Installing The Warning Light; Multiplex Systems Operating At 24 Volts; Pre-Operational Check; Figure 2-6 Example Of Warning Light Installation - Will Burt Night Scan Chief Installation, Operation & Maintenance Manual

2.9 INSTALLING THE WARNING LIGHT

As required by NFPA regulations, a red flashing or rotating light, located in the driving compartment, must be
automatically illuminated whenever the vehicle parking brake is not fully engaged and the light tower is
extended. The warning light is wired into the system via the interlock contact described above. A customer
provided, normally closed pilot relay should be installed on pins J4-8 and 9 of the base circuit board. See the
wiring schematics in section 4.4. A customer supplied flashing relay and lamp may then be installed in the
driving compartment such that the driver can see the lamp. One example using a Bosch relay is shown
below.

2.10 MULTIPLEX SYSTEMS OPERATING AT 24 VOLTS

When operating at 24 volts, the Night Scan Chief "chops" the voltage sent to the 12 vdc motors is the system.
As a result of this starting and stopping, voltage might be fed back through the power wires and into the
power supply. In some instances, this may lead to unexpected behavior in a multiplex system. In order to
mitigate this back feeding of voltage, an 820uF capacitor (Will Burt Part Number 204001) can be placed
across the positive and negative input terminals (TB3-5 and TB3-6) on the base circuit board. Please refer to
wiring schematic Figure 4-8. Note the direction of the capacitor for installation.

2.11 PRE-OPERATIONAL CHECK

Revision 1
TO BATTERY
( - )
R
WARNING
LIGHT
Figure 2-6 Example of Warning Light Installation
Before beginning installation, make certain that the area is free
of overhead power lines and other unwanted sources of
electricity. Follow OSHA safety regulations when working near
energized power lines. Be sure to allow sufficient clearance on
all sides of mast to allow for side sway.
For outdoor use only. Do not use in areas that have been
classified as hazardous as defined in Article 500 of the
National Electric Code.
Do not use in the presence of flammable gases or liquids
such as paint, gasoline or solvents. Do not use in areas of
limited ventilation or where high ambient temperatures are
TO BATTERY
( + )
BOSCH RELAY
86
30
0 332 209 151
OR EQUAL
87A
87
85
PIN- J4-8
PIN- J4-9
Night Scan Chief
2-6