User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-59
2.7.2 Lightning Protection for DC
I. Multi -level protection of power supply
The BTS power supply subsystem is normally in 5-level protection, as shown in
Figure 2-28.
.
.
.
3-phase AC
AC/DC
6kV
4 kV
2.5 kV
1.5 kV
Great power-absorbing
capability, slow
response, at cable inlet
of the room, optional
Normal power-absorbing
capability, quick
response, in front of
rectifier module
Low power-absorbing
capability, very quick
response, in rectifier
module
Level-1 protection
Level-2 protection
Level-3 protection
Level-4 protection
Considerable
power-absorbing
capability, normal
response, at the AC
distribution point
Figure 2-28
Illustration of lightning protection of BTS power
II. Principle of DC lightning arrester
Level-5 protection is a built-in integrated lightning arrester on the cabinet-top box.
The operation principle is as shown in Figure 2-29.
EMI
-48V
GND
Signal line
Wiring terminal
PGND
Lightning arrester
Figure 2-29
Illustration of lightning protection of BTS power
