GE Industrial Solutions Power Plus Control Units - Manuel (Page 10)

Power+™ Control Units
Chapter 2. Control Unit Setup
2–1 Overview
Both of the Control Unit protective functions are set with
the rotary selector switches on the front of the rating plug.
Table 5 contains a summary of the functions and the
available settings.
2–2 Ground-Fault Pickup
This function sets the pickup current for ground-fault
protection. The available settings are .2, .25, .3, .35, .4, .45,
.5, and .6 times the current sensor rating, S . The
maximum setting may be less than .6, depending on the
switch frame size. Figure 2 illustrates the time-current
curve for ground-fault pickup.
Current
Ground-Fault
Pickup Settings
Figure 2. Time-current curve illustrating ground-fault pickup.
2–3 Ground-Fault Delay
This function sets the delay before the switch opens when
the ground-fault pickup current is detected. The switch
settings MIN , INT , and MAX correspond to nominal time
delays of .10, .21, and .35 second, respectively. The delay
with I 2 T OUT is for the lower limit of each band. The delay
with I 2 T IN is at 200% of the pickup setting at the lower
limit of the band.
The
I 2 T OUT function, illustrated in Figure 3, establishes a
constant time delay. I 2 T IN biases the delay with a constant
slope, as shown in Figure 4.
Current
Delay Set Points
with I T OUT
2
Figure 3. Time-current curve illustrating ground-fault delay
with I 2 T OUT.
Current
Delay Set Points
with I
2 T IN
Figure 4. Time-current curve illustrating ground-fault delay
with I 2 T IN.
Parameter Pickup Settings Delay Settings Delay Curve
Ground-Fault Trip
.2, .25, .3, .35, .4, .45, .5, .6*
multiple of Sensor rating (S) .10, .21, .35 seconds
(Min, Int, Max)
I 2 T In, I 2 T Out
* Maximum setting is limited by the frame size.
Table 5. Summary of ground-fault trip settings.
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