Building Utilities 2: Prelims Flashcards
Sources of energy: 5
wind, water, nuclear, fossil fuel, solar (photovoltaic) and
geothermal
It converts solar energy directly into an electric current
Photovoltaic cells
Produce a rotary mechanical motion that drives electric
generators which in turn convert movement into electricity
Turbine
It is used to “step-up” (increase) the electrical power to very high
voltages transmitted by wires over long distances
Transformers
volt, ampere, watt are used in both metric and customary
outlets
Units of electricity
Unit of electrical pressure or potential
- Makes electricity flow through the wire
Volt
Term for flow of electricity
Current
unit used to measure the magnitude of an electric current
- The specific quantity of electrons passing a point in 1 second
Ampere
Unit used to measure the amount of power (energy) required to light
lamps, heat water, turn motors, etc…
Watts
Depends on both voltage and amperage
Wattage
Unit used to measure the consumption of electricity
Kilowatt-hour
– wood, glass, plastic;
good insulators
copper, aluminum, silver;
good
conductors
This material keeps the electricity from flowing where it is not wanted
Plastic
used to measure the amount of electrical resistance
Ohms
Power is supplied to a building through a
service entrance
The heavy wires that extend from a utility pole or an underground
source to the structure (or customer-owned post);
Drop
Wires are twisted into a?
Cable
Microsecond increases in voltage that are significantly above
the capacity of a wiring system or device to withstand
Surges
provided through:
▪ service entrance
▪ distribution panel
▪ lightning rod grounding
Surge protection
(GFCI)
ground fault circuit interrupters
Method of ensuring that excess voltage surges are
dissipated harmlessly into the earth;
Grounding
NEC
National Electrical Code
direct lightning strike voltage to the ground and away
from the building
Lightning rods
Electrical current is delivered throughout a building through a___
distribution
panel or service panel
From the distribution panel, electricity is routed to the rest of the building
through____
branch circuits
A circular path that electricity follows from the power supply source
to a light, appliance or other electrical device and back again to the power
source
Circuit
Each circuit is protected with a ___
circuit breaker
A device that opens (disconnects) a circuit when the current
exceeds a certain amount
Circuit breaker
When a breaker opens and power to the branch circuit is
disconnected.
Happens when the sum of the current drawn by the branch
circuit exceeds the rating of the main breaker
Trips
Installed in older homes instead of circuit breakers for the same
purpose but are replaced
Fuses
lighting, small appliance, individual or
dedicated
Types of branch circuits
T or F: “The NEC provides that 100 watts shall be the maximum load for each
household lighting outlet.”
True
Circuits that provide power to outlets whenever small appliances are likely to be connected
Small-appliance Circuits
T or F: “NEC provides that for each single receptacle shall be considered at
no less than 180 watts rating.”
True
When a motor starts, it needs n extra surge of power to bring it
to full speed called
Starting Load
Designed to serve a single large electrical appliance or device
Individual (dedicated) Circuits
Connected to the lighting outlets for the entire building
o Assign different lights in each room to different circuits, so when the
circuit trips, room will not be in total darkness
Lighting Circuits
located where there is a possibility for people to go ground
themselves and be shocked by the current flowing through their body to the
ground
GFCI (GROUND-FAULT CIRCUIT INTERRUPTER) receptacle
cut off the current at the outlet
GFCI (GROUND-FAULT CIRCUIT INTERRUPTER) receptacle
AWG
American Wire Guage
thousands of circular mils, an old measurement
of wire gauge
✔MCM
indicates a single conductor having flame-
retardant, moisture-resistant thermoplastic insulation
✔TW
indicates a single conductor having flame-
retardant, moisture and heat-resistant thermoplastic insulation
✔THW
standard unit of illumination, (also lx), metric system
Lux
unit to measure light intensity, (candela), English system
Footcandle
are rated by watts (energy used) and also by lumens (brightness)
Light bulbs
shines directly on an object from a light source
Direct
reflected from surfaces
Indirect
spread evenly in all directions with the light source
(bulb) not visible
Diffused
light shines mainly down as direct light with a small
portion directed upward as indirect light
Semi-direct
more reflected, but some light shines directly
Semi-indirect
reflect 94% of the light that strikes them
White surfaces
reflect only 2%, remainder of the light is absorbed
Black surfaces
act as secondary source of light when light is
reflected
Room surfaces
Provides overall illumination and radiates comfortable level of
