s s book 20.9

By Steve Sivell

Master Exam Prep

2

Use Restrictions

The copyright in all material (including still and moving images) provided in this reference (BOOK) is held by

the original creator of the material or its assignee. Except as stated herein, none of this material may be copied, reproduced,

distributed, republished, downloaded, displayed, posted or transmitted in any form or by any means, including without limitation,

by electronic, mechanical, photocopying or other recording means, without the prior written permission of

or the appropriate copyright owner.,

Disclaimer of Warranty

THE MATERIALS MAINTAINED ON OR ACCESSED BY WAY OF THIS REFERANCE ARE PROVIDED "AS IS"

WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING WITHOUT LIMITATION,

ALL IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-

INFRINGEMENT OR OTHER VIOLATION OF RIGHTS.

DOES NOT WARRANT OR MAKE ANY REPRESENTATIONS REGARDING THE USE, VALIDITY, ACCURACY, OR

RELIABILITY OF, OR THE RESULTS OF ANY USE OF, OR OTHERWISE RESPECTING.

Limitation of Liability

UNDER NO CIRCUMSTANCE (INCLUDING NEGLIGENCE AND TO THE FULLEST EXTENT PERMITTED BY

APPLICABLE LAW) WILL Steve Sivell BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE

OR CONSEQUENTIAL DAMAGES (INCLUDING WITHOUT LIMITATION, BUSINESS INTERRUPTION, DELAYS, LOSS

OF DATA OR PROFIT) ARISING OUT OF THE USE OR THE INABILITY TO USE THE MATERIALS MAINTAINED ON

OR IN THIS REFERENCE. IF USE OF SUCH MATERIALS RESULTS IN THE NEED FOR SERVICING, REPAIR OR

CORRECTION OF USER EQUIPMENT OR DATA, USER ASSUMES ANY COSTS ASSOCIATED THEREWITH.

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This book contains information obtained from authentic and highly regarded sources. Reasonable efforts

have been made to publish reliable data and information, but the author and publisher cannot assume

responsibility for the validity of all materials or the consequences of their use.

The purpose of this book is to impart knowledge on the subject covered in the book. All work

undertaken based on this text is the sole responsibility of the reader and user of the book.

The manufacturers operating instruction and testing procedures are the only reliable guide in any

specific use; manufacture specifications should be consulted before undertaking any work on electrical

equipment.

Dedication To God, To my wife Jackie - for her assistance, patience and understanding to make this work possible, To my

Children - Amber, John, Spencer, Jack, & Alicia,

To my Grandchildren - Nicky, James, Michel, & Elliana

& To my parents

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"Discovery consists in seeing what everyone else has seen and thinking what no one else has thought."

- Albert Szent-Gyorgyi, Nobel Prize for Medicine 1937

PROCEDURES FOR SUCCESS

1. Set a strict routine. Adhere to it.

2. Set goals and achievements. Award yourself for the achievements.

3. Avoid all distractions and stress. Choose a quiet place to study.

4. Be prepared. Have all books, pens, calculators and reference materials

5. Take detailed notes during studying and or classes. Your notes, study skills and habits are

what will help you pass the exam.

6. Start at the beginning.

7. DO NOT ASSUME ANYTHING!!!!! There are always things to learn.

8. Be willing to learn from others no matter what your skill level is. You can always learn from

others.

9. Studying is more than just reading. Analyze all material given to you carefully. Get a study

friend. Study for at least 8 hours a week.

10. Always ask questions. There are no stupid questions.

11. Never rush. Take a break when you are tired or frustrated during the exam, studying and

class.

12. Take as many practice tests as possible. Practice makes perfect.

13. Look for keywords that will indicate the answers.

14. Eliminate all wrong answers.

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15. When taking the exam, some answers will seem obvious. Choose what would be the most

correct answer.

Example: If your house were on fire, what would you do?

A. run around yelling fire B. call 911

C. get out of the house D. all the above

It would be easy to pick D, but in reality, the correct answer would be C.

16. If you are stuck on a question while taking the exam, pass it and come back to it. *Refer

to rule 11.

17. On the day of the exam, arrive early and be prepared.

18. The night before the exam, gather all material up, relax and get plenty of rest. *Refer to

rule 3 and 11.

19. This is a life-changing event gaining your Masters License. Treat it as such.

20. Do not waste my time, your time and your familys time. Note: YOU MADE THE

COMMITMENT! STICK TO IT!

Remember: there is no substitute for Ethics, Tenacity, Good Workmanship and Hard work.

Safety First

WARNING: This guide will not teach

you how to work on electrical

equipment. It will not teach you how to

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become an electrician. You will see pictures and or illustration of electrical components, electrical

devices, electrical equipment, electrical apparatus and the inside of electrical panels where arc

flash accidents occur, however you should never open these electrical components, electrical

devices, electrical equipment, electrical apparatus and the inside of electrical panels yourself.

Qualified Personnel vs. Unqualified Personnel

O.S.H.A 29 CFR 1910 Subpart S identifies two types of people that may come in contact with

electrical equipment on a jobsite; qualified and unqualified.

Qualified person

One who has been trained to avoid the electrical hazards when working on or near exposed

energized parts, equipment or apparatus

1) Familiar with the safety related work practices required in 29 CFR 1910.331-

1910.335;

2) Able to distinguish exposed live parts of electrical equipment;

3) Knowledgeable of the skills and techniques used to determine the nominal voltages

of exposed parts.

Unqualified person

Someone who has little or no training with regarding the hazard of electrical

Even though unqualified persons may not be exposed to energized parts,

training should still be provided so they can be familiar with any electrical-related safety

practice

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Electricity and its Effects on the Body

Electricity will follow the path of least resistance to ground; similar to water in a pipeline that

flows out of a valve when it is opened. Electricity becomes dangerous when you become part of

the circuit because the closest path to ground may be through you, causing an electrical shock.

When you are shocked by electricity, your muscles contract, if the lungs are involved in the path

of the circuit, voluntary respiration can be halted. If the heart is involved, fibrillation can occur

resulting in heart failure. As little as 50 mill amperes can cause death.

Realize that an electrical shock may not be strong enough to kill you but it could cause other

severe injuries, you to fall or be plunged into dangerous surroundings, and or first, second and

third degree burns

The effects

1 mA: Can be felt by the body

2-10 mA: Minor shock, might result in a fall

10-25 mA: Loss of muscle control, may

not be able to let go of the current

25-75 mA: Painful, may lead to collapse

or death

75-300 mA: Last for 1/4 second, almost always immediately fatal

Electrocutions have been a leading cause of occupational fatalities, many times ranking among

the top five. In addition to the thousands of fatalities annually, there is an average of 3,600

electrical-related disabling injuries. Electric shock severity is a matter of current deliver through

the body remember Ohms law tells us that current is =

(I= current, E= volts, R = resistance

in ohms) take a look at how much current and voltage the human body can with stand, first look

at table values below and then examples following the table

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Contact condition Resistance (ohms)

Body part Dry condition Wet condition

Hand holding wire 15,000 50,000 3,000 6,000

Finger thumb grasp 10,000 30,000 2,000 5,000

Finger touch 40,000 1,000,000 4,000 15,000

Palm touch 3,000 8,000 1,000 2,000

Hand around 1 metal conduit 1,000 3,000 500 1,500

Hand holding plies 1,000 3,000

Foot Immersed 100 300

Foot Immersed 200 500

Factors of Shock Severity

Electric Current

(1 second contact)

Physiological Effect Voltage required to produce

the current with assumed

body resistance

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1 mA Threshold of feeling, tingling

sensation.

100 V 1 V

3 mA Painful shock which may cause

indirect accidents

300 V 3 V

5 mA Accepted as maximum harmless

current

500 V 5 V

10-20 mA Beginning of sustained muscular

Contraction

("Can't let go" or muscle freeze

current.)

1,000 V 1O V

30 mA lung paralysis

usually temporary

3,000 V 30 V

50 mA Possible ventricular fibrillation

(heart dysfunction, usually fatal)

5,000 V 50 V

100-300 mA Certain ventricular fibrillation,

Fatal

10,000 V 100 V

4 A Heart paralysis, severe burns 400,00 V 4OO V

5 A Flesh burns, defibrillation,

respiratory paralysis

500,000 V 500 V

Look at just how dangerous getting shocked can be.


