2.Emergency circuits
Prior to installing these circuits, the NEC? and local or state code requirements should be reviewed. Steel raceways withstand fire (see Question 4); however, ordinary conductor insulation melts when exposed to elevated temperatures and a short circuit can be created. This is the reason for special protection of emergency and fire-pump circuits.
Methods of thermal protection include enclosing the raceways in a fire-rated enclosure, embedding them in concrete, wrapping them with a listed wrap system for protection from fire (sometimes called Electrical Circuit Protection System or Thermal Barrier Protection for Electrical components), and using conductors specifically rated to maintain the circuit.
The NEC does not require these thermal protection methods where conduit is installed in a fully sprinklered building.
