Electric Motor Repairer related Frequently Asked Q Interview Questions And Answers

I have the ability to make precisely coordinated movements of the fingers of one or both hands to grasp, manipulate, or assemble very small objects, quickly move your hand, your hand together with your arm, or your two hands to grasp, manipulate, or assemble objects, tell when something is wrong or is likely to go wrong. It does not involve solving the problem, only recognizing there is a problem, keep your hand and arm steady while moving your arm or while holding your arm and hand in one position, arrange things or actions in a certain order or pattern according to a specific rule or set of rules (e.g., patterns of numbers, letters, words, pictures, mathematical operations).

The motor which work or act on the applied input pulse in it, is called as stepper motor. This stepper motor is under the category of synchronous motor, which often does not fully depend of complete cycle. It likes to works in either direction related to steps. for this purpose it mainly used in automation parts.

Series motor cannot be started without load because of high starting torque. Series motor are used in Trains, Crane etc.

The function of commutator is to facilitate the collection of current from armature conductors. It converts the alternating current induce in the armature conductors into unidirectional current in the external load circuit.

The Feedback in Control System in one in which the output is sampled and proportional signal is fed back to the input for automatic correction of the error ( any change in desired output) for futher processing to get back the desired output.

If actual thrust is less than commanded thrust during takeoff with airspeed between 65kts and V1-6kts. FCOM 1 70.20.16

The different methods of starting an induction motor:

☛ DOL:direct online starter
☛ Star delta starter
☛ Auto transformer starter
☛ Resistance starter
☛ Series reactor starter

Repairing machines or systems using the needed tools, Determining causes of operating errors and deciding what to do about it, Conducting tests and inspections of products, services, or processes to evaluate quality or performance, Identifying complex problems and reviewing related information to develop and evaluate options and implement solutions, Using logic and reasoning to identify the strengths and weaknesses of alternative solutions, conclusions or approaches to problems.

Synchronous machines have capability to work on different power factor (or say different imaginary power varying the field EMF. Hence syn. generators r used for the production of electricity.

The purpose of brushes is simply to lead current from the rotating loop or winding to the external stationary load.

constant losses:
☛ Iron losses,
☛ Mechanical losses,
☛ Shunt field losses

Variable losses:
☛ Copper loss.

An electric generator is a machine that converts mechanical energy into electrical energy. An electric generator is based on the principle that whenever flux is cut by a conductor, an e.m.f. is induced which will cause a current to flow if the conductor circuit is closed. The direction of induced e.m.f. (and hence current) is given by Fleming's right hand rule.

My co-workers would describe my attention to detail as very strong. I can very easily point out discrepancies on a report and will notice the small things like an engine sounding slightly off. I think big-picture as well but have always had a knack for details.

The Knowledge of machines and tools, including their designs, uses, repair, and maintenance, arithmetic, algebra, geometry, calculus, statistics, and their applications, the practical application of engineering science and technology. This includes applying principles, techniques, procedures, and equipment to the design and production of various goods and services, principles and processes for providing customer and personal services. This includes customer needs assessment, meeting quality standards for services, and evaluation of customer satisfaction, the structure and content of the English language including the meaning and spelling of words, rules of composition, and grammar.

Motor Generator Sets are a combination of an electrical generator and an engine mounted together to form a single piece of equipment. Motor generator set is also referred to as a genset, or more commonly, a generator The motor generator set can used in the following different ways:
☛ 1.Alternating current (AC) to direct current (DC)
☛ 2.DC to AC
☛ 3.DC at one voltage to DC at another voltage
☛ 4.AC at one frequency to AC at another harmonically-related frequency

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.

In DC motors, Voltage equation is V=Eb-IaRa (V = Terminal voltage, Eb = Back emf in Motor, Ia = Armature current,Ra = Aramture resistance). At starting, Eb is zero. Therefore, V=IaRa, Ia = V/Ra ,where Ra is very less like 0.01ohm.i.e, Ia will become enormously increased.

The Shunt winding has a large number of turns so that it has appreciable inductance. When A.C is applied to a shunt motor, the large inductive reactance of shunt winding will reduce the field current too much. Consequently, Shunt motor will not usually run on A.C Supply.

If you haven't worked on automobiles in a professional setting, don't sweat it! You can include your experience working on your own cars or others. When you respond to this question, you want to go in depth about the type of work you have done, sharing your knowledge and areas of expertise. Rather than saying, "I have about 8 years of experience,"

Its Single Phase induction motor which mostly squirrel cage rotor and are capacitor start capacitor run.

DC Series motor has high starting torque. We can not start the Induction motor and Synchronous motors on load, but can not start the DC series motor without load.

Dc series is in the trains to get high starting torque while starting of the trains and operating voltage is 1500v dc.

When breaker is close at one time by close push button,the anti pumping contactor prevent re close the breaker by close push button after if it already close.