Abstract :
THE EFFECT of dirt on the life and general performance of electric equipment has been the subject of previous papers and discussions. Dirt is not a unique phenomenon on traction equipment alone. Industrial installations have the same or similar problems. Mention need be made only of electrical installations in such places as cement factories, chemical plants, mines, etc., where the dirt probelm is also serious. However, what makes the traction field different is that the electric equipment is part of a moving vehicle, that it is for the most part perhaps the least accessible of all electrical installations, and that failures of electric equipment will generally stop the traction vehicle somewhere remote from help and replacement parts, and thereby tie up a transportation system. Hence, there arises the interest in and need for features to keep traction equipment clean and prevent breakdowns because of dirt contamination.
