Tapco Adaptive Alpha Premier, Installation And Maintenance Manual

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4-2 A
LPHA
PID S
IGN
I
NSTALLATION AND
M
AINTENANCE
M
ANUAL
(PN 1260600601 R
EV
. B )
Electrical Installation
E
ARTH
-
GROUNDING SIGNS
4

Earth-grounding signs
Properly grounding each sign is necessary because it is an essential means of preventing shock, shock hazards, and potential fire
hazards.

Lightning strike protection
A sign bonded to an earth ground has a means of dissipating the high voltage and current from a lightning strike. The resistance of the
grounding electrode must be as low as possible. However, damage can still occur to a sign’s electronic equipment from lightning
voltage transients.
Though some surge protection is incorporated into a sign, to protect a sign from high-voltage lightning transients, surge protectors need
to be installed in accordance with NEC Articles 280 and 285 and local codes.
WARNING
Failure to properly ground the sign could result in elevated voltage from lightning entering the sign seeking a path
to earth. The high voltage can result in electric shock, fires, and the destruction of the sign from lightning.
The following guidelines must be
followed or the warranty will be void:
• Signs must be grounded in accordance
with Article 250 of the National Electrical
Code and in accordance with applicable
local codes.
• Do NOT terminate the ground on metal
poles or buildings. The metal will corrode,
resulting in deteriorated grounding
properties. Additionally, metal poles or
buildings are often mounted on material
that does not provide an effective ground.
Adaptive also recommends the following
guidelines:
• Use copper-clad ground rods as the
grounding electrode. They provide
effective grounding for an indefinite period
of time.
• Depending on the local soil conditions and
codes, more than one ground rod may
need to be installed.
• Since moisture becomes more stable at
greater distances below the earth's
surface, when possible, install the ground
rod so that eight feet extend below the
frost line to lessen the deviation in the
system's resistance.
• Verify the grounding electrode conductor
is securely attached at both ends.
G r ounding ele c t r o de
(g r ounding r o d)
F ound a tion
Si z e of g r ound r o d must b e in ac c o r dan c e
with n a tional and l oc al ele c t r i c al c o de s .
E quipme n t g r ounding c ondu c t or
Signs MUST BE EA R TH-G R OUNDED in ac c o r dan c e with Article 250 of the
N a tional E le c t r i c al C o de (NEC) and in accordance with local codes.
ance of less than 10 ohms. Verification of
ground resistance is essential.
The sign must be properly grounded or the warranty will be void.
I f y ou h a v e a n y question s , c onsult a c e r tified ele c t r ician.
C onne c t ed t o g r ound
lug on back of sign
P r o t e c t the g r ounding ele c t r o de
against p h y si c al damag e .
R e f er t o table 250.122 in the
NEC f or the p r o p er si z e of the
equipme n t g r ounding c ondu c t o r .
Y ou c an get a c o p y of the NEC f r om the
N a tional F i r e P r o t e c tion A ss oc a tion
a t ww w .nfpa.o r g .
October 2011
Ea r th- G r ounding Ou t d o or Signs
G r ound lug - l oc a t ed
on the back of the sign
For illustration purposes only. Not drawn to scale.
Document No. 97197008-ESN Rev B.
eSign requires ground resistance of less than 10 ohms.
Verification of ground resistance is essential. Verification of ground resistance is essential.