18
EARTH GROUND WIRING
A module with exposed conductive
parts is considered to be in compli-
ance with UL 1703 only when it is
electrically grounded in accordance
with the instructions presented be-
low and the requirements of the
National Electrical Code.
The array frame shall be grounded
in accordance with NEC Article 250
(USA) or the CEC.
All modules should be grounded. All
structures or metallic components in
direct contact with the modules or
electric wires should be properly
grounded too.
Each ledge on the module frame
has two larger holes for bolts
(0.205’‘diameter (5.2 mm)). These
ground holes are marked with
"earth indication mark" adjacent to
their location on the frame rail (see
Figure 16-1.).
Ground wires must be connected to
the module’s metal frame at one of
these locations.
Length of bolt should not be more
than 0.78’’ (20 mm) in order to
avoid contacting the back-sheet of
the module.
Lay-in lugs or grounding clips can be
used to ground Panasonic PV mod-
ules. Both methods are explained
below, please choose one.
Great care should be exercised to
ensure that corrosion caused by the
grounding means be avoided.
Corrosion can increase the re-
sistance of the grounding connec-
tion on the module, or can even
cause the grounding connection to
fail entirely. Corrosion can be
caused by the effects of weather,
humidity, dirt and so on. It can also
be caused when two dissimilar met-
als are in contact (galvanic reac-
tion).
The module frame material is alumi-
num/magnesium alloy.
All fasteners (nuts, bolts, washers,
screws, etc.) must be stainless steel
unless otherwise specified.
We recommend installing a light-
ning rod and SPD (Surge protection
device) to reduce damage or break-
down to the PV module caused by
lightning. Check with your local AHJ
on specific code requirements relat-
ed to the grounding of PV Systems.
GROUNDING METHODS
Where common grounding hard-
ware (nuts, bolts, star washers, spilt-
ring lock washers, flat washers and
the like) is used to attach a listed
grounding/bonding device, the
attachment must be made in con-
formance with the grounding device
manufacturer’s instructions.
Common hardware items such as
nuts, bolts, star washers, lock wash-
ers and the like have not been eval-
uated for electrical conductivity or
for use as grounding devices and
should be used only for maintaining
mechanical connections and holding
electrical grounding devices in the
proper position for electrical con-
ductivity. Such devices, where sup-
plied with the module and evaluat-
ed through the requirements in UL
1703, may be used for grounding
connections in accordance with the
instructions provided with the mod-
ule.
Backside of
Junction Box
Label
Microinverter
The ground holes are on the
backside of the module frame.
Ground Location
Figure 16-1.
Module Ground Position
(150) or (215)
