Electric Motor Repairer

The losses in a d.c. machine (generator or motor) may be divided into three types:

☛ Copper losses: These losses occur due to currents in the various windings of the machine.

☛ Iron or core losses: These losses occur in the armature of a d.c. machine and are due to the rotation of armature in the magnetic field of the poles. They are of two types

☛ Hysteresis loss: Hysteresis loss occurs in the armature of the d.c. machine since any given part of the armature is subjected to magnetic field reversals as it passes under successive poles.

☛ Eddy current loss: The voltages induced in the armature conductors produce circulating currents in the armature core known as eddy currents and power loss due to their flow is called eddy current loss. The eddy current loss appears as heat which raises the temperature of the machine and lowers its efficiency.

☛ Mechanical losses: These losses are due to friction and windage. These losses depend upon the speed of the machine. But for a given speed, they are practically constant.

The interviewer wants to know that you're not just interested in any place that will hire you. They want to know that you want to work for them, specifically. Before the interview, learn as much as you can about their garage. You can search customer reviews to learn about their reputation. An auto repair shop with good reviews reflects their values as well. Think about the places you have worked. What did you like most about them? If you can't find much online or through asking around beforehand, try to list at least three things you have read that you like about their garage. Prepare questions for any remaining areas that are unclear, but focus on values and qualities, such as work environment, employee training, and customer care.

Electric motor responsibilities are to disassemble defective equipment so that repairs can be made, using hand tools; record repairs required, parts used, and labor time; inspect and test equipment to locate damage or worn parts and diagnose malfunctions, or read work orders or schematic drawings to determine required repairs;

repair and rebuild defective mechanical parts in electric motors, generators, and related equipment, using hand tools and power tools; lubricate moving parts; measure velocity, horsepower, revolutions per minute (rpm), amperage, circuitry, and voltage of units or parts to diagnose problems, using ammeters, voltmeters, wattmeters, and other testing devices; scrape and clean units or parts, using cleaning solvents and equipment such as buffing wheels; solder, wrap, and coat wires to ensure proper insulation; read service guides to find information needed to perform repairs; adjust working parts, such as fan belts, contacts, and springs, using hand tools and gauges; inspect electrical connections, wiring, relays, charging resistance boxes, and storage batteries, following wiring diagrams; weld, braze, or solder electrical connections; reassemble repaired electric motors to specified requirements and ratings, using hand tools and electrical meters; rewire electrical systems, and repair or replace electrical accessories;

assemble electrical parts such as alternators, generators, starting devices, and switches, following schematic drawings and using hand, machine, and power tools; lift units or parts such as motors or generators, using cranes or chain hoists, or signal crane operators to lift heavy parts or subassemblies; remove and replace defective parts such as coil leads, carbon brushes, and wires, using soldering equipment; maintain stocks of parts; sharpen tools such as saws, picks, shovels, screwdrivers, and scoops, either manually or by using bench grinders and emery wheels; clean cells, cell assemblies, glassware, leads, electrical connections, and battery poles, using scrapers, steam, water, emery cloths, power grinders, or acid; reface, ream, and polish commutators and machine parts to specified tolerances, using machine tools; hammer out dents and twists in tools and equipment;

test equipment for overheating, using speed gauges and thermometers; test battery charges, and replace or recharge batteries as necessary; verify and adjust alignments and dimensions of parts, using gauges and tracing lathes; test conditions, fluid levels, and specific gravities of electrolyte cells, using voltmeters, hydrometers, and thermometers; steam-clean polishing and buffing wheels to remove abrasives and bonding materials, and spray, brush, or recoat surfaces as necessary; repair and operate battery-charging equipment; set machinery for proper performance, using computers; cut and form insulation, and insert insulation into armature, rotor, or stator slots; inspect batteries for structural defects such as dented cans, damaged carbon rods and terminals, and defective seals; drain and filter transformer oil and refill transformers with oil until coils are submerged; rewind coils on cores in slots, or make replacement coils, using coil-winding machines;

clean, rinse, and dry transformer cases, using boiling water, scrapers, solvents, hoses, and cloths; add water or acid to battery cell solutions to obtain specified concentrations; pour compounds into transformer-case terminal openings to seal out moisture; position and level battery cells, anodes, or cathodes, using hoists or leveling jacks, or signal other workers to perform positioning and leveling; seal joints with putty, mortar, and asbestos, using putty extruders and knives; bolt porcelain insulators to wood parts to assemble hot stools.