Example

An electrician working is using damp pliers on a 120 volt circuit, the damp pliers inadvertently

makes contact with the120 live conductor.

We know from the table above that the resistance will be approximately 1,500 ohms.

The current traveling through the body, will be about 80 milliamps since 120 volts

divided by 1500 ohms is .08 amps. =

,

= .

The worker is shocked and the current passes though the chest, possibly from the pliers in the

right hand through the body to the left hand grabbing a piece of grounded metal, the 80

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milliamp current will probably kill him.

Example

Same circumstance, however this time he is dry

I = E / R or Current = Voltage / Resistance

If E= 120 volts, and

R = 7,500 Ohms, Holding Pliers Dry (5,00010,000)

I = 120/ 7,500

I = 16 ma, muscular contractions

Providing around 7,500 ohms of resistance at 120 volts would deliver 16 milliamps, Luckily the

16 milliamps of current in this example should not kill the worker, just a very painful shock,

however if he is on a ladder, the muscle contractions could cause him to lose his balance, fall off,

and get killed

anyway.

How much current is needed to kill you?

Let us look at a 7andahalfwatt night light bulb / Christmas decoration light bulb

plugged into a 120volt outlet in a home.

Since wattage equals v, current can be calculated by dividing the wattage of the bulb by the

voltage of the outlet. .

= . Alternatively, 62.5 milliamps, well above the 50milliamp

limit to stop your heart if it were to go through your chest.

Resistance is reduced if you are wet or sweaty, or are not wearing the proper gloves

or shoes, making current (the part that kills you) much greater. Therefore let us

leave the electrical work to Qualified, properly trained and well equipped licensed

electrician.

Electrical work is not a hobby, leave it to the professionals! Leave it to the

professionals. So you dont become a 7 watt Christmas bulb.

Steve Sivell

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Arc Flash

An arc flash is a short circuit in an electrical panel box or any other piece of energized electrical

equipment. When the short happens and the circuit is completed through the air, the air breaks

down (Ionizes and forms plasma) to where it offers littletono resistance to the flow of

electricity.

The tremendous amounts of energy released in an arc flash make for a very bright, very hot, and

very loud explosion.

Quick note, the surface temperature of the Sun is approximately 9,9000 F an arc flash has a

temperature of 35,0000 F. This is in addition to plasma of vaporizing metal having a temperature

of 23,0000 F. In comparison with an atomic bomb, after 0.3 seconds, reaches only 12,632 0 F, this

arc is unbelievably hot.

An Arc Flash can result in severe burns, injuries and death.

Intense heat, blinding light, and explosive pressure are all characteristics of an arc flash explosion.

Temperatures in the fault can exceed 35,0000 F, and the intense pressure can send shrapnel and

molten metal flying toward the arc flash victim. The explosion also creates pressure

waves(exceeding 1000 psi) The detonation of any powerful explosive generates deadly blast

effect, propagated in a wave front of high pressure that spreads out at 1,600 feet per second from

the point of explosion. Normally, the detonation propels fragments of shrapnel at a high velocity.

Where fragments penetrate the skull, such injuries (referred to as ballistic trauma) are considered

"conventional" traumatic brain injuries; the blasts also causes invisible damage to the brain, as the

blast wave tremors the soft tissue, smashing it against the hard surface of the inner skull.

Actually, the lethal blast wave strikes twice. The initial shock wave of very high pressure is

followed closely by the "secondary wind": a huge volume of displaced air flooding back into the

vacuum under high pressure. These sudden and extreme differences in pressures routinely are

1,000 times as great as atmospheric pressure, Above about 20 PSI, your chance of survival is very

slim.

The NFPA 70E handbook, on page 129, states, "If the thermal energy exceeds 40cal/cm2, the

accompanying pressure wave might injure any worker who is near. Arc flash calculated by IEEE

>40 that clear in 5 cycles (83.335 milliseconds) ) to clear an arc blast (16.7 milliseconds or 1/60

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seconds or 016667, is the cycle time for 60 Hz AC electrical system), 1 millisecond: (ms) is one

thousandth of one second.

The an arc blasts incidents are not survivable to persons without proper PPE exposed, except in

the most mild circumstances that can damage hearing or brain function and a flash that can

damage eyesight.

The Result:

Rapid release of energy a fire ball exploding outward

Rapid release of heat can cause incurable burns

Blinding light - flash

Shock/Pressure wave Deadly, like a hammer hitting you in the chest

Sound wave Damage the ears acoustic wave trauma

Sudden spray of molten metal droplets

Hot shrapnel flying in all directions

Arc Flash

The plasma will conduct as much energy as is available and is only limited by the impedance of

the arc and the overall electrical system impedance.

This massive energy discharge burns the bus bars or wiring, vaporizing the copper or aluminum

and thus causing an explosive volumetric increase. The arc flash is a blast and is conservatively

estimated as an expansion in volume of 40,000 to 1. This fiery explosion devastates everything in

its path, creating deadly shrapnel and droplets of molten metal flying in many directions

The arc fault current is usually lower than the available bolted fault current that occurs during a

direct short circuit.

The arc fault current often below the rating/setting of the protecting circuit breaker or fuse

normally will not trip or trip fast enough to minimize the full force of an arc flash. The amount

of energy produced at the point of the arc is a function of the voltage and current present as well

as the time that the arc is sustained; this time is the most important part of the energy equation,

every second matters greatly. The transition from the arc fault to the arc flash takes a finite time,

increasing in intensity as a pressure wave develops. The challenge to protect against an arc flash

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is to sense the arc fault current and shut off the current in a timely manner before it develops

into a serious arc flash condition.

Arc Flash Analysis

An arc flash study must be completed for employers to identify arc flash hazard levels to protect

employees from known hazards as required by OSHA. OSHA 29CFR 1910 requires employers to

calculate the arc flash hazard, enact safe work practices and an appropriate safety program, and

provide the proper PPE and training to their employees. Specifics on how to meet arc flash

requirements are provided in the NFPA70E, IEEE 1584, and NEC.

Who needs arc flash safety training?

All employees who are around electrical equipment need a basic understanding of arc flash

hazards, but the qualified employees doing energized work need complete training in the hazards

and procedures of the electrical safety program. Qualified employees will need extensive training

in how to read the arc flash labels, follow the procedures of the program, recognize hazards,

choose and use the required Personal Protection Equipment.

No worker has ever been killed by an arc flash while working in an Electrically Safe Work

Condition! Working on energized equipment should be the EXCEPTION not the RULE. Work De-

Energized!

Safe Work Practices

Safety-related work practices are to prevent electrical shock or similar injuries by keeping workers

away from energized equipment and apparatus.

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Only properly training qualified workers should work around electrical equipment and apparatus

when working on de-energized or energized equipment or circuits.

Prior to use of or maintenance on electrical equipment, the employee should first determine:

Make sure Proper Personal Protection Equipment (PPE) is available and properly

used

Inspect all PPE prior to use

inspect all tools and equipment to be used making sure there is not any defects

and damage

Know if the equipment has an emergency shutoff switch and where it is located

prior to use;

Make sure there is sufficient work space around the electrical equipment or circuit

in order to maintain or operate

Make sure all personal metal jewelry is removed prior to using or working on

electrical equipment or circuits

De-energize electrical equipment before testing or repairing in accordance with the

Lockout Tag out standard 29 CFR 1910.147.

Make sure fuses, breakers and ground fault circuit interrupters (GFCI) have not

been damaged, tampered with and are working correctly;

Not located in a hazardous environment such as a damp/wet location

Not located in a hazardous environment such as to high temperatures

Not located in a hazardous environment such as flammable liquids and gases

Make sure the power cord and plug do not have any defects and damage such as

cuts in the insulation exposing bare wiring and all prong on the cord male end of

cord attachments for damage

Follow all OSHA , NFPA 70E and other applicable safety standards

If de-energizing the electrical equipment or circuit will increase the potential for an electrical

hazard or is necessary for testing and troubleshooting, the appropriate tools and personal

protective equipment (PPE) must be used and worn for the specific parts of the body to be

protected.

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O.S.H.A and N.F.P.A

What Is O.S.H.A. and the NFPA 70E?

