HAZARD MANAGEMENT GUIDELINE - ELECTRICAL ARC FLASH - March 2019
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ELECTRICAL ARC FLASH HAZARD MANAGEMENT GUIDELINE March 2019
This publication is supported by AGL
pursuant to an enforceable undertaking
Intellectual property licence
AEC grants SafeWork NSW a permanent,
CONTENTS
between AGL Macquarie ACN 167 859 494
irrevocable, royalty-free, worldwide, non-
and SafeWork NSW, dated 16 April 2018. 1.0 PREFACE 4
exclusive license to use, reproduce, distribute,
This document has been prepared by a cross electronically transmit, electronically 2.0 OBJECTIVES 6
section of Electricity generation industry distribute, adapt, and modify any materials
practitioners and professionals and is developed as a result of this enforceable 3.0 SCOPE 8
endorsed by the Australian Energy Council undertaking. 4.0 CONSIDERATION OF HUMAN FACTORS 10
(AEC). The contribution of AGL Macquarie,
Alinta Energy, Synergy, Delta Electricity, 5.0 ELECTRICAL ARC FLASH HAZARD MANAGEMENT 12
Stanwell, CS Energy, Hydro Tasmania, Snowy A commitment regarding linking the strategy 5.1 Overview of Hazard Management Process 12
Hydro, Thomson Bridge, Origin Energy, and promotion of benefits to the enforceable
ENGIE, HIESN and Palisade Asset Management undertaking 5.2 What is an Arc Flash? 13
is appreciated. AEC is committed to ensuring that any 5.3 What is Arc Plasma? 15
This document was published by the promotion of a benefit arising from this 5.4 Other products of an Arc Fault 15
Australia Energy Council (AEC) Level 14, enforceable undertaking will clearly link
the benefit to the undertaking and that the 5.5 When and where do electrical faults occur? 16
50 Market Street, Melbourne, VIC, 3000.
undertaking was entered into as a result of the Table 1: Increasing arc flash risks with work activity 19
alleged contravention.
5.6 Incident Energy / Heat Flux 19
Disclaimer
5.8 Effective implementation of arc flash controls 20
This document refers to various standards,
guidelines, calculations, legal requirements, 5.8.1 Labelling 20
technical details and other information.
Table 2: Typical electrical worker activities and suggested risk controls 23
Over time, changes in Australian Standards,
6.0 DEMONSTRATION OF INDEPENDENT COMPETENCY IN PERFORMING
industry standards and legislative
THE FOLLOWING TASKS 29
requirements, as well as technological
advances and other factors relevant to the 7.0 ADDRESSING THE HUMAN FACTORS 34
information contained in this document, Table 3: Typical human factor activities and suggested risk controls 36
may affect the accuracy of the information
contained in this document. Accordingly, 8.0 MANAGEMENT OF CHANGE 38
caution should be exercised in relation to 9.0 ANNEXES 39
the use of the information contained in this
document. Annex A: Arc Flash Risk Assessment and Control 40
Correspondence should be addressed to the Annex B: Arc-Rated Clothing and Personal Protective Equipment 47
GM Policy and Research, Australian Energy Annex C: Do’s and DON’T’s of Arc Flash Labelling 50
Council (AEC), Level 14, 50 Market Street,
Annex D: Arc Flash Incident Energy Calculation Methods (‘Theory’) 52
Melbourne, VIC, 3000.
Annex E: Calculating Incident Energy or Heat Flux (‘Practice’) 56
Annex F: Electrical Arc Flash Hazards Management Guideline Checklist 61
COPYRIGHT
Annex G: References 62
© 2019 Australian Energy Council
Annex H: Definitions 641.0 PREFACE
2
0 cal/cm
2
4 cal/cm
2
8 cal/cm
2
25 cal/cm
2
40 cal/cm
Electric arc flash is a serious hazard which has This Guideline recommends minimum industry PPE PPE PPE PPE PPE
CATEGORY CATEGORY CATEGORY CATEGORY CATEGORY
the potential for personnel injury, equipment standards, is advisory only and does not
damage and loss of business objectives. In
Australia, it has been found that there is a
need for increased awareness and greater
substitute for, or override, any legislation,
regulation or safety rules implemented by
jurisdictional regulators or Energy Industry
0 1 2 3 4
education within the Energy Industry to operators.
eliminate or minimise the risk of injury to
Supporting and detailed technical information Icons in this guideline. Refer to Diagram 18 in Annex B for a more detailed description of correct PPE categories.
persons from an arc flash.
has been provided in several annexes to
The guidance material on the elimination assist the development and implementation
or minimisation of arc flash hazards across of Energy Industry organisations’ specific arc
Australian workplaces is not available in flash hazard management systems. They have
an accessible or practical form and is not been provided for the purpose of information
available free of charge. Currently there are and guidance only.
several national and international standards
and a large volume of technical material
published by standards organisations, industry
associations and equipment manufacturers on Time to arc flash — 5 mS
electric arc flash. There is a need however for
Temperature of arc flash plasma — 5000°С
a consolidated guideline that incorporates the
collective electric arc flash hazard knowledge
and experience and the presentation in an
Metal Vapor
easy-to-read guideline that can be easily
accessed and shared by in the Australian
Energy Industry.
Further, there is a need for consideration of
the general effect of human factors and of the
specific requirements of young workers and
workers deemed ‘vulnerable’ (such as workers
with an inadequate amount of training or
competency in arc flash risk controls) in the
Energy Industry in managing electric arc flash
hazards.
