1. Common Electrical Hazards in the Workplace
By Dan Klimek
Sisk & Company

2. What we will cover today
Qualified vs non-qualified workers
Overview of why electricity is hazardous
Portable generators vs utility supplied electricity
Extension cords
GFCI
Overhead powerlines
Breakers and related building installations

3. Qualified vs Non-Qualified “electrical” workers
Qualified person: One who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.

4. Electrical Shock Received when current passes through the body
Severity of the shock depends on:
Path of current through the body
Amount of current flowing through the body
Length of time the body is in the circuit
LOW VOLTAGE DOES NOT MEAN LOW HAZARD
A small current that passes through the trunk of the body (heart and lungs) is capable of causing severe injury or electrocution.
Low voltages can be extremely dangerous because, all other factors being equal, the degree of injury increases the longer the body is in contact with the circuit.

5. Electrical Burns Most common shock-related, nonfatal injury
Occurs when you touch electrical wiring or equipment that is improperly used or maintained
Typically occurs on
the hands
Very serious injury
that needs immediate
attention

6. Falls Electric shock can also cause indirect or secondary injuries
Workers in elevated locations who experience a shock can fall, resulting in serious injury or death

7. Portable Electric Generators
Shocks and electrocution from improper use of power or accidentally energizing other electrical systems.
Carbon monoxide from a generator’s exhaust.
Fires from improperly refueling a generator or inappropriately storing the fuel for a generator.
Noise and vibration hazards.

8. Flexible Cords
(g)(2)(i)
Durably marked as to type, size, and number of conductors
Strain relief must be provided
Only cords with a secondary jacket can be used on job sites (standards specify the type of jackets)
(g)(2)(i) A conductor of a flexible cord or cable that is used as a grounded conductor or an equipment grounding conductor shall be distinguishable from other conductors. Types S, SC, SCE, SCT, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, and STOO flexible cords and Types G, G-GC, PPE, and W flexible cables shall be durably marked on the surface at intervals not exceeding 610 mm (24 in.) with the type designation, size, and number of conductors.

9. Extension Cords
The path to ground from circuits, equipment, and enclosures must be permanent and continuous
Grounding prongs must be on the cords
Inspect
before use
Protect cord
from damage
(f)(4)

10. Splices
(g)(2)(ii)
Flexible cords may be used only in continuous lengths without splice or tap.
(g)(2)(ii) Flexible cords may be used only in continuous lengths without splice or tap. Hard-service cord and junior hard-service cord No. 14 and larger may be repaired if spliced so that the splice retains the insulation, outer sheath properties, and usage characteristics of the cord being spliced.
Note: Black electrical tape does not provide suitable insulation and is not acceptable

11. Flexible Cords
(b)(3)(ii)(C)(3)
Extension cords must be visually inspected before each use on any shift. Examine the cord for:
Missing grounding pin
Damaged other jacket (tear in insulation)
Possible internal damage (pinched cord)
(b)(3)(ii)(C)(3) Each cord set, attachment cap, plug, and receptacle of cord sets, and any equipment connected by cord and plug, except cord sets and receptacles which are fixed and not exposed to damage, shall be visually inspected before each day's use for external defects, such as deformed or missing pins or insulation damage, and for indications of possible internal damage. Equipment found damaged or defective shall not be used until repaired;

12. Flexible Cords – Permitted Use
(g)(1)(ii)(A)-(L)
Pendants;
Wiring of fixtures;
Connection of portable lamps or appliances;
Portable and mobile signs;
Elevator cables;
Wiring of cranes and hoists;
Appliances to permit removal for maintenance and repair
(g)(1)(ii) Flexible cords and cables may be used only for: (g)(1)(ii)(A) Pendants; (g)(1)(ii)(B) Wiring of fixtures; (g)(1)(ii)(C) Connection of portable lamps or appliances; (g)(1)(ii)(D) Portable and mobile signs; (g)(1)(ii)(E) Elevator cables; (g)(1)(ii)(F) Wiring of cranes and hoists;
(g)(1)(ii)(I) Appliances where the fastening means and mechanical connections are designed to permit removal for maintenance and repair;
Stationary equipment to
facilitate interchange
Pendant, or
Fixture Wiring
Portable lamps,
tools or appliances

13. Prohibited Uses of Flexible Cords 1910.305(g)(1)(iv)(A)-(F)
As a substitute for the fixed wiring of a structure;
Where run through holes in walls, ceilings, or floors;
Where run through doorways, windows, or similar openings;
Where attached to building surfaces;
Where concealed behind building walls, ceilings, or floors; or
Where installed in raceways, except as otherwise permitted in this subpart.
(g)(1)(iv) Unless specifically permitted otherwise in paragraph (g)(1)(ii) of this section, flexible cords and cables may not be used: (g)(1)(iv)(A) As a substitute for the fixed wiring of a structure; (g)(1)(iv)(B) Where run through holes in walls, ceilings, or floors; (g)(1)(iv)(C) Where run through doorways, windows, or similar openings; (g)(1)(iv)(D) Where attached to building surfaces;
Concealed behind or attached to building surfaces
Substitute for fixed wiring
Run through walls, ceilings, floors, doors, or windows

14. GFCI Protection
(b)(3)(i)
Receptacles installed in bathrooms or on rooftops shall have ground-fault circuit-interrupter protection for personnel.
(b)(3)(i) All 125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms or on rooftops shall have ground-fault circuit-interrupter protection for personnel.