brightness for an entire room
General lighting
Light directed to a specific area or located to support a particular task
– known as specific, local or task lighting
Specific lighting
Used to create atmosphere and interest; Bright lights – stimulating
;Low levels of light – quieting
Decorative lighting
Fixtures that are wired and built into a building’s hard-wired system
wired and built into a building’s hard-wired system
either portable plug-in lamps or structural fixtures
Light fixtures
used to direct a light source downward to
“wash” over wall surfaces
Soffit lighting
directs light (usually fluorescent) onto ceiling
surfaces
Cove lighting
directs light upward to the ceiling and down
over the wall or window treatment
Valance lighting
directs all light downward, similar to soffit
except cornice lights are totally exposed at the bottom
Cornice lighting
Used as a source of
general or decorative
lighting when attached
to a dimmer switch
Wall fixtures
control the flow of electricity to outlets and to individual devices
Switches
Meaning of HOT in electrical
electricity is available in the outlet at all times
control fixtures, devices, or outlets
Single-pole switches
control light from two different switches
(three wires and two switches)
Three-way switching circuit
control fixtures from three
different locations; additional four-way switches maybe added to the
circuit to allow the lights to be controlled from any switch
Four-way switch & two three-way switches
acts as step-up transformer and
opens the full 120V to the appliance
Magnetic controlled switch
Allow the intensity of light fixtures to be controlled
Dimmer switches
used to make light adjustments from a
wireless remote control
Integrated dimming switches
can control many circuits
Wireless switches
A point in a circuit where other devices can be connected (NEC)
Outlet
A device (at an outlet box) to which any plug-in extension line,
appliance or device can be connected;
Receptacle
used for small appliances and lamps;
available in single, double or multiple units
Convenience receptacles
for the connection of lamp-holders, surface-mounted
fixtures, flush or recessed fixtures and all other types of lighting fixtures
Lighting outlets
(dedicated circuits) the connection
point of a circuit for only one electrical device
Special-purpose receptacles
for the connection of lamp-holders, surface-mounted
fixtures, flush or recessed fixtures and all other types of lighting fixtures
Special-purpose outlets & convenience outlets
activate alarms or a call to the police when contact
points are separated and break a circuit.
Door & window sensors
trigger an alarm when the noise of the breaking glass, voices or
forced entry is sensed.
Sonic detectors
record movement when the path of an intruder interrupts the
lines of the sensor.
Motion detectors
react to smoke or heat to activate an alarm and/or fire sprinkler
system & to notify the police & fire departments.
Fire detectors
are programmed to sound an alarm (some
may also open windows) when levels exceed established limits.
Carbon monoxide & radon detectors
detect leaks from appliances or furnace burners & shut-off
the gas line, open windows and sound an alarm.
Natural gas sensors
sense water leakage and sound an alarm and notify a public utility
or service company.
Water sensors
occupants with an alarm when an outside electrical
service, telephone, or cable line has been cut or disconnected.
Cut-line monitors alert
alert residents in a remote location of the potential
danger of pipes freezing.
Low-temperature sensors
link remote cameras (still/video) to a video-monitoring station.
Images can be recorded for future reference using a closed-circuit video
interfaced with a computer program. An alarm and a call to the policeman can
also be programmed.
Visual monitors
(infrared) and
alarms activate when set levels are exceeded.
body heat sensors
can activate alarms when light beams are blocked
between two points.
Light interruption sensors
which is changed frequently, allows access to selected visitors
who possess the proper code.
visitor code,
communications between entrances and other
locations including recorded ad synthesized voice responses to visitors.
Videophone intercom
systems that support personal, business, fax and
internet services.
Integrated multiple phone
allows web surfing on multiple
computers, smart TV’s, cellular phones and other devices simultaneously.
Internet sharing device
that allows communication between multiple computers,
printers and scanners.
Networking
Smart building system or home automation system
INTEGRATED SYSTEMS
linked together into a single network
o Electronically connected to one or more preprogrammed devices
such as:
▪ Keypads
▪ Touch screens
▪ Remote controllers
Chips
use light, not electronic, impulses to transmit
information; carry more information than copper; less subject to
magnetic interference
Fiber-optics