Handling Of Electronic Equipment - AEG DUA2.1 Technical Manual And User Manual

Handling, Installation and Case Dimensions
HF9024

2. HANDLING OF ELECTRONIC EQUIPMENT

A person's normal movements can easily generate electrostatic potentials of
several thousand volts. Discharge of these voltages into semiconductor devices
when handling electronic circuits can cause serious damage, which often may
not be immediately apparent but the reliability of the circuit will have been
reduced.
The electronic circuits are completely safe from electrostatic discharge when
housed in the case. Do not expose them to risk of damage by withdrawing
modules unnecessarily.
Each module incorporates the highest practicable protection for its
semiconductor devices.
However, if it becomes necessary to withdraw a module, the following
precautions should be taken to preserve the high reliability and long life for
which the equipment has been designed and manufactured.
1. Before removing a module, ensure that you are at the same electrostatic
potential as the equipment by touching the case.
2. Handle the module by its front plate, frame or edges of the printed circuit
board. Avoid touching the electronic components, printed circuit track or
connectors.
3. Do not pass the module to another person without first ensuring you are both
at the same electrostatic potential. Shaking hands achieves equal potential.
4. Place the module on an antistatic surface, or on a conducting surface which
is at the same potential as yourself.
5. Store or transport the module in a conductive bag. If you are making
measurements on the internal electronic circuitry of an equipment in service, it
is preferable that you are earthed to the case with a conductive wrist strap.
Wrist straps should have a resistance to ground between 500kΩ – 10MΩ. If a
wrist strap is not available you should maintain regular contact with the case to
prevent a build-up of static. Instrumentation which may be used for making
measurements should be earthed to the case whenever possible.
More information on safe working procedures for all electronic equipment can
be found in BS5783 and IEC147. It is strongly recommended that detailed
investigations on electronic circuitry or modification work should be carried out
in a special handling area such as described in the above-mentioned BS and
IEC documents.