F> Threshold And Drop-Off - ISA T1000 PLUS User Manual

DOC. MIE91093 Rev. 1.34 Page 50 of 145
The range should be the closest one to the nominal voltage.
The pre-fault amplitude is adjusted by the multi-function knob
and display; the value is computed from the nominal relay
(phase – to – phase) voltage VN:
V pre-fault = VN/1.73
Standard values are: 57.8 V for VN = 100 V; 63.5 V for VN =
110 V.
After this adjustment the pre-fault voltage is generated prior
to all tests, as the unit is OFF. Select ON: as the test is
started, the voltage goes to the fault value, that is adjusted by
the knob (20). Adjust the fault value at the same value as the
pre-fault.
. Connect the relay to the auxiliary voltage output sockets
(62).
. Set the "Automatic save at trip" function, as follows.
Test control > Save > Automatic at trip > ESC
NOTE: for other selections see the pop-up menu chapter.
. Connect the TRIP output to the STOP input.
. Set the timer with the following selections:
Timer start/stop > START > INT (RET)
STOP > EXT > Clean (Voltage) (RET)
Edge ESC
NOTE: stop clean or voltage according to the relay trip contact
connections.
1.6.3. F> Threshold and drop-off
The first session is finding threshold F>. Select ON, then,
modify the output frequency as follows:
AUX VAC/VDC > Aux VAC control > Frequency > Adjust
Slowly increase the auxiliary AC frequency. As the relay trips,
the result is saved.
1
NOTE: stored value is the voltage as relay trips. This
corresponds to the relay threshold only if the frequency did
not change very much while the relay timing T> elapsed, so,