HomeControllersRDC2

RDC2 Controller

The RDC2 is a generator-set controller. It is used on generator sets from Gas-KOHLER and Kohler, including the TP-6804, 10RESV, 12RESV and 14/20RES.

111
Generator sets
2
Brands
7–60 kW
Power range
3
Fuel types

Generator sets using this controller

111

Used across brands: Gas-KOHLER, Kohler

Also fitted to: Kohler 14/20RCA/RCAL, Kohler 14/20RES/L, Kohler 14/20RESA/L, Kohler 14/20RESA/RESAL, Kohler 20 kW Models, Kohler 20RESA/20RESAL/20RESC/RESCL, Kohler 20RESC/RESCL, Kohler 26RCA/RCAL, Kohler Model RESA/L or RESC/L, Kohler RESA/RESAL, Kohler TP-6984 4/26f.

Troubleshooting

60

Fault codes

CodeMeaningCauseRemedy
Battery Low WarningsLow battery voltage warnings are displayed on the controller display.Check the battery connections and ensure they are secure. Replace the battery if it is low on charge.
BusDeadLiveThe bus is measured to be dead when one of the generators is supposed to be supplying voltage to the bus (closed contactor)Bus metering V9A and V9B connections to V9 of paralleling protection harness are connected incorrectly.
BusDeadLiveThe bus is measured to be dead when one of the generators is supposed to be supplying voltage to the bus (closed contactor).Bus metering V9A and V9B connections to V9 of paralleling protection harness are connected incorrectly.
BusLiveDeadThe bus is measured to be live when no generators are connected to it (both contactors open).Bus metering V9A and V9B connections to V9 of paralleling protection harness are connected incorrectly.
CfgModelNumThe two generators that are intended to be paralleled have incompatible model numbers.Incorrect configuration of one of the generators. Different generator types. The paralleled generator sets must be the same kW model. (i.e. two 14 kW or two 20 kWor 26 kW models).
CfgSysVoltThe system voltage of the two generators intended to be paralleled is not the same.One of the two generators is incorrectly configured. Intermittent connections on RBUS network wiring.
ConCheckFailFailure to Auto-Discover APM connections.Wires 9A and 9B crossed between the generators. Wires 9A or 9B not connected.
ConNotDetermAPM connection auto-discovery is not complete. This means that the generator does not know which contactor is connected to it.Generators not yet started in RUN with other generator in OFF. See the APM instruction sheet for instructions to perform the auto-discovery procedure.
ContactorOkSuccessful auto-discovery of APM connections.Auto-discovery was activated by placing other generator in OFF and this generator in RUN.
Current A High WarningOver Current ParalleledPress AUTO or OFF *
EnpowerGeneratorVoltHighTrip OR EnpowerGeneratorVoltLowTrip OR EnpowerGeneratorFreqHighTrip OR EnpowerGeneratorFreqLowTripGenerator voltage and/or frequency out of spec while in generator mode and generator is connectedThe generator gets disconnected
ErraticSigThe power metering on this controller gives a signal that is not consistent with the system configuration. Reversing the power direction does not resolve the problem.Bad wiring to the CT. Too much tension on wires from the CT to the controller.
Faults Related to ParallelingIssues arise when paralleling the generator with other systems or units.
Faults Related to ParallelingParalleling issues occur, such as incorrect synchronization or failure to maintain parallel operation.Verify that all paralleling settings are correct in the controller parameters. Check the paralleling cables and connections for any faults.
Frequency High WarningOver Frequency ParalleledPress AUTO or OFF *
Frequency Low WarningUnder Frequency ParalleledPress AUTO or OFF *
GenTHDHighHigh Total Harmonic Distortion (THD) Measured THD is above 25%Generator power output is not stable and having high THD (THD means total harmonic distortion, which is a metric to measure the power quality. If the THD is high, the performance of your electronics will be affected; for example, you may see flickering lights).
GeneratorStartFailedGenerator not startingThe generator does not start as selected in user preferences.Check if the generator 2-wire start/stop wiring to IQ System Controller is loose. Check whether the generator breaker at the unit was tripped (if so turn the breaker off and then on. Also switch the controller to the auto position), whether the generator is out of fuel, or the starting battery of the generator was dead. Contact your installer or Enphase customer support if the problem persists.
GeneratorStopFailedGenerator not stoppingGenerator continues to run even though user preferences indicate it should have stopped.Check if the generator 2-wire start/stop wiring to IQ System Controller is loose. Turn off the generator manually and contact installer or Enphase customer support.
