Escalator Installation and Components

Escalator Installation - Learning Outcomes

• Understanding the major components in escalator installation is crucial
• Knowing the functions of the major components is important
• Understanding the safety functions in escalator installations is key
• Testing and commissioning escalator installations is essential

How Escalators Work

• Escalators utilize a complex system of components to move people
• Key components include: steps, handrail, driving mechanisms (gears, electric motor), chain guides, return wheels, and inner rails
• The entire system works in a coordinated fashion to move passengers up or down

Operation of Escalator

• The motor drives chains and sprockets
• Chains are responsible for driving the handrail and the step chains
• All components work together to ensure safe and smooth operation

Escalator Components (Panel or Balustrade)

• Includes hand rails, step, skirt guard safety switches, and other safety devices for operation and maintenance
• Current overload relay and main drive gear are examples of additional safety elements

Main Drive

• The main drive is the power source for the escalator, driving the step and handrail chains
• The main drive includes a vertical induction motor, a gear reducer, a brake governor, and a driving chain sprocket

Drive Chains

• Roller chains drive the main drive sprockets, which in turn drive other chains for steps and handrails.
• This part of the system is crucial in the operation of the escalators.

Steps

• Four wheels are present on each step
• Two driving wheels and two follower wheels are present
• Made from grease packed bearings with rubber or nylon tyres

Step Chains & Handrail Chains

• Step chains are connected to the driving wheels of the steps
• Steps travel along step tracks
• Handrail chains drive the handrails through friction sheaves (drive rollers)

Steps (Design and Materials)

• Step designs are typically standard across manufacturers
• Materials used are typically die-cast aluminum or stainless steel

Balustrade (Design and Materials)

• Balustrades may be solid with Formica or laminated panels, translucent with acrylic materials, or translucent with tempered glass
• Some designs combine these aspects

Balustrade (Lighting and Additional Safety)

• Lighting is often installed beneath handrails for translucent or transparent balustrades
• Modern designs often use self-supported glass panels

Comb & Combplate

• Made of either plastic or cast aluminum
• The teeth of the comb must be brittle to break on obstruction
• Comb teeth are accurately aligned with the tread boards to prevent wear and tear

Handrails

• Moving handrails support passengers to maintain balance
• Driven at or near step speed
• Commonly made with synthetic or natural rubber reinforcement in steel tape, steel wire or fibre wool
• Handrails have a lifespan exceeding five years

Emergency Stop Switches or Buttons

• Typically placed at the top and bottom landings of escalators
• Often red or yellow push buttons for emergency stopping.

Broken Step Chain Safety Device

• Situated at the bottom landing of the escalator's truss frame
• Controlled by a spring tensioning device
• Actively stops the escalator motor and step train if the step chains sag or break

Broken Drive Chain Safety Device

• Located in the upper truss part
• Activating the device stops the motor when the drive chain breaks

Skirt - Additional Safety Device

• Serves as an additional safety function
• An example of a safety device installed on the escalator.

Handrail Cut-off Safety Device

• Part of the safety mechanism of escalators
• Installed on the inclined side behind the skirt guard
• Ensures the escalator stops if the handrail stretches or sags beyond pre-set limits

Handrail Guard Safety Switches

• Located at upper and lower landings of the escalator
• Designed to stop operation when a foreign object, such as a person's fingers, is drawn into the handrail.

Drive Chain and Step Chain

• Drive chain and step chain are fundamental components of the escalator's operation

Apex Guard

• Serves a key role in the safety of the escalator design
• Specific details are included in the drawing

Escalators (Summary of Information)

• Escalators can be reversed when stationary
• Typical speed is 0.5 m/s
• Includes vertical speed of 11 m to 11 m
• The riding time for escalators can be up to 45 s, depending on the vertical distance

Escalator Components (Truss)

• Rigid steel construction, joined by reamer bolts
• Located at the base of the escalator

Escalator Components (Main Drive)

• Includes vertical induction motor, gear reducer, brake governor, and driving chain sprocket

Escalator Components (Drive Chains)

• Consists of step chain and handrail chain
• Essential for operating the handrails and steps

Escalator Components (Steps)

• Includes 4 wheels per step: 2 driving and 2 followers
• Made from grease-packed bearings with rubber or nylon tires

Escalator Components (Balustrade)

• Includes Formica or laminated panels (solid), translucent panels (acrylic or tempered glass)
• Combination designs are also possible

Escalator Components (Comb and Combplates)

• Made from plastic or cast aluminum
• The teeth must be brittle for safety functionality
• Accurately aligned to prevent wear

Escalator Components (Handrails)

• Provides support for passengers ensuring balance
• Driven at similar speed to the steps
• Material commonly includes natural or synthetic rubber reinforced in steel

Escalator Components (Controllers)

• Controls the up and down movement of the escalator
• Ensures safety features such as interlocks are engaged
• Powers lighting and manages maintenance control

Escalator Safety (Possible Accidents)

• Trapping between steps
• Falling at exit/entrance
• Falling during emergency stopping or reversals

Escalator Safety (Prevention)

• Broken step, chain, and motor issues
• Emergency stop mechanisms
• Stopping during overspeed conditions

Escalator Safety (Prevention - Additional details)

• Foreign objects (step rollers, skirt guards, apex guards) stopping handrail
• Handrail cut-off devices, and handrail guard safety switches

Escalator Safety (Notices)

• Guidelines for safe use
• Specific instruction for use, such as holding the handrails, facing the direction of travel, and not allowing pets

Escalator Safety (Maintenance Procedures)

• Procedures are in place to avoid damage or stop the escalator in case of accidents.
• Cordon off the areas where maintenance is taking place

Escalator Commissioning

• Includes operational tests, safety device inspections, electrical checks, and brake/insulation resistance tests.

Escalator Maintenance

• Safety switches condition
• General operation conditions (relays, combs/comb plates, lighting)
• Checks on chains (drive and step), handrails, apex and skirt guards, machine pit cleanliness

Explore the key components, functions, and safety features of escalators. Understand the mechanics behind how escalators operate, including the driving mechanisms, step chains, and safety devices. Learn about testing, commissioning, and the coordinated system ensuring smooth passenger transport.