Occupational Safety and Health Administration (OSHA): Is a part the US Department of Labor that

establishes, issues, and enforces national workplace safety regulations. OSHA publishes the

legally required safety mandates in the Code of Federal regulation (CFR) TITLES

1910,1926 and others.

National Fire Protection Association (NFPA) is a trade association that creates and maintains

standards and codes for usage and adoption by local governments, business.

Occupational Safety and Health Administration (OSHA) and the National Fire Protection Association (NFPA) have

written standards and regulations that build on one another and help keep all workers safer from electrical hazards in

the workplace.

The OSHA regulations and NFPA standards work so well together, OSHA provides the "shall" and NFPA provides

the "how".

NFPA 70E is a privately published safety standard published by NFPA primarily to assist OSHA.

OSHA has not incorporated the NFPA into the Code of Federal Regulations. (should be noted that when OSHA

prepared the electrical safety standards, OSHA consulted with the NFPA) OSHA bases its electrical safety standards

(found in Subpart S part 1910 and Subpart K part 1926) on the comprehensive information found in NFPA 70E

.

Example:

How the OSHA regulations and NFPA 70E standards work together.

OSHA mandates that all services to electrical equipment be done in a de-energized state. "Working live" can only be

done under special circumstances.

NFPA 70E defines those special circumstances and sets rigid safety limits on voltage exposures, work zone boundary

requirements and PPE necessary. (See NFPA 70E Article 130 and OSHA Subpart S part 1910333(a)(1) for complete

details).

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Personal Protective Clothing Ratings

Personal Protective Equipment (PPE)

Selecting the right clothing, Flame retardant clothing is assigned an ATPV rating by the manufacturer. The ATPV

value represents the amount of incident energy that would cause the onset of second-degree burns. It also signifies

the amount of protection the clothing provides when an electrical arc comes in contact with the fabric.

Most people working with electricity only require clothing that meets Category 1,2 or 3 protection characteristics.

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Personal Protective Clothing Characteristics

Hazard/Risk Category Clothing Description APTV Rating Cal/cm2

0 Untreated Cotton, Wool, Rayon,

Silk, or Blend. Fabric weight

>4.5oz/Yd2 (1 layer)

N/A

1 FR* Shirt and FR Pants or FR

Coverall (1 layer)

4

2 Cotton underwear plus FR shirt and

FR pants (1 or 2 layers)

8


FR pants plus FR coverall, cotton

underwear plus two FR Coveralls (2

or 3 layers)

25


FR pants plus multilayer flash suit

(3 or more layers)

40

Hard Hat Requirements

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Occupational Head Protection

29 CFR 1910.135(a)(1) states, "Each affected employee shall wear protective helmets when

working in areas where there is a potential for injury to the head from falling objects." The

standard also covers conditions where electrical hazards are present. 1910.135(a)(2) states,

"Protective helmets designed to reduce electrical shock hazard shall be worn by each such

affected employee when near exposed electrical conductors which could contact the head."

Although the OSHA standards themselves do not identify specific occupations or applications

where head protection is required, Appendix B to Subpart I Part 9 lists some examples terms of

what constitutes a "protective helmet," 29 CFR 1910.135

ANSI Z89.1-1986

ANSI Z89.1-1986 separates protective helmets into different types and classes.

Type 1 helmets incorporate a full brim (the brim fully encircles the dome of the hat)

Type 2 helmets have no encircling brim, but may include a short bill on the front

Electrical performance, ANSI Z89.1-1986

Class A Helmets are intended to reduce the force of impact of falling objects and to

reduce the danger of contact with exposed low-voltage electrical conductors. Proof-

tested at 2,200 volts.

Class B Helmets are intended to reduce the force of impact of falling objects and to

reduce the danger of contact with exposed high-voltage electrical conductors.

Proof-tested at 20,000 volts.

Class C Helmets are intended to reduce the force of impact of falling objects, but

offer no electrical protection.

Every hard hat conforming to the requirements of ANSI Z89.1-1986 must be appropriately

marked to verify its compliance. The following information must be marked inside the hat:

The manufacturer's name

The legend, "ANSI Z89.1-1986"

The class designation (A, B or C)

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Hand Protection

OSHA 1910.138(a) and 1910.138 (b) pertains to hand protection:

1910.138(a)

General requirements. Employers shall select and require employees to use appropriate hand

protection when employees hands are exposed to hazards such as those from skin absorption of

harmful substances; severe cuts or lacerations; severe abrasions; punctures; chemical burns;

thermal burns; and harmful temperature extremes.

1910.138(b)

Selection. Employers shall base the selection of the appropriate hand protection on an evaluation

of the performance characteristics of the hand protection relative to the task(s) to be performed,

conditions present, duration of use, and the hazards and potential hazards identified.

Gloves ANSI ratings

Cut resistant glove are designed to protect hands from direct contact with sharp edges such as

glass, metal, ceramics and other materials. Cut-resistance is a function of a gloves material

composition and thickness. You can increase your cut protection by increasing material weight

(i.e. ounces per square yard), using high-performance materials such as Spectra, Kevlar, etc., or

by using composite yarns made with varying combinations of stainless steel, fiberglass, synthetic

yarns and high-performance yarns.

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Electrical Protective Gloves

Rubber insulating gloves are among the most important articles of personal protection for electrical

workers. Gloves should also be electrically tested following ASTM D120/IEC903 specifications.

A glove system usually consists of:

Rubber Insulating Gloves - Classified by the level of voltage and protection they provide.

Liner Gloves - Are used to reduce the discomfort of wearing rubber insulating gloves in all seasons, for

year round use. Liners provide warmth in cold weather, while they absorb perspiration in the warm

months. These can have a straight cuff or knit wrist.

Leather Protector Gloves - Should always be worn over rubber insulating gloves to provide the mechanical

protection needed against cuts, abrasions and punctures. Look for those that are steam pressed on curved

hand forms to ensure proper fit over rubber gloves.

Electrical-Protective Glove Classification

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Employees who work in close proximity to live electrical current may require a variety of electrically

insulating protective equipment. The Occupational Safety and Health Administration (OSHA) outlines

this in their Electrical Protective Equipment Standard (29 CFR 1910.137) which provides the design

requirements and in-service care and use requirements for electrical-insulating gloves and sleeves as well

as insulating blankets, matting, covers and line hoses. Electrical-protective gloves are categorized by the

level of voltage protection they provide and whether or not they are resistant to ozone. Voltage protection

is broken down into the following classes:

Class 0 - Maximum use voltage of 1,000 volts AC/proof tested to 5,000 volts AC.





Once the gloves have been issued, OSHA requires that "protective equipment shall be maintained in a

safe, reliable condition". This requires that gloves be inspected for any damage before each days use.

Gloves must also be inspected immediately following any incident that may have caused damage. OSHA

requires that insulating gloves be given an air test along with the inspection.

Glove Testing

OSHA requires air testing, but does not explain how to perform the test. The test method is described in

ASTM F 496, As stated in ASTM specifications for In-Service Care and Use of Rubber Gloves and

Sleeves, gloves and sleeves should be expanded no more than 1.5 times their normal size for type I, and

1.25 times normal for type II during the air test. The procedure should then be repeated with the glove

turned inside out.

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In addition to this daily testing, OSHA requires Electrical protective equipment shall be subjected to

periodic electrical tests. OSHA does not elaborate on a period for these tests, but ASTM F 496 does

provide direction. It states that gloves being used in the field must be electrically retested every six

months.

Gloves that have not been placed into service after an electrical test shall not be placed into service unless

they have been electrically tested within the previous 12 months. See reference below for Testing Agency

information.

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Insulated Hand Tools

Introduction

Insulated tools must be used when working on or near exposed energized live conductors. Only

insulated tools that comply with the International Electro technical Commission standard 900

(IEC 900),

29 CFR 1910.335(a)(2)(I)

When working near exposed energized conductors or circuit parts, each employee shall use

insulated tools or handling equipment if the tools or handling equipment might make contact

with such conductors or parts.

General Requirements

Insulated tools are individually tested and certified by the manufacturer to be suitable for specific

working conditions. Generally, the maximum rated voltage for insulated tools is 1000 volts AC

and 1500 volts DC.

look for compliance with one or more of the following standards:

The International Electro technical Commission (IEC)

The American Society for Testing and Materials (ASTM)

The Detaches Institute for Norming (DIN-German Standard).

