standard for lighting.

Lighting Systems

Lighting design involves achieving the correct illumination levels (Lux) for the space's function.

Types of Lighting

1. Ambient: General illumination.
2. Task: Focused light for specific activities (reading, cooking).
3. Accent: Decorative lighting to highlight features.

Luminous Flux vs. Illuminance

• Luminous Flux: Total light output of a source (Lumens).
• Illuminance: Light falling on a surface (Lux = Lumens / $m^2$).

Auxiliary Systems

• Structured Cabling: Data and voice networks.
• CCTV: Security surveillance.
• FDAS: Fire Detection and Alarm System.
• Paging/BGM: Public Address and Background Music.

Calculation Example: Lighting Load

Summary

Electrical systems require careful planning to balance load, ensure safety through proper grounding and protection devices, and provide adequate lighting. Compliance with the PEC is mandatory to prevent fire hazards and ensure reliability.