Types of Electrical Trunking
Electrical trunking is a sophisticated system designed for housing and protecting electrical wires and cables. It enables safe, efficient, and organized electrical installations while maintaining compliance with safety standards. Below are the main types available in today's market:
Surface-mounted Trunking
Designed for installation on flat surfaces like walls and ceilings, this visible trunking provides easy access for maintenance and modifications.
Best for: Retrofit installations, commercial spaces, and situations requiring frequent access
Concealed Trunking
Installed inside walls or ceiling cavities, this trunking is completely hidden from view, creating a clean aesthetic appearance without visible cables or conduits.
Best for: Residential applications, high-end commercial spaces, and design-focused environments
Wireway Trunking
Specifically engineered for conductor management in power distribution systems, featuring both open and closed channel configurations for accessibility.
Best for: Industrial settings, large electrical installations, and distribution boards
Modular Trunking
Features interconnecting components that can be customized to create flexible configurations, allowing for easy system modifications and expansions.
Best for: Evolving installations, offices, and commercial spaces requiring frequent changes
Mini Trunking
Compact trunking designed for small-diameter cables, providing a discreet solution for routing low-voltage and communication cables.
Best for: Data cabling, communication networks, and residential applications
Plastic Trunking
Made from PVC or ABS, offering excellent electrical insulation, corrosion resistance, and cost-effectiveness.
Advantages: Lightweight, easy to cut and install, moisture-resistant, affordable
Metal Trunking
Constructed from aluminum or steel, providing superior durability, mechanical strength, and protection.
Advantages: Enhanced protection, electromagnetic shielding, heat resistance, suitable for harsh environments
Expert Tip: When selecting trunking material, consider the installation environment. PVC trunking is ideal for most indoor applications, while metal trunking is better suited for industrial environments or areas requiring additional mechanical protection.
| Trunking Type | Best Applications | Key Features | Installation Complexity |
|---|---|---|---|
| Surface-mounted | Commercial buildings, retrofits | Visible, easily accessible | Low |
| Concealed | Residential, high-end installations | Hidden, aesthetically pleasing | High |
| Wireway | Industrial, large power systems | High capacity, robust design | Medium |
| Modular | Dynamic environments | Flexible, customizable | Medium |
| Mini | Data cables, small networks | Compact, discreet | Low |
Specifications and Maintenance of Electrical Trunking
Understanding the technical specifications of electrical trunking is essential for selecting the right system for your specific requirements. Below are the critical specifications to consider:
Material Specifications
The material determines durability, environmental resistance, and installation characteristics:
- PVC Trunking: Moisture-resistant, economical, ideal for bathrooms and wet areas
- Steel Trunking: Maximum durability, physical protection, suitable for industrial environments
- Fiberglass Trunking: Chemical resistance, non-conductive, perfect for manufacturing facilities
- Aluminum Trunking: Lightweight, corrosion-resistant, good for coastal areas
Dimensional Specifications
Size selection directly impacts cable capacity and installation flexibility:
- Width/Height: Determines the number and size of cables that can be accommodated
- Length: Standard lengths range from 2-3 meters for easy handling
- Wall Thickness: Affects durability and protection level
- Fill Capacity: Industry standards recommend only filling to 40-50% of total capacity
Design Specifications
Construction features that impact installation and access:
- Cover Type: Snap-on, hinged, or screw-fixed options
- Base Design: Self-adhesive strips or pre-drilled mounting holes
- Internal Compartments: Single or multi-compartment designs for separating power and data
- Accessory Compatibility: Availability of joints, bends, tees, and adapters
Performance Specifications
Safety and environmental ratings to consider:
- IP Rating: Indicates dust and water resistance level
- Impact Resistance: Measured in joules (IK rating)
- Temperature Range: Operating temperature limits
- Fire Rating: Flame retardance and smoke emission properties
Maintenance Best Practices
Regular maintenance extends the lifespan of electrical trunking systems and ensures continued safety and functionality:
| Maintenance Task | Frequency | Purpose | Notes |
|---|---|---|---|
| Visual Inspection | Quarterly | Identify damage, wear, or loose components | Check for cracks, discoloration, and deformation |
| Cleaning | Semi-annually | Prevent dust build-up and deterioration | Use a damp cloth; avoid harsh chemicals |
| Fitting Check | Annually | Ensure secure connections and joints | Tighten screws and fasteners as needed |
| Cable Load Verification | During modifications | Prevent overloading and overheating | Ensure capacity remains below 50% |
| Seal Inspection | Annually | Maintain environmental protection | Replace damaged gaskets and seals |
Important: Never exceed the manufacturer's specified cable fill capacity. Overcrowding can lead to heat buildup, reduced cable lifespan, and increased fire risk. When in doubt, choose a larger trunking size or add additional runs.
