What type of cables are suitable for installation in vertical riser shafts without conduit?

The suitable cables for installation in vertical riser shafts without conduit are limited energy cables. These cables are specifically designed for applications where they carry lower voltage levels and are often used in telecommunications, security, and data communications. In vertical installations, the risk of fire and spread of flames is a significant concern, which is why limited energy cables come with insulation and overall construction that minimizes these risks while maintaining necessary electrical performance.

They are distinct from other types of cables due to their ability to meet specific fire safety code requirements, such as being rated for vertical installations without conduit. This allows for more flexibility in installation practices, ensuring that limited energy cables can be routed through riser shafts without the need for additional protective conduit, which might be required for other higher voltage or power cables that do not have the same fire-resistance features.