The Standards for
Electrical Safety and
the Need for Safer
Work Environments
Presented by: Martin Robinson
Ultrasound World 2009
January 18 – 21 2009
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How Dangerous are Live Inspections
A selection from table 130.7(C) (9) (a)
600 V Class Switchgear (with power circuit breakers or fused switches)
Task
CB or fused switch operation with enclosure doors closed
Reading a panel meter while operating a meter switch
CB or fused switch operation with enclosure doors open
Work on energized parts, including voltage testing
Work on control circuits with energized parts 120 V or below, exposed
Work on control circuits with energized parts >120 V, exposed
Insertion or removal (racking ) of CBs from cubicles, doors open
Insertion or removal (racking) of CBs from cubicles, doors closed
Application of safety grounds, after voltage test
Removal of bolted covers (to expose bare, energized parts)
Opening hinged covers (to expose bare, energized parts)
Risk Level (0 – 4)
0
0
1
2*
0
2*
3
2
2*
2
•Note: Above 600 Volts the Removal of bolted covers to expose bare, energized parts carries a
class 4 Risk Level (scale 0-4 where 4 is determined the riskiest)
3
Causes of Arc Flash
• The vast majority of arc flash incidents occur when
electrical equipment above 220 volts experiences a
phase to phase or a bolted fault
– These can occur due to:
•
•
•
•
•
•
•
Accidental contact with energized parts
Tools dropped on energized parts
Tracking across insulation surfaces
Wiring errors
Contamination, such as dust on insulating surfaces
Corrosion of equipment parts and contacts
Improper work procedures
Damage to The Human Body
• Damage to body occurs at the following temperatures
and pressures:
– Second-degree burn threshold “curable burn threshold”
• Skin temperature raised to 175°F for 0.1 second
– Third-degree burn threshold “incurable burn
threshold”
• Skin temperature raised to 200°F for 0.1 second
– Eardrum Damage > 720 lbs/ft²
– Internal Organ Damage >1728 lbs/ft²
Live Test
• 22,600 A rms, 480 V, fault initiated on line lug of size 1
starter, feeder protected by a 640-A noncurrent limiting over-current protective device and fault was
cleared in 6 cycles
• Test Mannequin is dressed in type 1 PPE
Test Results
• This arc flash incident would have severely injured a
worker; if this happened without appropriate levels of
PPE they would have received 3rd degree burns on
exposed skin, damage to hearing and lungs
NFPA and Its Implications on
Electrical Inspections
NFPA – Nation Fire Protection Association
Nation Fire Protection Association
• 1896
• World’s Leading Advocate of Fire Prevention
• Over 300 Codes and Standards
• Worldwide Influence
• Expert Consensus to Create Standards
NFPA – Nation Fire Protection Association
• NEC (NFPA 70) – National Electric Code
• NFPA 70B – Recommended Practice for Electrical
Equipment Maintenance
• NFPA 70E – Standard for Electrical Safety in the
Workplace
NEC (NFPA 70)
National Electric Code
• Established 1897 by efforts of Insurance, Architectural,
Electrical and allied interests
• Electrical Design, Installation & Inspection
– NOT to address Maintenance or Workplace Safety
NFPA 70B
Recommended Practice for Electrical Equipment
Maintenance
•Committee established 1968
– To address “preventative maintenance of electrical
systems and equipment used in industrial-type
applications with the view of reducing loss of life and
property.”
•2006 Edition
– Enhanced Focus on Safety
– Importance of Baseline Performance Data
– How to Apply RCM (Reliability Centered Maintenance)
NFPA 70B
Chapter 4: Why an Effective Electrical Preventive
Maintenance (EPM) Program Pays Dividends
•“Dependability can be engineered and built into
equipment, but effective maintenance is required to keep
it dependable.”
NFPA 70B
Chapter 4: Why an Effective Electrical Preventive
Maintenance (EPM) Program Pays Dividends
•“Electrical equipment deterioration is normal, but
equipment failure is not inevitable. As soon as new
equipment is installed, a process of normal deterioration
begins.”
•“An effective EPM program identifies and recognizes
these factors and provides measures for coping with
them.”
