HT instruments М75 - Manual (Page 38)

M72 - M73 - M74 - M75
EN - 36
4. If during measurement an excessive
contact voltage is detected (higher than
50V) the instrument does not perform the
test and emits a prolonged sound to
signal the anomalous situation. The
screen beside is displayed for 5 seconds
after which the instrument displays the
default screen of Ra test
5. The instrument dispalys the
symbol
when:

The instrument is operating in a
critical situation as for example in
presence of overvoltages
 The instrument cannot guarantee the
measuring uncertainty lower than
30% of the reading, according to
IEC/EN61557-1
6. If during measurement the green probe is
connected to the phase conductor and
the black probe is connected to the
protective conductor, the instrument does
not perform the test and emits a
prolonged sound to signal the anomalous
situation. The screen beside is displayed
for 5 seconds after which the instrument
displays the default screen of Ra test.
This can happen even if the wrong
connection is performed on the back side
of the power socket