General Industry 2015 Electric Safety

Industrial Electrical

Safety

John Newquist

Draft 4 26 2015

Dec 2013

Oct 2013

June 2014 –Wet Location

42-year-old Lynden Endress was washing

cattle on his farm.

That's when the power washer he was using

short-circuited, electrocuting him.

November 2014 - Troubleshooting

Dietrich believes the man was electrocuted by his wedding ring after it madecontact with a copper wire in the back of the machine.

Albert Washington, his brother-in-law, told officers that he turned the poweroff to the room. He asked for the power to be put back on to test the machineand then when a fault was noticed he tried to fix it without turning theelectricity off again, at which point he was electrocuted, according to theDaily Mail.

March 2014 – Use as Approved

1. Fall Protection in Construction (1926.501) 8,241 violations

2. Hazard Communication (1910.1200) 6,156 violations

3. Scaffolding in Construction (1926.451) 5,423 violations

4. Respiratory Protection (1910.134) 3,879 violations

5. Electrical – Wiring Methods (1910.305) 3,452 violations

6. Powered Industrial Trucks (1910.178) 3,340 violations

7. Ladders in Construction (1926.1053) 3,311 violations

8. Lockout/Tagout (1910.147) 3,254 violations

9. Electrical – General Requirements (1910.303) 2,745 violations

10. Machine Guarding (1910.212) 2,701 violations

Who needs

training? 1910.332(a)

Employees in occupations listedin Table S-4 face such a riskand are required to be trained.Other employees who also mayreasonably be expected to facecomparable risk of injury due toelectric shock or other electricalhazards must also be trained.

At a minimum, be trained in and familiar

with the following:

The skills and techniques necessary to

distinguish exposed live parts from other

parts of electric equipment.

The skills and techniques necessary to

determine the nominal voltage of exposed

live parts, and

The clearance distances specified in

1910.333(c) and the corresponding

voltages to which the qualified person

will be exposed.

March 2015

• Issues?

Table S4 Typical Occupational Categories of Employees Facing a Higher Than Normal Risk of Electrical Accident

Blue collar supervisors

Electrical and electronic engineers

Electrical and electronic equipment assemblers

Electrical and electronic technicians

Electricians

Industrial machine operators

Material handling equipment operators

Mechanics and repairers

Painters

Riggers and roustabouts

Stationary engineers

Welders

Ohm’s Law The equations of Ohm’s Law are:

Voltage = Current times Resistance

Current equals Voltage divided by Resistance,

Resistance equals Voltage divided by Current.

13,800 Volts / 1000 Ohms = 13.8 Amps

480 Volts / 0.1 Ohms = 4,800 Amps

480 Volts / 0.01 Ohms = 48,000 Amps

E

I R

Determine the Current

Voltage is 120 volts. Resistance is 12 ohms = amps.

Voltage is 480, resistance is 1 Ohm = amps

Voltage is 220 resistance is 2200 Ohm = amps

Electrical Current Effect

1 mA threshold for feeling

10-20 mA voluntary let-go of circuit impossible

25 mA onset of muscular contractions

50-200 mA ventricular fibrillation or cardiac arrest

E. A. Lacy, Handbook of Electronic Safety Procedures, Prentice- Hall: Englewood

Cliffs, New Jersey (1977)

Electricity and Conductors

• Electricity (or more specifically

current) does not flow to earth of

ground, it flows from its voltage

source back to its voltage source. –John Gryzwacz www.oshaprofessor.com

• Electricity flows through conductors

• Water, Metal, the human body can be

conductors

• Insulators are not conductors

Ventricular Fibrillation

When the heart is in ventricular fibrillation, the musculature of the ventricles undergoes irregular, uncoordinated twitching resulting in no net blood flow. The condition proves fatal if not corrected in a very short space of time.

Normal

National Electric Code

The National Fire Protection Code, got its

first electrical section in 1897

Concern about many electrical fires and

conflicting codes

Knob & Tube

1881 NY Board of fire underwriters:

When it becomes necessary to carry wires through partitions and floors, they must be secured against contact with metal, or other conducting substance, in a manner approved by the Inspector of the Board.

Electrical Grounding

1928 NEC "Groundingrequired in conductivelocations such as inbasements or in wallscontaining metal lath,even if the equipment wasfed by Knob and Tubewiring, nonmetallic cablelacking a groundingconductor.

Current travels both paths. Grounding involves providing a conductor to carry most of the current into the ground rather than into a body.

120 Volts on the body

• Current = Volts/Resistance

• If you are sweaty and barefoot,

then your resistance to ground

might be as low as 1000 ohms.

Then the current would be:

• I = 120 V/1000 ohm or 120 mA

– ventricular fibrillation

• “The fact is in the US there are

more electrocutions annually at

120 volts than any other

voltage.” – John Gryzwacz

Equipment Grounding

• 1928 NEC "Grounding required in conductive locations

• How does it work?

• The equipment grounding

conductor provides a safe path

for the fatal fault current to flow

back to its source and

instantaneously trip the circuit

protection device (circuit

breaker or fuse). – Gryzwacz

• Current travels both paths.

