Elevator breakdown

  • Description of defect

Lift stop operating can cause passengers being trapped inside the elevator car. This malfunction can be highly dangerous as it can cause the passengers to experience panic attacks. Electrical power failures also can lead to sudden and abrupt stops which can cause injuries to the passengers inside the car

 

  • Causes
  1. Electrical power failure due to severe weather condition and power grid problems
  2. Electronics and computer programs faulty
  3. Faulty backup generator
  4. Misuse and vandalism caused by passengers – pressing the destination button multiple times can cause the buttons to jam, forcing the lift door to open multiple times or for a long time, and urinating/spilling liquids in the lift car also can cause the lift to breakdown
  5. Elevator Automatic Rescue Device (ARD) faulty due to technical faulty, defects in battery, wearing and expiry of the device

 

  • Diagnostic/testing method

The general condition of testing conducted for UPS shall cover the supply voltage, absence of supply voltage, supply frequency, charge condition of the battery, physical location of UPS and position of moveable parts, operating mode and adjustment of regulating device and thermostats.

The leakage current and heating tests shall be performed at input voltage tolerance. Power failure simulation test shall be conducted at least once every 6 months to check that ARD and EBOPS properly functioned, and the battery capacity shall have minimum of 70% of the original specification (SS550)

 

  • Good practices

The power supply shall be automatically switched to emergency power supply from the standby generating system when there is a case of power failure of power interruption.

The ARD device shall bring the lift car to the nearest floor with the doors opened. The ARD shall have sufficient capacity to sustain a minimum of two consecutive emergency operations and be fully charged within six hours after the emergency operation (SS550)

 

  • Corrections

Uninterrupted Power Supply (UPS) shall be used to replace the requirement of Emergency Battery Operated Power Supply (EBOPS) in SS550 and it shall be complying with IEC 62040-1.

All projects must incorporate the use of UPS as emergency power supply and this power will be used to supply for lighting, ventilation alarm bell and intercom with the purpose to reduce the anxiety of trapped passengers.