Brannigans Building Construction CH.7 Non-Fire Building Systems Flashcards
although anhydrous ammonia is transported as nonflammable gas, it has a lower explosive limit of
15%
potential fires may be caused by worn out insulation on wiring that allows what?
conductors to touch, overloaded circuits or bad connections in junction box
one of the very first codes that NFPA published in 1897
national electrical code(nfpa 70)
the metal (copper or aluminum) that distributes electricity throughout building; wiring usually called this
conductors
runs of conductors supplying specific parts of a building and equipment are termed
circuits
amount of electricity flowing through conductors is expressed as
amperes (A)
wires are single or multiple strand conductors that are
bare or sheathed; usually covered with insulation
conductors are tested and rated for
current flow they carry and numbered in terms of gauge under American Wiring Gauge (AWG)
In AWG (American Wiring Gauge) the smaller the number =
larger diameter; i.e. 3 gauge wire will carry 100 A
14 gauge wire is used for
lighting circuits in building
some wiring uses metallic sheathing outside, commonly known as
BX cable
nonmetallic (NM) sheathed cables have taken the generic moniker
Romex (one particular brand of plastic covered wiring)
wiring often runs inside
conduit
durable tubing or an enclosure that protects exposed wiring from physical damage; electrical metallic tubing (EMT), redid metal conduit (RMC) and electric nonmetallic tubing (ENT)
conduit
technically 2 or more insulated conductors
cables
carries cables that are used to cover long distances in large commercial and industrial buildings
elevated cable tray
used to bring different runs of conductors together
junction boxes
brings all of conductors together with the power supply to provide control over the system; sometimes called panelboard
primary electrical service panel
plays critical role in overcurrent protection; gives occupants & FF’s ability to shut down entire system or portion of system
electrical service panel
when operating switches from panel it is best to use what ?
backside of hand w/ face turned away
single use device designed to stop the flow of electricity when excess current is flowing and should be thrown away once blown
fuses
old systems (overcurrent protection) use what?
round “plug” fuses screwed into panel
todays most common overcurrent protection for small residential and commercial buildings
circuit breaker
designed to “trip” circuit when excess current flow is detected; once excess flow issue is resolved it can be restored to provide current
circuit breaker
what type of buildings use cartridge fuses
large commercial and industrial buildings
single use circuit breakers that require specific amperage rated fuses; usually found in large commercial and industrial buildings
cartridge fuses
common pieces of equipment in large electrical systems in commercial and industrial buildings; they transform (adjust) voltage (electromotive force)
transformers
typical single family homes operate on how many volts?
110 volts
(factories 400+)
from life safety perspective, building codes require what type of buildings a secondary source of electricity to keep critical equipment such as fire pumps, smoke management, elevators and fire alarm systems running?
high rises, atrium & underground buildings
secondary sources of electricity; required to provide power w/in 10 secs of power outage
emergency power
systems that provide for buildings heating and cooling systems. and important building automation systems; have 60 secs to pick up electrical load of less critical systems
standby power systems
emergency generators are typically fueled by
diesel fuel or natural gas
natural gas generators connected to gas utility will have
continuous supply of fuel, has no operating time limit
provides information of generators such as operating temp and oil pressures; has manual start and stop buttons
control panel
transfer switches at generator and in fire command center allows FF’s to switch between
normal utility power and generator power
standard for emergency and standby power systems
NFPA 110
newest type of energy supply; large banks of old school lead acid batteries or modern lithium batteries which provide additional power for buildings electrical needs during peak power demand and charge batteries overnight when power costs are lower
energy storage systems
energy storage systems sometimes use what to charge batteries
solar panels and wind turbines
standard for installation of stationary energy storage systems
NFPA 855
groups of battery sets based on the kilowatt hours provided
battery systems arrays
NFPA 855 limits size of battery system arrays requiring how much space b/w them?
3 ft b/w each system
when extinguishing fire in battery systems, particularly those w/ lithium batteries, flammable gases are generated presenting possibility of what?
gas explosion
furnaces use a variety of fuels such as
natural gas, propane, fuel oil, rare cases coal
heart of furnace; transfers heat from combustion chamber to exterior of chamber
heat exchanger
furnaces are categorized in terms of type of relationship b/w
heat exchanger and combustion gas
furnace that simply pass hot exhaust gases over heat exchanger, allowing naturally buoyant heat to leave furnace to surrounding area
natural draft furnace
furnace that move heated air using fans that blow over heat exchanger
forced draft (forced air) furnaces
w/ combustion air blowers pull heated air across heat exchanger
induced draft furnaces
use secondary heat exchanger that condenses and removes hot exhaust gases for additional heat
condensing furnaces
form of furnace; typically use same fuels; steam created that is distributed to heating appliances throughout structure
boiler
in boiler; after steam passes through what steam cools off and then returns water to boiler where it is heated again to steam
radiator
more modern boiler systems use circulating pump and expansion pump for what?
circulating pump=move water through system
=expansion pump= control pressure
boilers are pressure vessels typically operating from 12 psi (cold water start) up to
30 psi (max operating pressure)
large commercial boilers can provide pressures as much as
160 psi for hot water
boilers are characterized in terms of
British thermal unit (BTU) output and horsepower (HP)
large boilers can produce upwards of how many HP & BTU?