• Grounding involves providing a

conductor to carry most of the

current into the ground rather than

into a body. -Bob Lomastro

•What’s its function or purpose?

• To prevent electrocution in the

event of a short circuit or fault in the

tool or equipment.

The GFCI operates by sensing the difference between

the currents in the Hot (ungrounded) and Neutral (grounded) conductors.

Under normal conditions, these should be equal.

The GFCI will shut off at 5 mA in 1/40th of a second.Image courtesy of Bob Lomastro www.safetywizard.com

GFCI’s –1971 NEC

Electrocution Deaths by Age Group •244 Victims In The Study

N

umbe

r

NIOSH Fatality Assessment Control Evaluation (FACE)

Double Insulated

Insulated from shock

Square with square

Watch out for no lab testing (NRTL)

Bottom two images courtesy of www.safetywizard.com

Power Taps

• 29 CFR 1910.305(g)(1)(iii)

reads as follows:

• "Unless specifically permitted

in paragraph (g)(1)(i) of this

section, flexible cords and

cables may not be used:

• (A) As a substitute for the

fixed wiring of a structure.

Fluorescent Lighting

Most common cause of electrocution among electricians

- Changing ballast while live.

Workers not de-energizing circuit nor wearing any PPE

Shall be de-energized before the employee works on or near them, unless the employer can demonstrate that de-energizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations.

Testing live to find fault or short is common reason.

Working Live

Insulated leads alones are not safe.

Wear rated gloves when testing.

#1 - Boxes with unused openings

Knockout Missing

1910.305(b)(1) Note: Circuit breakers are designed to protect property not people.

Missing Dead Fronts

#2 – Exposed live parts over 50 Volts

1910.303(g)(2)(i) Exposed wiring - missing electrical housing

#3 – Missing covers

1910.305(b)(2)

#4 - Hanging pendant boxes 1910.305(g)(1)(iii)

Box has

strain relief

and no

knockouts

Knockouts

can get

pushed into

box

Impro

per

strain

relief

#5 —Missing Grounding Conductor

1910.304(f)(4)

#6 – Disconnects not labeled

Label is tatteredNo labels on disconnects

1910.303(f)

#7 – Strain relief

Wire pulled out of shredder

1910.305(g)(2)(iii)

Missing on strain relief

#8 – Equipment not used per listing

Receptacle box not mountedBox used as an extension cord

1910.303(b)(2)

Nov 2013 Citation 2 Item 1 Type of Violation: Willful

29 CFR 1910.303(b)(2): Listed or labeled electrical equipment was notused or installed in accordance with instructions included in the listingor labeling:

On or about May 24, 2013, and at times prior thereto, Spiral "final"department, employees are allowed to use foreign material to operatecontrol panels.

Employees are using makeshift instruments, including but not limitedto clip binders and welding wire bent in the shape of shepherd's hooksto override the "forward" limit switch on the pipe conveyor consolepanel, so that the pipe can continue horizontally down the conveyorand the incoming pipe can immediately be worked on to reduceworkload buildup.

The practice of overriding the limit switch on the console panelexposes employee(s) to hazards associated with being struck by andcaught-in between conveyed piping, stopping blocks and otherstationary or transported objects.

#9 – 3’ Clear spaces

Storage in front of panel box

1910.303(g)(1)(ii)

Panel box blocked

#10 – Electrical Free of Hazards 1910.303(b)(1)

Ground prong stuck in receptacle Open wiring spliced out of box

#9 – 3’ Clear spaces

• 1910.303(g)(1)(ii)

Panel box blocked Storage in front of

panel box

Receptacles

Receptacles will have hot, neutral, and a grounding conductor

Insulated Gloves

Electrical gloves can protect the worker who must test circuits live.

Gloves can be bought for work with voltages under 500 volts. These areClass 00 gloves.

Gloves must be sized for each employee.

Test every six months.

Voltage

Detectors

• “Senses the steady state

electrostatic field

produced by AC voltage

through insulation without

requiring contact to the

bare conductor.

• A red glow at the tip and a

beeping noise (if not

switched OFF) indicates

the presence of voltage.” -

FLUKE

The detector will not work

on dc

Workers must test for the

absence of voltage.

AC Voltage

Detectors

Source: Fluke

Read the safety limitations

from the tester mfr

•Worker died when shocked pulling out barrel fuse with pliers

•Electrical circuits must be locked out before doing any work on the circuits if possible.

Fuse Pulling

Outdoor signs

Worker found unconscious taking out electric receptacle while still energized. Breakers were

not locked out. No labels in panel

Air Handlers

Worker touched an energized horizontal heating coil

Daily Checks

Cord and plug connected equipment should be check daily before use.

1910.334(a)(2)(i)

Portable cord and plug connected equipment and flexible cord sets (extension cords) shall be visually inspected before use on any shift for external defects

For example, if an internal fault should occur in the wiring as shown in the figure below, the equipment would not stop when the switch is released or would start as soon as a person plugs the supply cord into the improperly wired outlet. This could result in serious injury.

