Electrical Commissioning and Arc-Flash Safety presentation

Electrical Commissioning
and Arc Flash

BUILD. CONNECT. ACHIEVE.
Michael E. Luffred, ACP
Eaton Energy Solutions, Inc.

1

NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013

Learning Objectives
• General overview of OSHA regulations and the
relationship of it to consensus standard NFPA 70E.
• Understand the cause and intensity of arc flash
event.
• Highlight safety requirements around working on
energized electrical equipment.
• Discuss the electrical commissioning process as it
relates to arc flash.
• Learn measures that can be taken as a
commissioning provider to reduce the likelihood on
an arc flash event from occurring.
2


General Information
The following words derive from various sources
including the Code of Federal Regulations (USA), Title
29, Part 1910 and the NFPA Standard 70E–2012
Edition. When you see them in this slide presentation
their meanings are as follows:
Word
“shall”
“may”
“must”
“should”

3

Meaning
Law mandate the action (OSHA)
Almost always mandated, some limited exceptions
(OSHA)
Recommended policy, need to have very good
reasons to disregard
Recommended practice under normal
circumstances (OSHA)


Occupational Safety and Health Act of 1970
• AN ACT: To assure safe and healthful working conditions
for working men and women; by authorizing enforcement
of the standards developed under the Act; by assisting
and encouraging the States in their efforts to assure safe
and healthful working conditions; by providing for
research, information, education, and training in the field
of occupational safety and health; and for other
purposes.

4


Occupational Safety and Health Act of 1970
• SECTION 5. DUTIES: (a.k.a. The General Duties
Clause)
(a)

Each employer -(1)

shall furnish to each of his employees employment and a place of
employment which are free from recognized hazards that are causing or
are likely to cause death or serious physical harm to his employees;
(2) shall comply with occupational safety and health standards
promulgated under this Act.

(b) Each employee shall comply with occupational safety and health
standards and all rules, regulations, and orders issued pursuant to this
Act which are applicable to his own actions and conduct.

5


Federal Regulations, Standards and Codes
• OSHA is the agency responsible for enforcing workplace
safety.
• NFPA publishes consensus standards and has no
authority to police or enforce compliance.
• Governmental agencies do, however, reference various
NFPA documents or incorporate their language into codes
and regulations.

6


Definitions: Qualified Employee and
Competent Person (OSHA)
A Qualified Employee must be trained and competent to:
•Distinguish live parts from other parts of equipment.
•Determine the nominal voltage of live parts.
•Know the minimum approach distances to live parts.
•Know what precautions to take to work safely.
•Know how to carry out lockout/tagout procedures.
•Know how to manage and maintain a safe work area.
•Know how to use protective grounds.
7


Competent Person (OSHA) - continued
A Qualified Employee must be trained and competent to:
•Know how to use personal protective equipment (PPE).
•Know how to use insulating and shielding materials.
•Know how to use insulated tools.

Reference: OSHA 1910.269(a)(2)(ii) & 1910.332(b)(3)

8


Competent Person (OSHA) - continued
A Qualified Person Must
• Be certified by his employer before working on or near
energized equipment [1910.269.(a)(2)(vii)]
• Have his or her qualifications reviewed annually
[1910.269(a)(2)(iii)]

9


Qualified Person as defined by NFPA 70E
• Definition: Qualified Person - One who has skills and
knowledge related to the construction and operation of
the electrical equipment and installations and has
received safety training to recognize and avoid the
hazards involved. [Article 100]
• A person can be considered qualified with respect to
certain equipment and methods but still be unqualified
for others [Article 110.6(D)(1)(a)]

10


Qualified Person as defined by NFPA 70E
• [Such persons must additionally be trained in] the
decision-making process necessary to determine the
degree and extent of the hazard and the personal
protective equipment and job planning necessary to
perform the task safely. [Article110.6(D)(1)(b)(4)]
• An employee who is undergoing on-the-job training and
who, in the course of such training, has demonstrated an
ability to perform duties safely at his or her level of
training and who is under the direct supervision of a
qualified person shall be considered to be a qualified
person for the performance of those duties [Article
110.6(D)(1)(c)]
11


Training: OSHA Standard Number 1910.332
(a) Scope. . . employees who face a risk of electric shock
that is not reduced to a safe level by the electrical
installation requirements . . .

12


Note: Employees in occupations listed in Table S4
face such a risk and are required to be trained. Other
employees who also may reasonably be expected to
face a comparable risk of injury due to electric shock
or other electrical hazards must also be trained.
TABLE S-4. -- Typical Occupational Categories of Employees Facing a Higher
Than Normal Risk of Electrical Accident
Occupation: 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
Footnote(*) Workers in these groups do not need to be trained if their work or the
work of those they supervise does not bring them or the employees they
supervise close enough to exposed parts of electric circuits operating at 50 volts
or more to ground for a hazard to exist.

