AEDARSA ADVISOR SAFETY BULLETIN
December 5, 2002
To All Elevator Contractors and Accredited Agencies Our files: 5703-1, 5751-1 AEDARSA Edmonton AEDARSA Calgary 207, 8616 - 51 Avenue 209, 264 Midpark Way SE Edmonton AB T6E 6E6 Calgary, AB T2X 1J6 Ph: (780) 448 0184 Fax: (780) 448 0237 Ph: (403) 216 5750 Fax: (403) 216 5755
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Subject
US Elevator Ascension 2000 Hydraulic Elevator Controls
Risks Associated with Testing/Trouble Shooting Solid
State Controls
BACKGROUND
We were recently advised that on an initial inspection of a hydraulic elevator with Ascension 2000 controls in another jurisdiction, an inspector found the door monitor circuit to be functioning properly when first tested. During subsequent redundancy tests, printed circuit boards of the control were damaged when jumpers were placed on the wrong terminals. After the damage was repaired, door monitoring was again tested and found not to be functioning.
SAFETY ISSUE
An investigation revealed that the door monitor circuit can be turned on and off. It seemed that when jumpers for testing redundancy were put on the wrong terminals the setting for the door monitor circuit was turned off. During an investigation it was discovered that the door monitor circuit can also be turned off with the maintenance tool.
ANALYSIS
Putting jumpers in the wrong control circuits might have caused the door monitoring to be turned off. However, while it may be expected that the feature is intentionally turned “off” for construction purposes to be turned “on” before the device is placed in service, the final step could be missed. Given this scenario, assuming maintenance tools are used for switching on and off, it seems possible that door monitoring could be turned off during maintenance/ trouble shooting as well.
PREVENTIVE ACTION
Specific - Check all elevators equipped with Ascension 2000 controllers that your company maintains or inspects to ensure that the door monitoring circuits are functioning properly. Report the details (e.g. device location and provincial I.D. number) of any instances where the above defect is found to AEDARSA.
General - Elevator maintenance contractors should caution maintenance personnel and adjusters to the effect that when they conduct tests or use maintenance/diagnostic tools on solid state controls to ensure that all safety circuits, devices, systems function as originally intended after such procedures are completed.
Note: Door Monitoring - B44-94 Cl. 2.12.1.5(a); Redundancy – Cl. 2.12.1.5(b)
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