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AIRBREAK: A manually operated switch used to
interrupt or pick up load. Used by line workers for
visual working clearance.
AIR CIRCUIT BREAKER (ACB): Isolates
faulted lines. Protects substation. Air extinguishs
the arc caused by the switch opening.
ALTERNATE CURRENT (AC): Electric flow that regularly reverses
direction. Each forward then backward motion interval is
a cycle. U.S. current alternates at 60 hertz or
cycles per second.
ALTERNATIVE ENERGY SOURCES: Energy
sources like solar, wind, tidal, geothermal, fusion, or synthetic
fuels.
AMPERE (AMP): Unit to measure strength of electric
current. Proportional to the quantity of electrons flowing
through a conductor past a given point in one second.
ARRESTER: Protects the electrical system from lightning. Also
called Lightening Arrester
BASELOAD: Minimum amount of electric power
delivered or required over a given period of time.
BILLING DEMAND: The demand on which
consumer billing is based. Specified in the rate or by
contract. Not necessarily the actual
measured demand for the month. May be based on the
highest demand in the past year making it necessary
to refer to the consumer's rate contract.
BLOCK RATE: Rate structure incorporating
different KWH or KW prices for consumption at different levels.
Example: billing the consumer at one price for the first 100
KWH and another price for all subsequent hours.
BREAKER: A
device usually found in the home, on a pole or in a substation.
Opens automatically when a fault
occurs and disrupts power.
BRITISH THERMAL UNIT (BTU): Amount of heat energy necessary
to raise the temperature of one pound of water one degree Fahrenheit.
Each unit measures a specific quantity of heat energy.
BROWNOUT: Reduction of voltage when demand for electricity
exceeds generating capacity. Results in lights going dim, etc.
BUS: Electrical conductors
that connect all equipment to a common point.
BUSBAR: Rigid bar electrical conductors. Common
connection for two or more electric circuits.
BUSHING: Insulator found on electrical equipment where the
wires attach to equipment.
CAPACITY: Load capability of a generating unit, generating station,
or other electrical device.
CAPACITY COSTS: Cost of generating
electricity. Cost does not vary with consumption.
CAPACITOR: Used to correct poor power
factor by causing a rise in voltage.
CIRCUIT: Completed path traveled by an electric current.
CIRCUIT BREAKER: Automatic switch that interrupts a circuit when
too strong an electric current is present.
COGENERATION: Utilization of industrial waste heat to generate
electric power.
CONDUCTOR: Allows flow of electrons
as electricity. Copper and aluminum wires are used. Copper
is a better conductor because of its internal molecular makeup.
CROSSARM: Wooden timber attached to the top of the pole to which
the wires are attached.
DEMAND: The amount of load required by equipment actually taking
service in any 15 minute interval. Always less
than or equal to connected load of equipment at the location.
Demand is measured in kilowatts (KW).
DEMAND CHARGES: Rate component charge that covers cost of
serving demand or load including cost of fixed generating,
transmission and distribution capacity, costs that
do not vary regardless the level of energy used.
DEMAND METER: A demand meter measures kWh and highest
KW of demand for a given time period, typically the highest
demand created in a fifteen minute period.
DIRECT CURRENT (DC): Electricity that flows continuously in one
direction.
DISCONNECT SWITCH: Switch used to isolate equipment.
DISTRIBUTION: System of delivering voltage electricity
from transmission lines to individual consumers.
ELECTRIC CIRCUIT: An electric circuit consists of a power source,
connecting wires or conductors, and the item that uses electrical
energy.Energy using item is referred to as the load. There must
be a complete path from the negative terminal of the power source,
through the connecting wires and load, back to the positive terminal
of the source in order for current to flow. Absence of complete
path results in an open circuit.
ELECTRICITY: Energy converted from natural resources or fuels
and produced in a power plant. Electricity occurs in nature as
lightning or static friction.
ENERGY AUDIT: An analysis by trained personnel of the efficiency
of heating, cooling, ventilating and other energy systems within
a building.
