GE Industrial Solutions Spectra RMS Molded Case - Manual (Page 18)

GEH-702 Users Manual
17
Short Time Pickup (Standard)
This set point is used to establish the short time pickup
of the trip unit. The short time pickup of the trip unit is
calculated by multiplying the short time pickup value
times the breaker’s nominal ampere rating “C”. It is
important to note that changes to the long time pickup
value affect the short time pickup value. The available
range of short time pickup values is 1.5 to 9.0 in
increments of 0.5. The short time pickup parameter can
also be turned OFF. This is accomplished in the short
time delay menu.
Example:
Breaker Nominal Ampere Rating “C” = 400 amps
ST Pickup Setting = 9.0
ST Pickup Rating = 400 amps x 9.0 = 3,600 amps
Figure 10. Short Time Pickup
Short Time Delay (Standard)
This set point is used to allow momentary inrush
currents without nuisance tripping the breaker. It is also
used to establish the shape of the short time portion of
the time current curve. Twelve time delay bands and
four curve slopes are available. The short time delay is
a function of both the time delay band and the slope.
Figure 11. Short Time Delay with Slope Off
Figure 12. Short Time Delay Set to Maximum