Tools used in the conduct of this work include voltage testers, ohmmeters, ampere meters, punches, pipe-threaders, pipe benders, drills, pulling equipment, and a wide variety of hand tools including pliers, screwdrivers, wrenches, wire strippers hammers, chisels, power benders. Repair may include analysis and diagnosis of the reasons for a failure and repair/replacement of such parts as control wiring, transformers, switches, relays, contactors, circuit breakers, safety devices, heating elements, thermostats, light ballasts, light bulbs or other types of devices, commonly found in the electrically operated machinery or equipment.