Intense Light
Sound Waves > 140 db
Pressure Waves > 13.7 MPa
Shrapnel
Molten Metal Droplets
Diagram 1. Arc flash effects
4 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 52.0 OBJECTIVES Supporting and detailed technical information
has been provided in several annexes, namely:
The objectives of this Guideline are to: This Guideline supports the objectives of >> Annex A: Arc Flash Risk Assessment
the This Guideline supports the objectives >> Annex B: Arc-Rated Clothing and Personal
>> Provide an effective hazard management
of the National Electricity Network Safety Protective Equipment
process and set of recommended
Code (ESAA NENS 09) to promote nationally
practices appropriate to the Australian >> Annex C: Do’s and DON’T’s of Arc Flash
consistent practices within the Energy
context, for application where electrical Labelling
Industry for arc-rated clothing and Personal
arc flash hazards may be encountered >> Annex D: Arc Flash Incident Energy
Protective Equipment (PPE) for all work on
across the construction, operation, and Calculation Methods (‘Theory’)
or near electrical equipment where there is
maintenance of electrical apparatus within
a possibility of exposure to residual arc flash >> Annex E: Calculating Incident Energy or
the Energy Industry.
incident energy above 5J/cm2 (1.2cal/cm2). Heat Flux (‘Practice’)
>> Progressively eliminate or minimise
the risk of arc flash hazards through >> Annex F: Electrical Arc Flash Hazards
improving understanding and application Management Guideline Checklist
of arc flash hazards, their assessment and >> Annex G: References
their control. >> Annex H: Definitions
>> Provides an explanation as to how human
factors (that being the interaction of
individuals with each other, in teams, It is not the intent of this guideline to set out
with equipment and with management a detailed procedure, and as such, procedures
systems) and workplace safety culture should be developed by each Energy Industry
and attitudes contribute and can be organisation in accordance with the principles
influenced to eliminate or minimise the contained in this Guideline.
risk associated with arc flash. This guideline is supported by an online video
>> Advance the current arc flash literature on electrical arc flash hazards and potential
with the specific requirements of people control measures to reduce or eliminate the
deemed ‘vulnerable’ working within the risk of arc flash occurring. Like this Guideline,
Energy Industry. the online video is published by the Australia
Energy Council (AEC) Level 14, 50 Market
>> Provide education on arc flash hazards
and their assessment (through the Street, Melbourne, VIC, 3000.
calculation of incident energy or heat
flux and other technical information that
is considered beneficial to the Energy
Industry).
6 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 73.0 SCOPE
These Guidelines apply when Energy Industry This guide does not cover specific live line
workers are required to perform any activity work techniques, such as glove and barrier
on or near electrical equipment where arc or bare hand live line techniques.
flash and electric shock hazards exist [and
Other workplace hazards and associated
as a guide relates to minimum work on or
controls required for effective hazard
near energized equipment above Extra Low
identification and risk management not
Voltage (ELV) limits, i.e. 50 V ac (rms) or
covered within these Guidelines are to be
120V dc (ripple free)].
identified and effectively implemented by
Recommendations within these Guidelines risk assessment and subsequent application
relate to core electrical arc flash hazard of the hierarchy of control, and as referenced
management as well as electrical hazards in respective to applicable Acts, Regulations,
(e.g. electrocution) and other workplace Codes of Practice, Standards and Guideline.
hazards (e.g. working at height) where relevant.
This guideline includes high voltage and low
voltage. Arc flash risk is often incorrectly
only associated with high voltage equipment.
Whilst the probability of initiating an arc flash
is greater the higher the voltage (due to the
greater ability to breakdown insulation), arcs
Operating/
can initiate at low voltage. Low voltage arc Racking
flash often results in higher incident energy
at the working position, due to the increased
fault currents and a range of other factors.
Other
work
Electrical Test
work voltage
H
Cleaning
V
7
×
LV
Diagram 2. Low Voltage is far more dangerious than High Voltage Diagram 3. Exposure to arc flash
8 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 94.0 CONSIDERATION OF HUMAN FACTORS
Across Australia, the risk of arc flash incidents The types of human factors that can interfere
or incidents involving electrical hazards with safe and effective electrical arc flash
(such as working on energised equipment risk controls being implemented by electrical Vulnerable
when permitted by law) are affected by any workers can include (but are not limited to): EXPERIENCE
or ‘at risk’
range of human factors in people who perform
1. Training and competency: where electrical
tasks as electrical workers.
workers are not educated and competent
On occasion, electrical work is performed by in the arc flash hazard, they are unaware Apprenticeship (under 25 yr old) Electrical worker’s working lifespan Retirement (65 yr old)
people who are young (such as apprentices of the potential for an arc flash incident to
who are largely less than 25 years of age) or cause harm ;
who are deemed ‘vulnerable’ – perhaps as a 2. Errors, mistakes and lapses: where people
result of their age, experience or length of Diagram 4. Vulnerable or ‘at risk’ worker
make errors in process (across a very
service, their level of skill and competence wide range of reasons) that results in
or as a result of relevant and potentially compromising the effectiveness of an arc
multiplied ‘human factors’ that are present flash risk control;
across the Energy Industry. As these human
factors may contribute to electrical incident 3. Complacency: both with the risks and
WORKPLACE CULTURE TRAINING AND COMPETENCY
and accidents the management of (and with the process of arc flash risk controls; Peoples whose actions are affected by the where people are not aware of arc flash
interaction of (actual or perceived) workplace incidents or are unaware of the potential for
training in) human factors is an important 4. Time pressure: where the ability to culture, being bullied or facing peer pressure an arc flash incident to cause significant harm
issue for all electrical workers occurring in the properly implement an administration from team-members and/or their Supervisors /
Team Leaders and a lack of accountability
Energy Industry. control (such as a permit to work) is across all aspects of electrical works. ERRORS, MISTAKES AND
LAPSES
compromised;
By definition, human factors are the wide where people make errors in
process (across a very wide
range of issues that affect how people 5. Violations: where people deliberately range of reasons) that results in
perform tasks in their work (and non-work and willingly work ‘outside’ known MENTAL HEALTH compromising the effectiveness
ISSUES AND CONCERNS of an arc flash risk control
environments); how they interact with risk controls and expected skills and
each other across teams, equipment and competencies.
workplaces and how they interact with
management systems and technology. Human
6. Information overload: where the HUMAN
information is unclear, overwhelming or
factors are the social and personal skills which duplicated to people leading to confusion FACTORS COMPLACENCY
can complement (but also distract from) and errors (this often affects a contracted DISTRACTIONS
that can interfere with
both with the risks
and with the process
technical skills and they are important for safe workforce who are commonly assigned
that are both work and
non-work related and all
the effectiveness of of arc flash risk
and effective electrical work. higher risk work); lead to a ‘breaking’ or a risk controls across controls
person’s concentration the electrical
Electrical workers in the Energy Industry are 7. Distractions: that are both work and non- resulting in error (such as industry/Generation
non-work related Sector
deemed ‘vulnerable’ workers as they are a work related and all lead to a ‘breaking’ or distractions resulting from
type of worker that has a greater exposure a person’s concentration resulting in error mobile phones)
and are at increased risk of fatality or injury (such as non-work related distractions
/ incident than most - due to both the types resulting from mobile phones); TIME PRESSURE
INFORMATION where the ability to properly
of electrical work that they perform and
8. Mental health issues and concerns; OVERLOAD implement an administration
in recognition of the many ‘human factors’ where the information is control (such as a permit to
that interact with their safe and effective 9. Peoples whose actions are affected by unclear, overwhelming or work) is compromised
duplicated to people
performance of technical work in the Energy the interaction of (actual or perceived) leading to confusion and
Industry. workplace culture, being bullied or facing errors (this often affects a VIOLATIONS
contracted workforce who where people deliberately and willingly
peer pressure from team-members and/ are commonly assigned work ‘outside’ known risk controls and
or their Supervisors / Team Leaders and a higher risk work) expected skills and competencies
lack of accountability across all aspects of
electrical works.
