Charles O Reynolds, CECM1 Electrical Safety Subpart S

Charles O Reynolds, CECM 1

Electrical Safety Subpart S

High Voltage or Low Voltage


Some Work is More Dangerous



Electricity - The Dangers

• About 5 workers are electrocuted every week

• Causes 12% of young worker workplace deaths

• Takes very little electricity to cause harm

• Significant risk of causing fires


Electricity – How it Works

• Electricity is the flow of energy from one place to another

• Requires a source of power: usually a generating station

• A flow of electrons (current) travels through a conductor

• Travels in a closed circuit


Electrical Terms• Current -- electrical movement (measured in amps)

• Circuit -- complete path of the current. Includes electricity source, a conductor, and the output device or load (such as a lamp, tool, or heater)

• Resistance -- restriction to electrical flow

• Conductors – substances, like metals, with little resistance to electricity that allow electricity to flow

• Grounding – a conductive connection to the earth which acts as a protective measure

• Insulators -- substances with high resistance to electricity like glass, porcelain, plastic, and dry wood that prevent electricity from getting to unwanted areas


Electrical Injuries

There are four main types of electrical injuries:• Direct:

Electrocution or death due to electrical shockElectrical shockBurns

• Indirect - Falls


Electrical Shock

An electrical shock is received when electrical current passes through the body.

You will get an electrical shock if a part of your body completes an electrical circuit by…• Touching a live wire and an electrical ground, or• Touching a live wire and another wire at a

different voltage.


Shock Severity

• Severity of the shock depends on:Path of current through the

bodyAmount of current flowing

through the body (amps)Duration of the shocking

current through the body, • LOW VOLTAGE DOES NOT

MEAN LOW HAZARD

No Laughing Matter



Dangers of Electrical Shock

• Currents above 10 mA* can paralyze or “freeze” muscles.

• Currents more than 75 mA can cause a rapid, ineffective heartbeat -- death will occur in a few minutes unless a defibrillator is used

• 75 mA is not much current – a small power drill uses 30 times as much

* mA = milliampere = 1/1,000 of an ampere

Defibrillator in use

Electricity Can Kill



Burns• Most common shock-related

injury

• Occurs when you touch electrical wiring or equipment that is improperly used or maintained

• Typically occurs on hands

• Very serious injury that needs immediate attention


Falls

• Electric shock can also cause indirect injuries

• Workers in elevated locations who experience a shock may fall, resulting in serious injury or death


Electrical Hazards and How to Control Them

Electrical accidents are caused by a combination of three factors:Unsafe equipment

and/or installation, Workplaces made

unsafe by the environment, and

Unsafe work practices.


Hazard – Exposed Electrical Parts

Cover removed from wiring or breaker box


Control – Isolate Electrical Parts

• Use guards or barriers

• Replace covers

Guard live parts of electric equipment operating at 50 volts or more against accidental contact


Control – Isolate Electrical Parts - Cabinets, Boxes & Fittings

Conductors going into them must be protected, and unused openings must be closed


Control – Close Openings

• Junction boxes, pull boxes and fittings must have approved covers

• Unused openings in cabinets, boxes and fittings must be closed (no missing knockouts)

Photo shows violations of these two requirements


Hazard - Overhead Power Lines

• Usually not insulated

• Examples of equipment that can contact power lines: Crane Ladder Scaffold Backhoe Scissors lift Raised dump truck bed Aluminum paint roller


Control - Overhead Power Lines

• Stay at least 10 feet away• Post warning signs• Assume that lines are

energized• Use wood or fiberglass

ladders, not metal• Power line workers need

special training & PPE

Dangers of Overhead Power Lines



Hazard - Inadequate Wiring

• Hazard - wire too small for the current

• Example - portable tool with an extension cord that has a wire too small for the tool The tool will draw more current than

the cord can handle, causing overheating and a possible fire without tripping the circuit breaker

The circuit breaker could be the right size for the circuit but not for the smaller-wire extension cord

