RDC Controller

The RDC is a generator-set controller. It is used on generator sets from Kohler, including the 14RES and 20RES.

2
Generator sets
Kohler
Brand
14–20 kW
Power range
Bi-Fuel (NG/LP)
Fuel

Generator sets using this controller

2

Engines paired with this controller

2

Troubleshooting

10

Fault codes

CodeMeaningCauseRemedy
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
Faults Related to ParallelingIssues arise when paralleling the generator with other systems or units.
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.
LossOfComm2Communication Lost with Secondary Controller
Main Power Overload ShutdownThe generator shuts down due to a main power overload condition.

Symptoms & remedies

SymptomCauseRemedy
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.
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.

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.