Diagram 5. Human factors
10 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 115.0 ELECTRICAL ARC FLASH HAZARD MANAGEMENT 5.2 WHAT IS AN ARC FLASH? The term Arc Flash comes from an earlier
understanding that the burns from an arc
An electrical arc fault is often referred to
fault were similar to the flash burns from a
5.1 OVERVIEW OF HAZARD To achieve this, the following steps should to as an Arc Flash.
welding arc. That is, the heat was transferred
MANAGEMENT PROCESS be undertaken: Arc faults arise when current flows through to the individual by the radiant heat and light
a. Understand the hazard the air between phase conductors or between (infrared – ultraviolet) from the arc.
When workers are required to work on or
phase conductors and neutral or ground. Put
near electrical equipment, all reasonably b. Identify assets or asset groups with arc Recent research has shown that, although
simply, an arc fault could be described as an
practicable measures should be taken to flash hazard potential the radiant energy from an electrical arc
unexpected, violent, electrical short circuit in
protect workers from the harmful effects of c. Quantify the hazard (calculate the arc contributes to the energy received, the major
the air that produces an arc and associated
electric arc flash hazards through hazard flash incident energy on each asset or hazard to an individual comes from the plasma
by-products.
elimination and risk reduction. asset group) ejected by an arc.
When arc faults occur, the resulting energy
d. Assess the risk (using your organisation’s released may be enough to seriously burn
risk management framework) or otherwise injure nearby persons, ignite
e. Develop and implement risk treatments flammable materials (including clothing),
using the hierarchy of controls and cause significant damage to plant and
f. Validate control effectiveness equipment.
g. Monitor and review.
1.
Understand the HAZARD
Air Plasma Cloud of Plasma Molten
jets with hot gas “dust” droplets
O¯, N¯, Cu+ (CuO smoke) shower
2. HAZARD RISK
Identify assets or asset groups
with arc flash HAZARD potential
RD
3. HA
ZA RI
SK
Quantify the HAZARD (calculate
the arc flash incident energy on
each asset or asset group)
4.
Assess the RISK (using your
organisation’s risk management HAZARD RISK
A HAZARD is something that has the
framework) potential to harm you.
RISK is the likelihood of a hazard
causing harm.
Driven away 20,000°C Pressure
5. 6. 7. from source shock waves
of supply by and defening
Develop and implement RISK Validate control Monitor and magnetic sound
treatments using the hierarchy effectiveness review. forces
of controls
Diagram 6. Hazard management process Diagram 7. What is an Arc-flash?
12 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 135.3 WHAT IS ARC PLASMA? 5.4 OTHER PRODUCTS OF
Arc Plasma is the fourth (4th) state of matter AN ARC FAULT
(solid, liquid, gas, plasma) and is probably Along with the thermal effects of plasma
Copper Vapor 35,000 F
best described as ‘super-heated ionised gas’. and radiated heat/light, an arc fault may also
Molten Metal >1,800 F produce the following:
The arc plasma ejected by an electrical arc
Intense Light fault may be at temperatures more than >> Molten metal droplet spray and metal
Hot Air > 500 F 5000 degrees (C) and has sometimes been vapour;
Pressure Waves > 2000 lb/psf described as a “fireball or plasma ball” coming
>> Ejected debris;
Sound Waves > 140 db from an arcing fault.
>> Pressure wave;
Shrapnel > 740 mph Contact with this 5000-degree (C) plasma
“fireball” may lead to serious burns. >> Noise.
Importantly though, such contact may also The arc flash will melt and vaporise
ignite non-arc rated clothing and other conductors and other material, which the
Personal Protective Equipment (PPE) with sudden transition from solid to vapour results
burning clothing and PPE known as significant in a pressure wave from the rapid expansion
contributors to the seriousness of injury (for example copper expands 67,000 times in
outcomes. volume transitioning from solid to vapour).
Clothing and PPE often continue to burn and The high pressures can easily exceed hundreds
subsequently continue to impact even after or even thousands of kilos per square meter
the arc fault and contact with plasma have and can result in knocking workers off
ceased. ladders, rupturing eardrums and collapsing
a person’s lung. Material and molten metal
are expelled away from the arc at speeds
exceeding 1120 km/hr (700 mph) and are fast
enough for shrapnel to completely penetrate
the human body. The vaporised and molten
metal presents a hazard from both contact
and from the inhalation of hot and hazardous
compounds.
Arcs that occur in enclosures can be focused,
resulting in a higher-pressure rise directed
towards an enclosure opening (such as is
often the case when a panel door is open
and at the point where a person is likely to
be positioned).
Diagram 8. Other components of an Arc-flash
14 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 155.5 WHEN AND WHERE DO Any activity in the vicinity of energised
ELECTRICAL FAULTS OCCUR? conductors has the potential for arc flash,
but arc flash most commonly happens when
Unintended and uncontrolled electrical a person is working on an energised circuit
arc faults may occur in several workplace or equipment (knowing it is energised or
locations and circumstances, and during believing it is not). The risk increases by the
a range of activities. degree of interaction with the energised
equipment.
