Introduction: Why Cable Tray Selection Matters
In solar energy systems and other electrical installations, cable trays play a crucial role in cable management organising, protecting, and routing electrical wires and solar cables. Improper sizing or installation of cable trays can lead to safety hazards, inefficiencies, or non-compliance with electrical standards in Australia.
For commercial and industrial applications, selecting the right cable tray ensures that your system remains durable, accessible, and compliant with national safety codes. At Solar Rains, we supply custom-engineered cable tray solutions designed to meet these exact needs.
What Is a Cable Tray?
A cable tray is a structural system used to support, route, and protect insulated electrical cables and wires. It replaces traditional methods such as conduit piping or manual bundling with a more accessible, modular system.
Common types of cable trays include:
- Ladder trays: Strong, open design for airflow
- Solid-bottom trays: Good for minimal dust exposure
- Perforated trays: Balanced airflow and protection
- Wire mesh trays: Flexible and lightweight for short cable runs
In solar installations, cable trays help route DC and AC cables between inverters, junction boxes, and switchboards.
Why Cable Trays Are Essential in Solar Systems
Cable Organisation
Cable trays simplify the management of multiple cables, reducing tangles and improving troubleshooting access.
Safety Compliance
Proper tray installation reduces the risk of overheating, short circuits, and physical damage. It’s part of meeting AS/NZS 3000 wiring rules and AS/NZS 3013 fire hazard requirements.
Protection from Environmental Damage
Trays shield solar wires from UV rays, rain, corrosion, rodents, and other physical hazards.
Support for Future Expansion
Well-installed trays allow for easy upgrades when adding more panels, batteries, or inverters.
Cable Tray Sizes: What You Need to Know
Cable tray sizes vary based on the number and diameter of cables. In solar PV setups, these dimensions typically range from:
| Tray Width | Suitable Use Case |
| 50mm–100mm | Light cable runs, small rooftops |
| 150mm–300mm | Medium-sized commercial systems |
| 450mm–600mm | Industrial & large commercial infrastructure |
Depth: 25mm to 100mm depending on cable stacking.
Material Options: Aluminium, galvanised steel, stainless steel, or FRP.
To calculate the right size, consider:
- Cable type & insulation
- Ampacity (current carrying capacity)
- Tray fill rate (usually ≤ 40% for airflow)
- Future cable additions
Use this guide in consultation with your solar supplier or electrician.
Understanding Australian Standards for Cable Trays
Compliance is essential for safe and insurable installations.
Key standards:
- AS/NZS 3000 (Wiring Rules): Governs electrical wiring and cable support.
- AS/NZS 3013: Classifies systems based on fire resistance.
- AS/NZS 2053: Covers conduit and cable protection systems.
- AS/NZS 1668: Ventilation compatibility for enclosed trays.
Trays must also meet load rating, corrosion resistance, and UV stability for outdoor solar systems.
Inspection authorities often check tray design and mounting height during audits, especially in commercial or rooftop installations.
Tips for Choosing Cable Trays in Solar Installations
Proper cable tray selection plays a crucial role in ensuring the efficiency, safety, and longevity of your solar system. Whether you’re a homeowner or managing a commercial installation, these practical tips will help you make informed decisions.
Match Tray Material to Environmental Conditions
The tray material should be chosen based on your installation environment:
- Aluminium: Lightweight, corrosion-resistant, and ideal for coastal or high-humidity environments. It offers excellent durability for rooftop and outdoor installations.
- Galvanised Steel: A cost-effective option with good mechanical strength. Suitable for dry, indoor settings, but it may corrode faster in salty or humid climates.
- UV-treated FRP (Fibre Reinforced Plastic): Offers superior resistance to UV, chemicals, and corrosion. Best for exposed, industrial, or chemical-heavy areas despite a higher upfront cost.
Tip: Ask your solar supplier for datasheets or corrosion resistance ratings before choosing materials.
Secure Tray Fittings & Cables Properly
Even the best tray is ineffective if fittings are poorly secured. To ensure a safe and professional installation:
- Use cable clips, nylon cable ties, or stainless steel cable ties to keep cables neatly bundled and fixed in place.
- Avoid letting cables sag, rest on sharp tray edges, or lie unsecured—this increases risk of insulation damage or faults.
- Use tray clamps or brackets that are compatible with your roof type (tile, metal sheet, or concrete).
Plan for Structural Integrity and Weatherproofing
Good cable tray installation also means good structural planning:
- Maintain proper support spacing—typically every 1.2–1.5 meters—to prevent sagging.
- Use roof flashing solutions such as silicone seals or Dektite boots where trays pass through roofs to prevent leaks.
- Ensure trays are mounted at an appropriate angle to allow water drainage and reduce corrosion.
Consider waterproofing aids like Dektite Premium Roof Flashing
Label Cables and Trays Clearly
In large or growing solar systems, proper labelling is more than good practice—it’s essential for safety and compliance:
- Use solar-approved labels on all trays, cables, and junction points to indicate voltage types (AC/DC), battery links, and inverter paths.
- Choose weather-resistant labels that won’t fade or peel over time.
- Keep your circuit map updated for future maintenance or system expansion.
Tip: Clear labelling can reduce system downtime and help technicians troubleshoot faster.
Custom Engineering for Commercial Projects
For large-scale solar projects, custom cable tray engineering is highly recommended:
- Residential-grade trays may not meet load or layout requirements.
- Engineered trays can be designed to optimise space, support heavy-duty cabling, and integrate with existing infrastructure.
- Some solar power suppliers, like Solar Rains, offer design support, CAD schematics, and manufacturing-to-site supply.
See: Cable Tray – Customised Engineering Supply
Common Mistakes to Avoid
- Overfilling trays: Exceeds capacity, causes heat build-up.
- Undersized trays: No room for upgrades or proper airflow.
- Unsupported spans: Leads to sagging or deformation.
- Mixing cable types: AC & DC cables must be separated.
- Poor grounding: Fails safety tests.
FAQs
Aluminium and stainless steel are popular for their corrosion resistance. FRP is excellent in highly corrosive areas like coastal sites.
No. According to AS/NZS 3000, they must be segregated to prevent electromagnetic interference and enhance safety.
They are installed with brackets and roof flashing for waterproof sealing, such as Solar Rains’ roof flashing kits.
Not always, but they are strongly recommended for commercial-scale systems or rooftop arrays with high cable volume
Every 6–12 months or after extreme weather. Look for signs of corrosion, loose ties, or sagging cables.
Trusted solar product suppliers like Solar Rains offer customised cable tray systems tailored for Australian conditions.
Conclusion & Action Steps
Choosing the right cable tray system is vital for your solar installation’s safety, performance, and future scalability. Ensure your trays are compliant with Australian standards, properly sized, and made from weather-resistant materials.
Whether you’re managing a solar system for a warehouse, factory, or solar farm, expert guidance can help avoid costly mistakes.
Contact Solar Rains for customised cable tray design, quotes, and supply. Explore Solar Cable Tray Products today.