100 HP & 4 million BTU
all boilers require what to prevent an explosion when it is over pressurized
pressure relief devices
oil fueled furnaces are subject to what, in which burner fails to ignited atomized fuel oil spray inside combustion chamber; building up accumulated fuel eventually igniting causing vapor explosion
backfires
furnaces and boilers involved in fire should be
shut down using electrical control switches
AHU; comprising blowers/ fans, heating/ cooling elements and filters
air handling units
conduit through which air moves, usually metal or fiber glass
ducts
plates w/in ducts that open or close to control air flow
dampers
system that uses system of air handling units (AHU) that supply climate controlled air throughout building using network of ducts and dampers
HVAC systems
duct leaving AHU serving rooms of building with “fresh” climate controlled air is termed
supply air duct
duct bringing “Stale” air back to AHU is called
return air ducts
required in most HVAC systems since 1980 MGM grand high rise fire in Vegas; can automatically shut down system if not have to manually be shut down
duct smoke detectors
for air conditioning purposes, larger commercial HVAC systems use what type of chillers; water circulated through system
air or water cooled chillers
both air and water chillers use what to create chilled water
refrigeration condensers and evaporators
air and water chillers, in terms of ability to remove heat, they are measured in
tons
(1 ton = removal of 12,000 BTU/hr)
water cooled chillers used what, located on rooftops, in which circulating water is sprayed into air stream from large fan; heat is removed in air stream and discharged to atmosphere
cooling towers
T or F: cooling towers do not have fire sprinkler systems
False; some do have fire sprinkler systems
structures receive water from
water mains (most), wells or tanks
installed at point of entry into building on the supply in order for it to be shut off
main control valve
for a public water supply, where the main control valve is you will typically also find
water meter for system
in larger buildings, the meter and additional valves are placed in
pit outside structure
used to prevent contaminated water from entering back into public water supply; usually found at main control valves
backflow preventer
water is conveyed throughout a building through
piping (steel, iron, plastic) or tubing (copper)
in tall structures, this is needed to bring water at proper pressure to upper floors when the pressure in city water amins is inadequate
domestic water pumps (separate and distinct from fire pump)
during power outages, many mid rise buildings (5-7 stories) do not have
emergency generators
wastewater and sewage are moved out of building through
gravity controlled drainage system (typically composed of steel, iron or plastic piping)
laboratories often use what type of drains that are resistant to corrosion by acids
glass drains
section of pipe in drain from fixture that prevents backflow and sewers gases from entering room where fixture is located ; each water supplied fixture has this
“U” trap
each eater supplied fixture has a trap connected to drain along w/ associated vent stack that rises above roofline to control
air pressure in drain pines
in what areas is natural gas supplied to buildings by large city wide utility distribution systems
urban and suburban areas
individual tanks of propane are typically used in what areas?
rural areas
used to regulate installation of most gas piping systems
NFPA 54: national fuel gas code
reduce the pressure to usable levels for appliances that will use gas
regulators
regulators cut gas pressure down from about 100 psi to
0.25 to 0.5 psi
(commercial buildings 5 psi to supply large equipment)
in utility supplied natural gas systems, what 2 things are usually near each other ?
pressure regulator and meter
propane systems use what located near propane container
individual regulators
individual appliances, including furnaces, water heaters, and gas dryers are required to have individual
gas shut off valves
control valves in fuel gas piping systems are important to FF’s especially
service valves or main shut off valve
small or medium sized; gas cocks can be turned 1/4 to allow or stop gas flow
service valves
if not shut off valve found in fuel gas piping system, you will have to shut off
valve upstream, such as main shut off valve
in fuel gas piping system service valve (main shut off), if ridge is perpendicular to direction of pipe it would indicate valve is
closed
ASME (American Society of Mechanical Engineers) that regulate design and installation of elevators
A17.1 for new elevators
A17.3 for existing elevators
contain provisions for emergency power for selected elevators and smoke/heat vents at tops of hoist ways
model building codes
elevators are grouped into 2 general types
traction and hydraulic
type of elevator that uses electric motor to lift or lower car (cab) suspended on steel “rope” (cable) within an elevator shaft; usually found in taller buildings
traction elevator
elevator that uses hydraulic fluid under pressure to raise and lower a piston (jack) attached to bottom of car
hydraulic elevator
elevator typically installed in low rise buildings and are usually limited to 5 or 6 stories
hydraulic elevator
required for each elevator car for shut down and locked out/tag out during trapped occupant rescue
individual electric power switches
feature an electric motor that moves spooled hoist rope up and down, managed by control system
traction elevators
hydraulic elevators utilize a pressurized
hydraulic fluid pump and tank system