The ASTM, IEC, and DIN do not test the tools for compliance; they just set the

performance requirements for the insulation. The manufacturers do their own testing.

Use and Care of Insulated Tools

Keep tools clean and dry

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Inspect insulation prior to each use

If you doubt the integrity of the insulation, destroy the tool or have it re-tested

Follow the manufacturers temperature recommendations for use

Have a qualified person inspect and re-certify tools annually for safe use

Use other personal protective equipment as necessary

Noise & Light Levels

Dangerous noise levels and harmful light levels exist in many day-to-day workplace activities. The

following information pro-vides a better understanding of the comparison of various noise and

light levels to a number of locations and applications.

Hearing loss 29 CFR 1904.95

Employers shall make hearing protectors available to all employees exposed to an 8-hour time-

weighted average of 85 decibels or greater at no cost to the employees.

Hearing protectors must be made available to workers exposed at or above the action level of 85

db. OSHA requires that hearing protection be provided by the employers (and must be worn by

employees)

When is hearing protection required

noise exposures exceed 90 dB; and

employees are exposed to greater than 85 dB and have not yet had a baseline

audiogram or have experienced a standard threshold shift (loss of hearing).

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1910.95(b)(2) If the variations in noise level involve maxima at intervals of 1 second or less, it is to be considered

continuous.

TABLE G-16 PERMISSIBLE NOISE EXPOSURES (1)

Duration per

day, hours

Sound level dB slow response

8 90

6 92

4 95

3 97

2 100

2.5 102

1.5 105

.5 110

.25 or less 115

Footnote(1) When the daily noise exposure is composed of two or more periods of noise exposure of different

levels, their combined effect should be considered, rather than the individual effect of each. If the sum of the

following fractions: C(1)/T(1) + C(2)/T(2) C(n)/T(n) exceeds unity, then, the mixed exposure should be considered

to exceed the limit value. Cn indicates the total time of exposure at a specified noise level, and TN indicates the

total time of exposure permitted at that level. Exposure to impulsive or impact noise should not exceed 140 dB peak

sound pressure level.

Noise & Light Levels

Light Levels

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Location Recommended foot candle*

School

Library 150

Stairs 5

Auditorium 20

Class room 50

Lab 150

Gym 30

Bathroom 5

Office

Typing 200

Clerical work 150

Drafting 200

Hall 20

Entrance 10

Warehouse 20

Factory

Printing Area 100-200

Packaging 100

Warehouse 20

Assembly line 100

Assembly inspection 200

Exit/entrance 50

Hospital

Operating Rom 150

Exam Room 100

Eye inspection 50

Waiting room 30

Stairs 10

* The illumination levels are intended to be a minimum on the task referenced. To assure these

values at all times.

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Protective Eyewear

CFR 1910.132

"Protective equipment including personal protective equipment for eyes, face, head and extremities,

protective clothing, respiratory devices, and protective shields and barriers shall be provided, used and

maintained in a sanitary and reliable condition wherever it is necessary by reason of hazards of processes

or environment, chemical hazards, radiological hazards or mechanical irritants encountered in a manner

capable of causing injury or impairment in the function of any part of the body through absorption,

inhalation or physical contact." (29 CFR 1910.132(a))

Eye and face protection requirements are outlined in 29 CFR 1910.133:

Employers must ensure

1. Each affected employee uses an appropriate eye or face protection when exposed to

eye or face hazards from flying particles, molten metal, liquid chemicals, acids or

caustic liquids, chemical gases or vapors, or potentially injurious light radiation.

2. Each affected employee uses eye protection that provides side protection when

there is a hazard from flying objects. Detachable side protectors (e.g. clip-on or

slide-on side shields)

3. Each affected employee who wears prescription lenses while engaged in operations

that involve eye hazards wears eye protection that incorporates the prescription in

its design, or wears eye protection that can be worn over the prescription lenses

without disturbing the proper position of the prescription lenses or the protective

lenses.

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4. Each affected employee uses equipment with filter lenses that have a shade number

appropriate for the work being performed for protection from injurious light

radiation. (for example during welding or other hazardous light conditions)

Employers must comply with this Rule by using and providing for employees eyewear that are

constructed in accordance with any of the last three American National Standards Institute (ANSI)

national consensus standards or their proven equivalent:

ANSI Z87.1-1989 (R-1998), American National Standard Practice for Occupational

and Educational Eye and Face Protection,

ANSI Z87.1-2003, American National Standard for Occupational and Educational

Personal Eye and Face Protection Devices, or

ANSI Z87.1-2010, American National Standard for Occupational and Educational

Personal Eye and Face Protection Devices.

Protective Footwear Requirements

CFR1910.136

This regulation refers to the American National Standards Institute (ANSI) American National

Standard for Personal Protection - Protective Footwear (ANSI Z41) for its performance criteria.

1910.136(a), "Each affected employee shall wear protective footwear when working in areas where

there is a danger of foot injuries due to falling or rolling objects, or objects piercing the sole, and

where such employee's feet are exposed to electrical hazards.

Appendix B to subpart I identifies the following foot protection should be routinely considered

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ANSI Z41-1999 requires suppliers and manufactures of Protective Footwear to have independent

laboratory test results available to confirm compliance

A work boot that meets the impact and compression requirements

The ANSI Standards identification code and year of standard code must be legible

(printed, stamped, stitched, etc.) on one shoe of each pair of protective footwear,


ANSI FOOTWEAR STANDARDS CODE

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Example

ANSI Z41 PT 99 F I/75 C/75 Mt/75 EH PR

Interpreting the code

PT :

This line identifies The letters PT indicate the protective toe section of the standard.

99: the footwear meets compliance (1999).

F: identifies the applicable gender [M (Male) or F (Female)

I: impact resistance

75: the impact resistance rating (75, 50 or 30 foot-pounds),

C: (C) and the compression resistance rating

75:(75, 50 or 30 which correlates to 2500 pounds, 1750 pounds, and 1000 pounds of compression

respectively

Mt: metatarsal (Mt) resistance and rating, conductive (Cd) properties, electrical hazard (EH),

puncture resistance (PR) and static dissipative (SD)

75: The existence of metatarsal resistance (Mt) and the rating (75, 50 or 30 foot-pounds)

Metatarsal footwear is used to prevent or reduce the severity of injury to the metatarsal and toe

areas. The existence of metatarsal resistance (Mt) and the rating (75, 50 or 30 foot-pounds) is

identified.

EH: electrical hazard, manufactured with non-conductive electrical shock resistant soles and

heals. This is only a secondary source of protection against accidental contact with live electrical

circuits, electrically energized parts or apparatus. The footwear must be capable of withstanding

under dry conditions the application of 14,000 volts at 60 hertz for one minute with no current

flow or leakage current in excess of 3.0 mill amperes.

PR: puncture resistance

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CD: Conductive (Cd) footwear is intended to protect the wearer in an environment where the

accumulation of static electricity on the body is a hazard. It is designed to dissipate state

electricity from the body to the ground. The electrical resistance must range between zero and

500,000 ohms.


SD: Static dissipative, protection against hazards that may exist due to excessively low footwear

resistance, as well as maintain a sufficiently high level of resistance to reduce the possibility of

electric shock. The footwear must have a lower limit of electrical resistance of 106 ohms and an

upper limit of 108 ohms

CS: Chain saw cut resistant provides protection when operating a chain saw. This footwear must

meet the ASTM F1818 Specification for Foot Protection for Chainsaw Users standard.

DI: Dielectric insulation provides additional insulation if accidental contact is made with

energized electrical conductors, apparatus or circuits. It must meet the minimum insulation

performance requirements of ASTM F1117 and be tested in accordance with ASTM F1116

Remember is that neither the ANSI nor ASTM standard allows for the use of add-on type devices -

strap-on foot, toe or metatarsal guards - as a substitute for protective footwear

.

.

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Ladder Requirements

OSHA Regulatory Requirements

OSHA has separate regulations for portable wood ladders and portable metal ladders

29 CFR 1910.25

Portable Wood Ladders

wood ladders section is divided into application, materials, construction requirements, and

ladder care and usage.

Wood ladders should be constructed of a high-density wood that is free of sharp edges and

splinters.

