HT FULLTEST3, Руководство пользователя, Страница: 44 / 100

FULLTEST3
EN - 42
¾ 50% Ramp mode ( double ramp ) Æ When the START/STOP key is pressed, the
test voltage rises up to 50% of the nominal voltage then it takes 1s to reach 75%
of the nominal value then it uses another 5s to reach the nominal value. It is
subsequently maintained for a time defined by a programmable timer (see Fig.
38)
Fig. 38 : DIELECTRIC test in 50% Ramp mode
¾
Pulse mode
Æ
the effective test has a duration of 3 measurement cycles (60ms
@ 50Hz, 50ms @ 60Hz) according to IEC/EN61439-1 3rd edition
6.4.2. Typology of discharge current
The instrument is able to measure the dielectric leakage current in the following two
modes:
¾ IAPP Æ the instrument measures the total RMS value of the dielectric leakage
current (including capacitive components)
¾ IREAL Æ the instrument only measures the "real" part of the current, that is the
current in phase with the voltage and therefore associable with a loss of the
Resistive type (recommended in most cases). This last mode serves to "ignore"
the capacitive current component typically introduced by filters for electromagnetic
compatibility (whose current is obviously not associated with any type of loss /
break)
3. Check selected mode and correct it if needed by pressing the
MODE touch-
screen key first. MANUAL, RAMP, PULSE or BURN mode can be selected
4. Check selected test voltage (250 up to 5100V) and correct it if needed by
pressing the U
TES NOM
touch-screen key first
5. Check selected limit current and correct it if needed by pressing the LIMIT touch-
screen key first. Four independent preset limit currents are available for quicker
operations. Select the one closest to wished value and modify it by using the
+
and ʊ touch screen keys if needed
6. Check selected character of displayed current (I
APP
or I
REAL
) and correct it if
needed by pressing the CHAR touch-screen key first
7. Select measurement screen by pressing the touch-screen key and check all
settings again
8. Insert the measurement terminals between the COM input and the input
corresponding to the programmed test voltage and connect the instrument as
shown in Fig. 39. Always connect the
COM terminal to the GND ground if the
measured OUT output is earthed, otherwise any capacitive leakage currents
could be discharged to the ground and disturb the measurement