Chauvin Arnoux C.A 762 IP2X Notice De Fonctionnement page 24

■ Depending on the internal impedance of the voltage detector
there will be a different capability of indicating the presence
or absence of operating voltage in case of the presence of
interference voltage.
■ A voltage detector of relatively low internal impedance, com-
pared to the reference value of 100 kΩ, will not indicate all
interference voltages having an original voltage value above
the ELV level. When in contact with the parts to be tested,
the voltage detector may discharge temporarily the interfer-
ence voltage to a level below the ELV, but it will be back to
the original value when the voltage detector is removed.
■ When the indication "voltage present" does not appear,
it is highly recommended installing earthing equipment
before work.
■ A voltage detector of relatively high internal impedance,
compared to the reference value of 100 kΩ, may not permit
to clearly indicate the absence of operating voltage in case
of presence of interference voltage.
■ When the indication "voltage present" appears on a part that
is expected to be disconnected of the installation, it is highly
recommended confirming by another means (e.g. use of an
adequate voltage detector, visual check of the disconnecting
point of the electric circuit, etc.) that there is no operating volt-
age on the part to be tested and to conclude that the voltage
indicated by the voltage detector is an interference voltage.
■ A voltage detector declaring two values of internal im-
pedance has passed a performance test of managing
interference voltages and is (within technical limits) able to
distinguish operating voltage from interference voltage and
has a means to directly or indirectly indicate which type of
voltage is present.
SAFETY ADVICES
24