NFPA 70B
Chapter 4: Why an Effective Electrical Preventive
Maintenance (EPM) Program Pays Dividends
•“A well-administered EPM program reduces accidents,
saves lives, and minimizes costly breakdowns and
unplanned shutdowns of production equipment.”
•“(It is) a form of protection against accidents, lost
production and loss of profit.”
NFPA 70B
Chapter 21: Testing and Test Methods
•“Infrared inspections of electrical systems are beneficial
to reduce the number of costly and catastrophic
equipment failures and unscheduled plant shutdowns.”
•“(Infrared inspections) can reduce typical visual
examinations and tedious manual inspections and are
especially effective in long-range detection situations.”
NFPA 70B
Chapter 21: Testing and Test Methods
•Annual Inspection cycle
– Up to quarterly where warranted by
•
•
•
•
Loss Experience
New Installation
Environmental Changes
Changes in Operational or Load Conditions
NFPA 70B
Chapter 21: Testing and Test Methods
•“Maximum Possible Loading”
•“Open for Direct View of Components”
•But 70B, 70E and OSHA 1910 all call for an electrically safe
work condition whenever possible
NFPA 70E
Standard for Electrical Safety in the Workplace
•Established in 1976 to assist OSHA in developing electrical
safety standards
•2007 OSHA stated that it will
– “draw heavily form” aspects of 70E and NEC in a rare
revision of 1910.303 Subpart S
NFPA 70E
NOT “the standard that tells you to use PPE ”
It’s the standard that says:
– “Energized electrical conductors and circuit parts to which
an employee might be exposed shall be put into an
electrically safe work condition before an employee works
within the Limited Approach Boundary of those
conductors or parts.”
NFPA 70E
Summary
• Training Requirements
• Tasks Restricted to Qualified Personnel
• Electrically Safe Work Conditions
– LOTO Requirements
• If Not Feasible or Greater Hazard
– Electrical Hazard and Arc Flash Analysis
– Energized Electrical Work Permits
– Prescribed PPE Consistent with the Hazard
• Safety Related Maintenance Requirements
• Safety Requirements for Special Equipment
NFPA 70E
Approach Boundaries
NFPA 70E
Electrically Safe Work Condition
• Prior to working within the Limited Approach Boundary
• 50 volts or more
• Exemptions
– Greater Hazard
– Infeasibility
• Performing diagnostics and testing on electrical circuits that
can only be performed with the circuit energized
• Work on circuits that are part of a continuous process that
would otherwise have to be shut down
NFPA 70E
When Deenergized Work is not Possible
• Energized Electrical Work Permit is Required
– Work performed within the Restricted Approach Boundary
– Exemption made for testing, troubleshooting voltage
measurement, etc.; and for visual inspection outside the
Restricted Approach Boundary
• Document Shock Hazard Analysis
• Document Arc Flash Hazard Analysis
• Document Personal Protective Equipment (PPE) Required
NFPA 70E
When is 70E Applicable?
• Workers Exposed to Energized Electrical Conductors or
Circuit Parts
• Risk-Increasing Behavior
• Reason to Believe that Equipment Could Experience a
Sudden Change in State
NFPA 70E
Tasks & Hazard/Risk taken from Table 130.7(C)(9)
NFPA 70E
Table 130.7(C)(11)
• Category 3: Minimum Arc Rating of 25
• Category 4: Minimum Arc Rating of 40
NFPA 70E
NFPA 70E
Working with Infrared Windows Windows
• Maintains an Enclosed & Guarded Condition
• NOT Inherently risk-increasing
• “Under normal operating conditions, enclosed energized
equipment that has been properly installed and
maintained is not likely to pose an arc flash hazard.”
