Trinidad and Tobago Electrical Wiring Code governs electrical installations.
Laws include:
Electricity Commission Act (Chapter 54:70)
Electric Installations (Buildings) Act (Chapter 54:71)
Electricity (Inspection) Act (Chapter 54:72)
Wiring Standards and Regulations:
Part 1: Low Voltage Installations (TTS 171: PART 1: 2015)
Aligns with:
National Fire Protection Association (NFPA 70) National Electric Code (NEC 2011)
British Standards Institution (BS 7617:2008)
Part 2: High Voltage Installations (TTS 171: PART 2: 2002)
T&TEC Wiring for Lighting and Power (8th Edition, 2005)
Key Definitions and Roles
Permit: Written permission from the inspection department to start work on electrical installations.
Current Permit: Allows the supply authority to provide electricity to a specific installation.
Approved: Acceptable by the enforcing authority.
Accessible: Wiring or equipment can be exposed without damage to the building.
Electrical Inspectorate: Department responsible for the inspection and certification of electrical work.
Supply Authority: Trinidad and Tobago Electricity Commission (T&TEC).
Conductor Materials and Sizing
Understanding Conductors
Rationale: Essential for determining the appropriate conductors for installations.
Objectives include:
Define terms relevant to conductor specifications.
Apply rules for conductor sizing based on load and installation conditions.
Essential Definitions
Ampacity: Maximum continuous current a conductor can carry without exceeding its temperature rating.
Neutral Conductor: Grounded conductor in a 3-phase or 2-wire system.
Conductor Types:
Stranded Conductor: More flexible, made from multiple small wires.
Single Solid Wire: Stiffer, singular wire type.
Conductor Regulations
Minimum Size Requirements:
Depends on conductor type and usage conditions.
Observing termination temperatures is crucial.
Identification:
Colour coding helps identify functions:
Line 1 - Brown
Line 2 - Black
Neutral - Grey
Ground - Green/Yellow Stripes
Special Considerations for Cable Installation
Ensure cables are adequately protected against mechanical damage and environmental factors.
Follow regulations for installation in different environmental conditions (damp, corrosive, etc).
Service and Grounding Requirements
Importance of Proper Service Installation
Essential for safe and reliable electrical service in dwellings.
Key Terms for Residential Service
Service Line: Electric line supplying energy to consumers.
Point of Supply: Where the energy is supplied to the installation.
Disconnecting Means: Devices to disconnect electrical circuits from their source.
Overcurrent Protective Device (OCPD): Protects circuits from overload.
Panelboard: Main distribution board with circuit protection.
Installation Procedures
Proper identification of service equipment and adherence to regulatory standards is crucial.
Both overhead and underground service installations have specific codes.
Lighting Equipment and Requirements
Types of Lighting Sources
Incandescent: Traditional light; less efficient, high heat.
Fluorescent: More efficient, uses less energy.
High-Intensity Discharge (HID): Used for street and security lighting.
Light Emitting Diode (LED): Most efficient, long lifespan.
Key Terms in Lighting
Luminaire: Fixture containing the light source.
Ballast: Component to regulate current in fluorescent and HID lamps.
Wattage Marking: Maximum allowable wattage should be indicated on fixtures.
Thermal Protection: Required for some types of luminaires.
Electrical Drawings and Symbols
Understanding Types of Drawings in Construction
Orthographic Projections: Used to show views on two-dimensional planes (top, front, side).
Electrical Symbols: Must be recognized to interpret electrical drawings efficiently.
Block Diagrams: Simplified representations of electrical systems showing components and connections.
Wiring Diagrams: Detailed layouts showing the physical arrangement of circuits and components, essential for installation and troubleshooting.
Summary
Mastering T&T wiring code, conductor specifications, service requirements, lighting types, and electrical diagrams and symbols is essential for a successful career in electrical installations.