The dry 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 an oscillating blade. The arc-propagation resistance is defined by the length of arc-propagation damage along the wires in contact with the blade and by the extent of the damage to all adjacent wires undamaged by the vibrating blade. The test also evaluates the ability of the insulation to prevent further arc-propagation when the electrical arc is re-energized.
Visually examine samples to verify lack of obvious problems.
Perform a wet dielectric voltage withstand test of all sample wires (typically 2.5kV). All failed sections are removed.
Cut wires and prepare sample harnesses for testing.
Verify harnesses construction to specification.
Add harness to arc track resistance test stand.
Place new aluminium blade into abrasion system.
Set arc track resistance test equipment to proper circuit resistance and start test. Repeat for all 15 sample harnesses.
Start abrasion of wires. Continue abrasion until arc initiates and termination conditions are met.
Upon termination condition, photograph sample, and measure damage length.
Perform wet dielectric voltage withstand test on sample harnesses.