Full Product Manual

32 TP-7092 4/23
2.3.5 Engine Start Crank Cycle
The controller attempts to start the generator set three times (three crank cycles, 15 seconds crank and 15 seconds off). If the
generator set does not start in three attempts, the system shuts down on an overcrank fault. See the Faults section.
Cranking 1, 2, and 3 are displayed during the crank cycle. Pressing the OFF button during the crank cycle stops the cranking.
No other buttons are acknowledged during the crank cycle.
20 and 26 kW Models (RDC2.4 v 1.4.4 or later)
For RDC2.4 controllers with firmware version 1.4.4 or later, the 20 and 26 kW models will perform two crank cycles with 3 starting
attempts during each cycle. The controller attempts to start the generator set three times (three starting attempts, 15 seconds
crank and 15 seconds off). If the generator set does not start in three attempts, the controller pauses for 45 seconds, and then
performs another set of 3 starting attempts. If the generator set does not start during these crank cycles, the system shuts down
on an overcrank fault. See the Faults section.
2.3.6 Engine Cooldown
The engine cooldown time delay allows the engine to run after the loads have been removed.
The engine cooldown time delay is set to 5 minutes. The engine stops before the cooldown time delay expires if the temperature
drops below the cooled-down temperature level, or if the temperature rises above the high limit during the cooldown cycle.
If a transfer switch other than the Model RXT is used, an additional engine cooldown time delay may be programmed on the
transfer switch. To allow the smart engine cooldown on the RDC2 controller to operate most efficiently, set the cooldown time
on the transfer switch controller to zero or the minimum time allowed. Refer to the instructions provided with the transfer switch
for more information.
2.3.7 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 the Model RXT Transfer Switch Operation/Installation Manual for more information about transfer switch operation.
The 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 with Engine Cooldown
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 runs through the engine cooldown cycle and then stops.