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Product Analysis. Lab 3. Product Analysis Objectives. Combine previous lab experiences to better understand the workings of a completed product. Develop an appreciation for horsepower and wattage considerations in product design.
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Product Analysis Lab 3 Winter Quarter
Product Analysis Objectives • Combine previous lab experiences to better understand the workings of a completed product. • Develop an appreciation for horsepower and wattage considerations in product design. • Expand the library of electrical schematic symbols used to designate components. • Develop reverse engineering skills. Winter Quarter
Product Analysis Contents: • Power Conversion and Approximation • Schematic Components • Motor Discussion Winter Quarter
Power Conversion watt [for James Watt], abbr. W, unit of power, or work done per unit time, equal to 1 joule per second. It is used as a measure of electrical and mechanical power. One watt is the amount of power that is delivered to a component of an electric circuit when a current of 1 ampere flows through the component and a voltage of 1 volt exists across it. Winter Quarter
Power Conversion horsepower, unit of power in the English system of units. It is equal to 33,000 foot-pounds per minute or 550 foot-pounds per second or approximately 746 watts. The term horsepower originated with James Watt, who determined by experiment that a horse could do 33,000 foot-pounds of work a minute in drawing coal from a coal pit. Winter Quarter
Commonly Used Symbols: DC Source AC Source Motor Ground Resistor Capacitor Fuse SPST Switch N.C. Push Button Switch N.O. Push Button Switch Female Connector Male Connector Schematic Symbols Winter Quarter
Breakaway View Stator Winding Rotor Laminated Core Poles “Shaded” with Copper Wire Winter Quarter
Stator Winding Shading Coils Rotor Shading Theory Winter Quarter
Shading Theory Winter Quarter
Shading Theory Winter Quarter
Shading Segments Winter Quarter
Flux Wave Rotation Winter Quarter
f • N s rpm = p 120 x 50 2 rpm = = 3000 Motor Speed • Motor theory tells us that the speed of an ac motor is directly proportional to the frequency and inversely proportional to the number of poles as follows: • Thus, for a 2-pole motor running at 50 hz: Winter Quarter
Motor Slip • The rotor of an induction motor will not rotate at the theoretical speed due to slip. The equation for slip is: • Thus, if the anticipated rpm was 3600 and the actual rpm was 3440: Winter Quarter