ENERGY CHARGES: Rate component charge billed on the meter KWH
usage, principally reflecting the cost of fuel and other variable
costs. Non-demand metered rates contain KWH charges that also
recover capacity related costs.
ENTRANCE CABLE: Wire that runs down the side of a house and attaches
to the meter socket. This wire is owned by the customer and is
their own responsibility.
FUSE: A protection device found on the line. It is used to protect
the system from faults. For example, if a fault occurs beyond
the fuse point, the fuse will blow but the rest of the system
will stay alive. When the fuse is blown, it sounds like a gun
shot. Some older customer homes have fuses as well. Customers
are encouraged to check their fuse box or breaker box before
they call in with the power is out, to be sure the problem is
on the utility system rather than within the home.
GENERATION: The process of producing electricity; also, the amount
of electric energy, expressed in watt hours.
GENERATOR: A device that takes fuel or other mechanical energy
to produce electricity or electrical energy.
GIGAWATT (GW): One
billion watts, useful for describing the capacity of large electrical
energy systems.
GROUND: Used by line workers to ground electrical
conductors to prevent accidental electrocution when working on
lines.
GROUND ROD: A metal rod driven into the ground to which the ground
wire is attached. Each house has a ground rod except in large
cities, where the ground is usually attached to city water pipes.
HOT LINE WORK: A term used when line workers are working on the
electric system with a live (hot) line.
HYDROELECTRICITY: Producing electricity by using the force of
falling water to turn the turbine blades, usually accomplished
by damming a river to create a source of falling water.
INSULATOR: Any material that will not conduct electricity, such
as rubber. Used on poles to carry wire and insulate the conductor
from the ground.
INTERRUPTIBLE POWER: Power made available under special agreements
that permit curtailment of power delivered by the company to
the customer.
INTERRUPTIBLE RATE: Lower rate offered to customers, by special
contract, who agree to periodic or intermittent cut-offs. Usually
offered to industrial customers.
KILOWATT (KW): The rate at which electricity is used; a kilowatt
is 1,000 watts. The basic unit of demand. KILOWATT HOUR (KWH):
1,000 watt-hours. The basic unit of electric energy equal to
one kilowatt of power used for one hour. The amount of electricity
sold or consumed is measured in kilowatt-hours.
LIGHTNING ARRESTOR: A device designed to absorb shock from lightning
and prevent damage to substation equipment.
LOAD: The amount of electric power delivered or required at any
specified point on the system. Load originates at the equipment
of the customer. A light bulb is a load.
LOAD CONTROL: The load management technique of managing customer
loads by directly controlling the operating time of a customer's
major electric appliances, such as water heating, air conditioning
and space heating.
LOAD FACTOR: Percentage of time a customer uses the full load
potential, as measured by a demand meter. It is a determination
of the amount of time the customer is at full load.
LOAD MANAGEMENT: Various ways of bringing the demand for electricity
into balance with the supply, by the user or the utility or both
controlling the time at which power is used.
MEGAWATT (MW): The generating capacity of utility generating
equipment is expressed in megawatts, a megawatt is 1,000 kilowatts.
METER: A device that measures and records the amount of electricity
used.
METER BOX OR METER SOCKET: The box found on the side of the house
or mounted on a pole. The entrance cable comes into the top of
the box and comes out the bottom to feed the residence. In some
older residences, the meter box is inside the home.
NEUTRAL: Provides a return path for electricity and stabilizes
the system.
PATROL: The practice of looking over a power line for trouble
areas. This can be done on foot, in a vehicle or by helicopter.
PEAK POWER: Electricity supplied during a period of the greatest
demand.
PORTABLE TRANSFORMER: A transformer that can be moved quickly
to replace a faulted transformer. It is usually a self-contained
unit transported on a trailer.
POWER GRID: A network of electric power lines and associated
equipment used to transmit and distribute electricity over a
geographic area.
POWER TRANSFORMER: An electrical device that transforms voltage
to lower levels.
PRIMARY VOLTAGE: The voltage of the circuit supplying power to
a transformer is called the primary voltage, as opposed to the
output voltage or load-supply voltage, which is called secondary
voltage. In power supply practice the primary is almost always
the high-voltage side and the secondary the low-voltage side
of a transformer.
