RXT Transfer Switch Manual

TP-6807 1/16 33Section 3 Operation
Figure 3-8 shows the under frequency shed timing for a
60 Hz generator set. If the underfrequency condition
persists, the load shed timing can be affected by load
shed acceleration. See Section 3.5.5.
Frequency (Hz)
Frequency
Droop (Hz)
Time (seconds)
>59 Hz <1 Hz Never Shed
58.5 1.5 5.4
57 3 4.3
56 4 3.4
54 6 1.8
<52.5 Hz >7.5 Hz 0.3
Figure 3-8 Under Frequency Shed Timing for a
60Hz Generator
3.5.5 Load Shed Acceleration
Load shed acceleration is used to shed loads more
quickly if an overload or underfrequency condition
persists. If an overload condition is not cleared by
shedding a load, each subsequent load will shed more
quickly. The acceleration is more pronounced for an
underfrequency shed.
3.5.6 Changing Settings
The Generator Maximum Percent Capacity and
Generator Overloaded Percent settings can be
changed using a laptop computer connected to the
RDC2 or DC2 controller and Kohlerr SiteTecht
software. The load control settings are found in the
Genset System Configuration group. See Figure 3-9
and TP-6701, SiteTech Software Operation Manual.
Set the Generator Overload Percent at least 10% higher
than the Generator Maximum Percent Capacity.
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1. Load shed settings
Figure 3-9 SiteTech Screen