Terex Series AL4000, Operation & Service Manual

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LIGHT FIXTURE TROUBLESHOOTING (cont’d)
SYMPTOM CAUSES CORRECTIVE ACTIONS
SHORT LAMP Lamp damaged Check for outer bulb cracks. If air enters outer bulb, arc tube
LIFE may continue to burn for 100 hours before failure. Check for
bulb cracks where glass meets the base due to tightening lamp
too firmly in socket. Look for broken arc tube or loose metal
parts. Replace lamp.
Improper ballast Ballast nameplate data should agree with lamp line voltage
and lamp use. If improper ballast is used, the lamp life will be
shortened. A mismatch may also cause the ballast to fail.
LAMP Improper ballast Improper ballasting can cause flickering or erratic operation.
FLICKERS AND In the start-up period the lamp may ignite, start to warm-up
GOES OUT and then extinguish (cycle).
INTERMITTET
New lamp Under certain conditions new lamps may “cycle”. Usually
after three (3) tries to start at 30 to 60 second intervals, lamps
will stabilize and operate satisfactorily.
Defective lamp Replace lamp.
High spike ballast Ballast produce high spike current. Measure with oscillo-
scope. Replace ballast as required.
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