Visual inspection should reveal

No decay,

Irregularities including shake, wane and compression failures

Other weaknesses.

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Ladder length restrictions and step spacing. Uniform step spacing must not

exceed 12".

Care and usage

ensure the serviceability and safety of portable wood ladders.

Ladders should be maintained in good condition by keeping all joints tight; lubricating all

wheels, locks and pulleys

replacing worn rope; and routine cleaning.

Those that are defective must be destroyed or withdrawn from service. Allowing only one

person at a time on a ladder; not placing the ladder on top of other objects to increase height

or in front of doorways; and extending the ladder three feet over a point of support if

climbing to a rooftop among others

Ladder Requirements

Wood ladder construction requirements

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Ladder type Max length Special requirements

Type industrial step ladder

3 20

The minimum width

between side rails at the top,

inside to inside, shall be not

less than 11 1/2 inches.

From top to bottom, the

side rails shall spread at

least 1 inch for each foot of

length of stepladder. A

metal spreader or locking

device of sufficient size and

strength to securely hold the

front and back sections in

open positions shall be a

component of each

stepladder.

Type II -

Commercial Stepladder

312 Same as above.

Type III -

Household Stepladder

36 Same as above.

Rung Ladder 30 None

Side-Rolling Ladder 20 None

Two-Section Rung Ladder 60 Ladder rails must fit into

each other. Upper section

can be raised / lowered.

Trestle Ladder 20 None

Mason's Ladder 40 None

Painter's Ladder 12 None

None

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Ladder Requirements

Angle of Inclination

Make sure the ladder is about 1 foot away from the vertical support for every 4 feet of ladder

height between the foot and the top support( OSSHA requires of the height for ladder take

off)

1

4

Dis

tance t

o t

op s

upport

foot

29 CFR 1910.26

Metal ladders

Divided into general requirements and care and maintenance

The general requirements

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Free of sharp edges and

structurally sound

Metal ladders must have rungs that are knurled, dimpled or treated to improve slip

resistance. OSHA also places ladder length restrictions on portable metal ladders, Uniform

step spacing must not exceed 12". Proper care and maintenance of portable metal ladders

improves user safety. Ladders must be inspected for damage (bends or dents, loose rivets

or joints, etc.) and if defective, must be marked and taken out of service for repair or

replaced. Ladders must be kept clean so they do not become slippery.

Ladder Requirements

Fiberglass Ladders

OSHA does not address fiberglass ladders.

ANSI does have guidelines to follow when choosing ladders constructed of fiberglass.

ANSI 14.5 2000, fiberglass ladders should be made out of good commercial grade thermosetting

polyester resin reinforced with glass fibers.

Consideration:

electrical

corrosion resistance

outdoor weathering

thermal conditions

structural integrity

Ladder Usage

Proper Procedure

Before working with a ladder for the first time,

Read the manufacturer's instructions.

Does not use ladder if?

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1. sleepy

2. ill

3. taking medication

4. Bad weather conditions exist.

Do not use ladders in doorways or other high traffic areas. If a ladder must be used near a door

If a ladder must be used in doorways or high traffic area

1. make sure the door is locked

2. If the door has to be open or the ladder is in a raised position, ask a

coworker to stay with the ladder to make sure an accident does not occur.

3. Use fiberglass or wood ladders, rather than metal, near sources of electricity

to avoid electrical shock hazards.

Ladder Requirements

Inspection

According to ANSI A14.1-2000, a ladder should be thoroughly inspected each time it is used.

Rungs should be firm and unbroken,

braces fastened securely

Ropes, pulleys and other moving parts in good working order.

If an inspection reveals damage, the ladder should be repaired. If repairs are not feasible,

the defective ladder should be taken out of service

To ensure that ladders are being inspected, ladder inspection tags should be attached to

and filled out

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Proper Setup

feet of a ladder should be level and positioned solidly on the ground

If the ground is soft or uneven, proper support under the legs should be used

Test the ladder to verify it is secure. For stability, both sides of the ladder need to be

against the wall or other support.

The legs on a stepladder should be spread fully and locked into position

How to Climb

Make sure:

1. Hands, shoes and ladder rungs are dry;

2. Use a second person to hold the bottom of the ladder and prevent others from

disturbing ladder;

3. Keep a three-point grip on the ladder at all times (two hands and one foot or one

hand and two feet)

4. Avoid distractions that make you turn away from the front of the ladder

5. Climb slowly with weight centered between side rails; do not lean back

6. Never stand on the top two rungs of a stepladder

7. Never stand on the top four rungs of an extension ladder.

The OSHA 1917.119 for portable ladders and their construction and inspection requirements

must be followed.

Lockout/Tag out

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29 CFR 1910.147,

Lockout/Tag out helps reduce the death and injury rate caused by the unexpected energization

or start-up of machines, or the release of stored energy.

The standard covers the servicing and maintenance of machines and equipment in which the

unexpected energizing, start-up or release of stored energy could cause injury

29 CFR 1910.147 (a) (l) (i), 1910.147 (a)(2)(i). Normal production operations, cords and plugs

under exclusive control, and hot tap operations are not covered [29 CFR 1910.147 (a)(2)(ii)].

This is intended to apply to energy sources such as electrical, mechanical, hydraulic, chemical,

nuclear, and thermal.

Lockout/Tagout (LOTO)

The lockout device shall be used unless the employer can demonstrate that the utilization of a

tagout system will provide full employee protection. The tagout device shall be non-reusable,

attached by hand, self-locking, and non-releasing with a minimum unlocking strength of no less

than 50 pounds.

Lockout: a lockout device is placed on an energy isolation device (circuit breaker, slide gate, line

valve, disconnect switch, etc.) to ensure that the energy isolating device and equipment being

controlled cannot be operated until the lockout device is removed.

Lockout device: utilizes a positive means such as a lock (key or combination type) to hold

an energy isolating device in a safe position and prevents the energizing of a machinery

or equipment.

Lockout devices must be substantial enough to prevent removal

Tagout: Tagout device is placed on an energy isolation device to indicate that the energy isolating

device and the equipment being controlled may not be operated until the tagout device is

removed.

Tagout device a tag or other prominent warning device and a means of attachment)

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Training for LOTO

29 CFR 1910.147 (c)(7)(I). The affected employees shall be instructed in the purpose and use of

the energy control procedure and all other employees whose work operations are or may be in an

area where energy control procedures may be utilized. When tagouts are used, employees must

be instructed in the limitations of these devices.

Written Program

OSHA 29 CFR 1910.147 (c)(4) covers the minimal acceptable written program procedures.

Procedure must include:

1. A specific written statement of the intended use of the procedure.

2. Specific steps taken for shutting down, isolating, blocking and securing machines or

equipment to control hazardous energy.

(This must be done for each piece of equipment).

3. Specific steps for the placement, removal and transfer of lockout devices and the

responsibility for them.

4. Specific requirements for testing the effectiveness of the lockout devices, tagout

devices.

Removal of Lockout/Tagout Devices

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Before lockout or tagout devices are removed, the authorized employee shall ensure that.

1. Non-essential items are removed and machine components are operationally safe and

intact.

2. The area should be checked to ensure all employees are safely positioned or removed

3. All affected employees notified that lockout/tagout devices have been removed.

4. The lockout/tagout device must be removed by the person who applied the device.

5. If the person who applied the device is not available, the device may be removed by

another employee if the employer has established a specific procedure and training for

the removal of a lockout and or tagout

6. . When group lockout/tagout devices are used, a procedure equivalent to the personal

lockout/tagout system should be followed. [(29 CFR 1910.147 (f)(3)]

FUNDAMENTAL ELECTRICAL HISTORY

In 1600, the physician to Queen Elizabeth, Sir William Gilbert, coined the word electricity. It was

derived from the Greek word for Amber (electron). Amber is a hard fossil resin with a brownish

yellow translucent tent. When rubbed with wool, a phenomenon was observed. Sir William Gilbert

called this electricity.

In 1660, Otto Von Guericke, from Germany, invented the first electro static machine to generate

electricity. This was done by mounting a large ball of sulfur on a rod with a crank. When the device

was rotated, Von Guericke rubbed the sulfur with his dry hands causing the sulfur to build a charge.

The charge would attract feathers, small pieces of paper, or other small objects.