15. Ground-Fault Circuit Interrupter
This device protects you from dangerous shock
If a ground fault is detected, the GFCI can shut off electricity flow in as little as 1/40 of a second, protecting you from a dangerous shock
The GFCI continually matches the amount of current going to an electrical device against the amount of current returning from the device along the electrical path.
Whenever the amount of current going differs from the amount returning by approximately 5 milliamperes, the GFCI interrupts the electric power within as little as 1/40 of a second, protecting you from a dangerous shock.
GFCI’s are able to detect the loss of current resulting from leakage through a person who is beginning to be shocked. If this situation occurs, the GFCI switches off the current in the circuit.
GFCI’s are different from circuit breakers and fuses because they detect leakage currents rather than overloads.

16. GFCI Protection
(b)(3)(ii)(A)
Receptacle outlets (including cord sets) that are not part of the permanent wiring of the building shall have ground-fault circuit-interrupter protection for personnel.
(b)(3)(ii)(A) All 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are not part of the permanent wiring of the building or structure and that are in use by personnel shall have ground-fault circuit-interrupter protection for personnel. Note 1 to paragraph (b)(3)(ii)(A) of this section: A cord connector on an extension cord set is considered to be a receptacle outlet if the cord set is used for temporary electric power. Note 2 to paragraph (b)(3)(ii)(A) of this section: Cord sets and devices incorporating the required ground-fault circuit-interrupter that are connected to the receptacle closest to the source of power are acceptable forms of protection.

17. Arc Flash Event
A dangerous release of energy created by an electrical fault
Release will contain:
Thermal energy
Acoustical energy
Pressure wave
Debris

18. Lockout / Tagout
The most effective and fool-proof way to eliminate the risk of electrical shock or arc flash is to simply deenergize the equipment. . .

19. Overhead Powerline Hazards
Overhead powerlines are usually not insulated
Keep all rig masts, drill steel, cranes, booms etc, away from powerlines
If you get close to a powerline, electricity can flash over and be just as deadly as a direct contact
Beware of powerlines when you work with ladders and scaffolding
Overhead power lines must be deenergized and grounded by the owner or operator of the lines, or other protective measures must be provided before work is started. Protective measures (such as guarding or insulating the lines) must be designed to prevent contact with the lines.
Minimum clearance distances for employees working in the vicinity of overhead power lines are given in 29 CFR (c)(3).
PPE may consist of rubber insulating gloves, hoods, sleeves, matting, blankets, line hose, and industrial protective helmets.

20. shall be legibly marked to indicate its purpose
Labeling of Breakers
(f)(2) –(3)
Overcurrent devices or disconnecting devices:
shall be legibly marked to indicate its purpose
shall be of sufficient durability to withstand the environment involved.
(f)(2) Services, feeders, and branch circuits. Each service, feeder, and branch circuit, at its disconnecting means or overcurrent device, shall be legibly marked to indicate its purpose, unless located and arranged so the purpose is evident.
(f)(3) Durability of markings. The markings required by paragraphs (f)(1) and (f)(2) of this section shall be of sufficient durability to withstand the environment involved.

21. Cabinets, Boxes and Fittings 1910.305(b)(2)(i)
In completed installations, each outlet box shall have a cover, faceplate, or fixture canopy.
(b)(2)(i) All pull boxes, junction boxes, and fittings shall be provided with covers identified for the purpose. If metal covers are used, they shall be grounded. In completed installations, each outlet box shall have a cover, faceplate, or fixture canopy. Covers of outlet boxes having holes through which flexible cord pendants pass shall be provided with bushings designed for the purpose or shall have smooth, well-rounded surfaces on which the cords may bear

22. Hand-Held Electric Tools
Hand-held electric tools pose a potential danger because they make continuous good contact with the hand
To protect you from shock, burns, and electrocution, tools must:
Have a three-wire cord with ground and be plugged into a grounded receptacle, or
Be double insulated, or
Be powered by a low-voltage isolation transformer
Make sure generators are grounded and your cords are grounded back to the generator
(f)(5)(v)(C)(3)
Hazards of portable electric tools:
Currents as small as 10 mA can paralyze, or “freeze” muscles
- Person cannot release tool
- Tool is held even more tightly, resulting in longer exposure to shocking current
Power drills use 30 times as much current as what will kill.
Double-insulated equipment must be distinctly marked to indicate that the equipment utilizes an approved system of double insulation. The common marking is:

23. Let’s Review Qualified vs non-qualified workers
Only do work you are trained to do
Overview of why electricity is hazardous
Shock, burns, falls, etc.
Portable generators vs utility supplied electricity
Make sure they are grounded
Extension cords & GFCI
Inspect before use and protect from damage
Overhead powerlines
Keep clearance
Breakers and related building installations
Need to marked, look for damage

24. Questions?
Now for the quiz