The diagram below indicates the increase in
risk in the performance of tasks:
Work on the Vicinity of Inspection Operating Inspection Testing voltage, Work on the Racking Restoration Commissioning Racking Restoration
equipment equipment (panel closed) equipment (panel open) including proving equipment (panels closed) (panel open) after a fault or
ACTIVITY
(isolated, proven (panels closed) de-energised (isolated but operation of
de-energised and not proven de- equipment with
earthed) energised) possible defect
RISK
Work on plant, Person standing Person standing in Person operating Person inspecting Person testing Person removing Person racking Person switching Person switching Person racking Person switching
with isolations near electrcial front of electrical equipment with open panel, using open panel, using component from circuit breaker, electrical electrical circuit breaker, electrical
locked and equipment panel, reading a operating handle IR thermometer multimete open panel, panel closed, with equipment on equipment on for panel open with equipment on
tagged, earths meter on the front using insulated racking handle the first time racking handle after a fault
applied, barriers panel screwdriver
and signs
AFTER
FIRST TIME FAULT
PLANT
ISOLATIONS
ON ON ON
EARTH
Workers in Workers in Workers in Workers in Workers in live Workers in live Workers in live Workers in Workers in Workers in Workers in Workers in
standard PPE standard PPE standard PPE operating PPE work PPE (helmet work PPE (helmet work PPE (helmet operating PPE operating PPE operating PPE operating PPE operating PPE
(helmet, safety (helmet, safety (helmet, safety (helmet and face and face shield, and face shield, and face shield, (helmet and face (arc flash suit) (helmet and face (helmet and face (helmet and face
glasses, ankle to glasses, ankle to glasses, ankle to shield, safety safety glasses, safety glasses, safety glasses, shield, safety shield, safety shield, safety shield, safety
wrist hi visibility wrist hi visibility wrist hi visibility glasses, balaclava, balaclava, ankle to balaclava, ankle to balaclava, ankle to glasses, balaclava, glasses, balaclava, glasses, balaclava, glasses, balaclava,
clothes, safety clothes, safety clothes, safety ankle to wrist hi wrist hi visibility wrist hi visibility wrist hi visibility ankle to wrist hi ankle to wrist high ankle to wrist hi ankle to wrist hi
boots) boots) boots) visibility clothes, clothes, insulated clothes, insulated clothes, insulated visibility clothes, visibility clothes, visibility clothes, visibility clothes,
insulated gloves gloves, safety gloves, safety gloves, safety insulated gloves insulated gloves insulated gloves insulated gloves
with leather over boots) boots) boots) with leather over with leather over with leather over with leather over
gloves, safety gloves, safety gloves, safety gloves, safety gloves, safety
Safety observer Safety observer Safety observer
boots) boots) boots) boots) boots)
with LV rescue kit with LV rescue kit with LV rescue kit
16 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 17TABLE 1: INCREASING ARC FLASH RISKS WITH WORK ACTIVITY
5.6 INCIDENT ENERGY / HEAT FLUX Second-degree burns (also called
‘Partial Thickness Burns’) are possible
The amount of energy that strikes an on unprotected skin from exposure to arc
individual during an arc fault is termed fault incident energies. The onset of a second-
incident energy (sometimes referred to as degree burn on unprotected skin is likely to
Epidermis heat flux) and is usually measured in Joules/ occur at an exposure of 1.2 cal/cm2 (5 J/cm2)
cm2 (or calories/cm2). for one second.
Dermis
Hypoermis The arc energy is the energy in the arc, but Therefore, 5J/cm2 (1.2cal/cm2) is an important
(fat) the incident energy is the energy that reaches incident energy level threshold for arc fault
Muscle an individual or surface at a distance from hazard management.
the arc during an arc fault. The duration of an
Bone
arc fault is usually quite short and is primarily 5.7 RISK MITIGATION –
determined by the time it takes for over HIERARCHY OF CONTROLS
current protective devices to operate (i.e.
open the circuit). The model Work Health & Safety (WHS)
Regulations require duty holders to work
In general, the higher the fault current through the Hierarchy of Controls when
and/or the longer the protection clearing time, managing health and safety risks.
and/or and the shorter the distance from
the arc, the greater the incident energy. The ways of controlling risks are ranked from
Calculation of arc flash incident energy is the highest level of protection and reliability
2.5 cm = 5 J/cm2/second
covered in Annex D: Arc Flash Incident to the lowest – details of arc flash risk control
Second degree burns occur at 6 J/cm2 Energy Calculation Methods. measures are included in Annex A: Arc Flash
(1.2 cal/cm2) Risk Assessment.
Second degree burns equates to damage
through the epidermis, into the dermis
layer of the skin
Results in redness, blistering and pain.
Blistering may lead to permanent scars.
1 HIGHEST ELIMINATE MOST 1
Incident energy is the temperature
2 SUBSTITUTE 2
produced (in cal/cm2) at the distance
(usually eighteen inches) from the arc
3 Level of ISOLATE Reliability 3
flash.
health and of control
safety measures.
4 protection.
ENGINEER 4
5 ADMINISTRATE 5
6 LOWEST PPE LEAST 6
Hand 1 inch over It takes 1.2 cal/cm 2
flame for 1 second to create a second
equals 1 cal/cm2. degree burn. 1. Eliminate the hazard 4. Reduce the risk through engineering controls
2. Replace the hazard with something safer 5. Change/control the way people work
3. Separate the hazard from people 6. Protect the worker
Diagram 11. Arc flash control measures
Diagram 10. Second degree burns
18 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 195.8 EFFECTIVE IMPLEMENTATION >> Administration – such as permits to work,
signs, barriers and similar processes which Label example
OF ARC FLASH CONTROLS HEADER stays constant
ensure consistent work methods that
With arc flash, where the hazard cannot be
eliminated, it is often a combination of control
minimise risk; DANGER
measures used to mitigate the hazard. Whilst >> Administration – such as labelling; DANGER ARC FLASH HAZARD
As per OCE, ENG, G01, 01
greater details are outlined in Annex A: Arc >> Personal Protective Equipment (PPE) ARC FLASH HAZARD
As per OCE, ENG, G01, 01
Equipment
Coal Handling Plant 415V SWBD A Pass LS
Flash Risk Assessment, this is typically: and Clothing.
Name:
Voltage Level, Fault Current,
5.8.1 LABELLING
415 45.35
>> Elimination – elimination, where possible, INTERNAL AREA
Volts: kA:
is the most effective risk control /
Door OPEN
To clearly communicate the arc flash risk on may change Incident Energy
Cal/cmˆ²
12.4 Arc Flash Boundary, m: 1.90
mitigation method.
