DC Controller

The DC is a generator-set controller. It is used on generator sets from Cummins/Onan and Kohler, including the MDKAA, MDKAB, MDKAL and MDKAL11454B.

9
Generator sets
2
Brands
6–20 kW
Power range
2
Fuel types

Generator sets using this controller

9

Used across brands: Cummins/Onan, Kohler

Troubleshooting

19

Fault codes

CodeMeaningCauseRemedy
Check Engine‘Check Engine’ Fault Shutdown
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
"CHECK ENGINE" FAULT SHUTDOWNLow engine oil pressure; High engine temperature; High exhaust temperatureCheck engine oil level, repair any leaks and fill to the proper level (p. 17).; a. Check engine coolant level, repair any leaks and fill to the proper level (p. 18). b. Check V-belt tension (p. 20). c. Clean and service the cooling system as required to restore full cooling capacity (p. 18).; a. Open the sea cock. b. Remove any blockage in the sea water strainer. c. Prime the sea water pump (p. 22). d. Replace the sea water pump impeller (p. 22). e. Clean seaweed and pump debris from heat exchanger (p. 22). f. Remove blockage covering the sea water hull strainer.
"CHECK GENERATOR" FAULT SHUTDOWNGenerator overloadRun with less load.
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.
ENGINE CRANKS BUT DOES NOT STARTEngine not getting fuel; Blocked air inlet; Low engine temperature; Cranking voltage too lowA. Open any closed shutoff valve. b. Check fuel level and refill as necessary. c. Prime the fuel system (p. 24). d. Check for fuel (air) leaks at all fittings and tighten as necessary. e. Replace the fuel filter (p. 23).; Service as necessary.; a. Plug in, repair or install engine coolant and engine oil heaters. b. Replace the engine oil if it is not of the recommended viscosity for the ambient temperature.; a. Clean and tighten or replace the positive (+) and negative (- ) battery cable connectors and cables at the battery and the genset. b. Recharge or replace the battery. Specific gravity for a fully charged battery is approximately 1.260 at 80° F (27° C).
ENGINE DOES NOT CRANK FROM GENSET PANELEmergency Stop Switch OFF; "Check Generator" or "Check Engine" Fault; Cranking voltage too lowPush ON.; Service the fault as necessary and push fault reset button in. See “CHECK ENGINE” FAULT SHUTDOWN or “CHECK GENERATOR” FAULT SHUTDOWN.; a. Clean and tighten or replace the positive (+) and negative (- ) battery cable connectors and cables at the battery and the genset. b. Recharge or replace the battery. Specific gravity for a fully charged battery is approximately 1.260 at 80° F (27° C).
ENGINE DOES NOT CRANK FROM REMOTE PANELEmergency Stop Switch OFF; "Check Generator" or "Check Engine" Fault; Faulty remote circuitPush ON.; Service the fault as necessary and push fault reset button in. See “CHECK ENGINE” FAULT SHUTDOWN or “CHECK GENERATOR” FAULT SHUTDOWN.; Try starting at the genset control panel. If the genset starts, have the remote circuit repaired as necessary.
Engine does not stop runningMalfunctioning fuel solenoid or linkagePull the stop lever to the right and hold it there until the engine stops (see figure). PULL TO RIGHT AND HOLD UNTIL ENGINE STOPS
Fault Circuit Breaker CB2 tripsAC over-voltage, overspeed, high exhaust temperature, high coolant temperature, low oil pressure, and low coolant level (optional)
NO OUTPUT VOLTAGEA line circuit breaker is Off. A line circuit breaker has Tripped.Find out why the circuit breaker was turned Off, make sure it is safe to reconnect power, and then throw the circuit breaker On. Shut down the genset and have service performed as necessary to clear the short circuit or ground fault that caused tripping. Then Reset the circuit breaker and start the genset.

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.