Download Electrical Safety - Louisiana State University

Electrical Safety
Reference: The Power of Training
Electrical Safety
Commonwealth Edison Company
MABAS Division 10 - Com Ed Program
1
Knowledge Objectives
 The
Firefighter shall be able to:
– Explain the basic function of overhead
wires and equipment
– Identify Type A and S Meters
– Explain hazards of step potential, touch
potential, vehicles in contact with
energized lines, and downed wire
movement
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2
Performance Objectives
 Given
the proper tools and equipment,
the firefighter shall be able to:
– Remove residential meters
– Conduct low voltage electrical tests
– Cut service entrance “drip loops”
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Introduction
 This
program is designed to train
firefighters in properly removing meters
or cutting drip loops to disconnect
service to a residence that is on fire.
 ComEd prefers that the electrical
service be left intact
 Call ComEd for service disconnects
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If the Incident Commander
decides the service must be
disconnected immediately:
 Call
ComEd
 Open buildings main disconnect
 Remove meter if necessary
 Cut drip loops when meter cannot be
removed
 Utilize Voltage Tester to verify power
disconnect
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Firefighters are only to remove
the meter to the residence that is
on fire
MABAS Division 10 - Com Ed Program
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Transmission & Distribution
System
 Power
Plants
 Switchyard
 Transmission
 Substation
 Distribution Transformers
 Residential Service
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Residential Meters
 Removable
(type S)
 Non Removable (type A)
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Service Wires
 Identifying
Service Drop Cable
– Open Wire construction
– Triplex
 Identifying
telephone and cable wires
MABAS Division 10 - Com Ed Program
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Transmission Pole Configuration

Highest voltage is
usually located at
top of pole.
– Other voltages may
be present on pole
also
Transmission Poles
 Distribution Poles
 Secondaries
 Cable and Phone
may also be present

MABAS Division 10 - Com Ed Program
10
Downed Wires
 Voltage
Gradient is present
– Consider the Step Potential
 Guarding
wires and exposed live
electrical equipment
 Principles for guarding wires, and
electrical equipment
 Precautions
 Rescue Procedures
MABAS Division 10 - Com Ed Program
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All cables & wires must be
treated as energized until proven
dead !
MABAS Division 10 - Com Ed Program
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When service is to be interrupted
Follow these steps:
 Don
protective equipment
 Open Mains if possible
 Remove meter if necessary
 Cut the tap (drip loops) at the house
MABAS Division 10 - Com Ed Program
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Safety Equipment Needed
 Rubber
glove set
– Leather over rubber
 Eye/Face
protection
 Full Protective clothing recommended
 Voltage Tester
 Meter Cover
 Hotstick
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Rubber gloves and protectors
 Precautions
 Testing
and Inspecting
 Exchange
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Live Line Tool
 Also
known as Hotstick
– Inspect for damage prior to use
– Tool may be used for cutting drip loops
only!!
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Low Voltage Tester
 Tests
for de-energized circuits
 Tests for secondary voltage
 Checking & using
– Condition
– Operation
 Interpreting
the tester reading
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Removing a Type S Meter
 Protective
Clothing required
 Open disconnect if possible
 Remove meter
– Cut meter seal with wire cutters
– Remove meter retaining ring
– Contact top outer edge with a downward
and outward angle
– Grasp meter with two hands and pull
straight out. Do not twist meter while
removing
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Steps for Cutting Drip Loops
 Identify
the drip loop at building
 Identify the neutral wire first DO NOT
CUT
 X and Y conductors should be cut
– Separate two parts from each other
 Cut
neutral wire
 Avoid cutting support wire if present
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Summary
 This
program was designed to aid the
firefighter on the scene of a fire or
emergency to correctly and safely
remove electrical hazards.
 WHEN IN DOUBT, WAIT FOR ComEd
TO ARRIVE ON THE SCENE
MABAS Division 10 - Com Ed Program
20
Written Exam and Practical
 Take
15 question written examination
 Complete practical evaluation
– Cut Drip loop connection
– Identify type A and S meters
 Remove
type S meter
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