Installation of Austrian Fire-Resistant Cable Trays

Fire protection cable trays in Austria must comply with MLAR guidelines, use fire-resistant materials, and ensure proper routing, support, and firestopping to maintain circuit integrity and safety.

Regulatory Framework

In Austria, the Model Cable System Guidelines (MLAR) govern the installation of cable systems with fire protection requirements.

MLA

R aims to prevent the spread of smoke and fire and maintain the circuit integrity of electrical wiring during a fire. Compliance is mandatory when federal states adopt MLAR into local law. Cables must be routed through fire-resistant walls and ceilings, and any remaining gaps must be sealed to avoid compromising fire resistance.

Material Selection

Indoor trays: Painted steel or galvanized steel. Outdoor trays: Hot-dip galvanized or stainless steel. Corrosive or high-humidity environments: Aluminum alloy or fiberglass-reinforced plastic.

Fire-resistant cables: Use FRHF (Fire-Resistant Halogen-Free) cables, typically marked with orange or red sheaths, which minimize smoke and maintain functionality during fire.

Installation Guidelines

Route Planning: Align trays with the building structure, avoiding unnecessary detours or overlaps. Maintain the shortest and straightest path to reduce cable loss and simplify maintenance. Segregate power and signal cables using separate trays to minimize electromagnetic interference.

Supports and Fixing: Use threaded rod supports, 'L' angles, or slotted 'C' channels. Maximum distance between supports: 1. 2 meters to prevent sagging.

Provide additional support for bends, branches, and offsets. Firestopping at Penetrations: Seal all wall, slab, and shaft penetrations with fire-rated boards, firestop packs, mastic, or mineral wool. Ensure gaps around cables do not exceed 1 cm², and packing thickness is at least 24 cm.

Cover plates should be square, evenly painted, and properly installed. Cable Segregation and Protection: Fire-resistant cables should be installed on dedicated trays or separated by distance or protective plates. Maintain clearances for cable pulling and future maintenance.

Testing and Certification

Cable trays and fire-resistant systems should be tested according to EN 1363-1 and other relevant standards. Fire tests involve current-carrying cables to ensure the system maintains circuit integrity under high temperatures. The fire resistance classification is determined by the time until circuit failure or tray collapse.

Best Practices

Inspect all materials on-site for compliance with approved submittals. Store trays horizontally on flat surfaces with timber supports to prevent damage. Coordinate installation with other services to avoid clashes.

Ensure all civil and MEP clearances are completed before installation. By following these guidelines, fire protection cable trays in Austria will meet safety, regulatory, and functional requirements, ensuring reliable operation during normal conditions and fire events.