Wire Gauge

WIRE

Wire gauge measures wires ranging in size from number 36 to 0 American wire gauge (AWG)


Control – Use the Correct Wire

• Wire used depends on operation, building materials, electrical load, and environmental factors

• Use fixed cords rather than flexible cords

• Use the correct extension cord

Must be 3-wire type and designed for hard or extra-hard use


Extension Cords

• The OSHA standard requires flexible cords to be rated for hard or extra-hard usage. These ratings are to be indelibly marked approximately every foot of the cord. Since deterioration occurs more rapidly in cords which are not rugged enough for construction conditions, the National Electric Code and OSHA have specified the types of cords to use in a construction environment. This rule designates the types of cords that must be used for various applications including portable tools, appliances, temporary and portable lights. The cords are designated HARD and EXTRA HARD SERVICE.


Reading the jacket code

All extension-cord jackets are marked with a code that indicates (among other information) the American wire gauge (AWG) and the jacket material and its properties, according to standards established by the National Electrical Code.


Reading the jacket code

• S: Standard service (synthetic-rubber insulated, rated for 600v)SJ: Service junior (synthetic-rubber insulated, rated for 300v)ST: Extra-hard usage, thermoplastic (PVC)SE: Extra-hard usage, elastomerO: Oil-resistant, usually synthetic-rubber jacket, more flexible in cold temperaturesOO: Oil-resistant synthetic-rubber jacket and inner-conductor insulationW: Extra-hard usage, weather-resistant

• SJTW: Thermoplastic-jacketed, weather-resistant, rated for 300v

• SEOW: Oil-resistant and weather-resistant elastomer jacket, rated for 600v (photo below)

• SJOW: Oil-resistant and weather-resistant synthetic rubber, rated for 300v

• SJOOW: Oil-resistant and weather-resistant synthetic rubber (jacket and conductor insulation), rated for 300v

• SJTOW: Oil-resistant and weather-resistant thermoplastic, rated for 300v


Hard Service Extension Cords

• Examples of HARD SERVICE designation types include S, ST, SO, STO, SJ, SJO, SJT, & SJTO. Extension cords must be durably marked as per 1926.405(g)(2)(ii) with one of the HARD or EXTRA HARD SERVICE designation letters, size and number of conductors






Hazard – Defective Cords & Wires

• Plastic or rubber covering is missing

• Damaged extension cords & tools


Hazard – Damaged Cords

• Cords can be damaged by:AgingDoor or window edgesStaples or fasteningsAbrasion from adjacent

materialsActivity in the area

• Improper use can cause shocks, burns or fire


Control – Cords & Wires

• Insulate live wires • Check before use• Use only cords that are 3-wire type • Use only cords marked for hard or

extra-hard usage• Use only cords, connection devices,

and fittings equipped with strain relief• Remove cords by pulling on the

plugs, not the cords• Cords not marked for hard or extra-

hard use, or which have been modified, must be taken out of service immediately


Permissible Use of Flexible Cords

Stationary equipment-to facilitate interchange

DO NOT use flexible wiring where frequent inspection would be difficult or where damage would be likely.

Flexible cords must not be . . .• run through holes in walls, ceilings, or floors;• run through doorways, windows, or similar openings (unless physically protected);• hidden in walls, ceilings, floors, conduit or other raceways.


Grounding

Grounding creates a low-resistance path from a tool to the earth to disperse unwanted current.

When a short or lightning

occurs, energy flows to the ground, protecting you from electrical shock, injury and death.


Hazard – Improper Grounding

• Tools plugged into improperly grounded circuits may become energized

• Broken wire or plug on extension cord

• Some of the most frequently violated OSHA standards


Control – Ground Tools & Equipment

• Ground power supply systems, electrical circuits, and electrical equipment

• Frequently inspect electrical systems to insure path to ground is continuous

• Inspect electrical equipment before use

• Don’t remove ground prongs from tools or extension cords

• Ground exposed metal parts of equipment


Control – Use GFCI (ground-fault circuit interrupter)

• Protects you from shock• Detects difference in current

between the black and white wires • If ground fault detected, GFCI

shuts off electricity in 1/40th of a second

• Use GFCI’s on all 120-volt, single-phase, 15- and 20-ampere receptacles, or have an assured equipment grounding conductor program.


