Use of reduced emissions wire in switchgear equipments

Emphasis on safety in the workplace and reduction of damage due to fires has led to the introduction of new types of wire and cable which are insulated with materials that contain no halogens and produce less smoke and/or toxic emissions when burned. These wires and cables have been available for general building wire for several years, but not as Type SIS wire, which is required by ANSI/IEEE standards for use in switchgear equipment. Now Type SIS wire insulated with low smoke, low emission, halogen-free material is available. To investigate the performance of this wire under fire conditions, two identical equipments were built, one wired with standard SIS wire and one with low-emissions SIS wire. Wires were deliberately ignited in each cubicle and the results recorded. Measurements of the effects of emissions on the contact resistance of control devices were made, and the relative ease of cleaning was checked. A comparison of the results shows that the low-emissions wire did reduce the effects of the fire on both internal appearance of the equipment and on the contact resistance of control devices.<>