Huawei RRU3908 V1 Installation Manual page 11

Installing the DC RRU
n
Installing the RRU Cables
3. Cable Connections of RRU
DC RRU alarm cable
CPRI optical cable
DC RRU power cable
PGND cable
RRU RF jumper
Shielding layer of
the power cable
Waterproofed
alarm cable
Do not remove the dustproof cap from the feeder connectors that are not
in use. In addition, protection measures against damp, dust, and salt mist
must be taken. If the RRU is installed outdoors, you also need to wrap
the joint with waterproof tape, as shown in the following figures.
Insulating tape
Dustproof
cap
Press the strap on the exposed shielding layer of the power cable
tightly. Ensure that the lower edge of the exposed shield layer does not
exceed the position shown in the figure.
The alarm cable is preferably led out of the RRU from the narrower
cable trough in the middle of the cabling cavity. If the cable trough is
used by the CPRI optical cable, the alarm cable is led from the wider
cable trough near the middle one. In this case, the alarm cable must be
wrapped with 10 to 17 layers of waterproof tape so that the diameter of
the cable reaches 10 mm to 12 mm.
To avoid sharp bending, the optical cable must be pressed by the
strap next to the power cable during the optical cable installation.
Waterproof fillers should be installed in the unused cable trough.
The tape is wrapped spirally upwards, downwards, and then upwards
again in three layers. For every two adjacent tape layers, the tape on the
upper layer overlaps about half the width of the tape on the lower layer.
For details on how to add the OT terminals to the DC RRU power
cable, see page 36.
Case 2
Waterproof tape Insulating tape
Case 1
4. Closing the Cover Plate of
the RRU Cabling Cavity.
The screw on the cover plate is tightened until
the fastening torque is 14 kgf•cm.
The screws on the cover plate are tightened in
the order shown in the preceding figure.
17
M4
1.4N•m