FIREMAN SWITCH

Each Lift shall have a Fireman switch with glass front for access by the Firemen. The operation of this switch shall cancel all calls to this lift and shall stop at the next nearest landing if traveling upwards. The doors shall not open at this landing and the lift shall return to the ground floor. In case the lift is traveling downwards when the fireman’s switch is operated it shall go straight to the ground floor bypassing all calls enroute. The emergency stop button inside the car shall be rendered inoperative.

The fireman’s switch shall be located adjacent to the lift opening at the terminal floor and shall be at a height of approximately 2 m above the floor level. For easy identification of firemen’s lift which confirm to the local authorities requirements, a red and white diagonal striped backing shall be provided behind the glass of the firemen’s switch.

A permanent notice of prominent size indicating the floors served shall be provided and displayed adjacent to the firemen’s lift at the terminal floor. The notice shall be made of laminated plastic sheet or other approved materials with red letters on white background. Details of the notice shall be submitted to the Engineer-in-Charge for approval prior to fabrication.

• Automatic By-pass

Load weighing devices located either on car top or under the car cage shall be provided for all lifts. Whenever the load exceed 60-70% of the capacity load of the lifts, the lifts shall ignore all landing calls and only respond to car calls.

• Over load device

A load weighing devices shall operate when the load in the car exceeds the rated capacity. The operation of the device shall activate buzzer sound and flashing ‘overload’ signals. At the same time the car doors shall be prevented from closing. When the excess load has been removed form the car, the buzzer alarm shall be muted automatically and the car shall function normally. The sensitivity shall be 30 kg for Passenger lifts and 5% of the contract load for service lifts.

• Automatic self-leveling

All lifts shall be provided with automatic self-leveling feature that shall bring the lift car level to within ± 3 mm for passenger/service elevators and + 5mm for freight elevators of the landing floor regardless of load or direction of travel. The automatic self leveling feature shall correct for over travel and rope stretch.

Automatic Rescue Device

The ARD shall have the following specifications: a) ARD should move the elevator to the nearest landing in case of power failure during normal operation of elevator. b) ARD should monitor the normal power supply in the main controller and shall activate rescue operation within 10 seconds of normal power supply failure. It should bring the elevator to the nearest floor at a slower speed than the normal run. While proceeding to the nearest floor the elevator will detect the zone and stop. After the elevator has stopped, it automatically opens the doors and parks with door open. After the operation is completed by the ARD the elevator is automatically switched over to normal operation as soon as normal power supply resumes. c) In case the normal supply resumes during ARD in operation the elevator will continue to run in ARD mode until it reaches the nearest landing and the doors are fully opened. If normal power supply resumes when the elevator is at the landing, it will automatically be switched to normal power operation. d) All the lift safeties shall remain active during the ARD mode of operation e) The battery capacity should be adequate so as to operate the ARD at least seven times a day provided the duration between usage is at least 30 minute. In addition, all the car and landing doors shall meet the following general requirements. a) Car door locking devices Every car door shall be provided with an electrical switch to prevent the lift car from being started or kept in motion unless the car door is closed. A mechanical locking device shall also be provided to prevent door opening from inside the car whilst the car is in motion. b) Landing door locking devices Every landing door shall be provided with a mechanical locking device to prevent opening of the door from the landing side in normal cases unless the lift car is in that particular landing zone. c) Projections and recesses Sliding car and landing doors shall be guided on door tracks and sills for the full travel of the doors. The distance between the cars and the landing sills shall not exceed 35 mm. d) Door locking devices All doors locking devices, door switches and associated actuating rods, levers or contracts, shall be inaccessible from the landing or the car. e) Protective devices Protective devices shall be fitted to the leading edges of both car door panels. It shall automatically initiate reopening of the door in the event of a passenger being struck (or about to be struck) by the door in crossing the entrance during the closing movement. The obstruction of either leading edge when closing shall actuate the protective device to function. f) “Door open” alarm “Door open” alarm shall be provided in the car to initiate alarm and a continuous buzzer if a car or landing door has been mechanically kept open for a present period. The period shall be adjustable from 0-10 minute.