BC Chapter 4 Flashcards
(37 cards)
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
