Electric Lift Potential Brake Problem
Figure 1: An example of typical electromagnetic brake
arrangement at electric lift motor
This safety alert is intended for any person involved with
installation,inspection,examination,testing andmaintenance of
electric lift. There have been incidents (in 2011 and 2012) where
the electromagnetic brake failedto function properly, causing the
lift car to suddenly crash. These cases may have been caused by the
failure ofthe brake pads to be applied; the plunger (inside the
electromagnetic device) got stuck and failed to close thebrake
lever arm; and the lever arm for the pivot pin got jammed during
its activation because of some inherentdefects.
Recommended Actions:
Therefore, the following actions are recommended:
Lift maintenance service company must ensure that proper
lubrication is applied to any joint of the moving
parts, especially for the electromechanical braking system. This
activity must be consulted with the relevant
lift manual and manufacturer regarding the detail of maintenance
required (e.g. type of maintenance,
maintenance part/point, lubrication type, interval frequency,
etc).
1.
Proper documentation system must exist to support the above
exercise. This will also provide transparency
and enable audit checks to ensure the integrity of the
maintenance program.
2.
The supervisor must monitor and check on the work done, as well
as assess the understanding of their
technicians in carrying out the task to ensure that the task is
carried out satisfactorily.
3.
Refresher technical courses on the correct adjustment, oiling,
inspection and testing of the electromagnetic
brake mechanism shall be conducted for enhancing the knowledge
and skills of the lift servicing personnel.
4.
The electromagnetic brake mechanism shall be tested and examined
once every three months by the lift
competent personnel registered with the department. His
observation shall be recorded in the lift register.
5.
Further readings:
Howkins, R.E. 2006. Lift modernisation design guide. Elevator
World, Alabama, USA.1.
Annet, F.A. 1989. Elevators electric and electrohydraulic
elevators, escalators, moving sidewalks, and2.
Electric Lift Potential Brake Problem
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