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Elevator positioning system USP 30 / 100
Trouble Indication
Yellow
(page 62 - Reference D)
A permanent yellow light indicates either no or a weak ultrasonic signal. The receiver can either
identify no position at all of the sender or it cannot generate any absolute value.
Possible Causes
• Sharp bends in the wire (ca. 90% of all causes)
• Scratches of the wire
• Reflections in the damper
All the above types of failures will reduce, contaminate or reflect the ultrasonic signal.
Action, execution and relieve
a) Inspection of wire: bends or scratches
Ride through the shaft on the cabin top with inspection pace and inspect the wire ptically
and manually with your eyes and fingers for bends or scratches. Fix small bends manually;
only in few cases you need to change the wire.
b) Inspection of damper
It may be the case that the wire is fixed between the shells of the damper housing. In this
case the not absorbed signal will be reflected back into the wire and the receiver will not re-
ceive a clear signal. After you have checked the wire in the above way, you should open the
damper housing and check the position of the wire between the rubber shells.
Hint:
The wire will leave marks in the rubber; by this you can identify its former position.
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