13


(b) Content of training.
(1) Practices addressed in . . . standard. . . 1910.331 through 1910.335 that
pertain to their respective job assignments.
(2) . . . persons . . . who are not qualified shall also be trained in and familiar with
any electrically related safety practices not specifically addressed by 1910.331
through 1910.335 but which are necessary for their safety.
(3) Qualified persons . . . shall, at a minimum, be trained in and familiar with the
following:
(i) The skills and techniques necessary to distinguish exposed live parts
from other. . .
(ii) The skills and techniques necessary to determine the nominal voltage of
exposed live parts
(iii) The clearance distances . . . and the corresponding voltages to which
the qualified person will be exposed.
14


(c) Type of training.
The training required by this section shall be of the classroom or onthe-job type. The degree of training provided shall be determined by
the risk to the employee.

15


Training Requirements: NFPA 70E
Article 110.2(D)(1) adds to the definition by listing the
training requirements for a qualified person.
• Person receiving training on the job and under direct
supervision has demonstrated safe work practices to his
supervisor can be considered qualified.
• Implication: formal documentation of the person's
qualifications are not needed under this circumstance.
• Another implication: formal documentation would be
needed before same person could perform tasks without
direct supervision.

16


Re-training Requirements: NFPA70E
Article 110.2(D)(3) says that
retraining shall be performed
at intervals not to exceed
three years.

17


Your Employer's Electrical Safety Program
Your employer is required to develop, implement and
document a program of electrical safety. The program
must be tailored to the kinds of hazards you might
encounter.

18


Electrical Commissioning and Arc Flash

19


Introduction
• So what exactly is arc flash?
• And why is knowing about it and it’s prevention
important to electrical commissioning?

20


What is Electrical Commissioning?
• Commissioning Process for
Buildings and Systems ANSI/ASHRAE/IES Standard
202-2013
– Commissioning Process: A qualityfocused process for enhancing the
delivery of a project. The process
focuses upon verifying and
documenting that all of the
commissioned systems and
assemblies are planned, designed,
installed, tested, operated, and
maintained to meet the Owner's
Project Requirements.
21


What is Electrical Commissioning?
• The Commissioning Process
for Buildings and Systems ASHRAE Guideline 0-2005
– “The Commissioning Process is a
quality-oriented process for
achieving, verifying, and
documenting that the performance
of facilities, systems, and
assemblies meets defined
objectives and criteria.”

22


The Process of Commissioning
• Works to ensure that the
finished facility meets the
OPR.
• Integrated into every
phase of the project:
–
–
–
–

Project Initiation /Pre-Design
Design
Construction
Occupancy / Operations

• Commissioning is NOT
just testing at the end of
the job!
23


Commissioning Phases

24


What is an Arc Flash?

25


What is an Arc Flash?
NPFA 70-E 2012: “when an
electric current passes
through air between
ungrounded conductors or
between ungrounded
conductors and grounded
conductors.”

26


Arc Flash Event
• A dangerous release of energy created by an electrical
fault
• Release will contain:
–
–
–
–
–
–

27

Thermal energy (heat)
Toxic fumes
Blinding light
Acoustical energy
Pressure waves
Debris


Arc Flash Event
Injuries that can result from an
arc flash:
• Burns
• Respiratory system damage
• Hearing damage
• Skin penetration from flying
debris
• Eye and face injuries
• Possibly death

28


Arc Flash - ImportantTemperatures
•
•
•
•
•
•
•

29

Skin temperature for curable burn
Skin temperature causing cell death
Ignition of clothing
Burning clothing
Metal droplets from arcing
Surface of sun
Arc terminals

176°F
205°F
752°-1472°F
1472°F
1832°F
9000°F
35,000°F


Arc Flash Event
• Rapid heating & expansion of air and materials
surrounding area of arc.
– 67,000x expansion for copper that vaporize

• Fatal burns >10 feet
• Majority of hospital admissions are arc flash burns, not
shock
• 30,000 arcs, 7,000 burn injuries per year
• Over 2,000 people admitted to burn centers yearly with
severe arc flash burns

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Arc Flash Intensity
• Variables that affect the size and energy of an electric
arc flash are:
–
–
–
–
–
–
–

31

Amperage
Voltage
Arc gap
Closure time
Distance away from arc
3 phase vs. single – phase
Confined space


Some Statistics
• 4,383 workers were killed on the job in 2012
[BLS revised 2012 workplace facility data]

