6
.
4
Protective
G
round
C
onnection
6.5 Lightning Protection Grounding
In this solar system all the unloaded metal components and cases should be connected to
the ground.
Single inverter need grounding over a PE point, multiple inverters need connect all the
inverter PE cable and solar panels shelves to the same grounding point to achieve
equipotential.
Figure 6.8
Figure 6.9
21
22
Note:
Pay attention to the rain at the grounding wire terminal joint. Do not expose it
directly to the air. The recommended torque value for tightening the screw is 25kgf.cm.
1>It is generally recommended to install lightning protection devices (generally referred
to as lightning rods or lightning protection belts and down conductors at the top of
the building) to prevent lightning from hitting the PV array. (Note1)
2>Lightning protection devices and down-conductors and related equipment in
photovoltaic systems (including photovoltaic panels, inverters, cables, power
distribution equipment) shall maintain a safe separation distance S; Suggested value
of S: According to the general 5 storey height (about 15m) building roof, S takes 2.5m
enough, this distance can be simplified according to the inverse relationship of the
floor height. (Note2)
3>The lightning down conductor and the equipment ground wire eventually sink at a
total ground point, but the two cannot share the wire. That is, the equipment
grounding wire should be pulled separately, and the wire diameter requirement is
>6mm2 when the safety interval distance S is satisfied; (Note4)
4>Refer to GB/T 21714.3-2015 for the relevant design of the above lightning protection
lightning receptor system.
Note1:
Refer to IEC 61643-32 <Low Voltage Surge Protector (SPD) Part 32: Surge
Protectors Connected to the DC Side of Photovoltaic Devices—Selection and Use
Guide>, Appendix C.
Note2:
Refer to GB/T 21714.3-2015 <Lightning Protection Part 3 _ Physical Damage and
Life Danger of Buildings>, 6.3.1.
Note3:
Refer to 6.2.2 and 6.2.3 of IEC 61643-32.
Note4:
Refer to Chapter 7 and Appendix C of IEC 61643-32.
The lightning protection measures for photovoltaic systems shall be
carried out in accordance with the corresponding national standards and
IEC standards. Otherwise, photovoltaic devices such as components,
inverters and power distribution facilities may be damaged by lightning.
In this case, the company does not carry out warranty and assumes any
responsibility.
Photovoltaic panel
Inverter
Distribution
Cabinet
SPD
Power grid
Lightning
protection device
Grounding bar
1
2
3
4
Total grounding point
L
ig
h
tn
in
g
d
o
w
n
th
e
li
n
e
Equipment ground wire
Lightning down the line
Safety
interval S
WARNING