>> This means working on energised
electrical equipment, it is recommended that
3 WARNING
3
electrical equipment is properly labelled.
equipment when: WARNING Arc Flash Hazard | Wear Category 3 PPE
It is recommended that the Energy Industry Arc Flash Hazard | Wear Category 3 PPE
(a) it is necessary in the interests of health considers all labels as needing to meet the • Bus name or equipment name
and safety that the electrical work is • Bus voltage level
requirements of Danger Signage (Danger FOOTER stays constant • Activity to be performend
carried out on the equipment while the signs communicate a hazard, condition or • Incident energy level
equipment is energised, or situation that is likely to be life threatening). • Arc flash boundary
• PPE
Example: It may be necessary that life- It is recommended that the Energy Industry
saving equipment remain energised and considers all labels provide the critical risk
operating while electrical work is carried information clearly, concisely and consistently. Diagram 12. Arc flash label design
out on the equipment. Whilst minimum size of labels cannot be
(b) it is necessary that the electrical recommended, it is a recommendation of this
equipment to be worked on is energised Guideline that labels are located so they are
in order for the work to be carried out clearly visible, well placed and include all the
properly, or information required in international arc flash Effective Risk HAZARD
documents and in a format consistent with
(c) it is necessary for the purposes of Australian requirements. The details included
Control Measures
testing required under clause 155, or in the labels are shown in the illustration below
(d) there is no reasonable alternative however as a minimum, it is recomended
means of carrying out the work that all Arc Flash Hazard labels across the
Australian Energy Industry include
>> Substitution –Replacing the higher risk (as a minimum):
activity with a lower risk. Replacing a
standard switchboard with one that has >> Bus Name or Equipment Name;
been designed and tested for arc-resistant >> Bus Voltage Level; 1 Energised
Electrical
Equipment
construction
>> Activity to be performed; (HAZARD)
>> Isolate – isolation of hazard which can
>> Incident Energy Level;
be achieved by working on de-energised
(and earthed) electrical equipment or >> Arc Flash Boundaries; and 2 Arc Flash Prevention Measures
- Elimination (For maintenance personnel)
using techniques like remote switching/ >> PPE Level Required for varying activity
• Isolation
• Prove deenergised
racking and switchboard status (for example door • Earthing (HV conductors)
• Isolation and earthing check and confirmation
open / door closed).
>> Engineering – such as arc resistant
3 Electrical Equipment • Barriers and signs
Arc Flash (INCIDENT) • Permit issue
switchboards designed to contain >> PPE – which protect people from the - Remote operation
• Arc flash mitigation - Prevention of inadvertent energisation - LOTO
and redirect the arc flash. Alternately, incident energy if all other controls fail measures - Arc flash protection
incorporating faster protection settings and an arc flash occurs. OUTCOME - Arc resistant panels - Optimised protection settings
- Arc flash incident energy reduction
4
Person Injured by - Arc flash boundaries
during maintenance work using remote Arc Flash - PPE - Insulated tools and test equipment
Whilst the effective implementation of
rackable circuit breakers. (OUTCOME)
arc flash controls in aged plants can be
>5J/cm2 arc flash
incredibly troublesome, some practical incident energy
recommendations have been provided in
Annex A: Arc Flash Risk Assessment.
Diagram 13. Layering of controls
20 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 2122
that stage.
this Guideline.
Electric Arc Flash Hazard Management Guideline
the de-energisation, isolation and prove
It is not the intent of this guideline to set
The table demonstrates that the preferred
out detailed risk controls, and as such, risk
and what control measures are effective at
elimination of hazards is only possible after
Energy Industry organisation in accordance
controls should be developed, implemented
This table provides an example where typical
operators of the equipment. The table should
be considered as a guide and is advisory only.
steps required for electrical work (LV and HV)
with the principles or risk control contained in
and monitored and regularly reviewed by each
deenergised, which still results in hazard to the
TABLE 2: TYPICAL ELECTRICAL WORKER ACTIVITIES AND SUGGESTED RISK CONTROLS
CONDITION LEVEL OF RISK*
OF BOARD *REFER TO DIAGRAM 11 -
WHAT TO
TASK
ENERGISED ARC-FLASH CONTROL LOOK OUT FOR
PANELS MEASURES
STATE
Work scoped Energised Closed Correct understanding of the work
3
Work identified to be done Confirmation bias may exist
Work inspection Energised Open Plant is energised and is at risk of arc flash.
Plant may require inspection to The inspection must not place the persons inspecting at
fully determine the scope and 4 5 6 risk. If it does, it should be treated
work instructions, or to correctly
design the isolations.
Risk Assessment and Work Energised Closed Work instructions and risk assessments can be limited by
instructions prepared the knowledge and experience of the persons creating
3 5 them. Check and challenge to ensure all the work and
Work instructions and risk
risks are identified.
assessments completed
Isolations designed Energised Closed The design of the isolations determines the effectiveness
of the Elimination control. Inaccuracy or lapses have a
Isolations and earthing required
potential major impact.
making the work area safe need to
be designed. 3 Should be checked by another person to ensure accuracy
Checking drawings for accurate information
Identifying all possible energised supplies
Approval of the work, risk Energised Closed The approval process is to ensure the work scope, risk
assessment and isolation design 3 assessment and isolation design process have been
as per company procedures completed correctly and thoroughly.
De-energisation (remote) Unknown Closed Ensure other personnel are not in the vicinity and at risk;
Switching of plant by means that 3 5 Ensure remotely operated plant is confirmed to have
does not require the operator to operated correctly.
stand in the arc flash boundary
De-energisation (local) Unknown Closed Ensure only load breaking rated plant is used to break load
currents;
Switching of plant that require the
4 5 6
Electric Arc Flash Hazard Management Guidelines
operator to stand in the arc flash Operator should position themselves to stand to the side
boundary of plant where possible, to reduce the direct incident
energy from and arc flash.
23
Isolations applied Unknown Open Locks and Tags best practice;
Application of isolations as per Ensure 3 phase devices all phases operated correctly;
company procedures.
4 5 6
Ensure correct isolations devices identified, operated
correctly and confirmed in the correct state.
Prove circuits deenergised Deenergised Open Include all circuits that workers may be exposed to.
Prove the tester, before and after testing.
4 5 6
If the isolations are not correct, the prove deenergised test
may cause an arc flash.
Earths applied to HV conductors Deenergised Open If the conductor is energised, the earthing will cause an
and where required
4 5 6 arc flash.
