WS in cable trays refers to a Wiring System classification that indicates a cable's tested fire and mechanical performance under specific standards.

Meaning of WS

The WS code is a Wiring System classification used to denote that a cable, as part of a cabling system, has been tested and meets specific performance criteria for both normal and fire conditions according to standards such as AS/NZS 3013 . This classification ensures that the cable can maintain circuit integrity during fire and withstand mechanical impacts during normal service.

WS Ratings

• WS51W: Represents a lower level of mechanical protection and cutting strength. Suitable for lighter applications where minimal impact is expected .
• WS52W: Indicates a higher level of mechanical protection, with 6 times the impact strength and 3 times the cutting strength compared to WS51W. This rating is generally required for most mechanical service standards and essential fire-rated installations . Cables with a WS rating are tested for:

1. Fire resistance: Typically 2 hours (120 minutes) of circuit integrity under fire conditions.
2. Mechanical strength: Ability to withstand impacts and cutting forces at maximum operating temperatures (e.g., 110°C).
3. Water spray resistance: Simulating sprinkler conditions to ensure insulation integrity .

Practical Implications

When selecting cables for cable trays, the WS rating helps determine:

• Whether the cable is suitable for fire-rated installations.
• The level of mechanical protection required for the environment.
• Compliance with installation standards and safety regulations. In summary, WS in cable trays is a critical classification that ensures cables are fire-safe, mechanically robust, and compliant with regulatory standards, with WS52W being the preferred minimum for most demanding applications .