Abstract
The most important element of mobile equipment for servicing the agricultural water supply system is motor vehicles. Statistical studies have shown that 25 % of vehicle failures are related to electrical equipment failures, a significant portion of which is the contact brush assemblies of generators. To develop measures to improve the reliability of the contact brush assemblies of generators, it is necessary to conduct bench tests for durability. The most important link is the levels of variation of factors affecting reliability. In this regard, factors have been identified, mainly affecting the operability of the contact brush assemblies of generators. Based on statistical data and experimental studies, laws and distribution parameters were established for these factors, which made it possible to select the levels of influencing factors during multifactorial planning of tests of contact brush assemblies of generators for reliability.