Kohler 20EKOZD

252 Section 13 Generator Management Information TP-6953 7/19
Fuel Level Difference if only one of the generators is
stopped) or if the fuel level of a lower-order generator is
less than the fuel level of this generator (including the
Fuel Level Difference if only one of the generators is
stopped).
All Modes: More than one generator has the same order.
When the need for a change is detected, the order will
attempt to re-sort such that all generators have a unique
and sequential order and that the order matches the
order selection mode criteria (depending on mode). If
there is no valid configuration to be found after
10 seconds of trying, Generator Management will be
disabled until the order conflict can be resolved (this
may happen automatically by fuel level or runtime
changing, or may require user intervention).
Note: It is very unlikely that an order conflict will not be
resolved in runtime or fuel level mode. Manual
mode presents additional challenges in
re-sorting that may cause an un-negotiable
conflict in order numbers.
13.5.6 Start/Stop Threshold Calculation
The determination to start or stop a generator involves
the comparison of the actual load on the paralleling bus
with the Start Threshold (called the Start kW) and the
Stop Threshold (called the Stop kW) for the generator.
These thresholds are computed based on the order of
the generator, the kW rating of any lower-order
generators, and the availability of any lower-order
generators.
The Start kW is computed as:
Start kW = Capacity of lower order generators X Start Percentage
The Capacity of lower order generators is simply the
sum of a ll available generators with a lower Generator
Management Order than this generator.
If the Minimum Gens Online is set to 2, the lowest 2
available generators will have a start kW of 0.
TheStopkWiscomputedas:
Stop kW = Capacity of lower order generators X Stop Percentage
The Capacity of lower order generators is simply the
sum of a ll available generators with a lower Generator
Management Order than this generator.
If the Minimum Gens Online is set to 2, the lowest 2
available generators will have a stop kW of 0.
13.5.7 Start/Stop Accumulators
The Start/Stop Accumulators fill at a rate which is related
to the load on the system. The accumulators are full
when they reach 100%. When the start accumulator for
a generator is full (100%) the generator will start,
synchronize, and connect to the paralleling bus
(supplying the load). When the Stop Accumulator is full
(100%) the generator will soft-unload, disconnect from
theparallelingbus,andstop(acooldowncycleis
optional).
Start Accumulator
The Start Accumulator fills at the following rate:
Start Accumulator Fill Rate (%/s) =
Percent Difference
2
Start Delay
∗
100
The Percent Difference is computed as:
Percent Difference =
(System Load - Start kW)
Total Capacity of Paralleling Bus if the
system load is greater than the start kW.
0 if the system load is less than or equal to the start kW.
(The Total Capacity of Paralleling Bus is the sum of the
kW ratings of all the generators that are connected to the
paralleling bus).
The Time before a generator starts is the time required
to reach 100% at the given fill rate, or:
Time To Start =
100
Start Accumulator Fill Rate
Stop Accumulator
The Stop Accumulator Fills at the following rate:
Stop Accumulator Fill Rate (%/s) =
Percent Difference
2
Stop Delay
∗
100
The Percent Difference is computed as:
Percent Difference =
(Stop kW - System Load)
(Total Capacity of Paralleling Bus - Capacity of This Gen.)
if the system load is less than the stop kW.