Electrical System – Building Services Engineering (DBT253) Vocabulary

Vocabulary flashcards covering fundamental terms, units, personnel roles, protection measures, power generation sources, and distribution components related to building electrical systems.

Electricity

Energy produced by the free movement of electrons that powers devices creating light, heat, etc.

Conductor

A material that transmits electricity well, used to carry electric current without excessive loss.

Insulator

A material that poorly transmits electricity, used to prevent energy leakage and electrocution.

Ampere (A)

Unit of electric current flow, named after physicist André-Marie Ampère.

Volt (V)

Measure of electrical force or potential pushing current through a circuit.

Watt (W)

Unit of electrical power representing the rate of energy consumption.

Ohm (Ω)

Unit of electrical resistance; indicates difficulty faced by current flowing through a conductor.

Direct Current (DC)

Electric current that flows continuously in one direction; commonly supplied by batteries.

Alternating Current (AC)

Current that periodically reverses direction, rising to positive and negative peaks; produced by alternators at power stations.

Voltage Drop

Difference between supply voltage and receiving-end voltage, causing dim lights, hot motors, etc. when excessive.

Overcurrent

Any current exceeding equipment safety rating or conductor ampacity, including faults (short circuits) and overloads.

Voltage Surge

Large, sudden rise in voltage—often from lightning—that can damage building systems if not earthed.

Lightning Rod

Protective system that safely channels lightning current around a building into the ground.

Earthing (Grounding) System

Installation that directs unwanted electricity to the earth, protecting people and equipment.

Transformer Substation

Facility housing transformers, detectors, alarms and gas extinguishers for voltage conversion and fire safety.

Switch Board / Distribution Board

Panel distributing electricity within a building; medium and high-voltage boards require fireproof rooms.

Architect (Electrical Design Role)

Allocates space for electrical systems and coordinates with the electrical engineer during building design.

Electrical Engineer (Design)

Professional who designs distribution systems within architectural constraints per IEEE and Malaysian Electricity Regulations 1994.

Wireman

Qualified person who performs electrical wiring work.

Charge Man

Certified worker who operates and handles electrical apparatus.

Electrical Engineering Supervisor

Individual responsible for overseeing operation and maintenance of electrical equipment.

Cable Jointer

Technician skilled in connecting and terminating electrical cables.

Nominated Sub-contractor

Licensed electrical contractor appointed to install the distribution system.

Kilowatt-Hour (kWh)

Energy unit equal to using 1,000 watts for one hour; measured by electricity meters.

Power Factor

Ratio indicating how effectively current and voltage are in phase; unity (1) means no unused electricity.

Maximum Demand

Highest level of power usage recorded during a monitoring period, such as the startup of heavy loads.

Electricity Management

Practices like sensing A/C needs, dimming lights, or shutting pumps to reduce energy waste.

Power Station

Industrial facility that converts mechanical energy (turbine, engine, waterwheel) into electrical power.

Natural Gas Power

Electricity generation by burning natural gas to create hot gases that drive a turbine.

Coal / Petroleum Power

Steam generation from burning coal or oil to spin a turbine for electricity.

Hydropower

Electricity produced by flowing water turning a turbine connected to a generator.

Nuclear Power

Generation method where steam is produced via nuclear fission to drive turbines.

Wind Power

Conversion of wind energy into electricity using wind turbines.

Geothermal Power

Electricity generated from heat energy beneath Earth’s surface.

Biomass Energy

Power produced by combusting organic materials (wood, garbage, agricultural waste) to create steam.

Solar Power

Electricity derived from sunlight via photovoltaic cells or concentrating solar systems.

National Grid (Malaysia)

High-voltage transmission network (500 kV, 275 kV, 132 kV, 33 kV, 11 kV) transporting power across Peninsular Malaysia.

Transmission Line

High-voltage cable transporting bulk electricity from power plants to substations.

Substation

Part of the power system that transforms voltages, switches circuits, and provides protection and metering.

Step-Up Transformer

Device that raises voltage while lowering current for efficient long-distance transmission.

Step-Down Transformer

Transformer that lowers voltage and raises current for safe domestic or commercial use.

Feeder Pillar

Sheet-steel enclosure housing busbars and switchgear to distribute low-voltage power, often for street lighting.

High Voltage (HV) Supply

Electricity above 650 V, typically serving large campuses and factories.

Medium Voltage (MV) Supply

Electricity between 250 V and 650 V used for medium-to-large buildings and factories.

Low Voltage (LV) Supply

Electricity not exceeding 250 V, commonly supplied to homes and small buildings.