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

DOC. MIE91093 Rev. 1.34 Page 24 of 145
STOP > EXT > Clean (Voltage) (RET)
Edge ESC
NOTE: stop clean or voltage according to the relay trip contact
connections.
1.2.3. V> Threshold and drop-off
The first session is finding threshold V>. Select ON; slowly
increase the auxiliary AC voltage. As the relay trips, confirm
save results pressing the multi-function knob, and proceed.
NOTE: stored value is the voltage as relay trips. This
corresponds to the relay threshold only if the current did not
change very much while the relay timing elapsed; however,
trip timing is usually short, so current does not change very
much at release, and the measurement is accurate.
If threshold measurement was not good because you were
moving too fast, do not confirm test results and repeat the
test.
Next, we find the drop-off threshold for V>. From the voltage
above, slowly decrease the voltage; as the relay resets,
pressing the multi-function knob tripping values can be saved.
The TRIP LED (43) turns on for 5 seconds; during 5 seconds,
parameters at reset are displayed; then, the standard
measurement is restored.
NOTE: stored value is the voltage as the relay resets. This
corresponds to the relay drop-off only if the current did not
change very much while the relay timing elapsed; however,
reset timing is usually very short, so current does not change
very much at release, and the measurement is accurate.
1.2.4. V< Threshold and drop-off
The second session is finding threshold V<. Select ON; slowly
decrease the auxiliary AC voltage. As the relay trips, confirm
save results pressing the multi-function knob, and proceed.
Next, we find the drop-off threshold for V<. From the voltage
above, slowly increase the voltage; as the relay resets,
confirm save results pressing the multi-function knob, and
proceed.