Electrical Safety

1
Electrical Safety

• Reference The Power of Training
• Electrical Safety
• Commonwealth Edison Company

2
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

3
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

4
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

5
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

6
Firefighters are only to remove the meter to the
residence that is on fire
7
Transmission Distribution System

• Power Plants
• Switchyard
• Transmission
• Substation
• Distribution Transformers
• Residential Service

8
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

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Residential Meters

• Removable (type S)
• Non Removable (type A)

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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

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All cables wires must be treated as energized
until proven dead !
17
Service Wires

• Identifying Service Drop Cable
• Open Wire construction
• Triplex
• Identifying telephone and cable wires

18
When service is to be interruptedFollow these
steps

• Don protective equipment
• Open Mains if possible
• Remove meter if necessary
• Cut the tap (drip loops) at the house

19
Safety Equipment Needed

• Rubber glove set
• Leather over rubber
• Eye/Face protection
• Full Protective clothing recommended
• Voltage Tester
• Meter Cover
• Hotstick

20
Rubber gloves and protectors

• Precautions
• Testing and Inspecting
• Exchange

21
Live Line Tool

• Also known as Hotstick
• Inspect for damage prior to use
• Tool may be used for cutting drip loops only!!

22
Low Voltage Tester

• Tests for de-energized circuits
• Tests for secondary voltage
• Checking using
• Condition
• Operation
• Interpreting the tester reading

23
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

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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