Electrical Supply Systems

• Electrical services encompass importance of electrical/lighting/power and communication in professional contexts.
• An objective is to understand electrical services, utilities, and facilities in interiors.
• Electrical energy definitions, units, sources, and requirements should be well-understood.
• Electrical services include lighting and power as well as communication systems.

Electricity Supply Systems

• Electricity supply systems considerations include source, energy efficiency, and supply systems.
• Familiarity with electrical, lighting, power and communication requirements, use and planning are needed.
• 1/3 phase supply, electricity supply layout at city and building level is helpful to understand.
• Rules, regulations, and basic terminologies for electrical installations should be known.

Important Electrical Definitions

• Electricity is a form of energy involving the flow of electrons from atom to atom in a conductor.
• Electric current is measured in Amperes (A).
• The flow of electricity in a conductor is called current.
• Electric potential is measured in Volts.
• Electric resistance is measured in Ohms.
• Ohm's Law: Current (I) = Voltage (V) / Resistance (R), or V = IR.
• Traditionally, current flows from positive (+) to negative (-).
• Joule (J) equals the force caused by 1 amp per second flowing through 1 ohm of resistance.
• Watt (W) equals one joule per second.
• Kilowatt-hour (kWh) equals 1,000 watts exerted for 1 hour.
• Megawatt (MW) equals 1 million watts.
• Gigawatt (GW) equals 1 billion watts.
• Petajoule (PJ) equals 1 quadrillion joules.
• Current is the movement of electrical charge.
• Voltage is a measure of electrical force.
• Resistance is the opposition to current flow.
• The process of transferring charge by touching or rubbing is called charging by contact.

Electrical System Components and Design

• Types and identification of wiring, size, and electrical symbols are important.
• Electrical layout plans and considerations must be clearly defined.
• A conductor is a material in where electrons are able to move easily.
• Metals such as copper, steel, gold, and silver are good conductors.
• An insulator is a material in which electrons are restricted to move easily.
• Most plastics such as Plastic, Rubber and Glass are insulators.
• Types of electrical wiring systems suitable for normal and heavy loads should be well-defined in plans.
• Wiring should be installed following the National Electrical Code (NEC).

Renewable Energy

• There are conventional and renewable sources of various energies, including:
  • Coal
  • Natural Gas/Oil
  • Nuclear
  • Hydropower
  • Wind
  • Geothermal
  • Solar
  • Wave & Tidal Power
• A traditional or conventional energy disadvantage lies in the process that causes many environmental impacts.
• In India, the installed capacity of electricity includes coal, hydroelectricity, and renewable energy.
• Traditional energy sources have very poor overall conversion efficiency.
• Green power is preferable for the environment because its result is reduced carbon emissions and less pollution.

Distribution and Safety

• Two ways of electrical distribution include overhead and undergoind.
• Overhead distribution is cheaper.
• Underground systems are more expensive, safer, but difficult to locate problems.
• Underground transmission lines laid in trenches that include cables in groups of three.

Regulations and Standards

• Indian standards include NBC, NEC, and IS 4648: 1968 for residential electrical layouts.
• International standards include the IBC and ASHRAE 90.1.
• A metal doorknob might cause a spark due to static electricity.
• Electrical fires always occur in electrical systems that have an open circuit
• In open circuits, the electrical path is broken, stopping current flow.

Electrical Safety Practices

• Never disconnect any kind of safety device
• Dont touch electrical items with wet hands or feet
• Dont remove ground plug prong
• Use GFI in wet areas
• Discontinue use of extension cord that feels warm
• Avoid electrical wiring under carpet
• Determine the cause of blown fuses or breakers.
• Replace blown fuses with the exact same type

Types of Electrical Faults

• Common faults include: short circuit, overload, and ground (earth) faults.
• Short circuits involve diverted current, potentially causing high power losses and rapid temperature increase.
• An overload involves increase in conductor temperature, which may lead to insulation failure.

Circuit Protection

• Fuses protect circuits from shorts.
• Fuses have a low melting point and are designed to carry a full load of current under normal conditions.
• A circuit breaker is used as a molded case circuit breaker (MCCB) and residual current device.
• Miniature Circuit Breakers (MCBs) rated under 100 amps combine switching, overload, and short circuit protection.
• MCCBs have adjustable trip aspects for high models and are more suitable for powerful equipment.
• Residual Current Circuit Breakers (RCCBs) trip circuits with earth fault current.
• RCDs are an effective form of shock protection.

Electrical components

• The potential in earthing is considered to be at zero for all practical purposes.
• Types of wiring include: cleat, CTS or TRS, metal sheathed, casing and capping, and conduit.
• Important to use material and wiring that is durable, safe, visually appealing, cost-effective, accessible, and mechanically safe.
• The process of connecting metallic bodies to earth with negligible resistance is called earthing.
• Factors affecting earth resistance include material properties, temperature, and moisture of soil, depth, and amount of charcoal used.
• Conventional and maintenance-free earthing is used.

Wiring System

• Electricity boards supply power to a point outside premises.
• Insulation ensures wires get into the inside of electrical wiring systems.
• Key considerations for installations include service entrance, wire size, and cable or conduit.
• Service entrance must be suitably large for service capacity

Electrical Planning Design

• Electrical planning layout is initially determined by factors such as loading density, gross floor area, and expansion factor.
• During the second stage, furniture and appliances are then considered.