eSpace Audio Recorder
Maintenance Guide
3 Manual Maintenance
Issue 01 (2012-10-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd
18
z
RTN: indicates the DC ground for the DC power supply of a cabinet. Generally, the
positive pole of -48 V DC power in the cabinet is grounded through a power distribution
cabinet.
Reference Standard
z
Make sure that all the ground cables are not damaged, deteriorated, eroded, or burnt by
electrical arc.
z
The terminals and the captive screws of all ground cables in the cabinet are connected
properly, and they are not loose or eroded.
z
The resistance measured at each grounding point must be about one ohm.
z
The grounding resistance is less than 10 ohms.
Operation Procedure
Step 1
Check the appearance of ground cables.
Step 2
Check the ground cable connections.
Step 3
Use a multimeter to check the grounding status of all components in cabinets.
1.
Adjust the multimeter to the ohm range, and connect one probe to a fixed grounding
point in the telecommunications room.
2.
Connect the other probe to the grounding points in the cabinet in turn to measure the
resistance of each grounding point.
Step 4
Use an earth resistance tester to measure the grounding resistance of the grounding network in
the telecommunications room.
If an exception occurs in the grounding system, contact the telecommunications room administrator.
----End
3.3.3 Checking the Number of Spare Parts and Storage
Environment
Maintenance personnel must regularly (once a week is recommended) check spare parts
quantity, type, and storage environment.
Background
The formula for calculating number of spare parts is as follows:
Advised number of spare parts = Annual damage rate x Network capacity
For example, if the network capacity of boards is 100 and the annual damage rate is 1%, the
advised number of spare parts is 1.
The annual damage rate varies according to the site scenario.
The network capacity can be adjusted based on the actual sales contract
.
The advised number of spare parts is the minimum number of spare parts that users must store.