In the late 1700s, Luigi Galvani discovered electricity would move through certain materials.

Galvanis experiments proved electricity could flow through materials such as copper and iron.

In 1791, Alessandro Volta developed the first battery by stacking dissimilar metals such as copper and

nickel in an acidic chemical to form what is called the first voltic pile.

At approximately the same time, Benjamin Franklin theorized that electricity had positive and

negative charges. This was known as the legendary kite experiment.

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In the 1820s, Hans Christian Oersted, a Danish man, used the voltic pile or battery to prove that

electricity could be used to produce magnetism.

Around 1826, Andre Ampere, a Frenchman, demonstrated that a coil of wire acts like a magnet as a

current is sent through the wire. He also discovered that when passing a piece of iron or steel

through the coil, this piece of material would become magnetized.

Shortly after Andre Amperes experiments, Michael Faraday developed the first electric power

generator. By studying the works of Andre Ampere and Hans Christian Oersted, Faraday realized

that electric current could pass through the coil of wire from an electrical source. He then theorized

that the current would still pass through the wire when the wire was moved through a magnetic field.

By his experiments, Faraday proved that a current of electricity could be produced by moving the coil

of wire across the magnet. In other words, current would be induced into the coil.


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Brief Electrical History

George Simon Ohm

March 16, 1789 - July 6, 1854

George Simon Ohm, a German physicist, discovered that there is a direct proportionality between the

potential differences (voltage) applied across a conductor (resistance) and the resultant electric-

current.

This relationship or ratio between voltage, current, and resistance today is known as "Ohm's Law".

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Alessandro Volta

February 1745 March 1827

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Alessandro Giuseppe Antonio Anastasio Gerolamo Umberto Volta, An Italian physicist known

especially for the invention of the battery. In 1778 Volta studied what we now call electrical

capacitance, developing separate means to study both electrical potential (V) and charge (Q), and

discovering that for a given object, they are proportional. This may be called Volta's Law of

capacitance, and for this work, the unit of electrical potential has been named the volt.

Volta (working from Luigi Aloisio Galvani studies) realized that the frog's leg served as both a

conductor of electricity (we would call it an electrolyte) and as a detector of electricity. He

replaced the frog's leg with brine-soaked paper, and detected the flow of electricity by other

means familiar to him from his previous studies. He discovered the electrochemical series, and

the law that the electromotive force (emf) of a galvanic cell, In 1800, as the result of a

professional disagreement over the galvanic response advocated by Galvani, he invented the

voltaic pile, an early electric battery,


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Andr-Marie Ampre

January 20, 1775 June 10, 1836

A French physicist and mathematician, Ampere discoverer of electromagnetism. The SI unit of

measurement of electric current, the ampere, is named after him.

In magnetostatics, the force of attraction or repulsion between two current-carrying wires is

known as Ampre's force law.

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Luigi Galvani

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Luigi Aloisio Galvani

September 9, 1737 December 4, 1798

An Italian physician, who in 1771, he discovered that the muscles of dead frog legs twitched when struck

by a spark

Galvani discovered that when two dissimilar metals are connected in series with the frog's leg and to one

another, the leg would jump. Galvani was slowly skinning a frog at a table where he had been conducting

experiments with static electricity by rubbing frog skin. Galvani's assistant touched an exposed sciatic

nerve of the frog with a metal scalpel, which picked up a charge. At that moment, they saw sparks and the

dead frog's leg kick as if in life. The observation made Galvani the first investigator to appreciate the

relationship between electricity and animation or life. This finding provided the basis for the new

understanding that electrical energy (carried by ions), and not air or fluid as in earlier balloonist theories.


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govenor

James Watt

January 19, 1736 August 19, 1819

A Scottish inventor and mechanical engineer, James Watts improvements to the steam engine

were fundamental to the changes that brought on the Industrial Revolution. Watt is described as

one of the most influential figures in human history;

Watt developed the concept of horsepower and the SI (International System of Units from French:

Systme international d'units) unit of power, the watt.

Fact: The phrase running with your balls out or Balls to the wall came from

one of watts invention the Centrifugal Governor a device that controls the

speed of a steam engine, as the governor would spin and the steel

balls would extend outward the walls.


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Gustav Robert Kirchhoff

March 12, 1824 October 17, 1887

German physicist who contributed to the fundamental understanding of electrical circuits, in 1845, The

concepts in both circuit theory and thermal emission are named "Kirchhoff's laws" after him,

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Nikola Tesla

The Father of modern Electricity

Nikola Tesla (July 10, 1856 January 7, 1943):

Inventor and electrical engineer, One of NikolaTeslas contributions was Alternating current-

single and poly phase. Nikola Tesla is best known for developing the modern alternating current

(AC) electrical supply system and the transformer. 1890s -1900s, Teslas developments in the

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field of electromagnetism was based on the theories Michael Faraday. Tesla's patents and

theoretical work also formed the basis of wireless communication and the radio.

In 1891, Nikola Tesla invented the Tesla Coil, an air-cored, dual-tuned resonant transformer for generating

very high voltages. During the 1880s, Teslas work and patents formed the basis of the modern

alternating current system. Teslas patents included the A/C motor, Tesla coil, the A/C poly phase system

and many others

(The Tesla coil is responsible for all televisions including plasma and LCD). Nikola Tesla was awarded

the Patent for the radio (not Guglielmo Marconi).

FUNDAMENTAL ELECTRICAL HISTORY Nikola Tesla

In 1882, Tesla invented the induction motor and began developing various devices that use rotating

magnetic fields for which he received patents in 1888.

On 6 June 1884, Tesla first arrived in the United States, in New York City with little besides a letter of

recommendation from Charles Batchelor.

In the letter of recommendation to Thomas Edison, it is claimed that Batchelor wrote, 'I know two great

men and you are one of them; the other is this young man. Edison hired Tesla to work for his Edison

Machine Works.

In 1885, Tesla claimed he could redesign Edison's inefficient motor and generators, improving both

service and economy.

Edison responded, "There's fifty thousand dollars in it for you - if you can do it"

After months of work, Tesla finished the task and inquired about payment Edison claimed he was only

joking replying, "Tesla, you don't understand our American humor" Edison offered a $10 a week raise over

Tesla's US$18 per week salary, but Tesla refused it and immediately resigned

Tesla, in need of work, begun digging ditches for a short period. He used this time to focus on his AC

polyphase systems.

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In 1886, Tesla formed his own company, Tesla Electric Light & Manufacturing. The initial financial

investors disagreed with Tesla on his plan for an alternating current motor and eventually relieved him of

his duties at the company. Tesla worked in New York as a laborer from 1886 to 1887 to feed himself and

raise capital for his next project.

In 1887, he constructed a brushless alternating current induction motor, which he demonstrated to the

American Institute of Electrical Engineers (IEEE).

1888. Tesla developed the principles of the Tesla coil, and began working with George Westinghouse,

Westinghouse's system, which used Teslas alternating current, ultimately prevailed over Edison's direct

current. In 1897, at age 41, Tesla filed the first radio patent. ,

1898, Tesla demonstrated a radio-controlled boat to the US military, believing that the military would

want things such as radio-controlled torpedoes. Tesla claimed to have developed the "Art of

Telautomatics", a form of robotics

THEORY

Atom: The smallest particle of an element

STRUCTURE OF AN ATOM Proton: The particle in the nucleus of an atom with a positive charge

Mass of 1.673 x 10 -24 grams

Discovered by:

Ernest Rutherford, in experiments conducted between the years 1911 and 1919.

Neutron:

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The particle in the nucleus of an atom with no charge

Mass of 1.675 x 10 -24 grams

Discovered by James Chadwick in 1932

Nucleus: The dense, central core of an atom (made of equal amounts of protons and neutrons).

Electron:

The particle orbiting the nucleus of an atom with a negative charge

Mass of 9.10 x 10 -28 grams.

Discovered by J. J. Thomson in 1897

Electron shell:

The orbit of an electron or electrons around the nucleus. Each shell contains a fixed number of

electrons. It is associated with particular range of electron energy. Chemical properties of an atom are

determined by the outer shell.

Valence electrons:

The electrons in the last shell or energy level of an atom.

They are also known as free electrons.

Photon: The particle of energy/light having no mass. Photons are responsible for the movement of

valance electrons.

