A Survey of Problems in Telecommunication Equipment Resulting from Chemical Contamination

The deposition of natural and artificial materials onto electrical contact surfaces within telecommunication equipment has resulted in many equipment failures. Dealing with these contaminants is a continuing problem that requires the use of a variety of analytical techniques and imagination in order to find solutions. A number of problems that have occurred in the field are discussed in terms of 1) the nature of the problem, 2) analytical methods required, 3) identification of contaminating material and source, and 4) recommendations on equipment restoration. Chemical contamination of electrical contacts can result in the deposition of insulating films that produce electrical opens, as in the case of si!icone o!l degradation on arcing contacts or in the case of dust accumulation on Surfaces. These insulating films can also produce intermittent electrical problems. Alternatively, contaminants can result in electrical leakage as in the cases of water damage, silver migration, and ozone attack of hard rubber insulators. The sources of these chemicals can be a manufacturing procedure, the operating environment, or even outgassing from other parts within the equipment. Some of the areas reviewed include equipment damage from dust contamination, gases and vapors, floods, rain, and water leaks, fires, and contamination arising during manufacture.