praj-17/QA-MCQ-Open-ended huggingface dataset:
Title: Elevator
Context: The low mechanical complexity of hydraulic elevators in comparison to traction elevators makes them ideal for low rise, low traffic installations. They are less energy efficient as the pump works against gravity to push the car and its passengers upwards; this energy is lost when the car descends on its own weight. The high current draw of the pump when starting up also places higher demands on a building’s electrical system. There are also environmental concerns should the lifting cylinder leak fluid into the ground.

question: What type of installations are hydraulic elevators best suited for? 

answer: low rise, low traffic installations

question: Why do hydraulic elevators use more energy? 

answer: the pump works against gravity to push the car and its passengers upwards; this energy is lost when the car descends on its own weight

question: What else contributes to a higher demand from the electrical system? 

answer: The high current draw of the pump when starting up

question: What concerns arise when the lifting cylinder leaks fluid into the ground? 

answer: environmental concerns
Title: Elevator
Context: A climbing elevator is a self-ascending elevator with its own propulsion. The propulsion can be done by an electric or a combustion engine. Climbing elevators are used in guyed masts or towers, in order to make easy access to parts of these constructions, such as flight safety lamps for maintenance. An example would be the Moonlight towers in Austin, Texas, where the elevator holds only one person and equipment for maintenance. The Glasgow Tower — an observation tower in Glasgow, Scotland — also makes use of two climbing elevators.

question: What defines a climbing elevator? 

answer: a self-ascending elevator with its own propulsion

question: What settings are climbing elevators used in? 

answer: guyed masts or towers

question: What is the Glasgow Tower? 

answer: an observation tower in Glasgow, Scotland

question: How is the propulsion powered in a climbing elevator? 

answer: by an electric or a combustion engine
Title: Elevator
Context: A elevator of this kind uses a vacuum on top of the cab and a valve on the top of the "shaft" to move the cab upwards and closes the valve in order to keep the cab at the same level. a diaphragm or a piston is used as a "brake" if there's a sudden increase in pressure avove the cab. however, to go down, it opens the valve so that the air can pressurize the top of the "shaft", allowing the cab to go down by its own weight. this also means that in case of a power failure, the cab will automatically go down. the "shaft" is made of acrilic, is always round, due to the shape of the vacuum pump turbine. in order to keep the air inside of the cab, rubber seals are used. due to technical limitations, these elevators have a low capacity. they usually allow 1-3 passengers and up to 525 lbs.

question: What does this type of elevator use to propel the cage? 

answer: a vacuum on top of the cab and a valve on the top of the "shaft"

question: For sudden surges in pressure above the cab, what is used as a "brake"? 

answer: a diaphragm or a piston

question: How does it enable the cab to go down by it's own weight? 

answer: it opens the valve so that the air can pressurize the top of the "shaft"

question: What is the shaft made of? 

answer: acrilic

question: How much weight is permitted on a low capacity elevator? 

answer: up to 525 lbs
Title: Elevator
Context: In the first half of the twentieth century, almost all elevators had no automatic positioning of the floor on which the cab would stop. Some of the older freight elevators were controlled by switches operated by pulling on adjacent ropes. In general, most elevators before WWII were manually controlled by elevator operators using a rheostat connected to the motor. This rheostat (see picture) was enclosed within a cylindrical container about the size and shape of a cake. This was mounted upright or sideways on the cab wall and operated via a projecting handle, which was able to slide around the top half of the cylinder.

question: Until the mid 1900s most elevators lacked what? 

answer: automatic positioning of the floor on which the cab would stop

question: How were most elevators built before 1939 powered?  

answer: by elevator operators using a rheostat connected to the motor

question:  Many earlier built  freight elevators were controlled by what? 

answer: switches operated by pulling on adjacent ropes

question: A rheostat is the size and shape of what? 

answer: a cake

question: Where was the rheostat mounted? 

answer: upright or sideways on the cab wall
Title: Elevator
Context: The elevator motor was located at the top of the shaft or beside the bottom of the shaft. Pushing the handle forward would cause the cab to rise; backwards would make it sink. The harder the pressure, the faster the elevator would move. The handle also served as a dead man switch: if the operator let go of the handle, it would return to its upright position, causing the elevator cab to stop. In time, safety interlocks would ensure that the inner and outer doors were closed before the elevator was allowed to move.