Discovered by Gilbert Lewis in 1926

Ion: An atom that has lost or gained one or more electrons, becoming an electrically charged atom with

excessive positive or negative charge properties (made of two or more atoms).

A negative charged ION has more electrons in the outer shell than protons in the nucleus. The opposite

is true for a positively charged ion.

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STRUCTURE OF AN ATOM

Copper Atom

Atoms, All materials are made up of tiny "building blocks" known as atoms. In the center of the Atom are protons and neutrons, which are tightly bound together. The tightly bound clump of protons and neutrons

in the center of the atom is called the nucleus, and the number of protons in an atom's nucleus

determines its elemental identity. The tight binding of protons in the nucleus is responsible for the stable

29 Electrons

Third Electron

Shell

(from Nucleus)

Valance Electron

and

Outer Electron Shell 8 Electrons

2nd Electron Shell

(from Nucleus)

2 Electrons

1st (inner) Electron

Shell

(from Nucleus)

Nucleus

consisting of

29 Protons

and

29 Neutrons

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identity of chemical elements, In fact, if you could remove three protons from the nucleus of an atom of

lead, you will have achieved the old alchemists' dream of producing an atom of gold!

Neutrons are less influential on the chemical character and identity of an atom, although they are just as

hard to add to or remove from the nucleus, being tightly bound. If neutrons are added or gained, the atom

retains the same chemical identity, but its mass will change slightly and it may acquire nuclear properties

such as radioactivity.

Electrons have significantly more freedom to move around, electrons can be knocked out of their

respective positions (even leaving the atom entirely!). When electrons leave, the atom retains its chemical

identity, but an important imbalance occurs. Electrons and protons are unique in the fact that they are

attracted to one another over a distance.

If electrons leave or extra electrons arrive, the atom's net electric charge will be imbalanced, leaving the

atom "charged" as a whole, causing it to interact with charged particles and other charged atoms nearby

How does electricity work?

Where does electricity come from? Metals are conductors; typically, copper, so electric current can flow freely. With certain materials (such as metals) the atoms outer shell of electrons is loosely bound. The negatively

charged electrons are the smallest part of an electric charge. When influenced by a driving source, such

as the pressure from a magnetic field, the valence electrons free to move through the material move.

This movement of valance electrons that generate an electric charge, electron current (electric current) is

moving unidirectional through the conductor.

An electric current is the movement of electrons in one direction past a point in one second that is

equivalent to 6.28 1018 = 6,280,000,000,000,000,000 of electrons moving in a single direction past a

point in one second in a conductor, current flow is the Intensity of the flow of electrons (the rate). As the electrons move, a voltage is produce (Electro Motive Force, E.M.F.). This movement propagates

the material at speed of light

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MAGNETISM

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Folklore and Legend:

On the island of Crete, a shepherd named Magnes was tending to his flock of sheep.

Magnes placed his iron tipped staff on the ground and the staff mysteriously held in

place by an invisible force. Curiosity set in and Magnes began to dig. Slightly below

the surface was a rock that the staffs iron tip, by some strange force, appeared

attracted to. This strange rock was a loadstone (a natural magnet). The city of

Magnesia,( a mythical city-state in Plato's Laws) had been named after Magnes and the

rock called Magnetite. Sense that time the strange attraction of this mysterious rock

is magnetism.

The principles of magnetism are an important role in the operation of an AC motor,

transformers, alternators and generators. Therefore, in order to understand Motors, transformer,

transformers, alternators and generators you must understand magnets.

N S

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Magnets

Characteristics:

Magnets have two opposite poles: one north seeking pole and one south seeking pole.

The polarities of magnetic fields affect the interaction between

Magnets,

Opposites poles attract, Magnets are attracted to one anothers opposite poles when placed

within close enough proximity of each other.

N S N S

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like poles repel. Magnets repel one anothers like poles when placed within close enough

proximity of each other.

N S NS

This

attracting and repulsion action of the magnetic fields is essential to the operation of AC motors,

but AC motors use electromagnetism

Ferrous metals such as iron, nickel and steel, are attracted to Magnets

Due to the soft characteristics of iron, this ferrous metal only holds magnetism for a short

time. This type of magnet is known as a Temporary magnet.

Steel and other alloys: such as Alnico (made up of steel or iron, and aluminum, and

sometimes cobalt and copper) make for much stronger and permanent magnets.

Magnets

The attraction field that surrounds the magnet is known as the magnetic field. The attraction

or pulling force is strongest at the poles of the magnet.

Surrounding the magnet at the poles and extending from pole to pole are invisible lines of force.

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Magnetic Lines of Flux

The force that attracts ferrous metals such as iron or steel has continuous magnetic field lines,

called lines of flux, that run through the magnet,

N S

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Magnets

Magnetic Lines of Flux

These invisible lines run through the magnet, exit the North Pole, and return through the South

Pole. Although these lines of flux are invisible, the effects of the magnetic field can made visible

with a sheet of paper and some iron fillings, simply place the paper over the top of magnet

(covering the magnet), sprinkle the iron fillings onto the paper, and watch the fillings arrange

themselves along the lines of flux

N S

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MAGNETISM

Electromagnetism

As a conductor moves through a magnetic field, current will be induced into the

conductor from the magnetic field.

In a conductor, the negatively charged free electrons are the smallest part of an

electric charge in a conductor. When influenced by a driving source, such as a magnetic

field (flux), direct current or alternating current, the valence electrons move through the material. It is

this movement of valance electrons that generate an electric charge, electron current (electric current) and

magnetic field moving unidirectional through the conductor

When current flows through a conductor, it produces a magnetic field around the

conductor.(lines of flux)

N

S

Direction of rotation

Current flow

Maximum positive volts

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The strength of the magnetic field is directly proportional to the amount of current.

An electromagnet can be made by winding a conductor into a coil and applying a voltage. When

the conductor is coiled, the lines of flux around the coiled conductor combine to produce a

stronger magnetic field

This simple electromagnet has an air core.

MAGNETISM

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Adding an iron core to the electromagnet

Magnetic flux is more easily conducted through iron rather than air. When an insulated

conductor is wound around an iron core,

With an iron core a stronger magnetic field is produced for the same level of current.(as

compared to an air core).

Adding Turns of coils

The magnetic field created by the electromagnet can be increased can be increased in strength,

by increasing the number of turns in the coil

The more turns the stronger the magnetic field for the same amount of current.

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12 turns 6 turns

MAGNETISM

Electromagnet Characteristics, Polarity and the Ac Sine Wave

Alternating Current (AC) and the Sine Wave

Sine Wave:

Is a mathematical curve that describes a smooth repetitive oscillation over a period of time and

frequency from a positive oscillation to a negative oscillation. This oscillation would start at zero

(0) value and gaining in a positive peek amplitude of value and then decline back to a zero (0)

and the oscillation would start the negative oscillation, gaining in a negative peek amplitude of

value and then decline back to a zero (0)

Peek Amplitude: the peak deviation of from zero.

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P e a k

P e a k

+

-

3 6 00

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T I M E

MAGNETISM

Ac Sine Wave

An AC voltage/current is a measure of magnitude (strength) over time using an instrument

known as an oscilloscope. The oscilloscope displays the AC current as a sine wave.

The average time in seconds required to complete one cycle is what determines the frequency in

cycles per second, measured in hertz (Hz).

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Over a period 1/60 of a second is the average time for any 60 Hz current waveform to complete

a cycle. The angular frequency of the sine wave, is the rate of change of the function in units of

radians per second (this means the wave is measured in degrees for a total of 3600).

Frequency is calculated,

and

(1 second) / [(seconds) / (cycle)] / ( total seconds the device is on) = cycles / second = (Hz).

An American power supply operates at 60 Cycles per second so one cycle is 1/60 of a second. A

60 Hz power system has a period of 1/60 = 0.016667 milliseconds/cycle.

What is a millisecond?

