TB8 Electrical hazards Flashcards
Electrical deaths per year
700 deaths a year
What percent of workers are year electrical deaths
12%
How many firefighter deaths in 20 years to the electrical hazards
25 firefighter deaths
Current flow or electron flow
Amps
Push or pressure behind current flow
Volts
Measurement of resistance
Ohms
Power is the amount of current time is the voltage level at a given point
Watts
Watts = amps x volts
High voltage
600 V up to 59,999 V
G. P. M
Amps
Transmission line rangers
69 kV – 100 kV
How long can transmission insulator be from
3 feet to 20 feet long
LADWP HAS SOME Transmission lines at
138 kV to 230 kV
How many times is the voltage step down in the distribution system before it’s delivered to most consumers
3 times
How many receiving stations
21
How many distribution stations
150
Receiving station electricity
138 kV Dash 500 kV and step the voltage down to 34.5 kV which is referred to sub trans mission
How long have a high voltage capacitors been known to retain Deadly electrical charge after being shut down
Weeks
What are the most common Distribution transformers
Pole mounted transformer
Transformer circuits step voltage down
4.8 kV step down voltage to 120/240 V
Many commercials have service connectors of how many volts
34,500 V
The degree of shock and injuries depends on the amount of what passing through the body
Current and length of time current passes through
How much amps of the electricity through the body can cause death
1/10 of an amp electricity going through the body for just two seconds is enough to cause death
How many amps can cause paralyzation of muscles to freeze
10 ma
What are the four types of electrical injuries
Electrocution
electrical shock
electrical burns
electrical falls
When is heart paralysis and damage to organs occur
4 AMPs
Tissues Burn with currents greater than
5amps
Dry skin may have a resistance of
100,000 ohms or more
What skin resistance
1000 ohms
What is the most common shock related non-fatal injury
Burn
If within the 10 foot rule Performing a rescue apparatus operator should do what
Remien pedestal to provide personal safety
How many votes can overhead communication cable of a power pole be energized with
50 V
Street light voltage
120-6150 V
30/33/100 route for using Hose stream
30° fog pattern
33 feet from energize source
Minimum 100 psi tonight also strong stream will reduce conductivity
Identification of electrical hazard
Three horizontal strands of barrier tape
Tape states “do not enter “ “do not cross “
Tape between 1 inch and 3 inches
How many feet she vehicle be driving clear of wires for electrical emergency rescue considerations
35 feet
LA DWP can D energize lines in a relatively short time for rescues how long
5 to 10 minutes
Electrical hazards at wildland fire maintain safe distance from transmission towers minimum of
35 feet
How many minimum clearance of feet beyond the outer most wire of electrical transmission lines at wild land fire
100 feet
Explosive range for carbon monoxide
12.5 to 74%
How much do manhole covers weigh how far blown and what distance
300 pounds have been blown 75 feet into the air and a distance of 125 feet
The main fire hazard with an electrical vault in the cooling oil used for transformers has flash point of
Below 300°F
Hi voltage cables up to 230,000 V underground vault may be located close to the floor inside conduit containing how much oil pressure
200 psi of oil pressure
