Megger Easytest 20 kV - Hipot Operation Mode; AC Operation Mode

4-24
4.4.1 Hipot Operation Mode
During a time-limited
DC test, the breakdown detection of the system is active. If a
breakdown occurs during a test, the system aut
omatically terminates the test,
discharges the cable under test and shows the following system message:
If no breakdown occurs at run time, the following system message informs about the
successful completion of the DC test.
Furthermore, a permanent test (timer = 0 minutes)
can be used to, e.g., convert cable
faults. During a permanent test, the breakdown detection and, if available,
the
external voltage protection are inactive. The test can only be interrupted using the
HV
off button.
4.4.2 AC Operation Mode
Test frequency
adaptation
If a test profile with a preset amount of test periods
is selected, the system
automatically performs a frequency an adaptation at the beginning of the test.
For this purpose, the capacity of the cable under test is detect
ed and used to
determine the appropriate test frequency by means of the following specifications:
Test frequencies
:
0.1
Hz for C ≤ 0.5 µF
0.05
Hz for C > 0.5µF ≤ 1.0 µF
0.02
Hz for C > 1.0 µF ≤ 2.5 µF
0.01
Hz for C > 2.5 µF ≤ 5 µF
Afterwards, the actual test duration is recalculated by means
of the determined test
frequency and the specified test periods.
For an AC test profile with preset test duration
, the test frequency adaptation
does not affect the test duration.
Breakdown occured
clear
Test successful
No breakdown
clear