Reverse Polarity

On October 30, 2004,Employee #1 was apparentlytrying to use a portable electricgrinder at a work site when hewas electrocuted fromungrounded and reverse

polarity electrical sources.

Capacitors

Pleasant Prairie WI

OSHA’s investigation found the tempworker had inadvertent contact withelectrical equipment while trouble-shooting an electrical failure on a heat-sealing machine.

Company failed to require personalprotective equipment for employeesworking near exposed, energizedelectrical parts.

The company also did not developprocedures to de-energize circuits andequipment safely or ensure storedenergy capacitors were grounded.

Capacitors store

electricity

indefinitely. They

must be properly

drained before

working on

Clear Space again

1926.403(i)(1)

Sufficient access and working space shall be provided and maintained about all electric equipment to permit ready and safe operation and maintenance of such equipment.

Classified Locations

Combustible dust &

exposed wiring.

1. What mA typically causes muscle contractions? _____

2. A GFCI will shut off in _____ of a second.

3. When the musculature of the ventricles undergoes

irregular, uncoordinated twitching resulting in no

net blood flow is called ________ ________.

4. Live parts over ____ volts need to be guarded.

5. ____ feet of clear space must be maintained in front

of electrical panels.

Quiz

ELECTRIC ARC FACTS

•TYPICALLY LASTS

LESS THAN A SECOND

•EXTREMELY HIGH

RADIANT ENERGY

•EXPLOSIVE IN NATURE

CAN IGNITE AND/OR

MELT CONVENTIONAL

WORK CLOTHING

Electrical Statistics• As many as 80 percent

of all electrical injuries are from an arc-flash contact and ignition of flammable clothing.

• 2,000 people are admitted to burn centers

• Source: Cooper Bussmann

Arc Flash Incidents

Estimated 5-10 arc flash incidents per day

Numerous fatalities per year

Estimates as to costs of burn injury medical (skin grafts, therapy )and related costs (replacement worker, rehabilitation,) average between 1.0 and 4 million dollars.

And then we have a social cost!!!

Now which of you has seen this label?

The NEC 110.16, which reads: "Flash

Protection. Switchboards, panel boards,

industrial control panels, meter socket

enclosures, and motor control centers in

other than dwelling occupancies, which

are likely to require examination,

adjustment, servicing, or maintenance

while energized, shall be field marked to

warn qualified persons of potential

electric arc flash hazards*. The marking

shall be located so as to be clearly

visible to qualified persons before

examination, adjustment, servicing, or

maintenance of the equipment."

Field Marking

An arc flash is a short circuit

through the air

The temperature of an arc can reach approximately 35,000

degrees Fahrenheit or about four times as hot as the surface

If the marking is not there.• The system was turned over without the appropriate hazard warnings.

• It is not in compliance with the 2002 – 2014 National Electrical Code

• Article 90 in the NEC specifically states that this code is not an instruction manual for the untrained/unqualified persons (it’s for trained qualified workers). - Gryzwacz

• If we need to label equipment to inform alleged “qualified” workers of the hazards of electricity (including arc flash/arc blast) then perhaps they shouldn’t be considered to be qualified.

Common Causes of Electric Arcs

Dust and impurities

Corrosion

Condensation of vapor and water dripping

Accidental touching phase to phase

or phase to ground

Dropping conductive tools

Over-voltage across narrow gaps

Failure of insulating materials

Improperly designed or utilized equipment

Improper work procedures

An arc flash is a short circuit

through the air

The temperature of an arc can

reach approximately 35,000

degrees Fahrenheit or about

four times as hot as the surface

of the sun.

Electrical Processes Causing Flashes

Removing or installingcircuit breakers or fuses

Voltage testing

Working on control circuitswhen energized partsexposed

Applying safety grounds

Racking circuit breakers

Racking starters

Removing bolted covers

Arc Rated PPE

NFPA 70E

Provides

additional

guidance to

determine Arc

Flash

Assessments and

clothing

requirements.

PPE Categories

PPE will depend on which boundary and task you are in.

FR clothing must be work first at Category 1 work.

Also FR

clothing is not

permitted for

arc flash/arc

blast hazard

protection, the

clothing must

be “arc rated

(per ASTM).

Power Lines

10 foot safe clearance up to 50,000 volts.

Avoid storing material under the lines.

Scaffold hits power lines video

link.

Summary

Grounding involves providing a conductor to carry most of the current into the ground rather than into a body.

•Summary

Water and other liquids are good conductors of

electricity.

Lastly

A three-pronged plug should never be used in a twopronged outlet

•Questions?

This is very unsafe!

Background

• Classes: OSHA 10/30 Hour,

Incident Investigation,

Confined Space, Excavation

Safety, Cranes Signaling and

Rigging, Fall Protection,

Scaffold Safety, and many more

• 2170 Trained in 2014!!

71

• 34 years working with top

companies to achieve ZERO

injuries

• Certified Safety Professional

• OSHA 1983-2012

• Founding Member of ANSI Z359

• 815-354-6853

• [email protected]

Services: Mentoring safety

professionals in hazard recognition

and auditing, Site Safety Audits,

Custom Training, OSHA Litigation

Consultation, Expert Witness,