Daktronics AB-1600-1.5,2.5 - Manual (Page 25)

Electrical Installation
3-5
If the line voltage is above 120 volts, changing the transformer configuration will increase 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, the lamp
will receive increased voltage. This will greatly reduce lamp life. Connecting to the 120-volt tap will
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
All power routing and termination must comply with local codes and standards.
Proper grounding is necessary for reliable equipment operation. It also protects the equipment from
electrical disturbances and lightning. Failure to adhere to the following grounding methods will void
the warranty.
Ground displays according to the provisions outlined in Article 250 of the National Electrical
Code
® .
Do not use the steel support structure for grounding the display. The support is generally imbedded in
concrete, and if it is in earth, the steel is either primed or it corrodes, making it a poor ground.
The two considerations for power installations, new power installations and existing power
installations, differ slightly.
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
®
. Daktronics recommends a resistance to ground of 10 ohms or less.
Connect the display system 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 structure and 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. Do not use the support structure of the display 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.
Branch Circuit Grounding
A grounding electrode at separate structures/displays shall not be required where only one
branch circuit supplies the structure and the branch circuit includes an equipment-grounding
conductor for grounding the non-current-carrying parts of all equipment.