Daktronics Galaxy AF-3112 Primary Series, Руководство пользователя

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Figure 19: Ground Conductor
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.
A minimum of one grounding electrode must be installed for each display face. The
grounding electrode is typically one grounding rod for each display face. Other
grounding electrodes as described in Article 250 of the National Electric Code may
be used. Daktronics requires that the resistance to ground be 10 ohms or less. 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 should be
installed within 25 feet of the base of the display. The grounding electrode must be
connected to the ground terminal in the display panel board.
Note: This display is intended to be installed in accordance with the
requirements of Articl 600 of the National Electrical Code and/or other
applicable local codes. This includes proper grounding and bonding of the sign.
Power Installation
There are two considerations for power installation: installation with ground and
neutral conductors provided, and installation with only a neutral conductor provided.
For these displays, installation with ground and neutral conductors provided is used.
Electrical Installation
3-7
r Installation with Ground and Neutral Conducto s Provided
For this type of installation, the power cable must contain an isolated earth-ground
conductor. Under this circumstance, do not connect neutral to ground at the
disconnect or at the display. This would violate electrical codes and void the
warranty. Use a disconnect so that all hot lines and neutral can be disconnected.
Refer to
Figure 20
for installation details. The National Electrical Code requires the
use of a lockable power disconnect within sight of or at the display.