Huawei Airbridge cBTS3612 Installation Manual page 21

Installation Manual
Airbridge cBTS3612 CDMA Base Station
electrostatic charge carried by human body may go up to 30 kV, which will
remain on the human body for a rather long period of time. The operator's
cont act with the sensitive component and the resultant electric discharge
will cause damage to the component.
Before contacting/touching any equipment such as holding plug-in boards,
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circuit boards and IC chips, put on the anti -static wrist strap with one end
well grounded so as to prevent sensitive parts from getting damaged by
static electricity on the human body.
Before operators touch the board or module, they should release the
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electrostatic charge in their body. That is, before the operator touches a
board or a module, he or she must wear the anti -static grounded wrist strap.
The connecting line between the wrist and the grounding point should
connect in series with a resistance greater than 1 M¦¸ to protect people
from being accidentally shocked. The resistance value greater than 1 M, is
rather low in terms of electrostatic voltage discharging. The anti-static wrist
strap should be checked regularly. Using other cable to replace the cable
of anti-static wrist strap is strictly prohibited.
Electrostatic -sensitive board or module should not be in contact with the
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object with static electricity or the object that may easily generate static
electricity. For instance, packaging bags, delivery boxes and conveyor
belts made of insulating materials will generate st atic electricity by
themselves, and can cause electrostatic charging when in contact with
human body or the earth and might thus bring forth damages.
Electrostatic -sensitive
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discharging materials, such as anti -static packing bags. The board in stock
or in the course of transportation should be packaged with anti -static
packing bag.
Before the measurement device is connected to boards or modules, first
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discharge its static electricity, that is, the measurement device should be
grounded first.
The single board or module should not be placed near strong DC magnetic
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field, for instance, near the cathode ray tube of the oscilloscope. The safety
distance should be at least 10 cm.
Damage caused by static electricity is acc umulative. If the damage is slight,
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the component will not malfunction. However, as the number of damages
increase, the components may suddenly fail. The electrostatic discharging
damage to the component is of two types: obvious damage and hidden
damage. Hidden damage is not shown when the damage occurs, whereas
the component may become vulnerable and easily get damaged under the
condition of over- voltage and of high-temperature.
The correct way of wearing anti-static wrist strap is shown in Figure 1.
boards or modules
S-7
Precautions
Safety Precautions
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