• 775 worker fatalities were in construction
• 66 (9%) of these deaths were attributed to electrocution
• Electrocution is the third leading cause of workplace
death
• 3 of the 10 top most frequently cited OSHA standards
violated are electrical based
– Control of hazardous energy (lockout/tagout), general industry
(29 CFR 1910.147)

– Electrical systems design, general requirements, general industry
(29 CFR 1910.303)

– Electrical, wiring methods, components and equipment, general industry
(29 CFR 1910.305)
https://www.osha.gov/oshstats/commonstats.html

32


Some Statistics
• More than 30,000 non-fatal shock accidents occur each
year.
• In the construction industry, non-fatal electric shocks
injuries occur at a rate of 0.6 cases per / 10,000 workers
annually – highest in any industry
• Estimated 5 to 10 arc explosions occur in electrical
equipment every day in the U.S.
• Average cost per incident estimated at over $1,000,000
• The average cost of medical treatment for survivors of
arc flash is $1.5 million. Total costs have been estimated
at $12 – 15 million per incident.
33


Arc Flash at ExxonMobil

34


So what’s the point?
• Working on and around electrical equipment is
hazardous work.
• As a commissioning service provider we must
exercise and be a proponent of safe electrical work
practices while commissioning.
• Help the project team mitigate arc flash events.

35


Pre-Design Phase Actions
• Recognize that project requirements has arc
flash potential.
• Be prepared to help the owner capture their
arc flash requirements and associated safe
work practices in the OPR.

36


Design Phase Actions
• Specify Cx procedures that indicate a
reasonable level of effort to be safe
• HVAC & filtering of equipment should be
appropriate for the installations
• Design systems so that open & inspections
of critical systems can be performed without
disruptions to the mission.
• Recommend Arc Flash reducing equipment
and procedures.

37


Arc Flash Reducing Equipment
• Metal-clad switchgear

38


• Arc-Resistant switchgear

Arc
Flaps

Vent

VT Compartment
Control
Compartment

39

Manual
Close-Open
Plates


EEMAC G14-1 Table 1: Locations, Causes and Examples of Measures to
Decrease the Probability of Internal Faults or Reduce the Risk.

Locations where internal faults
are more likely to occur

Possible cause of internal
faults

Examples of measures

Inadequate design

Selection of adequate dimensions

Faulty installation

Avoidance of crossed cable connections. Checking of
workmanship on site.

Cable Termination Compartments
Failure of solid or liquid
insulation (defective or
missing)

Check of workmanship and/or dielectric test on site. Regular
checking of liquid levels.

Mal-Operation

Interlocks. Delays re-opening. Independent manual operation.
Making capacity for switches and grounding switches.
Instructions to personnel.

Corrosion

Use of corrosion inhibiting coatings and/or greases.
Encapsulation where possible.

Faulty Assembly

Checking of workmanship by suitable means.

Instrument Transformers

Ferroresonance

Avoidance of these electrical influences by suitable design of
the circuit.

Circuit Breakers

Insufficient maintenance

Regular programmed maintenance. Instructions to personnel.

Error by personnel

Limitation of access by compartmentation. Insulation
embedded live parts. Instructions to personnel.

Aging under electric stresses

Partial discharge routine tests

Pollution, moisture, dust,
vermin, etc.

Measures to ensure that the ingress specified service
conditions are achieved.

Disconnection Switches
Grounding Switches

Bolted Connections and Contacts

All Locations

40


• Arc flash reducing
maintenance switches

41


• Zone-selective interlocking

42


• Add current-limiting reactors

43


Construction Phase Actions
• Recognize the impacts of construction
changes
• Insist on equipment installations to be clean
and/or maintained once energized
• Temporary air filtration
• Good housekeeping
• Keep boundaries clear of stored materials
• Guarding of energized parts OSHA
1910.335 (a) – (b)
• Cx team practice safe work around
energized equipment.
44


Safe Work Practices
• Close and latch
compartment doors before
operating a switch.
• Switch remotely .
• Use a remote racking
device.

45


Safe Work Practices
• While switching, stand to the side and away as much as
possible from the prospectus path of the arc flash.

Bad practice – Exposed Back of Neck

46

Good practice – Entire Body Protected


Safe Work Practices
• Consider new methods to
perform familiar tasks.
– viewing windows or viewing
ports for infrared scanning.

47


Safe Work Practices
• Avoid leaning on switchgear or touching metallic
surfaces during switching procedures.
• Use the proper tools for the project.
• De-Energize equipment when feasible.
• Don’t work alone.
• Remove jewelry.
• Secure your phone.
• Use the one-hand method.