• Most Similar Task: Reading Panel Meters…
– PPE: Level 0
Hierarchy of Control
Fundamental Principal Upon Which 70E and OSHA are Based
Control Risk Wherever Practical:
1. Eliminate the Hazard
2. Reduce the Risk by Design
3. Apply Safeguards
4. Implement Administrative Controls
5. Use PPE
Purpose of Ultrasound Ports
• Remove High-Risk Behavior
• Maintain Enclosed & Guarded Condition
• Fully Loaded Inspections
• Access to Un-inspectable Gear
• Efficient Surveys
• Control Risk to Personnel, Plant & Processes
• Eliminate >99% of Arc Triggers During Inspection
Why Use Ultrasound Ports
Safe Access to Live Components
Minimise Manpower Requirements
Minimise PPE requirements
Inspections can be Completed Safely During Peak Load times
Increased Infrared Inspection Frequency
Better ROI on Equipment
Avoids the Triggers of Arc Flash
Ultrasound Port Program Cost Analyses
Electrical Panel Removal Man-hours
• 3 Man Live Electrical Inspection Team consists of:
– 2 x Electrical Engineers:
– 2 x Electricians for panel removal
– 1 x Ultrasound Engineer(Contracted)
Time For Live Inspection
1 hour 6 minutes
(excludes PPE Suit-up Time)
Cost Analysis of Energized IR Survey Removing Panels
Operation
Man Hours
Ultrasound Engr PPE Suit-up
0.5
Total Man
Hours
0.5
Electrician PPE Suit-up
0.5
1.0
Rate ($/hr)
$150
$75.00
$125
$125.00
Manpower Costs Per PPE Suit-up As Per NFPA 70E =
Operation
Man Hours
Total
$200.00
Cover Removal
0.5
Total Man
Hours
1.0
Rate ($/hr)
Total
$125
$125.00
Ultrasound Inspection
0.1
0.1
$150
$15.00
Cover Replacement
0.5
1.0
$125
$125.00
Ultrasound Engr Waiting Time
1.0
1.0
$150
$150.00
Electrician Waiting Time
0.1
.2
$125
$25.00
Manpower Costs Per Inspection of 1 Electrical Panel =
$450.00
Total Manpower Costs Per Inspection of 1 Electrical Panel =
$650.00
Cost Analysis of Energized IR Survey Using IR Windows
Operation
Man Hours
Ultrasound Engr PPE Suit-up
0
Total Man
Hours
0
Electrician PPE Suit-up
0
0
Rate ($/hr)
$150
$0
$125
$0
Manpower Costs Per PPE Suit-up As Per NFPA 70E =
Operation
Man Hours
Total
$00.0
Rate ($/hr)
0
Total Man
Hours
0
$125
$0
Infrared Inspection
0.15
0.5
$150
$22.50
Cover Replacement
0
0
$125
$0
Ultrasound Engr Waiting Time
0
0
$150
$0
Electrician Waiting Time
0
0
$125
$0
Cover Removal
Manpower Costs Per Inspection of 1 Electrical Panel =
Cost of IRISS VP!@ Ultrasound Port
Year 1 Manpower Costs Per Inspection of 1 Electrical Panel =
Total
$22.50
65.00
$87.50
5 Year Cost Benefit Analysis
Period
Cumulative Cost Without
IR Windows
Cumulative Cost Using
IR Windows
$ Savings Per
Inspection
Total %
Saving
Year 1
$650.00
$212.50
$437.50
67%
Year 2
$1,300.00
$235.00
$1,065.00
82%
Year 3
$1,950.00
$257.50
$1,692.50
87%
Year 4
$2,600.00
$280.00
$2,320.00
89%
Year 5
$3,250.00
$302.50
$2,947.50
91%
• Example shows a saving of nearly $3,000.00 over a 5
year period (91%) for 1 cable compartment in a Medium
Voltage Electrical Panel
Summary
• Companies looking to improve profitability, uptime and
safety should study the recommendations in the NFPA 70B
Standard for Electrical Preventive Maintenance.
• It is significant that the standards value Ultrasound
inspections as a critical part of an EPM program.
• Ultrasound Ports have now provided a way for the
companies to comply with the recommendations for
inspection processes, while complying with the mandates for
arc flash avoidance.
• NFPA and OSHA agree that electrical equipment should not
be opened unless it is de-energized.
• Ultrasound Inspection Ports will help companies to comply
with standards.
Thank You
For more Information Visit:
WWW.IRISS.COM
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