Lab 3 P. 1

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Product Analysis

Lab 3

Lab 3 P. 2

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

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.

Lab 3 P. 3

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Product Analysis

Contents:

• Power Conversion and Approximation

• Schematic Components

• Motor Discussion

Lab 3 P. 4

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

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.

Lab 3 P. 5

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Power Conversion

horsepower, unit of power in the English system ofunits. It is equal to 33,000 foot-pounds perminute or 550 foot-pounds per second or approximately 746 watts. The term horsepoweroriginated 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.

Lab 3 P. 6

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Schematic SymbolsCommonly 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

Lab 3 P. 7

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Breakaway View

Laminated Core

Rotor

Stator Winding

Poles “Shaded” with Copper Wire

Lab 3 P. 8

Engineering H192 - Computer Programming

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Shading Theory

Shading CoilsRotorStator Winding

Lab 3 P. 9

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Shading Theory

Lab 3 P. 10

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Shading Theory

Lab 3 P. 11

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

Shading Segments

Lab 3 P. 12

Engineering H192 - Computer Programming

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Flux Wave Rotation

Lab 3 P. 13

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

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:

rpm = 120 fNp

s

rpm = = 3000120 x 502

Lab 3 P. 14

Engineering H192 - Computer Programming

Winter Quarter Gateway Engineering Education Coalition

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:

sliprpm

rpmrpm

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