GeneratorVoltageImbalance OR GeneratorComBusPhaseDifferenceOORGenerator was overloaded.Generator breaker in IQ System Controller tripped, and the generator is disconnected.The system will try to reconnect the generator in 5 minutes. You should: • Open IQ System Controller door, turn off the generator breaker and turn it on again. (When you open IQ System Controller, the generator breaker lever will not be in ON position) • Ensure you do not overload the system while the generator is running.
LossOfComAPMThe Automatic Paralleling Module has stopped communicating on RBUS. (An APM was detected on the RBUS network but is no longer communicating).APM is unplugged. Primary controller is powered down. Check the battery connections. See previous page for more information. Intermittent connections on RBUS network wiring.
LossOfComAPMThe Automatic Paralleling Module has stopped communicating on RBUS. (An APM was detected on the RBUS network but is no longer communicating.)APM is unplugged. Primary controller is powered down. Check the battery connections. See previous page for more information. Intermittent connections on RBUS network wiring. Check RBUS communication connections.
LossOfComm2Communication Lost with Secondary Controller
LossOfComm2The primary controller has lost communication with the secondary controller. (A secondary controller was detected, then communication was lost.)RBUS disconnected, secondary controller battery disconnected, updating firmware in secondary controller, or intermittent RBUS connections.
LossOfFieldThis generator has absorbed more than 25% reactive power (magnetic excitation current) for 20 seconds Generator voltage on this generator is not calibrated correctly. Generator voltage on other generator is not calibrated correctly. Bus voltage on this generator is not calibrated correctly. Bus voltage on the other generator is not calibrated correctly.
LossOfFieldThis generator has absorbed more than 25% reactive power (magnetic excitation current) for 20 seconds.Generator voltage on this generator is not calibrated correctly. Generator voltage on other generator is not calibrated correctly. Bus voltage on this generator is not calibrated correctly. Bus voltage on the other generator is not calibrated correctly.
Main Power Overload ShutdownThe generator shuts down due to a main power overload condition.
Main Power Overload ShutdownThe generator shuts down due to a main power overload.Check the circuit breaker and ensure it is not tripped. If necessary, replace the circuit breaker.
MeterUnknownThis generator does not know if the metering is connected or the orientation of the connection. This means that the generators can’t share load accurately until this information is known.System commissioning and startup not yet complete. See the APM instructions.
MeteringOkThe generator has verified that the metering is connected correctly and that the direction is consistent with expected power direction.Status message indicates that the CT is connected to the generator correctly.
MeteringOkThe generator has verified that the metering is connected correctly and that the direction is consistent with expected power direction. Status message indicates that the CT is connected to the generator correctly.
NoCurrentThe generator has applied load (using the other generator) and has observed no current on the power sensing inputs.The CT is not connected to the controller. The output leads from the generator do not go through the CT in the correct direction. See the APM instructions.
Reactive Power Low WarningLoss of Field ParalleledPress AUTO or OFF *
Real Power High WarningOver Power ParalleledPress AUTO or OFF *
Real Power Low WarningReverse Power ParalleledPress AUTO or OFF *
SyncFailureThe generator has been attempting to synchronize for over 2 minutes without success.Generator is hunting. Advanced speed control settings need adjustment. Load is changing frequently to disturb the online generator.
Voltage L1-L2 High WarningOver Voltage ParalleledPress AUTO or OFF *
Voltage L1-L2 Low WarningUnder Voltage ParalleledPress AUTO or OFF *
Volts L1-L2Generator voltage high. Output voltage exceeds 120% of the system nominal voltage for more than 2 seconds.Contact an authorized distributor/dealer for service.
Volts L1-L2Generator voltage low. Output voltage falls below 80% of the nominal system voltage for more than 10 seconds.Reduce the load and restart the generator set. Model 20RCA/20RCAL only: Check enclosure thermostat and reset if tripped. See Section 5.6.

