9424200994 Rev N 477
Differential
Protection, Current, Phase
Differential (87)
Sets the type of operation
protection to traditional
phase current differential
Protection, Current, Phase
Differential (87)
Sets the element to operate
using maximum restraint
(MOT)
Protection, Current, Phase
Differential (87)
of operate current required
(%)
Protection, Current, Phase
Differential (87)
Sets the 1
st
slope of the
restraint characteristic to
(MOT)
Protection, Current, Phase
Differential (87)
when the measured
maximum restraint current
(%)
Protection, Current, Phase
Differential (87)
Sets the 2
nd
slope of the
restraint characteristic to
Protection, Current, Phase
Differential (87)
Sets the trip time delay to
100 ms
Harmonics Mode
Protection, Current, Phase
Differential (87)
Sets the harmonic restraint
for independent phase
Harmonic (%)
Protection, Current, Phase,
Differential (87)
restraint threshold to 12%
Harmonic (%)
Protection , Current, Phase
Differential (87)
restraint threshold to 35%
Step 2: Use BESTCOMSPlus to configure the BESTlogicPlus programmable logic shown in Figure 307.
• Blocking is disabled.
• OUT1 closes for 87 Trip.
• OUT2 closes for 87 Pickup.
• Fault recording is enabled.
Step 3: Prepare to monitor the 87R function operation. Operation can be verified by monitoring OUT2
(see Figure 307).
Step 4: To test the Minimum Restrained Pickup setting, connect two balanced three-phase current
sources to the BE1-11g in ABC rotation: 0.5∠0°, 0.5∠–120°, 0.5∠120° amps to terminals D1
through D6 and 0.5∠180°, 0.5∠60°, 0.5∠–60° amps to terminals F1 through F6 (0.25x tap).
Step 5: Slowly increase the A-phase current in CT circuit 1 or 2 until OUT2 closes and record the
pickup. This should occur at 0.70 A ±0.05 A. Verify that there is an 87A target on the front-panel
display.
Step 6: Slowly decrease the A-phase current in CT circuit 1 or 2 until OUT2 reopens and record the
dropout. See the functional test report for acceptable ranges.
Step 7: Reset to the current levels in Step 5 and reset all targets.
BE1-11g Phase Current Differential (87) Test