Kohler 20EKOZD

258 Section 14 Load Management TP-6953 7/19
Each priority will add after a time delay as specified
in the curve above.
In the example system illustrated in Figure 14-1,
the 99 kW generator is loaded to 25% of capacity
when it is supplying the critical load. Referencing
Figure 14-2, the time required to add priority 1 will
be approximately 42 seconds.
After the first priority adds, the generator power
output may increase, resulting in an increase in the
delay for subsequent loads to add.
25kW
Critical
loads
Most
important
non-
critical
loads
Least
important
non-
critical
loads
Additional
non-critical
loads
Load
Shed
Panel
Load
Shed
Panel
Generator
(99kW rating)
18kW 8kW 3kW 10kW 12kW 5kW
43kW
Figure 14 -3 Example System After Priority 1 Has
Been Added
In the example system illustrated in Figure 14-3,
the 99 kW generator is loaded to 43% of capacity
when it is supplying both the critical load and the
load that is interrupted by load shed priority 1.
Figure 14-2 indicates that load shed priority 2 will
add in about 240 seconds (4 minutes) after load
priority 1 is added.
The 51 kW that will be supplied by the generator
with priorities 1 and 2 added will extend the time to
add priority 3 to about 2400 seconds (40 minutes),
although the time delay may be shortened if the
load on the generator decreases and may extend if
the load increases.
The time to add priority 4 will be greatly extended
by the generator output power being so close to the
threshold to add load without exceeding the
Genset Maximum Percent Capacity that it will take
37,500 seconds (10 hours and 25 minutes) to add.
Note: In a r eal-world application, the requirements
of the load vary enough that priority 4 would
never add, as all that is required to reset the
timer is to exceed the 55 kW (Genset
Maximum Percent Capacity -15%)
threshold for a moment.
If the power requirement of the critical and priority
1 load dropped to 12 and 7 kW, respectively, the
total load on the generator would be 30 kW, which
would result in priority 4 adding in 60 seconds. After
priority 4 is added, the generator will be providing
40 kW, which will increase the time delay for priority
5 to about 170 seconds (nearly 3 minutes). The
generator will be providing 52 kW of load after
priority 5 is added, extending the delay for priority 6
to add to about 4200 seconds (1 hour and 10
minutes). Once priority 6 is added, the generator
will be supplying 57 kW.
12kW
Critical
loads
Most
important
non-
critical
loads
Least
important
non-
critical
loads
Additional
non-critical
loads
Load
Shed
Panel
Load
Shed
Panel
Generator
(99kW rating)
7kW 8kW 3kW 10kW 12kW 5kW
57kW
Figure 14-4 Example System After All Priorities Have
Been Added
3. Overload Shed. When the load on the generator is
too high to allow the generator to support sudden
increases in load without undesirable voltage
and/or frequency dips, the Load Management
system will remove unimportant loads so that the
critical loads continue to receive high quality
power.
In the Example system illustrated in Figure 14-1,
Figure 14-3, and Figure 14-4, the generator can
become overloaded if the power requirements of
the critical load and the priority 1 load increase.