Daktronics BA-2009, Руководство пользователя

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4-2 Scoreboard Maintenance
and Troubleshooting
WARNING: It is critical that the scoreboard circuit be fused at 15 A and that all
conductors used must be designed to pass a 15 A current in normal operation. Failure
to meet wiring and overcurrent protection device requirements is a violation of the
National Electrical Code
®
and will void the scoreboard warranty.
All power conductors are 14 AWG, except where 18 AWG wiring is called out on
the schematic. All signal conductors are 22 AWG.
Refer to the outdoor scoreboard schematics listed at the beginning of this section and
to the chart in
Section 2 to determine circuit specifications and maximum power
requirements for the models described in this manual.
Grounding
Reference Drawings:
Schematic; Gen III Outdoor LED,
16 Column Drvr ..................................................... Drawing A-177931
Note : Displays MUST be grounded according to the provisions outlined in Article
250 of the National Electrical Code and according to the specifications in this
manual. Daktronics recommends a resistance-to-ground of 10 ohms or less.
The contractor performing the electrical installation can verify ground resistance.
Daktronics Sales and Service personnel can also provide this service.
The display system must be connected to an earth electrode installed at the display.
Proper grounding is necessary for reliable equipment operation. It also protects the
equipment electrical disturbances and lightning
.
Note: The display must be properly grounded, or the warranty will be void.
Refer to the schematic,
Drawing A-177931 , for information on where to connect the
grounding wire. The connection is illustrated in the “Pwr In” detail of the Master
Configuration portion of the schematic.
The material for an earth-ground electrode differs from region to region and may
vary according to 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 it is in earth, the steel is usually primed or it corrodes, making it a
poor ground in either case.
Power Installation
There are two power installations to consider: installation with ground and neutral
conductors provided, and installation with only a neutral conductor provided. These
two power installations differ slightly, as described in the following paragraphs:
Installation with Ground and Neutral Conductors Provided
For this type of installation, the power circuit must contain an isolated earth-ground
conductor.