Service manual

Refer to the “Bonding” section under “Installation Materials and
Specifications” for bonding conductor to the ground rod and scoreboard
frame.
Once the conductor is bonded to the ground rod, it needs to be protected
from corrosion 3 feet above the ground level to the bonding with the
ground rod. Electrician’s tar type seal and wrap would be the most appro-
priate, but a cured plastic coat or sealed conduit could also be used.
Down conductors need to be guarded from physical damage and displace-
ment. A minimum of 6 feet should be protected above ground level. PVC
conduit is acceptable.
Make sure that any bends in the conductor do not have less than an 8-inch
radius. This provides a smoother path for current to flow, see Fig. 23 on
page 4-2.
A down conductor is recommended from each end of the scoreboard.
Attach the conductor bolt in the scoreboard endplate where applicable
using a terminal lug and bi-metal shim (see Fig. 24B & 24C, page 4-3).
Where pole mounting and endplates are present, drill a hole in the alu-
minum frame above or below the back ABS black plastic panel using the
same bonding hardware, see Fig. 27 below. The inside of this hole can be
reached from the top of the scoreboard. Make sure the anodized aluminum
is removed where the conductor is mounted.
Figure 27
If the scoreboard is mounted to a metallic mounting structure, the struc-
ture can be substituted for the main conductor only if it is at least 3/16
inch thick and meets the cross-sectional area of 57,000 cm. In addition,
wherever the scoreboard is bolted to this structure via unistrut or other
painted hardware, remove the paint in that area to make a good
connection.
In a few cases, the metallic mounting structure extends below the ground,
deep enough to eliminate the ground rod. In this case, the structure needs
to be connected to the main system ground. This eliminates any ground
potential differences. The majority of mounting structures are secured in
concrete.
Conductor Routing
4-5