question: Where is the elevator motor found? 

answer: at the top of the shaft or beside the bottom of the shaft

question: Moving the helve forward causes the cab to do what? 

answer: to rise

question: The more pressure applied to the handle caused what? 

answer: the faster the elevator would move

question: Why was the handle considered a "dead man switch"? 

answer: if the operator let go of the handle, it would return to its upright position, causing the elevator cab to stop

question: Eventually safety locks were used to guarantee what? 

answer: that the inner and outer doors were closed before the elevator was allowed to move
Title: Elevator
Context: Some skyscraper buildings and other types of installation feature a destination operating panel where a passenger registers their floor calls before entering the car. The system lets them know which car to wait for, instead of everyone boarding the next car. In this way, travel time is reduced as the elevator makes fewer stops for individual passengers, and the computer distributes adjacent stops to different cars in the bank. Although travel time is reduced, passenger waiting times may be longer as they will not necessarily be allocated the next car to depart. During the down peak period the benefit of destination control will be limited as passengers have a common destination.

question: What function does a "destination operating panel" feature? 

answer: a passenger registers their floor calls before entering the car

question: What is another benefit of a "destination operating panel"? 

answer: the computer distributes adjacent stops to different cars in the bank

question: What is one benefit of a "destination operating panel" 

answer: travel time is reduced as the elevator makes fewer stops for individual passengers

question: What is the downside to a :destination operating panel"? 

answer: passenger waiting times may be longer as they will not necessarily be allocated the next car to depart
Title: Elevator
Context: However, performance enhancements cannot be generalized as the benefits and limitations of the system are dependent on many factors. One problem is that the system is subject to gaming. Sometimes, one person enters the destination for a large group of people going to the same floor. The dispatching algorithm is usually unable to completely cater for the variation, and latecomers may find the elevator they are assigned to is already full. Also, occasionally, one person may press the floor multiple times. This is common with up/down buttons when people believe this to be an effective way to hurry elevators. However, this will make the computer think multiple people are waiting and will allocate empty cars to serve this one person.

question: What is one example of a limitation on the system?  

answer: the system is subject to gaming

question: What is generally unable to support variations in the number of people for a particular destination? 

answer: The dispatching algorithm

question: For what reason do people repeatedly push the up/down buttons on a panel? 

answer: people believe this to be an effective way to hurry elevators

question: Why is this a bad practice? 

answer: this will make the computer think multiple people are waiting and will allocate empty cars to serve this one person
Title: Elevator
Context: To prevent this problem, in one implementation of destination control, every user gets an RFID card to identify himself, so the system knows every user call and can cancel the first call if the passenger decides to travel to another destination to prevent empty calls. The newest invention knows even where people are located and how many on which floor because of their identification, either for the purposes of evacuating the building or for security reasons. Another way to prevent this issue is to treat everyone travelling from one floor to another as one group and to allocate only one car for that group.

question: What is one way to implement destination control? 

answer: every user gets an RFID card to identify himself

question: How does this help the system? 

answer: the system knows every user call and can cancel the first call if the passenger decides to travel to another destination to prevent empty calls

question: Newer systems know where and how many people are at a location for what reasons? 

answer: either for the purposes of evacuating the building or for security reasons
Title: Elevator
Context: During up-peak mode (also called moderate incoming traffic), elevator cars in a group are recalled to the lobby to provide expeditious service to passengers arriving at the building, most typically in the morning as people arrive for work or at the conclusion of a lunch-time period. Elevators are dispatched one-by-one when they reach a pre-determined passenger load, or when they have had their doors opened for a certain period of time. The next elevator to be dispatched usually has its hall lantern or a "this car leaving next" sign illuminated to encourage passengers to make maximum use of the available elevator system capacity. Some elevator banks are programmed so that at least one car will always return to the lobby floor and park whenever it becomes free.

question: What is another name for up-peak mode? 

answer: moderate incoming traffic

question: Generally, up-peak mode takes place during what times of the day? 

answer: most typically in the morning

question: What are the reasons for up-peak mode early in the day? 

answer: people arrive for work or at the conclusion of a lunch-time period

question: For what reasons are elevators routed one-by-one? 

answer: when they reach a pre-determined passenger load, or when they have had their doors opened for a certain period of time

question: Why is a "this car leaving next" sign used? 