48


• Owner training should address issues of
continuous inspection and cleaning as
appropriate
• Obtain copy of computer model of system
that was used to create short circuit study &
coordination study
• Instruments are appropriate for equipment
use
– Donnie’s Accident story
– http://www.donniesaccident.com/full-story

• Have appropriate PPE available

49


• Follow lock out and tag out procedures
• Utilize data loggers / remote sensing
equipment when possible
• Be cognizant of back feed.
– Cooling tower fans
– Dual feed systems

• Cleanliness
– Tripping hazards
– Conductive materials falling into limit approach
boundary

• Have facilities electrical representatives
participate in system functional testing.
50


• Labeling is completed as soon as possible.
• Don’t assume anything
–
–
–
–
–
–
–
–
–

51

Neutral isn’t energized
Unproven circuit breaker will trip
Overload setting is low enough
Cable terminations are tight
Housekeeping has been kept up
Labeling is correct
Lock-out /tag-out is the same as yesterday
Off is not hot
Recent installed relays / fuses are calibrated /
good


Occupancy & Operations Phase Actions
• Ensure that more than one person is
completely trained on the operation of the
equipment and can bring it back on line.
• Written procedures how to restore power.
• Short circuit, coordination and arc flash
study up to date
• Open and inspect critical equipment
• Ensure EMCS documentation and programs
are obtained from vendors and archived.
• Maintain equipment
– Lubricant deterioration
– Cleanliness
52


Arc Flash at New Campus East
• Evening of May 1, 2010
• Prep testing for upcoming Integrated System Test
• Flashover in the rear of 34.5 kV Switchgear SS-2 in
section 12 (tie breaker that connects to SS-1 cell)
• Phase A to ground
• Evidence of arcing in another section
• Fault of 23 cycles or .38 seconds

53


Pictures of SS2 Gear (Orientation 1 of 3)
SS2 Gear comprised of 14 Cubicles

Front Side
(Contains Breakers)

Back Side
(Contains: Cubicle Bus Bars,
Bushings/Boots and Cables)

54


NCE Overall Campus Single Line Diagram (2 of 3)

SS1

SS2

SS1/SS2
Switchgear

55


SS1/SS2 Switch Gear (3 of 3)

SS2 Gear comprised of 14 Cubicles

SS1

SS2
12 13 14

1 2 3 4 5 6 7 8 9 10 11

Issue with Hipot Testing
on 6MAY10
56

Location of Fault in Cubicle 12
on 1MAY10 at ~2200

Pictures SS2/SS1 Comparison
Tie Feeder to SS1 (where fault occurred-cubicle 12 in SS2 Gear)

Back Side (Bus Bars and Bushings)

Front Side (where ~900lb Breaker goes)

Tie Feeder to SS2 (SS1 Gear)

57


Damage to Components in SS2 Cubicle 12

Cubicle 12 Bus Bars that have to be replaced (Back Side)

Oxidation on Ground bar
In Cubicle 12 (Back Side)

58

~900lb SS2 Cubicle 12 Breaker
(Front Side)


Potential Cause of SS2 Failure
•
•
•
•
•
•

59

The cell in SS2 that failed on 1MAY10 was found to be “heavily
contaminated” with dust (Cx Team to investigate type of dust)
Bushing boot was found to have the beginning stages of “tracking”
“the formation of partially conductive paths across the surface of an
electrical insulator that degrade or destroy, its insulating capabilities”
Since contamination was found in SS2 it is assumed it also exists in SS1;
therefore SS1 must also be inspected for potential contamination
In order to remove contamination from SS2 all 84 boots (6 boots/cubicle, 14
cubicles) have to be replaced.
Cx Team and Electrical Experts are still determining if any modifications
need to be done to the gear or conditioning of electrical spaces to prevent
“contamination” of the gear from occurring again.


Removal of Boots and “Tracking” on Boots

Examples of Tracking

Removal of all 84 boots in SS2
(6 boots/cubicle, 14 cubicles)

60


Summary
• We can help our clients reduce their risks for arc flash.
• Cx providers have the same responsibilities as
electricians to perform safe work practices.
• Be a proponent of Arc Flash electrical safety…
the threat is real!

61


References
•
•
•
•
•

62

Code of Federal Regulations (USA), Title 29, Part 1910: Occupational
Safety and Health Standards (OSHA Standards – General Industry)
Code of Federal Regulations (USA), Title 29, Part 1926: Safety and Health
Regulations for Construction (OSHA Standards - Construction)
NFPA Standard 70E-2012: Standard for Electrical Safety in the Workplace
IEEE 1584-2002: Guide for Performing Arc Flash Hazard Calculations
Eaton White Paper: Innovative Techniques for Mitigating Arc Flash
Exposure (eaton.com/arcflash)


Questions?

63


Final Exam

Which panel will cause an arc flash event that will impact
your project?
64


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