Wipe on various lubricated and nonlubricated electric contacts in dusty environments

In wiping on a nonlubricated dusty electric contact surface, a trapping effect was found which showed that when wiping length is comparable to the size of the dust particles, even when particle size was outside of the hazardous size range, there could be serious contact failure. When dust particle sizes are within the upper limit of the hazardous size range, if the sliding length is long enough, the number of contact failures could be reduced. In wiping on various lubricated surfaces, permittivity and state of the lubricants played a major role in the failure performance. Waxes may cause serious contact failure. If a wax lubricant with high permittivity is used, the likelihood of failure is substantially increased. It is proposed that liquid lubricants with low permittivity should be used in a dusty environment, either for sliding electric contact or static contact application