Appendix A - Replacement of Modules and Parts
Confidential and Proprietary Information of ZTE CORPORATION 183
There are two power supplies for the heat exchanger. One is the
AC220V mains and the other is the DC-48V from the PSM plug-in
box. Open the front door and turn off the mains breaker in the
cabinet and then you can power off the heat exchanger.
ii.
Loosen the 3-core aerial socket connected with two power supply
cables for the heat exchanger; then disconnect the power cables
from the heat exchanger.
iii.
Open the front/back doors, loosen the 4 M6 bolts used to fix the
cabinet top boot and take off the top boot.
iv.
Loosen the 8 bolts used to fix the heat exchanger and take off the
heat exchanger.
v.
Install the new heat exchanger onto the cabinet and tighten the 8
fix bolts to ensure the sealing plate is tightly pressed.
vi.
Put the replaced faulty heat exchanger in the packing case and
label it marking the type and fault for easy identification and
handling in the future.
vii.
Connect the two 3-core aerial socket power cables with the heat
exchanger reliably.
viii.
Power on the new heat exchanger again.
4.
Confirmation
Observe if the cyclic fan in the heat exchanger works normally. If yes,
lift the top boot onto the cabinet and use the 4 M6 bolts to fasten it
and finally lock the front/back doors. The replacement is completed.
Trunk Cable Replacement
1.
Tools
i.
Multimeter
ii.
Scissors
2.
Preparation:
i.
Perform the fault observation and analysis and determine the
replacement is necessary.
ii.
Make sure that the type of the BTS trunk cable is the same as that
of the new trunk cable. Both trunk cables are digital cables
adopting the 75
Ω
coaxial cable.
iii.
Check the label of both ends of the trunk cables and make sure
that they are in the one-to-one correspondence relationship, means
one end connects the trunk interface at the top of the BS21 cabinet
and the other end connects the trunk device.
iv.
Test the new trunk cable with a multimeter to see whether the
circuit is through and whether there is any interrupted circuit or
short circuit.
v.
Prepare a damp-proof bag and carton, as well as some labels for
identification.