42 Chapter 7 Maintenance
NetSure 801 AG1 Power Supply System User Manual
Name
Quantity
Applications
Adjustable wrench
1 set
Wrench 6-angle or 4-angle bolts and nuts. Note: when in use, the adjustable tongue
shall turn to the inside of the spinning direction.
Electric soldering iron
1 piece
Weld components
Wash brush
1 piece
Clean the equipment and dust inside boxes
Handsaw
1 piece
Saw the bus and cables. Note: The saw blade shall not turn to the handle.
Electrician knife
1 piece
Peel off the skin of cables, etc.
Electrician rubber mallet
1 piece
Rectify cables or equipment location
Auxiliary materials (non-spare
parts)
Commonly-used auxiliary materials include insulating tape, self-adhesive label, soldering tin,
nylon bandage, etc.
Table 7-2 Common instruments for power equipments maintenance
Name
Quantity
Applications
Multimeter
2 to 3 pieces
Measure AC/DC voltage, current and resistance
Earth resistance tester
1 piece
Measure the earth resistance
Megommeter (500V and 1000V
withstand voltage)
1 piece/each
Dielectric strength test
AC/DC clamp-on amper meter
1 piece
Measure current
Contact Thermometer
1 piece
Measure the temperature of the surface and junction points of equipment
High/low-frequency noise tester
1 piece
Measure noise
*Ampere-hour meter
1 piece
Measure battery capacity
*AC/DC load meter
1 piece
Measure and test the load capacity of power net, rectifier and batteries
Note*: Those instruments marked with * may be configured or not to those relatively less-equipped equipment room according to
actual requirements
7.1.3 Reference Technical Specification For Maintenance
The power supply system consists of AC power supply, DC power supply and earthing system. To ensure
communication quality and power supply security, the power supply quality must conform to some basic quality
standards. Reference standards for AC, DC and earth resistance are shown in Table 7-3, Table 7-4 and Table 7-5.
Table 7-3 Quality standards for DC power supply
Standard
voltage (V)
Voltage variation
range at the
receiving end of
telecom equipment
(V)
Noise voltage (mV)
Maximum permissible
voltage drop of power
supply circuit (V)
Psophometrically
weighted noise
Peak-peak
value noise
Wide frequency noise
(effective value)
-48
-40 to -57
≤ 2mV
≤ 200mV
0 to 20Mhz
< 50mV
3.4kHz to 150kHz
150kHz to 30Mhz
3
Note: The voltage drop at the connectors of DC power supply circuit (including the fuse of the feed line output from the
discharging busbar, and battery connectors) shall be in conformity with the following requirements or the temperature rise shall
not exceed the permissible value: 1. If under 1000A, every hundred ampere
≤ 5mv; 2. If above 1000A, every hundred ampere ≤
3mv
Table 7-4 Quality standards for AC power supply
Nominal
voltage (V)
Voltage variation range
at the receiving end (V)
Nominal
frequency (Hz)
Variation range of
frequency (Hz)
Power factor
Below 100kVA
Above 100kVA
380
323 ~ 418
50
± 2.5
≥ 0.85
≥ 0.9
Remark: The voltage imbalance of three-phase power supply shall not exceed 4%
Table 7-5 Earth resistance reference standards for communication station
Name of the communication station
Earth resistance (Ω)
Comprehensive building, international telecom administration, tandem office, program
control exchange with over 10 thousand lines, and toll exchange with over 2,000 lines.
< 1
Program control exchange with more than 2,000 lines but less than 10 thousand lines, and
toll exchange with less than 2,000 lines.
< 3
Program control exchange with less than 2,000 lines, fiber terminal station, carrier repeater
< 5
