GE Industrial Solutions WavePro Low-Voltage Power Circuit Breakers - Manual (Page 25)

MicroVersaTrip Plus™ and MicroVersaTrip PM™ Trip Units
Chapter 2. Setup Mode
17
Band Time Delay, sec
OFF Disabled
1 0.10
2 0.21
3 0.35
Table 14. Lower-limit delays for ground-fault delay bands.
Figure 21. Time-current curve for ground-fault delay with I
2
T OUT .
Figure 22. Time-current curve for ground-fault delay with I
2
T IN .
Voltage-Unbalance Relay Pickup
This function compares the highest or lowest phase volt-
age with the average of all three phases and initiates a trip
if the difference exceeds the set point. The true rms volt-
age is computed for each phase. The range of set points is
from 10 to 50% of the unbalance, with an increment of
1%. The Trip Unit display is shown in Figure 23.
Figure 23. Trip Unit display for voltage-unbalance relay pickup.
Voltage-Unbalance Relay Delay
This function sets the delay time before a voltage-unbal-
ance trip occurs. The range of delays is 1 to 15 seconds, in
steps of 1 second. Choosing
OFF disables voltage-unbal-
ance protection. The Trip Unit display is shown in Figure
24.
Figure 24. Trip Unit display for voltage-unbalance relay delay.
Current-Unbalance Relay Pickup
This function compares the true RMS current in the
highest or lowest phase with the average of all three phases
and initiates a trip if the difference exceeds the set point.
The range of set points is 10 to 50% of the unbalance, with
an increment of 1%. The Trip Unit display is shown in
Figure 25.
Figure 25. Trip Unit display for current-unbalance relay pickup.
Current-Unbalance Relay Delay
This function sets the delay time before a current-unbal-
ance trip occurs. The range of delays is 1 to 15 seconds, in
steps of 1 second. Choosing
OFF disables current-unbal-
ance protection. The Trip Unit display is shown in Figure
26.