HT instruments SIRIUS87 - Manual (Page 23)

SIRIUS 87
EN - 21
 Mode U
t
(the instrument effects the test with a leakage current equal to
half the value of the selected rated current and calculates the contact
voltage as well as the R
a
earth resistance with a leakage current in phase
with the voltage or a leakage current phase shifted by 180° with respect
to the voltage).
Note: According to standard praxis it is recommended to effect RCD test both with phase
0° and with phase 180°. Therefore the test is to be repeated for both phase valves
of test current. If the RCD under test is of a type (which means sensitive to both
AC and unidirectional pulsing leakage currents) it is advisable to effect the test
both with sine wave and unidirectional pulse current with phase 0° and 180°.
The key
U
n
/I
n permits to select one of the following rated tripping currents of
the RCD (which can be shown cyclically when pressing the key):
 10mA.
 30mA.
 100mA.
 300mA.
 500mA.
The key
S▲ permits to activate the test for general or selective RCDs:
 if the test is effected for
selective RCDs the symbol S
must be
displayed.
 if the test is effected for general RCDs the symbol S
must be NOT
displayed.
The option for testing the selective RCDs requires an interval among the
tests of 60 seconds (30 seconds in case of tests at ½ I
n ). A timer is
displayed indicating the waiting time for the instrument to effect the test
automatically.
Example:
Test on a RCD with rated current of I n =30mA selective
a) the instrument effects the test at ½ I n 0°. If the RCD passed
the test, the message “OK” is displayed and the RCD does
not trip.
b) The instrument effects the test at ½ I
n
180°. If the RCD
passed the test, the message “OK” is displayed and the
RCD does not trip. At this stage 30 seconds elapse before
effecting next test.
c) The instrument effects the test at I
n
0°. If the RCD passed
the test, the message “OK” is displayed and the RCD trips
and the blinking symbol “rcd” is displayed. The operator
shall switch on the RCD. Anyway after the RCD tripping at
least 60 seconds will elapse before affecting next test.
U
n
/I
n
DIST
S▲