The wet arc-resistance test for wire insulation provides an assessment of the ability of an insulation to prevent damage in an electrical arc environment. In service, electrical arcs may originate from a variety of factors including insulation deterioration, faulty installation, and chafing. It has been documented that results of an arc-propagation test may vary slightly due to the method of arc initiation. Therefore, a standard test method must be selected to evaluate the general arc-propagation resistance characteristics of an insulation. This test method initiates an arc with droplets of saline solution. The arc-propagation resistance is defined by the length of arc-propagation damage along the wires and by the extent of damage to all adjacent wires undamaged by the water droplets.
The test also evaluates the ability of the insulation to prevent further arc-propagation when the electrical arc is re-energized.