GE Industrial Solutions WavePro Low-Voltage Power Circuit Breakers - Manual (Page 24)

MicroVersaTrip Plus™ and MicroVersaTrip PM™ Trip Units
Chapter 2. Setup Mode
16
Figure 17. Instantaneous overcurrent protection set point.
Frame Max. Amp
Rating
Setpoints Without
ST
Setpoints
With ST
2000 1.5–10.0 xIn 1.5–15.0 xIn
3200 1.5–10.0 xIn 1.5–13.0 xIn
4000 1.5–9.0 xIn 1.5–9.0 xIn
5000 1.5–7.0 xIn 1.5–7.0 xIn
Table 12. Instantaneous pickup settings for various frame sizes with
and without the short-time function.
On Trip Units with the user-selectable switchable instan-
taneous overcurrent and ground-fault option, X, an addi-
tional value of
OFF appears at the end of the listing of
numerical values. Choose this setting to disable instanta-
neous protection. The instantaneous
OFF selection is
interlocked with short-time pickup, so that only one
function can be turned off at a time.
Ground-Fault Pickup
The trip unit display for ground-fault pickup is shown in
Figure 18. This function sets the pickup current for
ground-fault protection. The available settings are listed in
Table 13 as multiples of xCT the current sensor rating, in
steps of 0.01 xCT. The maximum value is limited to 1200
A. Figure 19 illustrates the time-current curve for ground-
fault pickup.
Figure 18. Trip Unit display for ground-fault pickup.
Sensor, A Set Points
150–2000 0.20–0.60
3200 0.20–0.37
4000 0.20–0.30
5000 0.20–0.24
Table 13. Ground-fault pickup settings, as a function of sensor rating.
Figure 19. Time-current curve for ground-fault pickup.
Ground-Fault Delay
This function sets the delay before the breaker trips when
the ground-fault pickup current has been detected. The
Trip Unit display is shown in Figure 20. The choices are
listed in Table 14. The delay for
I
2
T OUT is at the lower
limit of each band. The delay for I
2
T IN is at 200% of the
pickup setting at the lower limit of the band.
The I
2
T OUT function establishes a constant time delay, as
shown in Figure 21. I
2
T IN biases the delay with a constant
slope, as shown in Figure 22.
With the X or GD options (switchable or defeatable
ground fault), an
OFF selection appears as an additional
time-delay set point. Selecting OFF disables ground-fault
protection.
Figure 20. Trip Unit display for ground-fault delay, showing
I
2
T
out.