1 millisecond: (ms) is one thousandth of one second. ( =. Or 1 - 10 - 10- 10 =

.001 or

=.001)

8.3 milliseconds (8.3, or .0083335), one half of an 60 Hz AC electrical system)

10 milliseconds (10 ms) a jiffy, cycle time for frequency 100 Hz

(I will be finished in a jiffy)

16.7 milliseconds (1/60 second, .016667), cycle time for 60 Hz AC electrical system

134 milliseconds time taken by light to travel around the Earth's equator

300 to 400 milliseconds the time for the human eye to blink

1000 milliseconds one second / the period of a 1 Hz oscillator

(See sine wave section)

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MAGNETISM

Electromagnetism and Faradays law

A marriage made to last

And now the wedding vow

Faradays law : Is any change in the magnetic environment of a coil of wire will cause a voltage

(E.M.F) to be "induced" in the coil of wire, Voltage will be generated no matter how the change

is produced.

The honeymoon

The change could result from change in the magnetic field strength, moving the coil of wire into

or out of the magnetic field (Flux), moving a magnet toward or away from the coil of wire,

rotating the coil of wire relative to the magnet, etc.

( The three things required to produce an A/C current are magnetism, coil of wire, and motion)

Shortly after the Honeymoon come the kids.

Induced current

Voltage(E.M.F) is induced across a conductor by merely moving it in close proximity through a

magnetic field (or moving the magnetic field (flux) in close proximity to the conductor).

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N S

The same effect is caused when a stationary conductor encounters

a changing magnetic field(such as illustrated in the electromagnet).

Note: This electrical principle is critical to the operation of AC induction motors, transformers,

and generators

MAGNETISM

Induced current

Previous examples illustrated the coil is connected to an Ac power source and a magnetic field is

developed in the coil (electromagnet) gaining in strength as the currents amplitude gains in

strength.

This is true when a stationary conductor (coil) encounters a changing magnetic field, and a

current induced into the second coil. The current and magnetic field strength in the secondary

coil is directly proportional to the number of turns in the coil, if the secondary (output) coil has

fewer turns the current and magnetic field will be less than primary coil (input).

This principle is crucial to the operation and understanding of Transformers and AC induction

motors.

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T I M E

Watch the meters, meters shows the buildup of magnetic flux during the first quarter of the AC

waveform.

1. First coil the voltage and current are zero in both circuits.

2. Middle coil shows as voltage and current increasing in the top coil, while simultaneously voltage

and current increase in the bottom circuit. As magnetic field builds up in the bottom

electromagnet, lines of flux from its magnetic field cut across the top electromagnet and induce a

voltage across the electromagnet. This causes current to flow through the

3. Third coil, current flow has reached its peak in both circuits.

Remember the magnetic field around each coil expands and collapses in each half cycle, and

reverses polarity from one-half cycle to another.

20 20 20

A C s o u r c e

T I M E

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MAGNETISM

Electromagnetism characteristics, AC current, and polarity

Electromagnets are like natural magnet, that both share the same characteristics, including a

north and south poles.

However, natural magnets do change their polarity, due to the alternation of AC current from

positive to negative, when the direction of current flow through the electromagnet changes, the

polarity of the electromagnet changes.

When electromagnets are connected to an AC source, the polarity and lines of flux change at the

frequency and amplitude of the AC source

SEE ILLUSTRATION ON NEXT PAGE OF AC SINE WAVE AND ELECTCTROMAGNET

W A T C H T H E M A G N E T I C F E I L D

S T R E N G T H A S T H E A /C G A I N S O R D E C R E A S E S I N A M P L I T U D E

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MAGNETISM

Electromagnets

A stich in time

Follow the current through time as the current oscillates from a positive oscillation to a negative

oscillation. This oscillation would start at zero (0) value and gaining in a positive peek amplitude

of value and then decline back to a zero (0) and the oscillation would start the negative

oscillation, gaining in a negative peek

Note:

N

N

NN

N

NS S

S

SS

1 9

8

7

6

5

4

3

2

S

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In the positive oscillation, the electromagnets South Pole is on the top and the North Pole is on

the bottom.

In the negative oscillation, the electromagnets South Pole is on the top and the North Pole is on

the bottom.

1. There is no current flow, and no magnetic field (Flux), is produced.

2. A magnetic field (Flux), builds up around the electromagnet and Current is flowing in a

positive direction.

3. At the peak of the sine wave the strength of the electromagnetic field has also peaked

and Current flow is at its peak positive value

4. The magnetic field begins to collapse and current flow decreases

5. No current is flowing, No magnetic field (Flux), is produced.

6. Current is increasing in the negative direction.

Note that the polarity of the electromagnetic field has changed. The north pole is now on the top

of the electromagnet and the south pole is on the bottom of the electromagnet.

In steps times 7 and 8, The negative half of the cycle continues through the cycle, returning to

zero at time 9. For a 60 Hz, this tot process repeats 60 times a second.

ALTERNATING CURRENT

In most modern facilities today, we use AC (alternating current). Most begin their study with DC (direct

current). Direct current is electricity flowing in a constant direction, possessing a voltage with constant

polarity; direct current voltage is typically produced by a battery or direct current generator and is a

constant voltage that may not be changed from the original source voltage to a different voltage.

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The three fundamental conditions that must be present to generate an alternating current are:

1. a conductor

2. magnetic field

3. motion

As a conductor is moved through the magnetic field, a current is induced into the conductor from the

magnetic field. The magnetic field causes the free electrons in the conductor to move and voltage is

developed. The voltage is proportional to the rate of change of the area of the coil facing

the magnetic field. Voltage is gaining in magnitude as a magnetic field is generated in

the coil.

The illustrations demonstrate the simplest form of an AC

generator with a loop of wire rotating between

poles of the magnets. the

THE SINE WAVE

Using the illustration of the simple AC generator, one can see that the conductor loop makes one

complete revolution or cycle. There are two cycles in each revolution. In the first half cycle (half

N

S

N

S


Current flow


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N

S

N

S

SN

S

3 6 0o

N

revolution of the positive cycle), the current starts at zero volts and the voltage rapidly climbs to the

maximum voltage. Then it returns to zero voltage. This is the first half revolution and is the positive

alternation of the cycle. Then in the negative alternation half of the cycle, the voltage climbs from

zero volts to maximum volts then back to zero. This completes the full 360 cycle. The 360

electrical degrees means the conductor will pass one North Pole and one South Pole. In the United

States we use 60 cycles (Hertz). This means 60 complete cycles in one second. Therefore, AC

changes directions 120 times a second; 60 positive and 60 negative.

90

0 360 180

270

One electrical degree is equal to part of a mechanical degree and is the complete cycle of the

conductor passing 1 pair of poles. See the illustrations above and below.

360 Mechanical Degrees 270 Mechanical Degree

Typical six pole generator Illustrates

360 Electrical Degrees

3 6 0o 2 7 0

o

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THE SINE WAVE

E= Volts

E

o 90 180 270 360

one cycle

0-180

S

N

0 volts

N

SMaximum Positive Volts

S

N

0 volts

sMaximum Negative volts

N

S

N

0 volts

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Parallel to magnetic lines

Maximum Voltage Back to zero

Remember Faradays Law: any conductor that passes through a magnetic field. An EMF is induced

in the conductor. In the illustration of the basic alternator above, as the conductor passes through

the magnetic field a voltage is induced into the conductor. As the conductor passes through the

magnetic field, the EMF is gaining magnitude. As the conductor is passed through the magnetic

field, the voltage falls as the conductor rotates out of the field.

THE SINE WAVE

Ways to quantify the magnitude of a sine wave:

Peak Voltage (Maximum):

Peak voltage is how much the voltage peaks, either positive or negative, from zero point of

reference. Peak voltage is a useful way of measuring voltage when trying to express the amount

of work that will be done when driving a specified load. Some manufacturers use peak voltage.

Root Means Square (RMS) Voltage:

N

S


Current flow


S

N

0 volts

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RMS voltage is a most common way to measure AC voltage. AC voltage is constantly changing

in magnitude and is at the maximum and minimum points in the cycle for only a fraction of the

cycle. The peak voltage is not a good way to determine how much work is done by an AC power

source. DC voltage is constant. The amount work done by DC voltages is calculated with the

use of Ohms Law Formulas. With AC voltage, the use of RMS voltage will give the ability to

predict how much work will be done by an AC voltage.

RMS voltage of a pure sine wave is approximately .707 of the peak (maximum) voltage. When

voltage is measured with a voltmeter, the voltage is generally given the RMS voltage of the

waveform.

RMS = .707

Maximum = .707

Example:

Th

s s book 20.9

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