Daktronics AB-1600-1.5,2.5 - Manual (Page 52)

Maintenance & Troubleshooting 4-8
4.5 Lamp Testing & Replacement
Reference Drawing:
Jack Designation & Layout, Test Fixture ...................................................Drawing A-96449
Daktronics designed this display for easy lamp replacement with front
access. Always replace non-functioning lamps prior to scheduled events,
or as soon as possible, for best viewing.
A 3.58-watt lamp is behind each lens. Use the controller lamp test to
locate bad lamps. Use the lamp test form located in Appendix C to
mark the location of bad lamps. Refer to Section 4.21 and Section
4.22 for the part numbers of replacement lamps and lenses.
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Daktronics-approved 3.58-watt lamps have an estimated life of
17,000 hours if operated at 11.0 volts. Always use Daktronics
approved lamps. Lamps purchased from Daktronics have tighter
specifications than similar lamps built in standard production. The
recommended lamps give the sufficient intensity and beam spread to
match the display design. Lamps not built to Daktronics
specifications will not perform as well, will not give the intended
results, and will adversely affect the beauty of the display.
•
A qualified individual who is capable of operating the controller equipment should do lamp testing.
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Display power must be OFF for lamp replacement.
The life rating of a lamp is the average value in hours within which 50% of a test quantity is expected
not to fail and within 70% of the rated life, 90% of a test quantity is expected not to fail. Lamp life will
increase if the average intensity of the lamp is less than the maximum intensity.
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Predicted lamp life is for lamps operating in a laboratory with continuous operation in a
stable temperature and mechanical environment. Actual lamp life will differ from predicted life
due to switched operation, varying temperature, mechanical vibrations due to wind, traffic and
display service, and actual hours of operation.
Typically, lamp failure rates for the 17,000 hour 11.0 volt lamp in the 1-
2 O displays is as follows.
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3% of the lamps normally fail upon reaching 35% of rated life (5,950 hours).
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10% of the lamps normally fail upon reaching 70% of rated life (11,900 hours).
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50% of the lamps normally fail upon reaching 100% of rated life (17,000 hours).
The balance of 50% of the lamps last longer than the rated life of 17,000 hours.
Example: The following chart shows predicted lamp failure for various displays based on a lamp
voltage of 11.0 volts, assuming the display is in operation for 18 hours a day. This chart is based on
the manufacturers’ test data and on laboratory conditions.
Figure 48: Lampbank and
Lens/Reflector Assembly