Time delay verification (roc frequency), Inhibit quantities (roc inhibit) – Basler Electric BE1-11g User Manual
Page 443
9424200994 Rev N
431
Step 3: Prepare to monitor the 81-1 function operation. Operation can be verified by monitoring OUT2
Step 4: Connect a 120 Vac voltage source capable of smoothly sweeping the frequency from 35 Hz to
75 Hz to terminals C13 (A-phase) and C16 (neutral).
Step 5: Set the ramp rate at 0.001 seconds/step (max level, lower if possible) and set the total number
steps at 1,000 (one second total for the sweep test).
Step 6: Set the frequency range of the sweep (ramp) for 55.0 to 64.7 Hz. This equates to a ROC of 9.7
Hz/sec (3.0% below the 10.0 Hz/sec pickup setting).
Step 7: Initiate the sweep (ramp) which simultaneously applies voltage to the BE1-11g and note that
there is no operation of OUT2.
Step 8: Increase the rate of change in increments of 1% (9.8, 9.9 Hz/sec) up to 9.9 Hz/sec and 0.5%
thereafter until OUT2 closes and record the pickup.
Step 9: Repeat steps 3 through 8 with the pickup value set at 2 Hz/sec. Begin the test by applying a
rate of change value 8% below pickup (1.84 Hz/sec or a frequency sweep range of 59 to 60.84
Hz). Increase the rate of change in 1% increments until OUT2 closes and record the pickup.
Step 10: (Optional.) Repeat steps 1 through 9 in Positive ROC mode. Additionally, verify that a sweep
from a high to low frequency does not cause an operation.
Step 11: (Optional.) Repeat steps 1 through 9 in Negative ROC mode by reversing the sweep rate from
high to low to simulate negative rate of change. Additionally, verify that a sweep from a low to
high frequency does not cause an operation.
Step 12: (Optional.) Repeat steps 1 through 11 for settings group 1, 2, and 3.
Step 13: (Optional.) Repeat steps 1 through 12 for 81-2, 81-3, 81-4, 81-5, 81-6, 81-7, and 81-8.
Time Delay Verification (ROC Frequency)
Time delay verification is not necessary for the ROC mode as the same timers are used as in the
over/underfrequency timing tests. Timing starts when the 81 Pickup goes high whether the cause is over,
under, or rate of change.
Inhibit Quantities (ROC Inhibit)
Operation in the rate of change mode can be inhibited by sensing voltage, negative-sequence voltage,
and frequency limits or range, the latter of which creates a “frequency window” of operation. The sensing
voltage inhibit is the same feature used for the over/underfrequency elements and has already been
tested. The following tests verify the negative-sequence and frequency limit inhibits.
Step 1: Use the Settings Explorer in BESTCOMSPlus to open the Protection, Frequency, Frequency
(81-1) screen and send the operational settings in Table 180 to the BE1-11g.
Table 180. Operational Settings (ROC Inhibit)
Setting
Value
Description
Element Mode
Rate of Change
Enables 81-1 function for Rate of Change mode
Source
Phase VT
Sets source to Phase VT
Pickup
2 Hz/sec
Sets pickup to 2 Hz/sec
Time Delay
0 ms
Sets time delay to minimum
Voltage Inhibit
40 V
Sets voltage inhibit pickup to 40 V
Over Frequency Inhibit
64 Hz
Sets overfrequency inhibit to 64 Hz
Under Frequency Inhibit
46 Hz
Sets underfrequency inhibit to 46 Hz
Negative Sequence Inhibit
20%
Sets negative-sequence inhibit to 20%
Step 2: Use BESTCOMSPlus to configure the BESTlogicPlus programmable logic shown in Figure 295.
BE1-11g
Frequency (81) Test