How to Choose Electrical Trunking
Selecting the optimal electrical trunking system requires careful consideration of various factors to ensure safety, compliance, and efficiency. Follow this comprehensive selection guide to make an informed decision:
Environmental Considerations
The installation environment dictates the material and protection level required:
- Indoor Dry Areas: Standard PVC trunking is typically sufficient
- Outdoor Exposure: UV-stabilized PVC or metal trunking with higher IP rating
- Wet/Humid Areas: IP65 rated or higher with moisture-resistant properties
- Chemical Exposure: Fiberglass or specialized chemical-resistant trunking
- High-Temperature Areas: Metal trunking with appropriate temperature rating
Load Capacity Planning
Ensure the trunking can safely accommodate current and future cable requirements:
- Current Cable Volume: Calculate total cross-sectional area of all cables
- Heat Dissipation: Consider heat generation from power cables
- Future Expansion: Add 30-50% capacity for future needs
- Cable Type Separation: Determine if power and data cables need separation
- Bending Radius: Ensure trunking dimensions accommodate minimum cable bend radius
Expert Tip: When calculating trunking size requirements, use the formula: Trunking cross-sectional area = (Sum of cable cross-sectional areas) ÷ 0.4. This ensures you'll maintain the recommended 40% maximum fill ratio.
Additional Selection Criteria
| Selection Factor | Importance | Considerations |
|---|---|---|
| Compliance & Standards | Critical | Verify conformity with local electrical codes, IEC standards, and fire safety regulations |
| Aesthetic Requirements | Variable | Consider color options, profile design, and visibility in the finished installation |
| Maintenance Access | High | Evaluate ease of cover removal and accessibility for future modifications |
| System Integration | Medium | Check compatibility with junction boxes, outlet modules, and other system components |
| Cost Analysis | High | Balance initial purchase cost against installation time, durability, and long-term maintenance |
Warning: Never mix metal and plastic components in the same trunking system without proper isolation. This can compromise the system's electrical safety and integrity, potentially creating hazardous conditions.
How to DIY and Replace Electrical Trunking
Installing or replacing electrical trunking can be a straightforward DIY project when approached methodically. Follow these step-by-step instructions for a professional-quality installation:
Safety First: Before beginning any electrical work, always turn off the power at the circuit breaker and verify with a voltage tester that the circuit is dead. Never work on live circuits unless you are a qualified electrician.
Tools and Materials Required
- Electrical trunking in appropriate size and material
- Measuring tape and pencil for marking
- Spirit level to ensure straight installation
- Hacksaw or trunking cutter for precise cuts
- Electric drill with appropriate bits
- Screwdriver (Phillips and flathead)
- Wall plugs and screws for mounting
- File for smoothing cut edges
- Optional: Adhesive for additional securing
Installation Process
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Preparation and Planning
Turn off the power to the circuit you'll be working with. Plan your trunking route, considering the most direct path while avoiding obstacles. Mark the planned route on the wall using a pencil and spirit level to ensure straightness.
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Measure and Cut the Trunking
Measure the required lengths of trunking carefully. Use a hacksaw or specialized trunking cutter to make clean, straight cuts. File any rough edges to prevent cable damage and ensure proper fitting of joints and covers.