PUBLIC SERVICE BOARD: A governmental agency whose members are
appointed by the Governor to regulate electric utilities in Vermont.
The board makes the final decisions regarding allowed revenue,
rate structure, service territories, and the construction of
major utility facilities.
PUBLIC SERVICE DEPARTMENT: An agency whose members represent
the public's interest before the Public Service Board in regulatory
proceedings.
PUBLIC UTILITIES COMMISSION: The state governmental agency that
regulates electric utilities.
PUBLIC UTILITIES REGULATORY POLICIES ACT (PURPA): A federal law
setting out rate design standards for consideration by states.
PURPA requires utilities to buy power at equitable rates from
businesses that generate it as a by-product of some other industrial
process (co generation).
RIGHT OF WAY: Private property acquired, at a fair price by a
utility for generation, transmission and distribution facilities.
Also, land obtained to run lines to houses. Signed agreements
are obtained from land owners.
SCADA: This stands for "Supervisory Control And Data Acquisition".
It is the remote control of breakers and generators from the
Control Center. Loads are also monitored in this manner.
SERVICE CHARGE: The rate component charge to each customer that
is to recover costs associated with providing electric service
to a customer that are not related to the amount of KWH provided.
The charge covers metering, cost of billing, record keeping,
meter reading and the service wire to the house.
SUBSTATION: A set of transformers that change the voltage of
electrical energy to levels appropriate for end use.
SYSTEM LOSSES: The difference between the system net energy or
power input and output resulting.
TARIFF: The schedule of all
rates and services offered by CVPS or CVEC filed with the state
PSB or PUC.
TEMPORARY SERVICE: Refers to electric service installed
on a temporary basis to allow for construction of a new structure.
Once a structure is completed, the temporary service is removed
and permanent service installed.
THREE PHASE: An AIC system with three currents, delivered on
three separate wires with a forth wire as a neutral. Found on
main lines and to service large customers.
TIME-OF-DAY-RATE: Also know as time-of-use (TaU) rate; charges
customers according to when they use electricity. Customers pay
more for electricity used during peak demand periods and pay
less during the offpeak periods. These rates are structures
to be reflective of the variation in the cost of service within
the billing period.
TRANSFORMER: An electromagnetic device for changing the voltage
of alternating current electricity. Every transformer has a primary
coil and one or more secondary coils. The primary coil receives
electrical energy from a power source and couples this energy
to the secondary coils by means of a changing magnetic field.
The energy appears as an electromagnetic force across the coil,
and if a load is connected to the secondary the energy is transferred
to the load. The voltage at which electric power is used in motors
and lamps is less than that required for distribution. It is
necessary to raise the voltage at the generating station to the
value required for transmission, which is called "step up" the
voltage. Then to lower it at the point of consumption to the
values required by the motors and lamps, which is called "step
down". The transformer is what makes these changes in voltage.
TRANSMISSION LINE: Wires or cables through which high voltage
electric power is moved from point to point.
VOLTAGE (VOLT): The unit of electromotive force or electric pressure.
It is the electromotive force which, if steadily applied to a
circuit having a resistance of one ohm, will produce a current
of one ampere. When two charges have a difference of potential
the electric force that results is called electromotive force
(emf). The unit used to indicate the strength of the emf is the
volt. The terms potential, electromotive force (emf), and voltage
are often used interchangeably.
VOLTAGE REGULATOR: A device used to regulate voltage. It is used
to maintain constant voltage levels on the electric system.
WATT: The electrical unit of power or rate of doing work. The
rate of energy transfer equivalent to one ampere flowing under
a potential of one volt at unity power factor.
WATT HOUR: The basic unit of electric energy equal to one watt
of power supplied to or taken from an electric circuit steadily
for one hour. The amount of electricity sold or consumed is measured
in kilowatt-hours.
WEATHERHEAD: Used to protect the entrance cable from the elements,
i.e. water running down the cable into the meter socket.
