2-6 
Item  Requirements 
Protection 
grounding
 
z  If a grounding strip is available at the site, attach 
the yellow-green PGND cable of the AP to the 
grounding strip. The PGND cable must have a 
cross-section area of at least 6 mm
2
 (0.01 in
2
) 
and a length not longer than 3 m (9.84 ft).  
z  If no grounding strip is available at the site, 
hammer a 0.5 m (1.64 ft) or longer angle iron or 
steel tube into the earth. The angle iron should be 
sized at least 50 × 50 × 5 mm (1.97 × 1.97 × 0.20 
in.); the steel tube should have a wall thickness of 
at least than 3.5 mm (0.18 in.) and be zinc-plated. 
Weld the yellow-green grounding cable to the 
angel iron or steel tube and treat the joint for 
corrosion protection. With a cross-section area of 
at least 6 mm
2
 (0.01 in
2
), the grounding cable 
should be as short as possible. Do not coil the 
cable. 
z  Make sure the lightning arresters of all devices 
and the peering devices connected to these 
devices are well grounded.  
Grounding 
lead
 
The grounding lead is a metal conductor connecting 
the grounding strip to the grounding grid. The PGND 
cable of the device should be attached to the 
grounding strip. The grounding lead should not be 
longer than 30 m (98.43 ft). A zinc-plated flat steel 
with a cross-section area of 40 × 4 mm (1.57 × 0.16 
in) or 50 × 5 mm (1.97 × 0.20 in) is recommended. 
The grounding strip and the grounding lead should 
be jointed using a 35 mm2 yellow-green PGND 
cable or directly welded together with the joint 
treated for corrosion protection. 
 
AC power 
grounding
 
z  Make sure you use the power cable with a PE 
terminal but not the cables with only L and N 
wires.  
z  It is strictly prohibited to connect the N wire of the 
power cable to the protection ground of any other 
communications device, and the L and N wires 
must be connected correctly.