Hazard – Overloaded CircuitsHazards may result from:• Too many devices plugged

into a circuit, causing heated wires and possibly a fire

• Damaged tools overheating• Lack of overcurrent

protection• Wire insulation melting, which

may cause arcing and a fire in the area where the overload exists, even inside a wall


Hazard – Overloaded Circuits

• If the circuit breakers or fuses are too big (high current rating) for the wires they are supposed to protect, an overload in the circuit will not be detected and the current will not be shut off. A circuit with improper overcurrent protection devices – or one with no overcurrent protection devices at all – is a hazard.


Control - Electrical Protective Devices

• Automatically opens circuit if excess current from overload or ground-fault is detected – shutting off electricity

• Includes GFCI’s, fuses, and circuit breakers

• Fuses and circuit breakers are overcurrent devices. When too much current:

Fuses melt Circuit breakers trip

open



• To prevent too much current in a circuit, a circuit breaker or fuse is placed in the circuit. If there is too much current in the circuit, the breaker “trips” and opens like a switch. If an overloaded circuit is equipped with a fuse, an internal part of the fuse melts, opening the circuit. Both breakers and fuses do the same thing: open the circuit to shut off the electrical current



• The basic idea of an overcurrent device is to make a weak link in the circuit. In the case of a fuse, the fuse is destroyed before another part of the system is destroyed. In the case of a circuit breaker, a set of contacts opens the circuit. Unlike a fuse, a circuit breaker can be re-used by re-closing the contacts. Fuses and circuit breakers are designed to protect equipment and facilities, and in so doing, they also provide considerable protection against shock in most situations. However, the only electrical protective device whose sole purpose is to protect people is the ground-fault circuit-interrupter.


Power Tool Requirements

• Have a three-wire cord with ground plugged into a grounded receptacle, or

• Be double insulated, or• Be powered by a low-voltage

isolation transformer


Tool Safety Tips

• Use gloves and appropriate footwear• Store in dry place when not using• Don’t use in wet/damp conditions • Keep working areas well lit• Ensure not a tripping hazard• Don’t carry a tool by the cord• Don’t yank the cord to disconnect it • Keep cords away from heat, oil, & sharp edges• Disconnect when not in use and when

changing accessories such as blades & bits • Remove damaged tools from use


Preventing Electrical Hazards - Tools

• Inspect tools before use• Use the right tool

correctly• Protect your tools• Use double insulated

tools

Double Insulated marking


Temporary Lights

Protect from contact and damage, and don’t suspend by cords unless designed to do so.


Clues that Electrical Hazards Exist

• Tripped circuit breakers or blown fuses

• Warm tools, wires, cords, connections, or junction boxes

• GFCI that shuts off a circuit

• Worn or frayed insulation around wire or connection


Lockout and Tagging of Circuits

• Apply locks to power source after de-energizing

• Tag deactivated controls

• Tag de-energized equipment and circuits at all points where they can be energized

• Tags must identify equipment or circuits being worked on


Safety-Related Work Practices

To protect workers from electrical shock:Use barriers and guards to prevent

passage through areas of exposed energized equipment

Pre-plan work, post hazard warnings and use protective measures

Keep working spaces and walkways clear of cords


Safety-Related Work Practices

• Use special insulated tools when working on fuses with energized terminals

• Don’t use worn or frayed cords and cables

• Don’t fasten extension cords with staples, hang from nails, or suspend by wire.


