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30
30.1
30.1.1
30.1.2
30.1.3
30.1.4
Undercurrent protection (UCP)
Undercurrent protection (UCP)
Prepare the terminal for verification of settings as outlined in
this chapter.
Measuring the operate limit of set values
Undercurrent in any phase
Dependbility test
Procedure
1.
Inject a three-phase balanced current, close to the rated secondary
current.
2.
Measure the the current in a single phase, with an external device.
3.
Activate the UCP_CR binary input.
4.
Slowly reduce the current in the selected phase until the start signal
UCP_STHIGH appears
5.
Compare the measured current with the set value ILHigh<.
6.
Continue to slowly decrease the current in the selected phase until
the start signal UCP_STLOW appears.
7.
Compare the measured current with the set value ILLow<.
8.
Repeat item 1-7 for the other two phases.
Time delay test
Procedure
1.
Inject a three-phase balanced current, close to the rated secondary
current. Prepare for a change of the injected current to a value be-
tween the set values ILLow< and ILHigh<.
2.
Change the level of the injected current and measure the operating
time of the UCP function. Use the UCP_TRHIGH signal. Compare this
operating time with the set value tHigh.
3.
Inject a three-phase balanced current, close to the rated secondary
current. Prepare for a change of the injected current to a value well
below the set value ILLow.
4.
Change the level of the injected current and measure the operating
time of the UCP function. Use the UCP_TRLOW signal. Compare this
operating time with the set value tLow.
Completing the test
Continue to test another function or complete the test by setting the test mode off.
Chapter 13
Verifying settings by secondary
section 2 "Preparing for test"
injection
in
155
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