Permit issued/job briefed Deenergised/ Open Permit issue is the formal acknowledgement by the work
earthed party that they correctly understand the permit conditions
Work party correctly briefed on
and will adhere to all safety instructions.
the safety precautions required
for the work to be undertaken. If 1 5 6 Last chance to confirm the safety precautions are correct
under a permit, the correct permit and the work can be completed safely.
issue is adhered to.
Complacency and inattention at this step place the work
party at risk.
Work party undertakes the work Deenergised/ Open Ensure work party is either competent to perform the
as per the work scope. earthed work, or adequately supervised.
1 5 6
Beware of scope creep, which may result in work beyond
what the risk assessment and isolation design allowed for.
Permit relinquished and cancelled Deenergised/ Open Permit holder and operator should check and confirm the
earthed state of the plant, to ensure it is safe to reenergise.
Work party relinquishes permit 1 5 6
and the operator cancels Left tools, earths or incorrectly replaced covers or fittings
can result in arc flash upon reenergisation
Earths removed Deenergised Open As soon as earths are removed, HV conductors are unsafe.
Removal of earths from 1 5 6 All earths must be removed, as reenergisation on an earth
conductors will result in a short circuit and potential arc flash risk.
Isolations restored to allow plant Unknown Open Ensure restoration of isolation will not inadvertently
to be energised 4 5 6 energise the plant as this can result in the isolation failing.
Reenergisation (remote) - Energised Closed Ensure other personnel are not in the vicinity and at risk;
Switching of plant by means that 3 5 Ensure remotely operated plant is confirmed to have
does not require the operator to operated correctly.
stand in the arc flash boundary
Reenergisation (local) Energised Closed Ensure only load breaking rated plant is used to break load
currents;
Switching of plant that require the
operator to stand in the arc flash 4 5 6 Operator should position themselves to stand to the side
boundary of plant where possible, to reduce the direct incident
energy from and arc flash.
Electric Arc Flash Hazard Management Guidelines
Operational testing Energised Open Plant is energised.
Plant may require checking 4 5 6
and testing to ensure operating
24
correctly6.0 DEMONSTRATION OF INDEPENDENT COMPETENCY
IN PERFORMING THE FOLLOWING TASKS
Supporting information has been provided in
several ‘informative’ annexes to assist with the Whilst definitions of electrical work (and electrical workers) differ across all Australian States
minimum competency requirements of Energy and Territories, it is the intent of this guideline to recommend the minimum competency
Industry organisations’ as they progress their requirements for workers who are (or have the potential to be) exposed to the harmful effects of
specific arc flash hazard management system. electric arc flash hazards.
The annexes provided are for information and It is recommended that the Energy Industry considers, as a minimum, the following:
guidance only.
TYPE OF MINIMUM COMPETENCY MINIMUM EDUCATIONAL TYPE OF MINIMUM COMPETENCY MINIMUM EDUCATIONAL
WORKER REQUIREMENT REQUIREMENT WORKER REQUIREMENT REQUIREMENT
Electrical Engineers >> Arc Flash Risk Assessment >> Registered and / or Operators >> Arc Flash Risk Assessment >> Registered and / or
>> Arc Rated Clothing and Australian recognised >> Arc Rated Clothing and Australian recognised
Personal Protective Equipment qualification in Electrical Personal Protective Equipment Operator Qualification
(including the limitations of Engineering (including the limitations of >> Electrical Plant Specific
arc flash PPE and incorrect Arc >> Instruction, Supervision, arc flash PPE and incorrect Arc Operator Training
Flash PPE) Information or Training in Flash PPE) >> Instruction, Supervision,
>> Arc Flash Labelling Human Factors >> Arc Flash Labelling Information or Training in
>> Arc Flash Incident Energy Human Factors
Calculation Methods (‘Theory’) Electrical >> Arc Flash Risk Assessment >> Registered and / or
>> Calculating Incident Energy or Contractors >> Arc Rated Clothing and Australian recognised Trade
Heat Flux (‘Practice’) Personal Protective Equipment based Qualification
>> References (including the limitations of >> Instruction, Supervision,
arc flash PPE and incorrect Arc Information or Training in
>> Definitions
Flash PPE) Human Factors
Electricians >> Arc Flash Risk Assessment >> Registered and / or
>> Arc Flash Labelling
>> Arc Rated Clothing and Australian recognised Trade
based Qualification >> References
Personal Protective Equipment
(including the limitations of >> Instruction, Supervision, >> Definitions
arc flash PPE and incorrect Arc Information or Training in
Flash PPE) Human Factors
>> Arc Flash Labelling Health & Safety >> Electrical Arc Flash Hazards >> Registered and / or
>> References Practitioners / Management Guideline Australian recognised
>> Definitions Professionals Checklist qualification in WHS (or
related discipline)
>> Instruction, Supervision,
Information or Training in
Maintenance >> Arc Flash Risk Assessment >> Registered and / or Human Factors
>> Arc Rated Clothing and Australian recognised
Maintenance Qualification Technical Trainers >> Arc Rated Clothing and >> Registered and / or
Personal Protective Equipment Personal Protective Equipment Australian recognised
(including the limitations of >> Specific and / or directly (including the limitations of qualification in WHS (or
arc flash PPE and incorrect Arc related industry experience arc flash PPE and incorrect Arc related discipline)
Flash PPE) >> Instruction, Supervision, Flash PPE) >> Instruction, Supervision,
>> Arc Flash Labelling Information or Training in >> Arc Flash Labelling Information or Training in
Human Factors Human Factors
>> References
>> Definitions
28 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 29 Electric Arc Flash Hazard Management Guidelines 307.0 ADDRESSING THE HUMAN FACTORS
WORKPLACE CULTURE TRAINING AND COMPETENCY
Human factors play a significant role in how The recommended actions for organisations Peoples whose actions are affected by the where people are not aware of arc flash
interaction of (actual or perceived) workplace incidents or are unaware of the potential for
people organise, manage and conduct various to consider if human factors are or have the culture, being bullied or facing peer pressure an arc flash incident to cause significant harm
activities and how they respond to various potential to interfere with the effectiveness of from team-members and/or their Supervisors /
Team Leaders and a lack of accountability
situations. In the context of electric arc flash, risk controls are outlined below. All suggested across all aspects of electrical works. ERRORS, MISTAKES AND
these human factors and consideration of Human Factor risk controls have been LAPSES
where people make errors in
‘vulnerable’ people has gained considerable provided are for information and guidance process (across a very wide
attention. only and are still subject to a risk assessment range of reasons) that results in
MENTAL HEALTH compromising the effectiveness
per team, site or workplace.
