Appendix D: External Lightning
Protection
Protection devices are most often installed from each data line
to the local earth ground, and should be selected to begin
conducting current at a voltage as close to the system's
normal communication level as possible, but never lower. For
RS485 communication lines, the selected voltage rating is
typically 6-8 V. Transient suppressors should be installed as
close as possible to the port that is being protected, and the
user must provide an extremely low impedance connection to
the local earth ground of the SolarEdge device. This ground
connection is crucial for proper suppression device operation.
The ground connection should be made using a heavy gauge
wire and kept as short as possible. If the cable between the
SolarEdge device and the protection device must be longer
than 1m/3.3 ft., a copper strap or a braided cable intended for
grounding purposes must be used for the protection device to
be effective. In addition to the high frequency nature of
transients, extremely high current may flow.
A protective device with surge discharge ratings of In: 10kA
8/20
μ
s and Imax: 20kA 8/20
μ
s is recommended.
Revenue Grade Energy Meter with Modbus Connection Installation Guide MAN-01-00609-1.0
68
Appendix D: External Lightning Protection