Daktronics AB-1600-1.5,2.5 - Manual (Page 32)

Electrical Installation 3-6
If the line voltage is above the rated voltage, changing the transformer configuration will increase the
lamp life. Refer to the lamp life chart in this sub-section to determine the estimated lamp life based on
the line voltage check.
If the measured input line voltage is over the particular transformer’s rated input voltage, increased
voltage will be delivered to the lamp. This will greatly reduce lamp life. Reconfiguring the transformer
output may reduce lamp voltage and increase lamp life.
Contact a local electrician or the local power company if line voltage is substantially above or below
normal.
3.4 Power to the Display
Only qualified individuals should perform power routing and termination to the display. It is
the responsibility of the installer to ensure the installation will comply with local codes and
standards.
> Run power through conduit according to National and local electrical codes.
> Power cannot route through the display. Do not use the support conduit, located inside the display,
for power routing.
The following subsections address the routing of incoming power through a power disconnect switch
and the termination of incoming power at the display’s power termination panel. Daktronics completes
all power routing and connection within the display past the power termination panel prior to shipment.
When terminating the incoming power to the term panel, balance the individual power phases as evenly
as possible. Current draw per line, as noted on the sales literature or schematic is the high leg current
draw.
For a 2V display, bring power into both faces. The termination panel for the echo face is located in the
right end of the display. Connect power as stated above. The display has built-in surge protection.
However, for this to be effective the display must be properly earth-grounded.
Grounding
Ground displays according to the provisions outlined in Article 250 of the National
Electrical Code 7. Daktronics recommends a resistance to ground of 10 ohms or less.
The display system must be connected to earth-ground. Proper grounding is necessary for reliable
equipment operation. It also protects the equipment from damaging electrical disturbances and
lightning. The display must ground properly or the warranty will be void.
The material of an earth-ground electrode differs from region to region and from conditions present
at the site. Consult the National Electrical Code and any local electrical codes that may apply. The
support structure of the display cannot be used as an earth-ground electrode. The support is
generally embedded in concrete, and if in earth, the steel is either primed or it corrodes, making it a
poor ground.