Increasingly there is growing awareness for ISSUES AND CONCERNS of an arc flash risk control
consideration of the general effect of human
factors and of the specific requirements of
people deemed ‘vulnerable’ and currently HUMAN
working in the Energy Industry. The human
factors involved in incidents / accidents
FACTORS COMPLACENCY
DISTRACTIONS both with the risks
around electrical arc flash incidents in the that are both work and
that can interfere with and with the process
the effectiveness of
Energy Industry are: non-work related and all
risk controls across
of arc flash risk
lead to a ‘breaking’ or a controls
the electrical
>> Workers being inexperienced or having person’s concentration
resulting in error (such as industry/Generation
never received formal training (or been non-work related Sector
deemed competent) in electrical arc flash distractions resulting from
mobile phones)
hazards and the expected risk controls;
>> Workers making unintentional errors TIME PRESSURE
because of performing familiar tasks INFORMATION where the ability to properly
OVERLOAD implement an administration
out of habit or whilst on ‘auto-pilot’ or where the information is control (such as a permit to
perhaps because they are complacent or unclear, overwhelming or work) is compromised
duplicated to people
have made a mistake; leading to confusion and
errors (this often affects a VIOLATIONS
>> Workers making intentional errors or contracted workforce who where people deliberately and willingly
violating the procedures of safe work; are commonly assigned work ‘outside’ known risk controls and
higher risk work) expected skills and competencies
>> The self-imposed or actual pressure and
stress of insufficient time, high workloads
and interruptions / distractions;
>> Technical / other information overload
Diagram 14. Human factors
(this includes when safe work procedures
are ambiguous or confusing);
>> When personal stress or mental health
factors (such as relationship breakdown,
death of a family member etc) are
involved or are involved to a level that
workers are not used to dealing with; and
>> When the workplace contributes to an
unsafe workplace culture.
34 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 35TABLE 3: TYPICAL HUMAN FACTOR ACTIVITIES
AND SUGGESTED RISK CONTROLS
HUMAN FACTOR CONSIDERATION OF HUMAN FACTOR RISK CONTROL HUMAN FACTOR CONSIDERATION OF HUMAN FACTOR RISK CONTROL
Training and >> Commit to an implementation of the minimum competency Information >> Simple english documentation and signage
Competency requirements when working on / around electrical arc flash hazards Overload >> Local signage
>> Instruction, Supervision, Information or Training in Human Factors >> Removal of detail not required by person undertaking activity
>> Appropriate worker selection and monitoring to the ongoing >> Diligence towards the creation of simple software systems and
suitability of workers selected to perform relevant works processes toward Permit to Work Systems and other isolation tasks
Errors, Mistakes >> Verification activities. Isolation, plant ID and activity required Distractions >> Ensure levels and type of supervision matches the actual (or
and lapses >> Appropriate worker selection and monitoring to the ongoing potential) of arc flash hazards and risk
suitability of workers selected to perform relevant works >> Stop and think processess (Take 5)
>> Stop and think processess (Take 5) >> Ongoing safety observation process (Behavioural based)
>> Ongoing safety observation process (Behavioural based) >> Management, Team Leader and Supervisor and Peer walkdowns
>> Management, Team Leader and Supervisor and Peer walkdowns
Mental Health issues >> Ensure levels and type of supervision matches the actual (or
Effective QA documentation – Switching or job instruction
and concerns potential) of arc flash hazards and risk
>> Interlock and control – error tolerent equipment
>> Stop and think processess (Take 5)
>> Ongoing safety observation process (Behavioural based)
Complacency >> Ensure levels and type of supervision matches the actual (or
potential) of arc flash hazards and risk >> Management, Team Leader and Supervisor and Peer walkdowns
>> Commit to arc flash awareness activities by way of alerts, training, >> Employee Assistance Programs (EAP) and other Mental Health
refreshers, tool box talks, and lessons learned (post industry First Aid assistance in the event of worker disclosure of mental
incidents and accidents). health issues and concerns
Time Pressure >> Executive and Senior Management oversight Workplace >> Cultural audit
>> Proper planning and resourcing for activities Culture and other >> Accountability process implement for all levels of business
organisational /
>> Higher risk activities emphasised in risk assessment team factors >> Ensure levels and type of supervision matches the actual (or
>> Management, Team Leader and Supervisor and Peer walkdowns potential) of arc flash hazards and risk
>> Stop and think processess (Take 5)
Violations >> Ensure levels and type of supervision matches the actual (or
>> Ongoing safety observation process (Behavioural based)
potential) of arc flash hazards and risk
>> Management, Team Leader and Supervisor and Peer walkdowns
>> Accountability process implement for all levels of business
>> Executive oversight of competing business drivers
36 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 378.0 MANAGEMENT OF CHANGE 9.0 ANNEXES
The effective management of change is Annex A: Arc Flash Risk Assessment
especially important within the Energy
Annex B: Arc-Rated Clothing and Personal Protective Equipment
Industry because it supports communication,
teamwork and the effective coordination of Annex C: Do’s and DON’T’s of Arc Flash Labelling
activity toward the elimination or minimisation Annex D: Arc Flash Incident Energy Calculation Methods (‘Theory’)
of risk of injury to persons from an electrical
arc flash hazard. Annex E: Calculating Incident Energy or Heat Flux (‘Practice’)
Any organisations management of change Annex F: Electrical Arc Flash Hazards Management Guideline Checklist
method should be applied to any electrical Annex G: References
arc flash hazard management program and in
conjunction with Annex F: Electrical Arc Flash Annex H: Definitions
Management Guideline Checklist.
