- Category:Engineering and Construction
- Document type:Assignment
Types of elevators/lifts/escalators
Hydraulic elevators are often supported by a piston at the bottom. The piston pushes the elevator up from one floor to the other. Hydraulic elevators travel at a speed of two hundred feet per minute. There are two types of hydraulic elevators. The first type is holed hydraulic elevators which has a sheave extending below the elevator pit. The extension accepts the piston as the elevator descends. It travels at a maximum speed of sixty feet per minute. The second type is hole-less hydraulic elevators which has a piston on either side. It uses combination of a piston and ropes to move the elevator up and down. It travels at a maximum speed of sixty feet per minute (Bangash, and Bangash 34).
Traction elevators are elevators lifted by ropes that pass over a wheel attached to the electric motor over the elevator. Traction elevators are utilized for mid and high rise application. They move at a higher speed than hydraulic elevators. Their counter weight makes them more effective and efficient. Traction elevators are further divided into three types. The first type is geared traction elevators which have a gearbox attached to the motor; the gear box drives the wheel which moves the ropes. These elevators can move at a maximum speed of five hundred feet per minute. The second type is gear-less traction elevators which has the wheel directly attached to the motor. They are capable of moving at a maximum speed of two thousand feet per minute. The last type is machine-room-less elevators. They do not have machine room over the elevator shaft (Bangash, and Bangash 45).
Pneumatic elevators are often raised and lowed by air pressure. The elevator uses simple principles of physics. The differences between air pressure beneath and above the vacuum elevator transport the cab by air. The vacuum turbines or pumps pulls the cab to the next flow and lowers it down. Their compact design makes them ideal for homes (Bangash, and Bangash 56).
These are domestic elevators intended to move passengers from one floor to the other. The elevators can be built inside the homes or on the outside. They can be hydraulic, pneumatic vacuum or cable elevators. More often, domestic elevators are designed to carry two to four passengers comfortably and safely (Bangash, and Bangash 58).
These are small freight elevators used to carry objects rather than individuals. Whenever laundry or groceries need to be sent down and up the floor without making several trips, individuals can simply place the groceries in the dumbwaiter and press the button to send them up the stairs. The elevators are often constructed adjacent or into a wall (Bangash, and Bangash 60).
Cleat type escalators were invented by Jesse Rono. They did not resemble present escalators too closely. In Cleat-type escalators, passengers are often tilted upward at an angle and its treads comprised of cleated metal. Reno worked on the model for several years and the escalators gained installation from Toronto to Cape Town (Bangash, and Bangash 64).
Spiral or Mitsubishi escalators
Spiral escalators are located in corners or on the sides of the room. They increase the usability of space floor. Their elegantly layout enable the visitors to smoothly move into the building. The escalators have graceful arcs flowing through the building space. Spiral escalators increases passenger perspective and enhance new contours to the surrounding areas (Bangash, and Bangash 68).
Performance criteria, safety guidelines and compliance for elevators/lifts/escalators
There are several performance criteria for lifts and escalators. Elevators are extensively utilized in airports, public places, and shopping mall and in several places to move individuals from one floor to the other. They stops or slows down when being used. Its demand is increased by its low failure rate, its durability less noise and stable performance. Lifts are electronic devices that raise and lower individuals and goods from one floor to the other. Escalators are moving staircases that carry individuals between floors in a building (American Society of Mechanical Engineers 34).
Freight or passenger elevators should be operated only by authorized persons who have the knowledge and skill of operating the system except when they are operated by double-button or automatic control. No individual is allowed or supposed to operate elevator unless the person is eighteen years and over and is identified by their ability to perform their duties properly and in a competent manner and does not have any physical or mental defect. Elevators operators should ensure all provisions guiding the use of elevators are complied with. They should report any defect or violation while using elevators. Additionally, no individual is supposed to use elevators designed as power-driven freight elevators, the only persons authorised to use the power-driven elevators are designated and operator assistants who should not be more than three. No individual is supposed to use hand elevators, dumbwaiters and gravity elevators (Emmitt et al. 35).
