OPERATION SUMMARY - Section 3
MTS-1700 SERIES OPERATION AND REFERENCE MANUAL 3-39
CU A002 15A
MANTA TEST SYSTEMS
9. For each new value of frequency, repeat steps 2 and 4 to 8.
3.3.14.3 TARGET/SEAL-IN TEST.
To check the target and seal-in features of a DC current-operated target:
1. Connect relay, as in Figure 3.7. Select I4-DC current mode.
2. If you haven’t done so, perform steps 2-4 of the pickup check above.
3. Turn [PREFAULT] on, press [FREQ], and adjust the frequency until the relay operates.
4. Press [CURRENT], and adjust the DC current to 0.2A or 2A, as required, to operate the target.
5. To test the seal-in feature, adjust the frequency back to normal, and the contacts should remain closed
until the DC current is removed.
Note: If the above adjustments are made in the FAULT state rather than prefault, a complete dynamic
test can be performed which simulates real world operation.
3.3.14.4 UNDERVOLTAGE INHIBIT TEST.
To check the undervoltage inhibit function:
1. If you haven’t done so, perform steps 1-4 of the pickup check in Section 3.3.14.1.
2. Turn the [MODIFY] knob to adjust the voltage to a level below the inhibit setting.
3. Press [FREQ], and adjust the frequency to a value which would normally cause the relay to trip. The
relay should restrain from operating ([TONE] led stays off).
4. Press [VOLTAGE] and increase the voltage. The relay should trip when the voltage reaches the inhibit
level. This step can be done in the dynamic operation mode to freeze the readings at the time of the
trip, if desired.
3.3.14.5 FREQUENCY RATE-OF-CHANGE TEST.
To check a frequency rate-of-change element:
1. If you haven’t done so, perform steps 1-6 of the timing test in Section 3.3.14.2. The initial fault
frequency (start of the ramp) will be the frequency you had set in the FAULT state. This can also be set
via the menu using the SETTINGS RAMP FREQ INITIAL selection. This frequency is generally the
same as the prefault.
2. Press [MODE/MENU], and set up the ramp end frequency and ramp rate via the SETTINGS RAMP
FREQ FINAL and SETTINGS RAMP FREQ RATE selections. Exit the menu by pressing [MODE/
MENU].
3. Press [STATIC/DYNAMIC] to select DYNAMIC operation mode. Press [FAULT] to initiate.
4. When the relay operates, the [STOP/RESET] button will illuminate. Press [TIME] to read the operate
time. Press [TIME] again to toggle between time in seconds/cycles. Press [STOP/RESET] to return to
the prefault state, and to prepare for the next test.
5. This test should be repeated at ramp rates slightly above and below the element’s
∆
f/
∆
t setpoint.
Repeat steps 2-4 for each new ramp rate.
(Note: You can actually initiate the fault with the menu still active. This allows you to modify the
ramp rate for successive trials without having to re-enter and exit the menu. See Section 5.1.2
for a description of this feature).