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Prepare Mounting Points
Mark screw positions along the trunking route at approximately 50cm intervals. For heavier cable loads, reduce this spacing. Drill holes at the marked positions and insert wall plugs if mounting on masonry or concrete.
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Mount the Trunking Base
Position the trunking base against the wall, aligning with your markings. Secure it with screws at each mounting point, working from one end to the other to maintain alignment. Check periodically with a spirit level to ensure the trunking remains straight.
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Install Accessories and Joints
Add any necessary accessories such as internal/external corners, tees, and joint covers. Ensure these are securely attached to maintain system integrity and appearance.
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Install Cables
Carefully lay the cables inside the trunking, avoiding twists and crossovers. Maintain proper separation between power and data cables if using the same trunking. Leave some slack at connection points to reduce strain.
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Attach the Cover
Once all cables are properly positioned, snap or screw the cover into place, working from one end to the other. Ensure the cover is securely attached along the entire length.
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Test and Inspect
Before restoring power, verify all connections are secure. After restoring power, test the circuits to ensure proper function. Perform a final visual inspection to check for proper installation and appearance.
Professional Tip: When running cables through trunking, avoid filling more than 40-50% of the available space. This prevents overheating, makes future modifications easier, and reduces cable wear from tight bends or pressure points.
Frequently Asked Questions
Yes, electrical trunking is designed with safety as a primary consideration. It provides physical protection for cables, prevents accidental contact with live conductors, and helps maintain proper separation between different circuit types. Most trunking systems are manufactured from flame-retardant materials that don't support combustion, reducing fire hazards. Additionally, quality trunking includes features like rounded internal corners to prevent cable damage during installation and sealed designs to protect against dust and moisture intrusion. When properly installed according to local electrical codes, trunking significantly enhances the overall safety of electrical installations.
Electrical trunking offers numerous advantages for both residential and commercial installations:
- Organization: Creates a structured pathway for cables, eliminating clutter and improving the appearance of electrical installations
- Protection: Shields cables from physical damage, moisture, dust, and environmental hazards
- Safety: Prevents accidental contact with electrical conductors and reduces fire risks
- Maintenance: Facilitates easy access for repairs, modifications, and cable replacements
- Flexibility: Allows for future expansion and adaptation of electrical systems
- Compliance: Helps meet building codes and electrical standards
- EMI Reduction: Metal trunking can provide electromagnetic interference shielding
- Heat Dissipation: Properly sized trunking improves airflow around cables, reducing heat buildup
Yes, electrical trunking can be used for high-voltage cables, but specific considerations must be addressed:
- The trunking must be appropriately rated for the voltage level being carried
- Metal trunking with proper grounding is typically required for higher voltage applications
- Adequate spacing between cables must be maintained to prevent arcing
- Special high-voltage trunking may include additional insulation or barriers
- Installation must comply with relevant electrical codes and standards for high-voltage systems
- High-voltage cable trunking generally requires installation by qualified electrical professionals
Always consult manufacturer specifications and local electrical regulations before using trunking for high-voltage applications to ensure safety and compliance.
Electrical trunking comes in numerous specialized types to address specific installation requirements:
| Trunking Type | Description | Common Applications |
|---|---|---|
| PVC Trunking | Lightweight, non-conductive plastic trunking | General purpose indoor installations, residential applications |
| Metal Trunking | Steel or aluminum construction with high mechanical strength | Industrial environments, EMI protection, high security areas |
| Dado/Skirting Trunking | Wall-mounted systems with integrated outlet positions | Offices, classrooms, laboratories, commercial spaces |
| Floor Trunking | Recessed systems installed within floor structures | Open plan offices, retail spaces, exhibition halls |
| Cable Basket Trunking | Open mesh design for maximum ventilation | IT server rooms, telecommunications, high-density installations |
| Fiber Optic Trunking | Specialized systems for fiber protection with controlled bend radius | Data centers, telecommunications, high-speed networks |