TB 8 Electrical Hazards Flashcards
According to NIOSH, electrical accidents in the US account for #_____ deaths per year
700
OSHA statistics indicate that electrocution accounts for ____%of worker deaths annually
12%
NIOSH statistics also document that over the last __years, electrocutions to first responders have resulted in more than ___deaths in the fire service.
20
25
Los Angeles Fire Department (LAFD) resources respond to over ______electrocutions, wires down, and other electrical emergencies annually.
3000
_____ is one of the basic charges of energy
Electricity
_______ _________ can be stationary, as in static electricity
Electrical Charges
An _____ _______is a movement of charge
Electric Current
True/False.
When two objects with the “same” charges touch and redistribute their charges, an electric current flows from one object to the other until the charge is distributed according to the capacitance of the objects.
False. Different Charges
What is Current flow, or electron flow; it is what flows on a wire or conductor like water flowing down a river.
AMPS
The measure of Current that flows from points of HIGH voltage to points of LOW voltage on the surface of a conductor is ….
AMPS
Quantity of electricity is expressed in ______,
e.g. water is measured in gallon per minute(gpm).
AMPS
What is the difference in electrical potential between two points in a circuit
VOLTS
What is the push or “pressure” behind current flow through a circuit.
VOLTS
Electrical pressure is measured in ______
E.g. in water hydraulics would be (psi).
VOLTS
The measure of 1000 volts.
KILOVOLTS
Measurement commonly used by LADWP
KILOVOLTS
Electrical “resistance” is measured in ________
E.g. The resistance to a flow of water through a hose would be termed friction loss
OHMS
OHMS. ________ determines how much current will flow through a component.
Resistance
E.g. very high resistance = small amount of current flow
OHMS. _______are used to control voltage and current levels.
Resistors
____________defines the relationships between power (watts), voltage (volts), current (Amps), and resistance (ohms).
OHM’s LAW
_______=amps(current) x volts
WATTS(power)
_____= watts(power)
———————
Volts
Amps(current)
________= Watts(power)
———————-
Amps(current)
Volts
voltages in excess of 60,000 volts. Usually transmission voltage.
Extremely High Voltage
voltage from 600 volts up to 59,999 volts.
Usually found in customer distribution system.
High Voltage
Referred to as “Primary circuit voltage” or “Primaries”
High Voltage
In the LADWP system the primary distribution lines are usually______
4.8 Kv
_______ is below 600 volts
Low Voltage
_____ is called “secondary circuit voltage” or “secondary”
Low Voltage
Electricity Fire Hydraulics
Hose = Water= Pressure= Gpm’s= Friction Loss=
Conductor Current Voltage Amps Ohms
What are the 3 ways Getting electricity to the consumer can be broken down ?
Generation , Transmission, Distribution Systems
_________is where the electrical energy transformation process originates and where a complete circuit starts.
Generation Power Plants
_________use mechanical energy, such as water pouring through a dam or the motion of a turbine driven by steam, to produce electricity.
Generators ( generation system)
___________create electricity by using other forms of energy such as “fossil fuel steam plants, hydroelectric dams, nuclear power plants “
Generators
Generation facilities generate electricity between_____ &______ volts.
4000 and 20,000 volts.
True/False.
Generators produce enough volts to deliver power long distances to connect different parts of the city together.
False.
In order to raise the voltage for generation stations they rely on _________?
Transformers
_________ take the electricity from the generation plant and begin the flow of current over the longdistances needed to carry it over transmission lines.
Switchyards
_______utilize their own magnetic fields to lower required amps while proportionately raising the pressure (voltage), sometimes to over one million volts.
Switching Facility Transformers
_______ are called “step up” transformers because they step voltage up
Switching Facility Transformers
What are the 2 main components of the transmission system.
Grids & Transmission Lines
What are the layouts of the electrical distribution system which is a system of wires, substations, and switchyards throughout the transmission system.
Grids
__________are used to carry the electricity from generation stations in a system of wires that carry electricity to the grid.
Transmission Lines
__________are used to carry high voltage electricity the long distances from generating plants to distribution stations.
Transmission Lines
What are the Most common transmission lines in Los Angeles
Overhead Transmission Lines
_______are also called high-voltage or high-tension wires.
Overhead transmission lines
Voltages on transmission lines range from___ to____
69 Kv to 100 Kv
Most of the transmission lines coming into Los Angeles are _____
230 Kv or higher
All voltages above ____are referred to as transmission voltages.
69 Kv
Strings of insulators on transmission towers can range from ____ to _____long depending on the voltage they are trying to hold back from contacting the towers that support them.
3-20 ft
LADWP has transmission lines with voltages of _____ to ______?
138 Kv— 230Kv
The component of the electric system that delivers electrical energy to the consumer or residence consists…..
Distribution stations & lines.
Distribution System
The ______________ is a group of electric stations, high- and low-voltage power lines and poles, surface and underground transformers located through out the city.
Distribution System
How many times is voltage “stepped down” in the distribution system before it is delivered to most consumers?
3
What are Substations that utilize transformers to change high-voltage electricity into lower voltage? ( Begins at the receiving station)
LADWP DISTRIBUTION STATIONS
What carry electricity from the distribution system to homes, offices and factories which require low-voltage electricity.
Distribution Lines
________ _______ ________consists of wires mounted on steel or wood poles(Most common type in City of Los Angeles).
Overhead Distribution System
_______ are lines inserted in conduits or ducts and buried in ground
Underground Distribution
How many receiving stations does LADWP have?
21
Receiving stations receive electricity @ ______ to ____ Kv
138Kv to 500 Kv