3Com SECPATH U200-CS, Руководство по установке

Страница: 49 / 130

4-9
Serially connected to a signal cable, a signal lightning arrester must satisfy the requirements of network
performance indexes such as data transmission bandwidth, as well as the lightning protection
performance requirement. Therefore, before installing a signal lightning arrester, you need to consider
such performance indexes of the lightning arrester as lightning protection, bandwidth, transmission loss,
and port type.
Three signal lightning arrester options are available for the U200 series. Their specifications are as
follows:
z
Maximum discharge current 2.5KA/protection voltage 25V–SMB-75J/SMB-75J–1W–10Mbps
z
Maximum discharge current 2.5KA/protection voltage 25V–BNC-75K/BNC-75K–10Mbps
z
Use with U-shape ports, maximum discharge current 3KA/common-mode 400V/differential mode
170V–RJ-11
z
The signal lightning arrester should be grounded as near as possible. The grounding resistance
must be less than 4 ohms. The grounding resistance must be less than 1 ohm if there are special
grounding requirements.
z
Connect the grounding cable to the special-purpose grounding cable of the signal lightning arrester
and connect it to the earthing network, instead of connecting it to the lightning rod or lightning strip.
Connecting the Power Cable
Power Supply Port and PGND Terminal
A U200 series device only supports AC power input. The AC power socket and power switch are
located on the left of the front panel, as shown in Figure 4-10 and Figure 4-11.
Figure 4-10
AC power socket of the U200-S
Figure 4-11
AC power socket of the U200-A/U200-M
For the specifications of the AC power socket, see Table 4-2.