GE MicroVersaTrip PM User Manual

MicroVersaTrip Plus™ and MicroVersaTrip PM™ Trip Units
Chapter 2. Setup Mode
17
Figure 14. Trip Unit display for short-time pickup coupled with
long-time pickup.
The time-current curve for short-time pickup is
shown in Figure 15.
Figure 15. Time-current curve illustrating short-time pickup.
Short-Time Delay
The Trip Unit display for short-time delay is shown
in Figure 16. This function delays the breaker trip on
a short-time trip. The choices of time-delay bands
are listed in Table 12. The delay with
I
2
T IN is for a
current of 600% of
xLT at the lower limit of the
band. The delay with
I
2
T OUT is for the lower limit of
each band.
On ANSI Trip Units ordered with the user-selectable,
switchable instantaneous overcurrent and ground-
fault option, “X,” an additional value of
OFF appears
at the end of the delay band settings. Choosing
OFF
disables short-time protection. The short-time OFF
band is interlocked with instantaneous pickup, so
that only one function can be turned off at a time.
The
I
2
T OUT function, illustrated in Figure 17, estab-
lishes a constant time delay.
I
2
T IN biases the delay
with a constant slope, as shown in Figure 18.
Figure 16. Trip Unit display for short-time delay.
BB
BB
aa
aa
nn
nn
dd
dd
TT
TT
ii
ii
mm
mm
ee
ee
DD
DD
ee
ee
ll
ll
aa
aa
yy
yy
ss
ss
,,
,,
ss
ss
ee
ee
cc
cc
1 0.10
2 0.21
3 0.35
Table 12. Lower-limit delays for I
2
T OUT short-time delay bands.
Figure 17. Time-current curve for short-time delay with I
2
T OUT.
Figure 18. Time-current curve for short-time delay with I
2
T IN.

GE MicroVersaTrip PM Specifications

General

Brand	GE
Model	MicroVersaTrip PM
Category	Circuit breakers
Language	English