Live Earth Safety Precautions - Megger MFT1800 Series User Manual

1.2

Live earth safety precautions

A 'Live' earth is one that carries current from the mains supply, or could do so under fault conditions. The following
warnings apply in addition to those listed previously:
„ All persons involved must be trained and competent in isolation and safety procedures for the system to be
worked on. They must be clearly instructed not to touch the earth electrode, test stakes, test leads, or their
terminations if any 'Live' earths may be encountered. It is recommended that they wear appropriate rubber
gloves, rubber soled shoes, and stand on a rubber mat.
The earth electrode under test should be isolated from the circuit it is protecting before testing commences. If
„
this is not possible, ART (attached Rod Technique) may be used to measure electrode resistance.
The instrument terminals should be connected to the system under test through isolation switches that are rated
„
to handle the likely maximum fault voltages and currents that could be encountered at the installation. The
isolation switch must be open whilst any personal contact is made with the remote test stakes, or the connecting
leads, e.g. when changing their position.
The instrument terminals should be connected to the system under test through fuses that are rated to handle
„
the likely maximum fault voltages and currents that could be encountered at the installation.
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS
Users of this equipment and/or their employers are reminded that Health and Safety Legislation requires them to
carry out valid risk assessments of all electrical work so as to identify potential sources of electrical danger and risk of
electrical injury such as inadvertent short circuits. Where the assessments show that the risk is significant then the use
of fused test leads constructed in accordance with the HSE guidance not GS38 'Electrical Test Equipment for use by
Electricians' should be used .
This instrument is internally protected against electrical damage when used for the purposes of testing low voltage
electrical installations as defined herein. If used in a manor other than those defined in this user guide, the protection
capabilities could be impaired with potential risk to the operator and the instrument.
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Safety
MFT1800 series 9