“Elevator Technology and its Engineering are very difficult topics to understand. I have seen many Engineering Graduates passing out from Institutes like IIT, but failing to understand how an Elevator works and the Controlling Logic behind AN ELEVATOR”.
I was working in a MNC which was No 1 in the Elevator Industry in the world. I worked in that Company from August 1987 till February 1997. Later I decided to resign from the Company and join one of the Contractors of the same Company who was in to actual installation and commissioning of the Elevators. He was No 1 contractor in the Company and had established his business for around 7 years.
Elevator installation, Commissioning and Maintenance are very risky businesses. There’s absolutely NO scope for any human error or even the equipment malfunction at all. One HAS to do everything right and then only leave the Elevator for regular use of the passengers.
Most of the commissioning and maintenance of the Elevator is done from the ‘TOP’ of the Elevator Car, whereas the passengers travel from ‘INSIDE’ the Elevator Car. The installation part of the Elevator is done by using bamboo or steel scaffolding, which is erected in the vertical passage called Elevator Shaft or the Hoist way. The Elevator ‘runs’ in this fire resistant, enclosed hoist way and takes passengers up and down. Modern and advanced methods of Elevator Installation don’t require the bamboo scaffolding to be erected in the hoist way. These methods are called w/o scaffolding installations and are quite common these days.
Once the installation of the Elevator is completed, the bamboo scaffolding is removed from the hoist way and commissioning part starts. In the commissioning part, the Elevator Engineer fine tunes the Elevator which mainly involves things like –
- Ensuring proper functioning of all the buttons and bulbs inside the Elevator as well on every floor.
- Smooth starting and stopping of Elevator on each floor and opening of doors.
- Ensuring that the Elevator stops at the exact floor level.
- Adjusting open and close timing of the door.
- Ensure noiseless, jerk less and smooth ride of the Elevator.
This fine tuning is done through the Elevator Controller and Elevator Machine which is normally installed on the highest slab or on the top of the Elevator hoist way. There is a room constructed around this top side of the slab known as Machine Room. In recent times due to shortage of space we even see Machine Room Less (MRL) Elevators. In MRL Elevators, the Elevator Controller is accommodated on some floor; usually on the top floor and the motor and machine are accommodated in the hoist way itself.
The Safety factors that the Elevator Engineer checks while commissioning involve –
- Passenger Safety –
- Ensuring that the Elevator won’t start before the doors are closed completely.
- Proper functioning of STOP, ALARM and DOOR OPEN buttons inside the Elevator.
- Activation of certain safeties in case of Elevator over speeding.
- Ensuring that the Elevator won’t cross the top or bottom most levels significantly by adjusting LIMIT SWITCHES installed at these levels.
- Ensuring that the Elevator reaches to the nearest landing safely in case of Power Failure.
- Ensuring that the Elevator door reopens while someone is entering the Elevator at the time of door closing.
- Elevator Engineer’s Safety –
- Activation of certain safeties while going on the top of the Elevator and coming out from there.
- Ensuring that the Elevator runs ONLY IN SLOW SPEED when operated through buttons on Elevator top while in maintenance.
- Ensuring that Elevator will not respond to any calling buttons inside the Elevator or to buttons on every floor, while in maintenance
- Activation of certain safety switches on the Elevator top to ensure safety of the person working while in maintenance.
- Mechanical – Ensure that a railing on the Elevator top is firmly in place to the waist level minimum, to avoid a fall from top of the Elevator in to the hoist way.
- Elevator Equipment Safety –
- General safety factors associated with Safety of Elevator Car, Elevator Controller and the Elevator Machine.
If any of the above Safety Factors are not adjusted properly or in worst case bypassed, there is a 100% chance of an Accident to the Passenger or to the maintenance guy or to the equipment. The chance of an Accident is ever increasing as there is a thing called Elevator Working Logic. Some part of the logic needs to be adjusted and set by the Engineer through the Controller and the Machine. The program involves lot of permutations and combinations which if not adjusted properly will surly lead to an accident.
But one need not worry at all as the programs in Modern Elevator Controllers are FACTORY SET and the Engineer has to hardly adjust a few things associated with actual installation of the Elevator.
In the decade of 1980 the Elevator Industry started using more and more compact Electro – mechanical relay based Controllers. Prior to that Conventional Relay based Controllers were common which were very huge in size due to many big Relays and big Coils in place. This was just like those Relay based big radios, TVs and other equipment.
Gradually Elevator Industry started manufacturing Electronic SMART Controllers with a very few relays. These Controllers are also called PLC Controllers (with Computer based technology). Certain logic of the Elevator is now programmable through the Circuit board (PCB) installed in the Controller, called the Logic Board.
A handheld device is used to program the entire Elevator Control System and is attached to the Logic Board on the Controller.
So for a 20 years old building, which wants to upgrade their Elevator/s can just go for an option of changing the Elevator Controllers and the machines with the latest ones.
In an Elevator Company, the department which handles such contracts is called as Modernisation Department. So after leaving the Elevator MNC in 1997, I started undertaking Elevator Modernisation Contracts in South Mumbai area along with the contractor whom I had joined hands with.
To be cont’d…14