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Installation and Maintenance Manual
Federal Signal
www.fedsig.com
Maintaining and Servicing the Allegiant
5. Inspect the dome for cracks, crazing (hairline cracks) and other defects.
Reinstalling the Dome
To reinstall the dome:
1. Reinstall the dome. To prevent cross-threading the barrel nuts, back them
counterclockwise until you hear the click of the threads engaging.
2. Tighten the barrel nuts to 16-24 in-lb.
Replacing a PCB
The Allegiant 45 light bar has two end and two intermediate ROC PCBs as well as a
controller PCB (Figure 9). The 53, 61, and 70 bars also have center ROC PCBs. They
are configured at the factory per the customer order. The end and intermediate ROC
PCBs snap onto a common reflector.
The 21-inch Allegiant light bar has a single ROC board set. This set is configured at
the factory per customer order.
STATIC SENSITIVE DEVICE: This light bar circuitry can be damaged by
electrostatic discharge (ESD). Follow anti-static procedures when servicing
this light bar.
Figure 9 Locations of ROC PCBs (53-inch light bar shown)
FRONT OF BAR
END PCB
END PCB
INTERMEDIATE
PCB
CTR PCB
CONTROL PCB
PS
DS
INTERMEDIATE
PCB
