Eltek Valere Theia He-t User Manual page 48

Frequency Monitoring
The inverter repeats the test sequence but with the frequency trip limits. First, the upper
frequency trip level is ramped down from the maximum allowed frequency level, 50.3 Hz,
and decreased until it equals the current grid frequency. The time it takes from equalization to
disconnection is measured.
Second, the under frequency monitoring is checked. The trip level is ramped up from the
minimum allowed frequency level, 49.7 Hz, and increased until it equals the current grid
frequency. The time it takes from equalization to disconnection is measured.
48
f
AC max
f
AC off
t
max
t
off
PASS
FAIL
f
AC min
f
AC off
t
min
t
off
PASS
FAIL
After the test is successfully finalized, the
test results are displayed. Press NEXT to
confirm each result. After entering FINISH
on the last result, the inverter goes back to
the Inverter Command menu.
The test results are stored in Commands >
Inverter Commands > Results Self Test
If the test fails 4 times, contact Eltek Valere.
User Manual THEIA HE-t String Inverters
Maximum allowed frequency; trip
level
Disconnection frequency level;
equalization
Maximum allowed disconnection
time
Time from equalization to
disconnection
The third sequence is successfully
carried out
The third sequence has failed – try
again later
Minimum allowed frequency; trip
level
Disconnection frequency level;
equalization
Minimum allowed disconnection
time
Time from equalization to
disconnection
The fourth sequence is successfully
carried out
The fourth sequence has failed – try
again later
357115.013, Issue 1.0, 2011 March