OPERATION SUMMARY - Section 3
MTS-3000 SERIES OPERATION AND REFERENCE MANUAL 3-13
CU M004 01A
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If the chosen AC values were close to the relay operate point - but did not pick it up - the MODIFY knob
can be used to continuously vary one parameter until the pickup point is determined. Consider, for
example, that the voltage and phase angles were appropriate, but the current was too low.
10. Reselect IA current amplitude adjust mode by pressing F1 on the current module. Note that the initial
press selects amplitude adjust mode, the second press phase angle adjust mode, the third press
deselects that channel (LED will go out), and the fourth press selects amplitude adjust mode again.
11. Press and hold the FAULT button, and rotate the MODIFY knob slowly clockwise until the relay being
tested operates, as verified by the DIGITAL I/O visual (LED) and audible indicators.
12. If it’s desired to verify the operate point more precisely, the MODIFY knob is rotated
counterclockwise and clockwise, as required, to lower and raise respectively the output current
through the operate point.
Now consider that a timing check is to be done on the relay under test at a current well above the operate
point. For this example, it will be assumed that the relay minimum pickup occurred at 7.00 amps and the
timing check is to be performed at 10.00 amps.
13. Disable the outputs by pressing ENABLE. The ENABLE LED and the AC output warning LEDs will
go off. This permits the readjustment of current amplitude to be done ‘off line’.
14. Press FAULT. Its status LED will light.
15. Reselect IA current amplitude adjust mode by pressing F1 on the current module. Press 1, 0,
.
, 0, and
ENTER on the MODIFY keypad. This new value appears in the IA channel display.
16. Press ENABLE to re-enable the AC outputs. The ENABLE LED lights.
17. Press the FAULT button briefly only. This automatically latches the system into Dynamic Fault mode,
the FAULT LED begins to flash slowly to indicate the FAULT mode is active, and the timer reading in
the first line of the Control Module display begins incrementing. The AC output warning LEDs light,
and the programmed AC values appear at the AC output terminals.
18. When the relay operates, it trips off the AC outputs of the MTS, freezes the timer and AC output
readings, and enters the ‘Post Fault’ state, as indicated by extinguishing of the FAULT LED and
illumination of the TRIP LED located above the RESET pushbutton.
19. Once the timing results have been observed and, if necessary, recorded, the system is returned to
normal by pressing RESET. This resets the timer and V/I readings, and extinguishes the TRIP LED.
Note the important difference in this ‘dynamic fault’ mode compared to the ‘static fault’ mode described in
steps 1-12.