38 Electric Arc Flash Hazard Management Guideline Electric Arc Flash Hazard Management Guidelines 39ANNEX A: ARC FLASH RISK ASSESSMENT AND CONTROL WHS RISK MANAGEMENT REQUIREMENTS FOR
REQUIREMENTS ENERGISED WORK:
ASSESSING THE RISK OF ARC FLASH TO ASSESS THE RISK, CONSIDER: For work on or near energised electrical 1. A documented risk assessment;
equipment (including the isolation, testing for 2. Area clear of obstructions to allow for
The WHS Act and Regulations require persons >> What is the potential impact of the deenergised, and restoration of the equipment
who have a duty of care to ensure health and hazard? easy access and exit;
required for safe access), works must be
safety to ‘manage risks.’ This eliminates or >> Severity of the electrical hazard assessed for risk. 3. Point of supply clearly marked, labelled
minimises health and safety risks so far as is such as direct contact causing and capable of being operated quickly
reasonably practicable. As per Work Health & Safety Regulation 34 (with exceptions);
electrocution, fire or explosion
Duty to Identify Hazards requires a duty
Risk assessment involves considering what causing serious burns or death. 4. Following consultation with a person with
holder to identify of reasonably foreseeable
could happen if someone is exposed to a >> Number of persons exposed to management control of the workplace;
hazards (including arc flash hazards).
hazard and the likelihood of it happening. the hazard 5. Inadvertent contact prevented;
WHS regulation 35 requires risk management
As per Model Code of Practice - Managing >> Likelihood of the hazard causing harm 6. Carried out by a competent person;
to eliminate, and if not possible, to minimise
Electrical Risks in the Workplace (published >> Likely, unlikely, possible or would it be risks “so far as is reasonably practicable”. 7. With tools, testing equipment and PPE
as approved code of practice under Section a rare event
As per Work Health & Safety Act Division suitable for the work, properly tested and
274 of WHS Act), a risk assessment is to be
>> Frequency of exposure 4 Section 157 electrical work on energised maintained in good working order;
prepared. Control/mitigation measures are to
be put in place to reduce the level of risk so OTHER FACTORS THAT MAY AFFECT electrical equipment – when permitted, is not 8. In accordance with a SWMS; and
far as is reasonably practicable. CONSEQUENCES & LIKELIHOOD ARE: carried unless: 9. With a safety observer, competent
RISKS CAN ARISE FROM THE >> Equipment working conditions a. It is necessary to do carry out the work in to implement control measures and
(wet condition, outdoors, confined space) the interests of health and safety. rescue the worker if necessary (with
FOLLOWING: the exception that not required if work
For example, it may be necessary that
>> Work practices (isolations, permits)
>> The properties of electricity (in the form life-saving equipment remain energised identified there is no serious risk and
and availability of work procedures to
of a hidden risk) as electrical currents and operating while electrical work is consisting only of testing
carry out electrical maintenance
are mostly invisible, have no smell or carried out; Until the arc flash hazard has been eliminated
sound (noting that some equipment does >> Experience, skill and capability of relevant
b. It is necessary that the electrical or isolated, personnel inside the arc flash
emit a sound when energised such as workers.
equipment is energised in order for the limit should be using PPE appropriate for the
Transformers and HV lines); energy level (cal/cm2).
work to be carried out properly;
>> Work environment such as wet weather,
c. It is necessary for the purposes of testing Electrical equipment shall be treated as
confined spaces and hazardous
required under clause 155; energised until it is isolated and proven
atmospheres;
d. There is no reasonable alternative means deenergised.
>> Competency of the individual carrying out
of carrying out the work. CONTROLS FOR ARC FLASH
the electrical work.
Work should be carried out in accordance of TYPICALLY RELY TO THE FOLLOWING
the requirements for energised work. PRINCIPLES:
>> Reduction of arc flash energy;
>> Reduce the exposure of personnel to the
arc flash;
>> Protect people from the arc flash though
application of the Hierarchy of Controls;
>> Increase the commitment to experience,
skills and capabilities of relevant workers.
40 Electric Arc Flash Hazard Management Guideline - Annex A Electric Arc Flash Hazard Management Guidelines - Annex A 41HIERARCHY OF CONTROL RISK MITIGATION – ISOLATION ARC FLASH BOUNDARIES
Isolation of arc flash risk involves the Arc Flash Boundaries are the distances
separation of personnel from the energised from energised equipment that should be
electrical equipment and conductors. maintained to manage arc flash risk.
1 HIGHEST ELIMINATE MOST 1 Isolation is most effective for personnel
The boundaries are set around two key
who do not need to operate or work on the
criteria:
2 SUBSTITUTE 2 electrical equipment.
>> The distance for the standard levels of
Level of Reliability Some controls that may isolate the arc flash
3 ISOLATE 3 PPE to protect the person;
health and of control risk are:
safety measures. >> The amount of energy a person in the
4 ENGINEER 4 >> Restrict proximity to energised electrical working position will be exposed to
protection.
plant; during an arc flash.
5 ADMINISTRATE 5 >> Restrict switch rooms and substations to The determination of the appropriate
authorised personnel only; boundaries is by the reviewing Annex D – Arc
6 LOWEST PPE LEAST 6
>> Use Arc Flash boundaries; Flash Incident Energy Calculation Methods.
1. Eliminate the hazard >> Restrict access when switching or live The boundaries are defined as:
4. Reduce the risk through engineering controls
2. Replace the hazard with something safer 5. Change/control the way people work work is undertaken;
>> Arc Flash boundary (outer boundary):
3. Separate the hazard from people 6. Protect the worker >> Use remote switching and racking The flash boundary is the farthest
equipment; established boundary from the energy
>> Follow permit to work system and source. If an arc flash occurred, this
Diagram 15. Hierarchy of controls diagram to re-draw in new style electrical safety procedures; boundary is where an employee would be
exposed to a curable second-degree burn
>> Keep away from the arc flash boundary.
(1.2 cal/cm2).
RISK CONTROL / MITIGATION – RISK MITIGATION – SUBSTITUTION
ELIMINATION Substitution requires a hazard to be replaced
Elimination is the most effective risk control/ with a less dangerous hazard. With electrical
mitigation method. The elimination of arc equipment, there is little opportunity to
flash risk requires that there is no exposure of substitute.
personnel to energised electrical equipment,
either by the physical separation for the
energised equipment, or by the effective
isolation (and earthed if high voltage)
and proof that electrical conductors are 0
deenergised.
Whilst the isolation and earthing of
conductors eliminates the risk, the process
to isolate, prove deenergised and earth
conductors still has arc flash risk.
4
CONTROLS THAT MAY ELIMINATE THE
ARC FLASH RISK ARE: 2
1.
0
7m
>> Eliminate the need to be near energised
electrical conductors – relocate the work. 3
.4
>> Isolate and earth conductors, so they are
no longer energised.
3m
Diagram 16. 3D/Isometric to show boundary and people with PPE
42 Electric Arc Flash Hazard Management Guideline - Annex A Electric Arc Flash Hazard Management Guidelines - Annex A 43You can also read
