HT instruments М75 - Manual (Page 33)

M72 - M73 - M74 - M75
EN - 31
6. Keep GO pressed for at least one second to perform the leakage current measurement
in phase with the positive semiwave of the network voltage (0°), or keep GO pressed
for at least one second and, when the hyphens on the display start disappearing, press
GO again to perform the measurement with the leakage current in phase with the
negative semiwave of the network voltage (180°)
CAUTION
The message “Measuring” on the display means that the instrument is
measuring. During this phase never disconnect test leads.
7. At the end of the test, if the detected
tripping time is lower than 300ms (40ms
for I
∆n
=30mA x5), the instrument emits a
double sound to signal the positive
outcome of the test and displays a screen
like this
Tripping time
Test current value
8. At the end of the test, if the detected
tripping time is higher than 300ms (40ms
for I
∆n
=30mA x5), or in case the RCD
does not trip, the instrument emits a
prolonged sound to signal the negative
outcome of the test and displays a screen
like this
Tripping time
exceeding the limit
Test current value
4.14.1. Anomalous cases which may occur during RCD tests
1. If during measurement a higher input
voltage than 265V is detected (for
example, both cables connected to the
phase conductors of a 400V three-
phases plant) 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 RCD test