ADInstruments PowerLab Owner's Manual page 6

If multiple portable socket outlets are used, they are subject to the following constraints:
Earthing and Ground Loop Noise
The prime function of earthing is safety, that is, protection against fatal electrocution.
Safety concerns should always override concerns about signal quality. Secondary
functions of earthing are to provide a reference potential for the electrical equipment
and to mitigate against interference.
The earthing (grounding) stud provided on the back panel of the PowerLab is a
potential equalization post and is compatible with the DIN 42801 standard. It is directly
connected to the earth pin of the power socket and the PowerLab chassis. The earthing
stud can be used where other electronic equipment is connected to the PowerLab, and
where conductive shields are used to reduce radiative electrical pick-up. Connection to
the stud provides a common earth for all linked devices and shields, to reduce ground-
loops.
The earthing stud can also be used where a suitable ground connection is not provided
with the mains supply by connecting the stud to an earthed metal infrastructure,
such as a metal stake driven into the ground, or metal water piping. This may also be
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• Do not touch the subject to which the PowerLab (or its peripherals) is connected
at the same time as making contact with parts of the PowerLab (or its peripherals)
that are not intended for contact to the subject.
• Cleaning and sterilization of equipment should be performed in accordance
with manufacturer's instructions. The isolation barrier may be compromised if
manufacturer's cleaning instructions are not followed.
• The ambient environment (such as the temperature and relative humidity) of the
system should be kept within the manufacturer's specified range or the isolation
barrier may be compromised.
• The entry of liquids into equipment may also compromise the isolation barrier. If
spillage occurs, the manufacturer of the aff ected equipment should be contacted
before using the equipment.
• Many electrical systems (particularly those in metal enclosures) depend upon
the presence of a protective earth for electrical safety. This is generally provided
from the power outlet through a power cord, but may also be supplied as a
dedicated safety earth conductor. Power cords should never be modified so as
to remove the earth connection. The integrity of the protective earth connection
between each piece of equipment and the protective earth should be verified
regularly by qualified personnel.
• Avoid using multiple portable socket-outlets (such as power boards) where
possible as they provide an inherently less safe environment with respect to
electrical hazards. Individual connection of each piece of equipment to fixed
mains socket-outlets is the preferred means of connection.
• They shall not be placed on the floor.
• Additional multiple portable socket outlets or extension cords shall not be
connected to the system.
• They shall only be used for supplying power to equipment which is intended to
form part of the system.
Owner's Guide