Preventing Electrical Hazards - Planning

• Plan your work with others

• Plan to avoid falls

• Plan to lock-out and tag-out equipment

• Remove jewelry

• Avoid wet conditions and overhead power lines


Avoid Wet Conditions• If you touch a live wire or other electrical

component while standing in even a small puddle of water you’ll get a shock.

• Damaged insulation, equipment, or tools can expose you to live electrical parts.

• Improperly grounded metal switch plates & ceiling lights are especially hazardous in wet conditions.

• Wet clothing, high humidity, and perspiration increase your chances of being electrocuted.


Preventing Electrical Hazards - PPE

• Proper foot protection (not tennis shoes)

• Rubber insulating gloves, hoods, sleeves, matting, and blankets

• Hard hat (insulated - nonconductive)


Preventing Electrical Hazards – Proper Wiring and Connectors

• Use and test GFCI’s

• Check switches and insulation

• Use three prong plugs

• Use extension cords only when necessary & assure in proper condition and right type for job

• Use correct connectors


Training

• Deenergize electric equipment before inspecting or repairing

• Using cords, cables, and electric tools that are in good repair

• Lockout / Tagout recognition and procedures

• Use appropriate protective equipment

Train employees working with electric equipment in safe work practices, including:


Summary – Hazards & Protections

Hazards• Inadequate wiring• Exposed electrical parts• Wires with bad insulation• Ungrounded electrical systems

and tools• Overloaded circuits• Damaged power tools and

equipment• Using the wrong PPE and tools• Overhead powerlines• All hazards are made worse in

wet conditions

Protective Measures• Proper grounding• Use GFCI’s• Use fuses and circuit

breakers• Guard live parts• Lockout/Tagout• Proper use of flexible

cords• Close electric panels• Training


Summary

Electrical equipment must be: Listed and labeled Free from hazards Used in the proper manner

If you use electrical tools you must be: Protected from electrical shock Provided necessary safety equipment


When You Don’t Lockout


Arc Flash Kills


Another Arc Flash Accident



Lockout - Tagout

• Control of Hazardous Energy

• OSHA Standard 1910.147


• January 12, 2004• Company faces $92,000 in fines after worker dies

making electrical repairs • OSHA has cited ConAgra Foods Refrigerated Foods

Co. for failing to protect workers from electrical hazards following an investigation of a worker's death July 8 at the company's Montgomery, Ala., processing plant. The agency is proposing penalties totaling $92,000.


• On the day the employee died, company officials reportedly instructed workers to repair a malfunctioning overhead light fixture. The workers couldn't locate the correct circuit breaker because none of them were labeled, so they tried to trip the appropriate breaker by "short circuiting" the line, an unsafe work practice. The breaker didn't trip, and one worker received an electrical shock. A worker then cut a neutral wire in the electrical junction box, left it unprotected and told a supervisor repairs would be made the next morning.


• Night-staff employees weren't advised that a repair had been attempted, and they also weren't told about the condition of the wiring or the plan to complete the job the next day. Two night-shift workers tried to repair the fixture; they, too, attempted to short circuit the line and received electric shocks


• One of the workers, an electrician, told management about the problems they were having making the repair and suggested waiting until the next day. According to OSHA's investigation, he was instructed to fix the light right away. Co-workers later found the electrician dead, with a pair of wire strippers in his hand, still in contact with the 277-volt electrical circuit.


ACCIDENT SUMMARY No. 60

Accident Type: Electrocution

Weather Conditions: Indoor Work

Type of Operation:Installing and Trouble-shooting

overhead lamps

Size of Work Crew: 15

Competent Safety Monitor on Site: Yes

Safety and Health Program in Effect: Inadeqaute

Was the Worksite Inspected Regularly:

Yes

Training and Education Provided: No

Employee Job Title: Electrician

Age & Sex: 53-Male

Experience at this Type of Work: Journeyman

Time on Project: 1 Month


• BRIEF DESCRIPTION OF ACCIDENT

The employee was attempting to correct an electrical problem involving two non-operational lamps. He proceeded to the area where he thought the problem was. He had not shut off the power at the circuit breaker panel nor had he tested the wires to see if they were live. He was electrocuted when he grabbed the two live wires with his left hand and then fell from the ladder


• ACCIDENT PREVENTION RECOMMENDATIONS

• The employer should not allow work to be done on electrical circuits unless an effective lock-out/tag-out program is implemented.

