1.1 The test method described in these requirements is intended to evaluate the fire resistive performance of electrical cables as measured by functionality during a period of fire exposure, and following exposure to a hose stream.
1.2 To maintain the functionality of electrical cables during a fire exposure the cables are tested using a fire resistive barrier. The fire resistive barrier is the cable jacketing if the jacketing is designed to provide fire resistance. If the cable jacketing is not designed to provide fire resistance, the electrical cables are either placed within a fire resistive barrier or installed within an hourly rated fire resistive assembly (see 1.4). Fire resistive cables intended to be installed with a non-fire resistive barrier (such as conduit) are tested with the non-fire resistive barrier included as part of the test specimen. Otherwise fire resistive cables incorporating a fire resistive jacket are tested without any barrier.
1.3 To demonstrate each cable's ability to function during the test, voltage and current are applied to the cable during the fire exposure portion of the test, and the electrical and visual performance of the cable is monitored. The cable is not energized during the hose spray, but it is visually inspected and electrically tested after the hose spray.
1.4 The functionality during a fire exposure of non-fire resistive electrical cables which are intended for installation within fire barriers or for installation within hourly rated fire resistive assemblies is determined by tests conducted in accordance with the UL Outline of Investigation for Fire Tests for Electrical Circuit Protective Systems, Subject 1724.
1.5 Two fire exposures are defined: a normal temperature rise fire and a rapid temperature rise fire. The normal temperature rise fire is intended to represent a fully developed interior building fire. The rapid temperature rise fire is intended to represent a hydrocarbon pool fire. See 1.7.
1.6 Two hose stream exposures are defined: a normal impact hose stream and a low impact hose stream. The low impact hose stream is applied only to cable intended to contain the identifying suffix "CI" to identify it as CI cable in accordance with the Standard for Cables for Power-Limited Fire-Alarm Circuits, UL 1424, and in accordance with the Standard for Cables for Non-Power-Limited Fire-Alarm Circuits, UL 1425.
1.7 The fire exposure and hose stream tests are not intended to be representative of all fire conditions. Conditions vary with changes in the amount, nature, and distribution of fire loading: ventilation; compartment size and configuration; and heat conducting and dissipating characteristics of the compartment in which the fire resistive cable is installed. These requirements provide a relative measure of fire performance of comparable fire resistive cables under the specified fire exposure, hose stream and electrical conditions.
1.8 The results of these tests represent one factor in determining the acceptability of fire resistive cables for use in specific applications. Application of these test results to predict electrical performance of fire resistive cables in actual installations requires careful evaluation. This test method is not to be interpreted as having determined the acceptability of cables for use after fire exposure.