Electrical Safety Handbook Flashcards
Electrical Safety Handbook
Whaer is Voltage?
The difference in electrical potential between two points in a circuit
Electrical Safety Handbook
What is Current
A flow of electrical charge
Electrical Safety Handbook
What is Resistance?
its similar to the effect of friction on the flow water in a pipe.
HIgh resistance=insulator
Low resistance=conductor
Resistance is measured in Ohms
Electrical Safety Handbook
What is grounding
Is the process of mechanically connecting isolated wires and equipment ot the earth, with sufficient capacity to carry any fault curren and to ensure the wires and equipment remain at the same potential (same voltage) as the earth
Electrical Safety Handbook
What causes electrical equipment to become faulty?
- worn out or deteriorated
- improperly installed
- improperly maintained
- improperly used
- dameged or broken
- adverse weather/natural events exposure
Electrical Safety Handbook
What is arcing and how hot does it get?
an electrical arc is a sudden flash of elevtricity between two points of contact. and arc is extremely hot. 20,000C, 35000F
Electrical Safety Handbook
What are the safe limits of approach for live lines?
- 750-150000 volts is 3M or 10ft
- 150001-250000 volts is 4.5M or 15ft
- 250001 and higher is 6M or 20ft
Electrical Safety Handbook
How far can a conductor Swing or sag when heated
1.8m
Electrical Safety Handbook
What are the two problems that potential gradient or voltage differance create?
Step Potential and touch potential
Electrical Safety Handbook
The effect of electricity on the body and the severity of the shock depends on what?
- COndition of the skin
- Area of skin exposed to the electrical source
- Pressure of the body against the source
- moisture level of the surface of the skin
Electrical Safety Handbook
Any vivtim of electrical shock should be assessed for the following effects on the body
- Contraction of chest muscles, cuasing breathing difficulty and unconciousness
- respirator distress caused by temporary paralysis of the respirator center
- rapid irregular heart beat (ventricular fibrilation) mainly resulting from contact with low boltages
- burns to tissue at the entrance and exit points
- fractures cause by muscle spasm
- injuries such as fractures, contusions, internal bleeding due to calls
Electrical Safety Handbook
Does standard response protective clothing provide protection from electrical hazards
NO
it will provied electrical arc flash protection
Electrical Safety Handbook
How far away should you use the shuffle step form an energized vehicle
10M or 33ft
Electrical Safety Handbook
What are the three parts to a typical electrical system
- generation
- transmission
- distribution
Electrical Safety Handbook
What does GFCI stand for
ground fault circuit interrupters
Electrical Safety Handbook
What steps are outlined when responding to downed wires
- Before getting out of your vehicle, examine the surroundings carefully and make sure you are parked well away form fallen wires.
- Stand well back, at least 10M or more away. Look for and locate all wires ends
- Establish the safe zone, at least 10M away from wires and aything the wires bay be touching
- Secure the area
- Do not attempt to more any fallen wires, call and wait for elevtrical utility personnel.
Electrical Safety Handbook
What are the safe distances for using water on live electrical equipment?
use a 700 Kpa nozzle
1. 0-750 volts 1.5M 5ft
2. 751-15000 volts 4M 13ft
3. 15001-500000 volts 7M 23ft
Electrical Safety Handbook
What should not use on a electrical fire?
- strait water stream
- foam
Electrical Safety Handbook
What is the standard precautionary approach to fiight fires on power line equipment?
- wear full trunout gear and SCBA
- position the apparatus upwind and out fo the line of fire of the vehicles tires
- evaculate people located in path of smoke plume and at safe distances from a ground gradient grid or tire explosion
Electrical Safety Handbook
High voltage power line are insulated by air space. At what distance would flames degrade the insulating quiality of the air to the point of enabling electricity to jump to the surface?
If flames are within 2m or 7ft of the live conductors