• The employer should not allow work to be done on energized electrical circuits or circuits which are not positively de-energized or tagged out.


You will learn…

Purpose of Lockout-Tagout Requirements for LOTO Types of Hazardous Energy Procedures for LOTO


Electric shock can kill

• as low as 30 volts can carry enough current to kill


Use Safe Electrical Practices

• Use non-conducting tools• • Check circuits dead before working

• Lock & Tag source breakers not switches

• Ensure all control power is de-energized

• Discharge all capacitors after Lockout


LOCKOUT/TAGOUT PROCEDURES

KNOW YOUR PROGRAM REQUIREMENTS!


Types of Energy

• Electrical • Mechanical • Chemical • Thermal • Hydraulic • Pneumatic


Mechanical Energy Hazards

• 2 Types • Kinetic – in motion

• Potential - stored


Kinetic Energy Hazards

• Energy of moving machinery can cause

Lacerations Fractures Loss of life - Bowater Amputations

Graphic Picture Coming Up


Lockout Failure• Accidental Start Up of Machines can be costly

when someone is working on equipment!


Potential Energy Hazards

• Energy stored in machinery • Weights & Springs • Pistons under pressure • Hydraulic controls

• Stored potential energy can be released during work causing injury or death


Chemical Energy Hazards

• Chemicals have energy that can

start fires cause skin burns generate harmful gases or

fumes • Before working – release, drain or

vent chemicals safely


Thermal Energy Hazards

• Energy of Heat (and cold) • Hot equipment & fluids will burn you • Cold fluids can cause injury also • Quick release of compresses gases can

freeze your skin • Allow equipment to reach a safe

temperature before starting work.


Hydraulic Energy

• Energy of Liquids Under Pressure

pressure can cause equipment to move

rapid release can cause injury or ejection of system parts

Relieve pressure slowly into a proper container


Pneumatic Energy Hazards

• Energy of Compressed Gases uncontrolled release can cause

injury rapid de-pressurization creates

extreme low temperature • Properly vent all systems before

starting work


ONLY TRAINED AND AUTHORIZED EMPLOYEES

VERIFY – VERIFY –VERIFY


First Step In LOTO

• Know your equipment & systems

hazards isolation points procedure for Lockout

• Working on unfamiliar machinery is a hazard


Who Can Lockout Equipment?

• Only Employees who have been trained and authorized by management


Items needed for LOTO

• Written LOTO schedule • Locks & Tags - identified to the worker • Hasps - for placing locks & tags • Breaker Clips - for electrical LOTO • Blank Flanges (pancakes)- for fluid lines • Valve Covers - for LOTO of Valves • Plug Buckets - for electrical plugs

Upcoming Slides

• The next few slides are not in your book. They were added last night to this presentation.

• These slides are a part of the M&M Mars Lockout/Tagout presentation.


Charles O. Reynolds, CECM

Types of LOCKOUT EQUIPMENT

Lock -must have

name, company name & number

Tag

Hasp Lockable Valve Cover

Plug CoverCircuit Breaker Lockout Device

Watchman


Types of Lockout Locks

Operations Personal Lock

Maint Personal Locks

Transfer Lock

Temporary Associates only

Example for Contractor use

Lock Box Locks Only

Contractors can not use the following Colors

NO NONO

NO

NOYes


Lock Box UseIn the situation where there are multiple work groups (e.g., plumbers, carpenters, electricians, & metal workers, etc.,) involved in a single project, group lockout procedures will be implemented; these will include the use of a lock box

