Thermal Overload Protection, One Time Constant, Fahrenheit/Celsius Lfpttr Lcpttr (26) - ABB RET670 Commissioning Manual

Section 10
Testing functionality by secondary injection
10.5.7 Thermal overload protection, one time constant, Fahrenheit/
Celsius LFPTTR/LCPTTR (26)
Prepare the IED for verification of settings as outlined in section
section "Preparing for test"
Check that the input logical signal BLOCK is logical zero and that on the local HMI, the logical
signal TRIP, PICKUP and ALARM are equal to logical zero.
10.5.7.1 Measuring the trip and time limit of set values
Testing the protection without external temperature compensation (NonComp)
1. Quickly set the measured current (fault current) in one phase to about 300% of
minimise the trip time), and switch the current off.
2. Reset the thermal memory on the local HMI under Main menu/Reset/Reset temperature/
ThermalOverload1TimeConst(PTTR,26)/LFPTTR:x, Main menu/Reset/Reset temperature/
ThermalOverload1TimeConst(PTTR,26)/LCPTTR:x,
3. Switch the fault current on and take note of the temperature, available on the local HMI under
Main menu/Test/Function status/Current protection/
ThermOverLoad1TimeConst(PTTR,26)/LFPTTR:x/TEMP, Main menu/Test/Function status/
Current protection/ThermOverLoad1TimeConst(PTTR,26)/LCPTTR:x/TEMP,
4. Check the time until the actual temperature TEMP has reached the
injection.
Monitor the signal ALARM until it appears on the corresponding binary output or on the local
HMI.
5. Measure the LFPTTR/LCPTTR (26)protection trip time.
Use the TRIP signal from the configured binary output to stop the timer.
6. Take the TEMP readings.
Compare with the setting of
7. Activate the BLOCK binary input.
The signals ALARM, PICKUP and TRIP should disappear.
8. Reset the BLOCK binary input.
9. Check the reset limit (TdReset).
Monitor the signal PICKUP until it disappears on the corresponding binary output or on the
local HMI, take the TEMP readings and compare with the setting of
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
Disabled .
10.5.7.2 Completing the test
Continue to test another function or end the test by changing the
Restore connections and settings to their original values, if they were changed for testing
purposes.
148
in this chapter.
TripTemp .
1MRK 504 154-UUS B
"Requirements" and
IRef (to
AlarmTemp level during
ReclTemp .
TestMode setting to Disabled .
Commissioning manual
M14950-2 v7
M14950-8 v3
M14950-10 v10
M14950-48 v5