4-5
PGND Cable Connection
Importance of the PGND Cable
A correct connection of the protection ground (PGND) cable on the device chassis is an essential
safeguard against lightning strokes and electromagnetic interference (EMI). When installing or using
the firewall, make sure the PGND cable is correctly connected.
The power input end of the firewall is equipped with a noise filter. The neutral ground of the power input
end is directly connected to the chassis and is called PGND (also known as chassis ground). You need
to securely connect the PGND cable to the earth ground to safely lead induced current and leakage
current to the ground and reduce the electromagnetic susceptibility (EMS) of the firewall. The PGND
cable can also protect the firewall against high lightning voltage resulting from external network lines.
Connecting the PGND Cable
The grounding screw of the device is located on the lower right corner of the rear chassis panel and is
marked with a grounding sign, as shown in Figure 4-6.
Figure 4-6
Connect the grounding terminal of the PGND cable to the firewall
(2)
(1)
(3)
(4)
(5)
(6)
(1) Rear chassis panel
(2) Grounding screw
(3) Grounding sign
(4) Grounding screw hole
(5) OT terminal
(6) PGND cable
Follow these steps to connect the PGND cable:
Step1
Remove the grounding screw from the firewall chassis.
Step2
Put the supplied OT terminal of the PGND cable on the grounding screw.