When using escalators, users need to consider some safety guidelines. Individuals need to watch the direction of moving steps of the escalators with extra care. They need to be more careful when wearing eyewear of bifocals. Children need to be held with one arm to prevent them from fall when using the escalators and leave one hand to hold the handrail of the escalator. Users need to grasp the hand rail as they step onto the moving steps of the escalators. Additionally, individuals should not step on the escalators moving in an opposite direction. It is recommended that, users should not take with them electric scooters, strollers, wheel chairs, hand cars or other similar items when using the escalator (American Society of Mechanical Engineers 56).
Lifts and escalators should comply to set rules and standards. The safety components for lifts and escalators should be approved by EMSD. Escalator and lift works such as maintenance, installation, demolition and any alteration should be undertaken by registered escalator or lift contractors. Registered escalator and lift engineers should inspect the lift and escalator and unsure the lift has safety working order before it is used. This is normally done after major alterations. Additionally, the EMSD is entrusted with the role of setting standards for lifts and escalators. For instance, the CoP on the construction and design of escalators and lifts and the code of lifts and escalators works. The lifts and escalators should meet such standards (Emmitt et al. 46).
Examples of electrical power management systems and their features
Power Relays PR60/PR80
Power relay systems are designed to switch off high currents and are designed to be used under hash environmental conditions. It has bistable PR80 and Monstable PR60 which are utilized as battery isolation switches and are capable of disconnecting currents of up to 300 A. Both the two models offer different mounting styles and high degree of protection against dust or water which triggers installation in every type of vehicle. The double or single pole battery master switch of type BMS01 offers several functions such as deactivating electronic system of the vehicle prior to switching off its battery (ETA 9).
Thermal Circuit breakers of type 412, 413, 4120, 483 and 452
These breakers provide high level of performance, which are unrivalled in the market. The systems are qualified for several severe conditions with outstanding vibration and shock resistance. The systems are mainly designed to protect heavy current main distribution wires and various construction rigorous demands. Pull and push actuation prevents the danger of various accidental disconnection of crucial circuits. For instance, in applications where large cables are utilized, there exist the risk of short circuit, in this case, thermal actuation with high fault rating ability are used (ETA 8).
Circuit breaker system type 1170
Circuit breaker of type 1170 is a breaker for protecting loads and various electrical systems. The breaker has a snap-action mechanism, rapture captivity of four hundred and trip-free mechanism offers comprehensive safety. The mechanism of snap-action ensures that there is switch-on function without detrimental arcing, the trip-free mechanism make sure there is reliable disconnection even if the reset button is blocked. Circuit breaker has a retained clip which ensures there is good and proper electrical connection and fixed fit on the terminal block (ETA 7).
Power distribution system (SocketPlus 12)
Socket Plus power distribution system is designed specifically for mounting rail in combination with the circuit breaker of type 1170. The system can be effectively be bridged both on the output and in the input side which enables different types of circuit designs. Its spring loaded terminal makes it easy for mounting. The power distribution system has two terminals on its input side and four terminals on its output side, the terminal obviate extra probable terminals. This helps in saving valuable installation space (ETA 7).
Circuit breaker type 1620
There exists a problem of installation space with big construction machines, however, the integration of several functions by keeping similar outer dimensions results to downsizing also in the mobile machinery. The response to the problem is the installation of circuit breaker of type 1620. The development of the circuit breaker is based on the development of type 1610 which has been sold for several years. Circuit breaker has MINI footprint and provides all types of reset including manual release facility, autoreset and modified (ETA 6).
ETA. Power management Systems. 2015. Retrieved From < http://www.e-t- a.com/fileadmin/user_upload/Ordnerstruktur/pdf-> Data/Broschures_Magazines_etc/Broschures/Broschures_e/B_Baumaschinen_e.pdf
Bangash, M Y. H, and T Bangash. Lifts, Elevators, Escalators and Moving Walkways/travelators. Leiden: A.A. Balkema, 2006. Print.
American Society of Mechanical Engineers. Safety Code for Elevators and Escalators: Includes Requirements for Elevators, Escalators, Dumbwaiters, Moving Walks, Material Lifts, and Dumbwaiters with Automatic Transfer Devices. , 2013. Print
Emmitt, Stephen, R Barry, and Christopher A. Gorse. Barry’s Advanced Construction of Buildings. Chichester, U.K: Wiley-Blackwell, 2010. Print.