The answer to this question is not as straight forward as one may think. Fire alarm cables (Power-Limited) can be installed exposed (not in raceway) as long as it is protected against physical damage.

On most installations, a basic rule of thumb to use is that any fire alarm cable installed above 7 feet can be installed exposed; below 7 feet the cables shall be in a raceway.

The National Electrical Code requires that fire alarm cables passing through a floor be sleeved in a raceway up to a height of 7 feet, as described above. This is to offer protection from physical damage to the cable itself. Below we have a picture of an installation at a new office building.

When fire alarm cables enter or exit a raceway that is being used to provide protection against physical damage, NEC 300.15(C) requires that a fitting be used on the ends of the conduit in order to protect the cables from abrasion.