Fire alarm cable trays are low-voltage cable trays

Fire alarm cable trays are not strictly low-voltage cable trays; they are typically installed in dedicated trays, though some fire alarm cables may share trays with low-voltage circuits under specific code conditions.

Classification and Code Requirements

Fire alarm cables, such as Type FPLP, are power-limited fire alarm circuits and are generally considered Class 2 or Class 3 circuits, which are low-energy but not automatically treated as standard low-voltage data or telecom circuits . According to NEC Article 760.139, fire alarm cables can share the same cable tray with communications circuits if they are properly rated and installed, but they are usually recommended to be in dedicated trays to minimize interference and ensure life-safety compliance .

Separation and Installation Practices

While low-voltage cable trays are designed for telecom, security, and A/V wiring, fire alarm cables are often segregated from general low-voltage circuits to prevent electromagnetic interference and maintain system reliability . In practice, some projects may have a small percentage of fire alarm cables sharing trays with data cables, but maintaining a minimum separation (e.g., 6 inches) is recommended when sharing trays . Dedicated containment is preferred for life-safety circuits, especially in compliance with BS 7671, BS 8519, and BS 5839 standards in the UK or NEC standards in the US .

Summary

• Fire alarm cables are power-limited circuits and not automatically classified as standard low-voltage cables.
• Dedicated trays are recommended, but sharing with low-voltage communications cables is permitted under NEC 760.139 if proper separation and ratings are observed .
• Low-voltage cable trays are primarily intended for telecom, security, and A/V wiring, not for general fire alarm circuits .
• Proper installation ensures compliance, reduces interference, and maintains life-safety system integrity . In conclusion, while fire alarm cables operate at low energy levels, they are not automatically considered low-voltage cable tray circuits and should be installed according to code requirements, often in dedicated trays or with controlled separation from other low-voltage wiring.