Surge Protector Sensor; Appearance Of The Mdf - Huawei UA5000 Manual

UA5000 Universal Access Unit
Environment Monitoring
Figure 10-6 Appearance of the MDF

10.1.7 surge protector Sensor

The surge protector has the over-voltage protection function against lightning. It can protect the
power supply device and the powered devices.
Appearance
The surge protector has the over-voltage protection function against lightning. It can protect the
power supply device and the powered devices. The following uses SPD27SZ as an example.
Figure 10-7
Issue 01 (2012-08-17)
NOTE
l From the point of detection, each protective unit can be seen as a "switch". All protective units in the
MDF form a parallely-connected "switch " array. In normal situation, all "switches" are disconnected,
and the detection points are in high level, and the MDF status detected by the ESC board is normal.
l If a subscriber line connected with the protective unit has over voltage or over current, the "switch"
will be connected. The detection point will be connected to the PGND point of the equipment. The
voltage and current will be released to the ground, and alarm signals will be generated at the same time.
The ESC board detects the alarm signals and reports the MDF status to the NMS client.
l In general, the protective unit has a LED. When the protective unit is faulty, the LED is on.
and Figure 10-8
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
show the appearance of the SPD27SZ surge protector.
10 Sensors
176