Book 29 Elevators Flashcards
Book 29 Elevators
There are numerous (over 60) elevator manufacturers
Currently, there are two types of elevators:
Cable operated elevators (sometimes referred to as an electric elevator)
Hydraulic operated elevators
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Book 29 Elevators
CABLE ELEVATORS
A typical cable elevator consists of an elevator shaft for the car to travel within, an elevator car, cables attached to the car, counterweights, vertical tracks, emergency safety brakes, and an equipment room for the electrical equipment (electric motor and winding drum) to raise or lower the elevator.
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Book 29 Elevators
DRUM TYPE
A winding drum type elevator consists of a car attached to one or more ( 1 or more cables!! ) cables that pass around a winding drum and to a moving counterweight.
Both sets of cables run in the same grooves (counterweight cables unwind when car cables wind and vice-versa).
The equipment room for drum type may be located in a basement or on the roof of a building.
Limitations in the length and diameter of the winding drum restricts this type of elevator to ___-foot lifts and slow speeds.
150
Book 29 Elevators
TRACTION TYPE
Traction type elevators are used for higher lifts and greater speeds than drum type elevators and use a traction sheave instead of a winding drum.
In this configuration, cables passing over the traction sheave unwind as fast as they wind and car speed is dependent on the size of the traction sheave and the electric motor speed. There are two types of traction equipment:
High speed direct traction or gearless type traction consists of a slow speed DC motor directly coupled to a traction sheave with a brake wheel mounted on the motor shaft.
Geared traction type uses a high speed motor. The motor is geared to a traction sheave through worm gears with a brake wheel between the worm gears and motor.
equipment room is usually located on the roof or above an elevator shaft in high-rise buildings.
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Book 29 Elevators
HYDRAULIC ELEVATORS
generally limited to ___ story buildings.
Older type use water, newer use hydraulic oil
Some less modern hydraulic elevators and hydraulic elevators that travel over six stories may use cables and
counterweights.
The equipment rooms for hydraulic elevators are normally located at the lower level of a building, but can be at any floor level or ___ to ___ feet away from the elevator shaft.
Equipment room consists of -
Controller or relay panel
Hydraulic power unit.
6
50 to 100
Book 29 Elevators
freight elevators can be as large as ___ feet by ___ feet and have a carrying capacity of up to ___ tons.
Usually not under computer control and will service the entire building
12 x 14’
3
Book 29 Elevators
The door on the elevator car is referred to as the inner or car door and travels with the elevator car.
The door that is seen from each floor of a building is referred to as the outer or hoistway door.
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Book 29 Elevators
Four types of doors:
Swing Hall
Single Slide
Center Opening
Two Speed
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Book 29 Elevators
GIB BLOCKS
They are made of various plastic or phenolic materials.
Gib blocks are approximately __” wide, __” high, __” thick
Installed every ___-inches across the underside of the door panel.
Normal hoistway doors can be expected to utilize two gib blocks.
3” wide, 1” high, 1/2” thick
18”
Book 29 Elevators
A centrifugal force governor is provided on most elevators to guard against overspeeding (when a car travels in excess of ___% of top speed, the governor will activate a safety stop device).
On elevators capable of high speeds, wedges are forced between two jaws and the vertical rail is gripped with increasing force to slow a runaway elevator car to a gradual stop.
20
Book 29 Elevators
Have the trapped passengers verify the status of the Emergency Stop Button.
Remember that if an elevator is stalled due to a malfunction, (one that can be quickly corrected, i.e. overheated relay, loss of power from an activated main switch, etc.), it is necessary for the Emergency Stop Button to be activated before power will be returned to an inoperative elevator, (placed in the normal/run position.)
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Book 29 Elevators
Instruct the passengers to push the Door Open Button (if so equipped).
If the elevator car is within a few inches of the landing floor, and the power is off in the equipment room, instruct the passengers to try to manually open the car door. This may require some effort as the car door operates the hoistway door through a clutch mechanism. Moving the car door will release the latch on the hoistway door and allow the door to be opened.
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Book 29 Elevators
If there is power to the elevator, turn the power off for at least 30 seconds and then back on again.
(at least 30 seconds is necessary to clear any previous programming in the elevator computer).
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Book 29 Elevators
If an elevator is equipped with a recall system, a key can be used to recall the elevator to the ground floor and open its doors. If the elevator returns to the ground floor but does not open its doors, instruct the passengers to push the Door Open Button
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Book 29 Elevators
There are generally three valves in this unit, one to raise the car, one to lower the car, and one that will level the car to a floor landing. Most bleeder valves have a manual lowering screw built into the valve and are marked:
ML, MAN, or MANUAL
near the lowering screw. No valve should be fully opened. Open the bleeder valve slowly, just enough to hear the sound of fluid flowing, and the elevator car will slowly lower.
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