answer: to encourage passengers to make maximum use of the available elevator system capacity
Title: Elevator
Context: Independent service is a special service mode found on most elevators. It is activated by a key switch either inside the elevator itself or on a centralized control panel in the lobby. When an elevator is placed on independent service, it will no longer respond to hall calls. (In a bank of elevators, traffic is rerouted to the other elevators, while in a single elevator, the hall buttons are disabled). The elevator will remain parked on a floor with its doors open until a floor is selected and the door close button is held until the elevator starts to travel. Independent service is useful when transporting large goods or moving groups of people between certain floors.

question: How is the special sercice mode enabled? 

answer: by a key switch either inside the elevator itself or on a centralized control panel in the lobby

question: What is the impact on an elevator set to independant service mode? 

answer: it will no longer respond to hall calls

question: At what times is Independant service best utilized? 

answer: when transporting large goods or moving groups of people between certain floors

question: During independant service mode how is a single cab in a hall kept from being used? 

answer: the hall buttons are disabled
Title: Elevator
Context: Inspection service is designed to provide access to the hoistway and car top for inspection and maintenance purposes by qualified elevator mechanics. It is first activated by a key switch on the car operating panel usually labeled 'Inspection', 'Car Top', 'Access Enable' or 'HWENAB'. When this switch is activated the elevator will come to a stop if moving, car calls will be canceled (and the buttons disabled), and hall calls will be assigned to other elevator cars in the group (or canceled in a single elevator configuration). The elevator can now only be moved by the corresponding 'Access' key switches, usually located at the highest (to access the top of the car) and lowest (to access the elevator pit) landings. The access key switches will allow the car to move at reduced inspection speed with the hoistway door open. This speed can range from anywhere up to 60% of normal operating speed on most controllers, and is usually defined by local safety codes.

question: Who is authorized to provide inspection and/or maintenance of the elevator? 

answer: qualified elevator mechanics

question: What is the purpose of the Inspection service?  

answer: to provide access to the hoistway and car top for inspection and maintenance

question: What action initiates it's activation? 

answer: a key switch on the car operating panel usually labeled 'Inspection', 'Car Top', 'Access Enable' or 'HWENAB

question: WWhat's the first thing to happen when the switch is activated? 

answer: the elevator will come to a stop if moving

question: Once activatated, what is the only way to deactivate it? 

answer: The elevator can now only be moved by the corresponding 'Access' key switches
Title: Elevator
Context: Phase one mode is activated by a corresponding smoke sensor or heat sensor in the building. Once an alarm has been activated, the elevator will automatically go into phase one. The elevator will wait an amount of time, then proceed to go into nudging mode to tell everyone the elevator is leaving the floor. Once the elevator has left the floor, depending on where the alarm was set off, the elevator will go to the fire-recall floor. However, if the alarm was activated on the fire-recall floor, the elevator will have an alternate floor to recall to. When the elevator is recalled, it proceeds to the recall floor and stops with its doors open. The elevator will no longer respond to calls or move in any direction. Located on the fire-recall floor is a fire-service key switch. The fire-service key switch has the ability to turn fire service off, turn fire service on or to bypass fire service. The only way to return the elevator to normal service is to switch it to bypass after the alarms have reset.

question: What initiates Phase one mode? 

answer: a corresponding smoke sensor or heat sensor in the building

question: What happens when an elevator goes into Phase one mode? 

answer: The elevator will wait an amount of time, then proceed to go into nudging mode to tell everyone the elevator is leaving the floor

question: Where does the elevator go from there? 

answer: the elevator will go to the fire-recall floor

question: How is the elevator enabled for service after the incident? 

answer: The only way to return the elevator to normal service is to switch it to bypass after the alarms have reset

question: What happens if the mode is activated on the fire-recall floor? 

answer: the elevator will have an alternate floor to recall to
Title: Elevator
Context: Phase-two mode can only be activated by a key switch located inside the elevator on the centralized control panel. This mode was created for firefighters so that they may rescue people from a burning building. The phase-two key switch located on the COP has three positions: off, on, and hold. By turning phase two on, the firefighter enables the car to move. However, like independent-service mode, the car will not respond to a car call unless the firefighter manually pushes and holds the door close button. Once the elevator gets to the desired floor it will not open its doors unless the firefighter holds the door open button. This is in case the floor is burning and the firefighter can feel the heat and knows not to open the door. The firefighter must hold door open until the door is completely opened. If for any reason the firefighter wishes to leave the elevator, they will use the hold position on the key switch to make sure the elevator remains at that floor. If the firefighter wishes to return to the recall floor, they simply turn the key off and close the doors.

