GE Industrial Solutions MicroVersaTrip PM - Manual (Page 26)

MicroVersaTrip Plus™ and MicroVersaTrip PM™ Trip Units
Chapter 2. Setup Mode
16
Long-Time Pickup
The first setup-mode display is always the long-time
pickup setpoint, as illustrated in Figure 10. This set
point establishes the breaker’s nominal ampere rat-
ing,
xLT, as a fraction of the rating plug value, xIn
( xLT = LT multiplier x xIn). Press the VALUE key to
scroll through the available choices. Press ENTER to
store the desired set point.
Figure 10. Trip Unit display for long-time pickup.
The choices for UL breakers are 0.50 to 1.00 times
xln in steps of 0.05. The pickup value tolerance band
is 0% to +20% of the set point.
The choices for ANSI breakers are 0.50 to 1.10 times
xln, in steps of 0.05. The pickup value is defined for
−1
0% to +10% of the set point.
Figure 11 illustrates the long-time pickup settings.
Figure 11. Time-current curve illustrating long-time pickup.
Long-Time Delay
The Trip Unit display for long-time delay is illus-
trated in Figure 12. This function allows normal
momentary overloads without nuisance tripping.
The time delays at the lower limit of the bands at
600% of the long-time current setting,
xLT, are listed
in Table 11. Figure 13 illustrates the effect of this
delay on trip time. Press the
V A L U E key to cycle
through the four choices of time-delay bands. Press
ENTER to store the desired value.
Figure 12. Trip Unit display for long-time delay.
B B B Baa a an n n nd d d d D D D Deee ellllaa a ayyyy,,,, sssseee eccc c
1 2.4
2 4.9
3 9.8
4 20
Table 11. Lower-limit delays for long-time delay bands.
Figure 13. Time-current curve illustrating long-time delay.
Short-Time Pickup
The short-time pickup function establishes the cur-
rent at which short-time trip is activated. Short-time
pickup is coupled with long-time pickup and the
choices of pickup settings are from 1.5 to 9.0 times
the long-time setting,
xLT, in steps of 0.5 xLT. The
Trip Unit display is illustrated in Figure 14.