Kohler 38RCL, Operation, Page: 18 / 72

TP-6810 7/16 18 Section 2 Generator Set Operation
2.4.6 Automatic Operation with Model
RXT Transfer Switch
The Model RXT transfer switch connects to the RDC2
controller through the ATS interface board on the
transfer switch. Also see Section 2.7, Model RXT
Transfer Switch Operation.
The RDC2 controller must be in AUTO mode for
automatic transfer switch operation.
Automatic Start
The RDC2 controller receives utility source voltage
sensing data from the Model RXT transfer switch.
1. If the utility source voltage falls below an
acceptable level, the controller starts the engine
start time delay.
2. If the utility source is not restored before the time
delay expires, the generator set starts.
3. After the Normal-to-Emergency time delay, the
ATS is signaled to transfer the load to the
emergency source.
Automatic Stop
1. When the utility source is restored, the
Emergency-to-Normal time delay starts.
2. When the Emergency-to-Normal time delay
expires, the load is transferred to the utility.
3. The generator set stops.
2.4.7 Automatic Operation with Other
Transfer Switches
If a Kohler Model RDT transfer switch is used, the
engine start contacts from the ATS must be connected
to engine start leads 3 and 4 on the generator set.
The RDC2 generator set controller must be in AUTO
mode to respond to remote start/stop signals from an
ATS or remote switch. Press the AUTO button on the
RDC2 controller to put the generator set into automatic
mode.
Automatic Start
The engine start contacts on the ATS close to signal the
generator set to start, and remain closed while the
generator set is running.
Automatic Stop
The engine start contacts on the ATS open to signal the
generator set to stop.
2.5 Exercise
The RDC2 controller can be set to automatically run the
generator set at the same time and day every week or
every other week. Exercising the generator set every
week or every two weeks is required in order to keep the
engine and alternator in good operating condition.
Three exercise modes are available: unloaded cycle,
unloaded full speed, and loaded full speed. See
Sections 2.5.1 through 2.5.3 for information about the
exercise modes. A loaded exercise can be set at the
RDC2 controller only if a Model RXT transfer switch is
connected.
Note: With the RDT transfer switches, it is possible to
have two exercise settings (one unloaded
exercise set at the generator set controller, and
another exercise set at the ATS controller). If the
exercise times overlap, the ATS exercise setting
takes priority.
If a Model RDT transfer switch is used, refer to the
instructions provided with the transfer switch to set a
loaded exercise at the ATS, if desired.
2.5.1 Unloaded Cycle Exercise with
Complete System Diagnostics
An unloaded cycle exercise runs the generator set
without signalling the transfer switch to transfer the
electrical load from the utility source to the generator set.
The Unloaded Cycle exercise with diagnostics is the
recommended exercise mode and is the factory-default
exercise setting.
The Unloaded Cycle exercise runs the engine for
20 minutes in the cycle shown in Figure 2-1 and
described below.
D
Runs at reduced speed for 10 minutes to warm up
and exercise the engine.
D
Ramps up and runs at full speed for 3 minutes.
Engine diagnostics are performed during this
full-speed portion of the cycle, which provides the
best test of engine and alternator power backup
capability. Diagnostic tests at full speed can identify
potential problems with the power output and alert the
operator before an emergency event.