Utility Specialist

Volt unit of electrical force and is roughly analogous to psi in a water pipe or hose. volt ampere ohm One __________ is required to push one__________ of current across one __________ of resistance Voltage __________ = Current X Resistance 120 volts typical voltage limit for residential use, excluding large appliances 240 volts typical voltage limit for air conditioners, electric heaters and kitchen ranges in residential use 2.4kV - 34.5kV typical voltage for primary distribution lines 765kV typical maximum voltage for transmission lines Ampere measure of electrical current and is similar to the flow rate (gpm) commonly used to measure water flow 60 - 200 amps typical household limit of amps 15 - 30 amps typical individual circuit limit of amps Ohm standard unit of resistance to the flow of electric current and equals the resistance of a circuit in which a force of 1 volt maintains a current of 1 amp Watt measure of power, one kilowatt is approximately 1.33 horsepower Ohm's Law Volts(FORCE) = Amps(CURRENT) X Ohms(RESISTANCE) Watts (POWER) in relation to Amperes and Voltage Watts(POWER) = Volts (FORCE) X Amps (CURRENT) Conductivity the capacity of a material to transmit electricity Electrical potential condition that allows electricity to flow from one object to another Potential Difference difference in voltage between two points Electrical Resistance determines how much energy is required to move electricity along a conductive pathway Great Conductors Aluminum, Copper & Beethoven Poor Conductors Porcelain, Epoxy, Fiberglass and Tyga Enviromental Factors Increasing Likelihood of Air Flashover High Humidity, High Particulate Matter (Brushfire, Dust Storm) Powerhouse source of most power or energy distributed throughout the United States and includes fossil fuels, water or wind turbines and nuclear reactors 13kV - 24kV typical voltage at generation: pre-departure voltage at generating station transmission lines carry extra high voltage energy (100kV - 765kV) from generation transmission substation decrease voltage from transmission to subtransmission subtransmission lines voltages ranging from 22 kV - 161kV transmitting electricity from transmission substation to distribution substation distribution substation decrease voltage from subtransmission to distribution, 2.4kV - 34.5kV (primary) distribution lines carry electricity at 2.4kV - 34.5kV but unlike subtransmission, ends at the user, not a substation distribution transformer reduces voltage to be carried along secondaries or services, typically 240 volts secondary service wires lower voltage, generally between 120 - 480 volts and connecting the transformer and point of use distribution feeder circuits originate at terminals of a circuit breaker or a circuit re-closer in the distribution substation. Also called main-feeder or express-feeder as they supply primary or branch circuits. Multiple feeders may radiate from a given substation protective equipment shields the system from faults, short circuits and current surges by de-energizing the system near the source of failure