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Section 11
Testing functionality by secondary injection
10.
Compare the measured trip time with the setting according to the formula.
11.
Reset the thermal memory.
12.
Continue to test another function or end the test by changing the test mode setting to Off.
11.5.7.2
Completing the test
Continue to test another function or end the test by changing the TESTMODE setting to Off. Restore
connections and settings to the original values, if changed for testing purposes.
11.5.8
Thermal overload protection, two time constants TRPTTR
Prepare the IED for verification of settings as outlined in section
section
11.5.8.1
Checking operate and reset values
1.
Connect symmetrical three-phase currents to the appropriate current terminals of the IED.
2.
Set the Time constant 1 (Tau1) and Time Constant 2 (Tau2) temporarily to 1 minute.
3.
Set the three-phase injection currents slightly lower than the set operate value of stage IBase1,
increase the current in phase L1 until stage IBase1 operates and note the operate value.
4.
Decrease the current slowly and note the reset value.
Check, in the same way, the operate and reset values of IBase1 for phases L2 and L3.
5.
Activate the cooling input signal, thus switching to base current IBase2.
6.
Check the operate and reset values (for all three phases) for IBase2 in the same way as
described above for stage IBase1.
7.
Deactivate the input signal for stage IBase2.
8.
Set the time constant for IBase1 in accordance with the setting plan.
9.
Set the injection current for phase L1 to 1.50 · IBase1.
10.
Connect a trip output contact to the timer and monitor the output of contacts ALARM1 and
ALARM2 to digital inputs in test equipment.
Read the heat content in the thermal protection from the local HMI and wait until the content is
zero.
11.
Switch on the injection current and check that ALARM1 and ALARM2 contacts operate at the
set percentage level and that the operate time for tripping is in accordance with the set Time
Constant 1 (Tau1).
With setting Itr = 101%IBase1 and injection current 1.50 · IBase1, the trip time from zero
content in the memory shall be 0.60 · Time Constant 1 (Tau1).
12.
Check that all trip and alarm contacts operate according to the configuration logic.
13.
Switch off the injection current and check from the service menu readings of thermal status and
LOCKOUT that the lockout resets at the set percentage of heat content.
14.
Activate the cooling input signal to switch over to base current IBase2.
Wait 5 minutes to empty the thermal memory and set Time Constant 2 (Tau2) in accordance
with the setting plan.
15.
Test with injection current 1.50 · IBase2 the thermal alarm level, the operate time for tripping
and the lockout reset in the same way as described for stage IBase1.
16.
Finally check that start and trip information is stored in the event menu.
170
"Preparing for test"
in this chapter.
Observe the maximum permitted overloading of the current circuits in the IED.
© 2017 - 2022 Hitachi Energy. All rights reserved
1MRK 504 165-UEN Rev. K
"Requirements"
and
Transformer protection RET670
Commissioning manual
M14950-48 v5
SEMOD53632-3 v5
SEMOD53632-11 v7
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