BC Chapter 4 Flashcards
Minimum width of a circular staircase tread:
p. 96
10”
Exit stairs must meet strict requirements to ensure safe passage during an evacuation. Features include:
(3)
p. 98
- Fire-resistance rating of the enclosure
- Separation when exterior stairs are utilized
- Features to ensure safety during emergency and non-emergency use.
Fire escapes are usually anchored to the building, and the anchor points may fail without warning due to factors including:
(3)
p. 99
- Damage from freeze-thaw cycle
- Corrosion from weather and pollution
- Inadequate mortar hold the anchors
Building codes have traditionally required a minimum of one smokeproof stair enclosure for stairs serving buildings _______ stories or higher.
More recently, codes also require protection for stairs serving floor levels more than _______ feet below the level of exit discharge.
p. 99
5 floors
30 feet
___________ fire protection uses moving mechanical or electrical parts that work as a system and require a power source for operation.
Sprinklers, fire alarm systems, extinguishers.
p. 99
Active fire protection
_________ fire protection does not require any system or activation or movement.
__________ fire protection relies on building construction and materials to contain fire.
ex. : fire walls, stair enclosures.
p. 99
Passive fire protection
Escalator speeds are standardized at ________ft/min.
Older escalators usually operate at speeds of either _____ or ____ feet/min.
p. 101
100
90 or 120
Uses of elevators:
(3)
p. 104
Passenger
Freight
Service
The practical upper limit for hydraulic elevators is ______ stories.
p. 104
6 stories
Types of elevators:
(4)
p. 105
- Drum
- Traction
- Machine Room-Less (MRL)
- Dumbwaiters (cargo only)
Elevators can be either AC or DC and require up to ____ volts.
p. 106
500 volts
On elevators with ______ motors the brakes do not play any part in actually stopping the elevator car. The traction motor stops the car and then the brakes are applied to hold the car in place.
p. 108
DC motors
The excellent safety record of elevators can be attributed to:
(3)
p. 108
- Strict regulation of equipment
- Rigorous engineering to reduce likelihood of failure
- Numerous safety devices designed to limit the effects of failures.
An electric switch that terminates power before the elevator reaches the upper or lower limits of the hoistway.
p. 108
Terminal Device
Large springs or hydraulic pistons at the bottom of the pit that act as shock absorbers if the terminal switch fails.
For normal speed; not free falling cars.
p. 108
Buffers
Also known as the speed governor, this switch slows the drive motors when the elevator starts to exceed a safe speed.
p. 108
Speed-reducing switch
Also connected to the speed governor (speed-reducing switch), this switch is activated if the speed reducing switch fails to slow the car sufficiently.
p. 108
Overspeed switch
Tapered pairs of steel jaws that wedge against the guide rails and bring the elevator to a stop. These are designed to stop a free-falling car.
p. 109
Car safeties
A building with ____ or fewer elevators may contain elevators in a single hoistway.
____ or more elevators must have at least _____ hoistways.
Where more than one hoistway is provided up to ______ elevators may be located in one hoistway.
p. 110
3
4 2
4
Used for express elevators that serve only upper floors of tall buildings. There are no entrances to the shaft on floors between the main entrance and the lowest floor served.
p. 110
Blind Hoistway
If a blind hoistway has only one car, access doors will be provided for rescue every ___ floors.
p. 111
3 floors
A top exit is provided on all ___________ elevators.
On __________ elevators a top exit is option if a ___________________ is provided.
p. 112
Traction elevators
Manual lowering valve.
In a refuse or laundry chute, where are sprinklers required?
p. 114
At the top of the chute and in it’s termination room.
Pipe chases contain piping for services including:
(5)
p. 116
- Hot and Cold Potable water
- Drain lines
- Steam
- Hot and cold water for HVAC
- Sprinkler piping
In multi-story buildings, with a few exceptions, codes require that HVAC ducts be enclosed in a fire-rated shaft enclosure.
NFPA 90A requires that enclosures be ____ hour rated for building less than 4 stories.
An ______ hour rated for buildings 4 stories or greater.
p. 120
1-hour
2-hour
A building heating and cooling system that uses water as theheat-transfer medium.
p. 120
Hydronic systems
Automatic Smoke Control
The following systems can signal HVAC controls to transfer to Smoke Control:
(3)
p.123
- Smoke detectors
- Heat detectors
- Sprinkler waterflow switches
- *not pull stations
The primary benefit of an automatic smoke control system:
p. 123
Fast activation even when occupants are absent or asleep.
Primary disadvantage of automatic smoke control systems:
p. 123
Multiple elements must be coordinated for maximm benefit.
Fire Alarm, Auto Sprinkler, HVAC zones.
The advantage to manual smoke control is:
(2)
p. 124
- elimination of system disruption from false alarms
- more specific system control
Curtain boards are used to:
(2)
p. 124
- reduce dissapation of heat
- activate smoke/heat vents faster
Curtain boards depth should not be less than _____% of the ceiling height.
And should not be spaced farther than ______ times the ceiling height.
p. 124
20%
8 times
In a _____________ smoke control system the airflow to the stairwell can be adjusted depending on the number of open doors.
p. 128
compensated smoke control system
High voltage is defined as ______ volts, or higher.
p. 128
600 volts
The most common voltage delivered via transformers to medium and large buildings is carried via ___ phase ____/____ volt transformers.
p. 128
3 phase
208/120
If unspriklered, transformer rooms must be enclosed in ___ hour fire rated construction.
If sprinklered they may have ___ hour rated construction.
p. 130
3-hour
1-hour
Generator day tanks may have up to ___ gallons of fuel.
p. 130
60 gallons
