TB 8 - Electrical Hazards Flashcards
How many deaths per year?
700
What are AMPs?
Current flow (GPM)
* It’s what flows on a wire or conductor
What are Volts?
Electrical pressure or push measured in volts
OHMS
Watts = Amps x Volts
Amps = Watts / Volts
Volts = Watts / Amps
What is OHMS Law?
One OHM is the resistance value through which one volt will maintain a current of one AMPERE.
WATTs?
Power is the amount of current times the voltage level at a given point measured in wattage or watts
Extremely high voltage?
60,000 +
High voltage?
600 - 59,999 volts
- usually found in customer distribution system = primaries (typically 4,800 kv)
What’s considered Low voltage?
600 volts
Electricity to Fire Hydraulics?
Conductor =
Current=
Voltage=
Amperes =
OHMS =
Hose
Water
Pressure
GPM
FL
Generation facilities generate how many volts?
4,000 - 20,000 volts
What do switching stations do?
Considered a step up transformer and sends long distances sometimes over 1 million volts
The transmission system consist of two components?
Grid - layout of electrical distribution system
Transmission lines - carry electricity from gen stations
Transmission lines voltage ranges?
69kv - 1000kv
* Most of the transmission lines coming into LA are 230 kv
Insulators spacing range from __ft?
3 - 20 ft long
Underground transmission lines in most congested areas if the city range from ____kv?
138kv - 230 kv
LADWP has how many receiving stations?
21
RECEIVING STATION BREAK DOWN -
Receive voltages of 138kv to 500kv and step it down to 34.5kv ; which is known as sub-transmission.
There are 150 distributions stations that receive volts of 34.5 kv and step it down to 4.8 kv ( known as primary circuit)
Each primary serves approx. how many customers?
750
What are high voltage capacitors?
-Stores energy
- Hold deadly charge
- Older versions contain chemicals
Overhead transformers step down voltage from 4.8kv to ____v
120/240
4 types of electrical shock?
1) Electrocution
2) Electrical Shock
3) Burns
4) Falls
___th of an amp going through the body for __ sec can cause death
1/10th
2 seconds
Currents above ___mA can paralyze or muscles to freeze
10mA
Muscle tissue burns at __mA?
5
People have stopped breathing from volts as low as __ volts.
49
How many ____mA of current does it take to causes respiratory paralysis?
30 mA
Overhead communication lines can be energized with up to ___ v
50
Rescue considerations for electrical emergencies
Pt trapped in cars should remain in car and attempt to drive clear of wires of how many feet minimum?
Remain how many feet from outermost wire of transmission line?
35 ft min
100ft
Spotting apparatus
Spot app at least __ span ( the distance of __ poles) from affected wire or pole?
One
Two
Electrical Hazards - WILD LAND
Safe distance from transmission lines/ towers?
What’s the clearance?
35 ft
A minimum of 100 ft beyond the outermost wire
Vault/manhole fire
Main fire hazards lies in the cooling oil which has a flash point of ___f
300°f
Carbon monoxide explosive range
12.5 - 74
Manhole covers weigh ____lbs and can be thrown ___ft into the air and up to ___ft away.
300 lbs
75ft
125ft
High voltage cables up to ______volts may be located close to the floor inside a conduit. Cooling oil in underground vaults is pressurized to __psi oil pressure
230,000 volts
200 psi oil pressure
According to TB 008 Electrical Hazards at Fires, extremely high voltage is in excess of ______ volts.
60,000 volts
According to TB 008 Electrical Hazards at Fires, what is the main fire hazard in an electrical vault?
Cooling oil used in transformers
According to TB 008 Electrical Hazards at Fires, how far and how high have manhole covers been blown away?
75 feet high; 125 feet away
According to TB 008 Electrical Hazards at Fires, how often does LADWP test the rubber gauntlet gloves and at how many volts?
10,000 volts and every 60 days
According to TB 008 Electrical Hazards at Fires, high voltage is from _____ to _____ volts.
600 to 59,999
According to TB 008 Electrical Hazards at Fires, the overhead communication cables normally found on the lowest level of a power pole can be energized with up to how many volts?
50 Volts
According to TB 008 Electrical Hazards at Fires, the primary distribution lines are usually ________ in the LADWP system.
4.8kv
According to TB 008 Electrical Hazards at Fires, LADWP has how many receiving stations?
21
According to TB 008 Electrical Hazards at Fires, high-voltage capacitors have been known to retain a deadly electrical charge for _________ after power has been removed from the circuit?
weeks
According to TB 008 Electrical Hazards at Fires, the severity of injury from electrical shock depends on the amount of electrical current and the length of time the current passes through the body. An amperage of ______ going through the body is enough to cause death?
1/10 amp
According to TB 008 Electrical Hazards at Fires, when can department members work in violation of the Aerial proximity to power lines policy and what shall the Apparatus Operator do to provide for personnel safety?
Participating in an actual rescue attempt; AO shall remain at the pedestal
