6
Power Installation
3.2 Grounding
Displays MUST be grounded according to
the provisions outlined in any applicable
local and national electrical codes and
according to the specifications in this
manual. Daktronics requires a resistance to
ground of 10 ohms or less.
The display system must be connected to an
earth-ground electrode installed at the
display, as shown in
. Proper
grounding is necessary for reliable
equipment operation and protects the
equipment from damaging electrical
disturbances and lightning. Refer to
Drawing B-329675
for more information on
grounding.
The display must be properly grounded, or
the warranty will be void.
Important points about grounding:
•
Follow local and national codes:
The material of an earth-ground electrode differs
from region to region and from conditions present at the site. Consult any local and
national electrical codes that may apply.
•
Do NOT use the support structure as an earth-ground electrode:
The support
structure is generally embedded in concrete. If embedded in earth, the steel is either
primed, or it corrodes, making it a poor ground.
•
Provide one grounding electrode for each sign structure:
The grounding electrode is
typically at least one grounding rod for each sign structure. Other grounding
electrodes as described in any applicable local and national electrical codes may be
used.
•
Confirm that resistance to ground is 10 ohms or less
: This is required by Daktronics
for proper display performance. If the resistance to ground is higher than 10 ohms, it
will be necessary to install additional grounding electrodes to reduce the resistance.
The grounding electrode must be connected to the ground wire inside the display.
Figure 4: Correct Grounding
