Wipe on various lubricants 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 the length of wipe was comparable to the size of the dust particles, there could be serious contact failure. When the dust particle size was within the upper limit of the hazardous size range, the number of contact failures could be reduced if the sliding length was long enough. In wiping on various lubricated surfaces, the permittivity and state of the lubricants played a major role in the performance. Wax lubricants seemed to be the worst, and this is thought to be mainly due to the effect of permittivity and the physical state of the lubricants. It is suggested that the size of the particles and the trapping effect also contributed to failure. Liquid lubricants with lower permittivity were found to give much better contact behavior in dusty environments