Symptoms & remedies

SymptomCauseRemedy
ATS Status or Configuration menus are not displayed on the RDC2 controllerCheck the RBUS connections from the RDC2 controller on the generator to the interface board on the RXT transfer switch.
ATS settings are not correctly configuredOn systems equipped with the DC2 controller, a personal computer and Kohlerr SiteTecht software must be used to adjust the ATS settings. See Section 4.3.
ATS status and settings are not correctCheck the ATS status and settings. Use the RDC2 controller menus and/or connect a personal computer (PC) to the RDC2 or DC2 controller on the generator set and use the Kohlerr SiteTecht program on your PC.
Application code version number is outdatedCheck the application code version number on the RDC2/DC2 controller. Check TechTools for the latest information about application code updates, and obtain the latest version if necessary.
Battery acid can cause blindness and burn skin.If battery acid splashes in the eyes or on the skin, immediately flush the affected area for 15 minutes with large quantities of clean water. Seek immediate medical aid in the case of eye contact.
Battery acid is electrically conductive and corrosive.Add 500 g (1 lb.) of bicarbonate of soda (baking soda) to a container with 4 L (1 gal.) of water and mix the neutralizing solution. Pour the neutralizing solution on the spilled battery acid and continue to add the neutralizing solution to the spilled battery acid until all evidence of a chemical reaction (foaming) has ceased. Flush the resulting liquid with water and dry the area.
Battery acid on skinFlush the affected area for 15 minutes with large quantities of clean water and seek medical aid if necessary.
Battery acid splashes in the eyesImmediately flush the affected area for 15 minutes with large quantities of clean water. Seek immediate medical aid.
Battery short circuitsDisconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery.
Battery short circuits can cause bodily injury and/or equipment damage.Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (–) lead first when disconnecting the battery. Reconnect the negative (–) lead last when reconnecting the battery. Never connect the negative (–) battery cable to the positive (+) connection terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together.
Bodily injury and/or equipment damageBattery short circuitsDisconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. Never connect the negative (--) battery cable to the positive (+) connection terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together.
Controller resetElectromagnetic interference (EMI)Inspect the distributor cap and rotor for specific features. Replace them if necessary with updated parts.
Cooling Fans Cycle at Low Temperatures (48RCL only)Update the controller with software version 4.05 or higher.
Corrosion, loose terminals, damaged wiring or connectorsUnplug connectors and check terminals and leads for corrosion. Remove corrosion from terminals and leads. Tighten loose terminals. Check wiring harnesses for continuity or short circuits. Recrimp or replace loosely connected lead terminals.
D burn skin.Always wear splashproof safety goggles, rubber gloves, and boots when servicing the battery. If battery acid splashes in the eyes or on the skin, immediately flush the affected area for 15 minutes with large quantities of clean water. Seek immediate medical aid in the case of eye contact.
Display ErrorsInstall controller software version
Engine HuntingA number of factors can result in engine hunting.Perform the following steps: 1. Disconnect ATS to prevent automatic starting. 2. Confirm under what conditions the generator hunts. 3. Update firmware and install vent tubes on the fuel regulator as described. 4-11. Follow additional troubleshooting steps including checking Engine Speed Gain Adjustment, air intake tube, fuel source setup, fuel pressure, solenoid valve operation, and throttle plate movement.
Engine does not startLow oil pressure or oil levelCheck and refill oil if necessary. Refer to the 'Oil Check' section for details.
Engine overheatsCoolant level is low or coolant is contaminatedCheck and refill coolant if necessary. Refer to the 'Cooling System' section for details.
Engine speed sensor has failed or engine stalled.Contact an authorized distributor/dealer for service.

Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.