question: How is the Phase-two mode enabled? 

answer: Phase-two mode can only be activated by a key switch located inside the elevator on the centralized control panel

question: What actions must a firefighter take to activate Phase-two mode? 

answer: manually pushes and holds the door close button

question: What does Phase-two do? 

answer: enables the car to move

question: What is the purpose of the Phase-two mode? 

answer: This mode was created for firefighters so that they may rescue people from a burning building

question: Where is the Phase-two key switch to be found? 

answer: on the COP
Title: Elevator
Context: Once the elevator arrives at the floor, it will park with its doors open and the car buttons will be disabled to prevent a passenger from taking control of the elevator. Medical personnel must then activate the code-blue key switch inside the car, select their floor and close the doors with the door close button. The elevator will then travel non-stop to the selected floor, and will remain in code-blue service until switched off in the car. Some hospital elevators will feature a 'hold' position on the code-blue key switch (similar to fire service) which allows the elevator to remain at a floor locked out of service until code blue is deactivated.

question: Upon arriving at the desinated floor, what does the elevator do? 

answer: it will park with its doors open and the car buttons will be disabled to prevent a passenger from taking control of the elevator

question: What steps do medical personnel take at that point? 

answer: Medical personnel must then activate the code-blue key switch inside the car, select their floor and close the doors with the door close button

question: Where then does the elevator go? 

answer: The elevator will then travel non-stop to the selected floor

question: Once it arrives what does the elevator do 

answer: will remain in code-blue service until switched off in the car

question: What does the hold feature do? 

answer: allows the elevator to remain at a floor locked out of service until code blue is deactivated
Title: Elevator
Context: When power is lost in a traction elevator system, all elevators will initially come to a halt. One by one, each car in the group will return to the lobby floor, open its doors and shut down. People in the remaining elevators may see an indicator light or hear a voice announcement informing them that the elevator will return to the lobby shortly. Once all cars have successfully returned, the system will then automatically select one or more cars to be used for normal operations and these cars will return to service. The car(s) selected to run under emergency power can be manually overridden by a key or strip switch in the lobby. In order to help prevent entrapment, when the system detects that it is running low on power, it will bring the running cars to the lobby or nearest floor, open the doors and shut down.

question: What sequence of events happens when the power shuts off in a traction elevator and the elevators all stop? 

answer: One by one, each car in the group will return to the lobby floor, open its doors and shut down

question: What do any passengers experience at this point? 

answer: People in the remaining elevators may see an indicator light or hear a voice announcement informing them that the elevator will return to the lobby shortly

question: After all cars go to the lobby, what is the next step? 

answer: the system will then automatically select one or more cars to be used for normal operations and these cars will return to service

question: How are the selected cars then readied for passengers?  

answer: The car(s) selected to run under emergency power can be manually overridden by a key or strip switch in the lobby

question: What is a safety feature to prevent entrapment? 

answer: when the system detects that it is running low on power, it will bring the running cars to the lobby or nearest floor, open the doors and shut down
Title: Elevator
Context: In hydraulic elevator systems, emergency power will lower the elevators to the lowest landing and open the doors to allow passengers to exit. The doors then close after an adjustable time period and the car remains unusable until reset, usually by cycling the elevator main power switch. Typically, due to the high current draw when starting the pump motor, hydraulic elevators are not run using standard emergency power systems. Buildings like hospitals and nursing homes usually size their emergency generators to accommodate this draw. However, the increasing use of current-limiting motor starters, commonly known as "soft-start" contactors, avoid much of this problem, and the current draw of the pump motor is less of a limiting concern.

question: How do hydraulic elevators work in emergencies? 

answer: emergency power will lower the elevators to the lowest landing and open the doors to allow passengers to exit

question: Once the passengers have exited, what happens? 

answer: The doors then close after an adjustable time period and the car remains unusable until reset, usually by cycling the elevator main power switch

question: For what reason are hydraulic elevators not powered by the standard emergency system? 

answer: due to the high current draw when starting the pump motor

question: What are current-limiting motor starters referred to as? 

answer: "soft-start" contactors