Building Service Electrification: Power Distribution

Study Notes

Definition: The process of delivering electrical power from the source to the various parts of a building.
Key components:
- Main switchboard: receives power from the utility company and distributes it to the building.
- Distribution panels: divide the power into smaller circuits for each area of the building.
- Branch circuits: supply power to individual devices or lighting fixtures.
Types of power distribution systems:
- Radial system: power is distributed from a central point to individual devices.
- Ring main system: power is distributed through a loop, providing redundant paths.

Principles:
- Diversity factor: accounts for the fact that not all devices will be in use at the same time.
- Demand factor: calculates the maximum current required by a circuit.
- Voltage drop: ensures that the voltage at the end of the circuit is within acceptable limits.
Circuit design considerations:
- Cable sizing: selecting the correct cable size based on the current rating and voltage drop.
- Fault current: designing the circuit to withstand fault currents and protect against electrical shock.
- Earthing and bonding: ensuring the safety of the circuit by providing a safe path to earth.

Types of lighting installations:
- General lighting: provides overall illumination for a space.
- Task lighting: provides focused lighting for specific tasks.
- Display lighting: highlights specific features or displays.
Lighting design considerations:
- Lumen output: selecting the correct light source based on the required lumen output.
- Color temperature: choosing the correct color temperature for the task or space.
- Lighting controls: designing the lighting system to be controlled and dimmed.

Hazards:
- Electric shock: caused by direct contact with live electrical components.
- Electrical fires: caused by faulty wiring or overloaded circuits.
Safety measures:
- Insulation and protection: using insulation and protection devices to prevent electrical shock.
- Earthing and bonding: ensuring the safety of the circuit by providing a safe path to earth.
- Testing and inspection: regularly testing and inspecting the electrical system to identify hazards.

Power distribution is the process of delivering electrical power from the source to the various parts of a building.
Main switchboard receives power from the utility company and distributes it to the building.
Distribution panels divide the power into smaller circuits for each area of the building.
Branch circuits supply power to individual devices or lighting fixtures.
Radial system distributes power from a central point to individual devices.
Ring main system distributes power through a loop, providing redundant paths.

Diversity factor accounts for the fact that not all devices will be in use at the same time.
Demand factor calculates the maximum current required by a circuit.
Voltage drop ensures that the voltage at the end of the circuit is within acceptable limits.
Cable sizing requires selecting the correct cable size based on the current rating and voltage drop.
Fault current must be designed for in the circuit to withstand fault currents and protect against electrical shock.
Earthing and bonding ensure the safety of the circuit by providing a safe path to earth.

General lighting provides overall illumination for a space.
Task lighting provides focused lighting for specific tasks.
Display lighting highlights specific features or displays.
Lumen output is used to select the correct light source based on the required lumen output.
Color temperature is chosen based on the task or space.
Lighting controls design the lighting system to be controlled and dimmed.

Electric shock is caused by direct contact with live electrical components.
Electrical fires are caused by faulty wiring or overloaded circuits.
Insulation and protection prevent electrical shock.
Earthing and bonding ensure the safety of the circuit by providing a safe path to earth.
Testing and inspection regularly identify hazards in the electrical system.