Typical Lock Box


Page______of______

LOCKOUT / TAGOUT EQUIPMENT LIST - LOCK BOX SYSTEM

Date: Lock Box ID Number: Transfer Lock Number: ________________

Area: ___________________________ Shift: _______________________ (1) Transferred Shift: __________________

System Locked Out: ________________________________________________ (2) Transferred Shift: __________________

LineNumber

DATE LOCKED

OUT

DATEUNLOCKED

EquipmentIsolation

Lock Number

EQUIPMENT IDENTIFICATIONLOCKED OUT

POSITION(or tagged)

1

2

3

4

5

6

7

8

9

Signature – Group Lockout Leader: Lockout Group Member: ___________________________________(1) Signature – Transferred Group Lockout Leader: Lockout Group Member: ___________________________________(2) Signature – Transferred Group Lockout Leader: ___ ______ Lockout Group Member: ___________________________________Lockout Group Member: _____________________________________________ Lockout Group Member: ___________________________________Lockout Group Member: _____________________________________________ Lockout Group Member: ___________________________________Lockout Group Member: _____________________________________________ Lockout Group Member: ___________________________________

Maintaining Effective Protection

• Continuous effective protection must be maintained using one of the following two methods:

Direct Lockout/Tagout Transfer Use of Transfer Locks/Tags



The Transfer Lock Process

• These slides are in your book.



Use of Locks & Tags

• Use only those issued to you

• Never use another workers lock or tag

• Ask your supervisor if you need more LOTO equipment


6 Step LOTO Procedure

• Prepare for Shutdown

• Shutdown Equipment

• Isolate all energy sources

• Place Locks & Tags

• Release Stored Energy • Verify Equipment Isolation


More Graphic Pictures Coming Up…

• Here are 3 very graphics pictures where verification was not done!!!!!


This lineman had done this kind of work for years….


But today something went wrong!


This man does not go home to his family tonight….


1. Prepare for Shutdown

• Understand equipment hazards

• Notify other workers of shutdown


2. Shutdown Equipment

• Use normal shutdown procedure

• Turn all switches to OFF

• Shut all control valves

• Disable all sources of energy


3. Isolate All Energy Sources

• Shut valves

• Open breakers & disconnects


4. Place Locks & Tags on

• Valves

• Breakers / electrical disconnects

• Block or disconnect all lines

• Lock and tag blank flanges


5. Release or Block all Stored Energy

• Discharge capacitors • Block or release springs • Block elevated parts • Stop rotating flywheels • Relieve system pressure • Drain fluids • Vent gases • Allow system to cool


6. Verify Equipment Isolation

• Check all other workers are clear • Check locking devices securely placed • Check isolation• Attempt normal startup • Return Controls to OFF/Neutral


Release from LOTO

• Inspect Area and Equipment • Ensure all Machine Guards in place • Move tools away from equipment • Inform others of startup • Restore system connections • Remove Locks & Tags • Restore equipment to normal • Conduct normal startup


Who can remove Locks & Tags?

• Only the employee who placed the tag

• or• a supervisor, after obtaining

permission from the worker who placed the tag.


If we can’t find the worker we must make every attempt to locate the

employee:

1. Call their home

2. Call their cell phone

3. Call their pager

4. Attempt to locate through relatives

5. Call any other location where it is known that the employee might be


When the Employee Returns to Work

1. You must immediately inform the employee that his/her lock was cut off and removed from the lockout/tagout procedure.

2. Issue an Employee Safety Violation Report.

3. Consider if retraining is necessary.


A piece of equipment already has a locked and tagged. Do I have to

place my own locks & tags?

•YES. Each person working on the equipment must place their own locks and tags to ensure their safety.

• ANOTHER GRAPIC PICTURE


Lockout-Tagout Protects YOU!

• USE Proper Lockout - Tagout

Procedures

• Please be careful when working on

equipment


Questions?

• Thanks YOU!

Documents

Charles O Reynolds, CECM1 Electrical Safety Subpart S