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Cummins/Onan HDCAD Generator Set

The Cummins/Onan HDCAD is a 12 kW (15000 kVA) Diesel standby generator set. It is available at 120 V, 1-phase, 60 Hz and rated 100 A. It holds about 6.3 L (1.7 gal) of oil and 5.8 L (1.5 gal) of coolant, with a maximum ambient rating of 40 °C. Starting uses battery rated 650 CCA at 12 V. The set measures 1050×620×686 mm (41.3×24.4×27.0 in), weighs about 300 kg (661 lb) and produces 69 dBA at 3 m.

12 kW
Standby
6.3 L
Oil capacity
3
Document types

How to read your Cummins/Onan serial & model number →

Specifications

FuelDiesel
Frequency60.0 Hz
Standby power12 kW
ControllerIntegrated Microprocessor Based Engine and Generator Controller
Oil capacity6.3 L
Voltage options120 V, 240 V
Phase1
Rated current100 A
Circuit breaker50 A
Battery cranking650 CCA
Battery voltage12 V
Coolant capacity5.8 L
Max ambient40 °C
Dimensions (L×W×H)1050×620×686 mm
Dry weight300 kg
Sound level69.0 dBA @ 3 m

Maintenance & consumables

ItemSpecCapacityPart #Interval
Air filter—18000 hr find
Fuel filter—720 hr find
Oil filter—50 hr find
Belt—150 hr find
Coolant5.8 liter—
Coolant filter— find
Oil6.7 liter—

Common questions

What is the power rating of the Cummins/Onan HDCAD?

The Cummins/Onan HDCAD is rated 12 kW standby.

What fuel does the Cummins/Onan HDCAD use?

The Cummins/Onan HDCAD runs on Diesel.

Troubleshooting

25

Fault codes

CodeMeaningCauseRemedy
1HIGH TEMPERATURE FAULT—CODE NO. 1(The engine coolant temperature exceeded 230° F [110° C])1. Check the engine coolant level and add coolant as necessary. 2. Check for and remove any objects blocking the air inlet or outlet openings in the bottom of the genset. 3. Watch the temperature gauge (optional) and run fewer appliances at the same time to keep down the engine temperature.
2LOW OIL PRESSURE FAULT—CODE NO. 2(The low oil pressure cutoff switch closed for more than 10 seconds)1. Check the engine oil level and add oil as necessary. 2. Drain the excess oil if the oil level is above the Full mark on the dipstick. (The oil will foam if the level is too high and result in possible loss of oil pressure.)
3SERVICE CHECK—CODE NO. 3(A second-level fault occurred)Check the second-level fault code by momentarily pressing Stop. The second-level fault will be one of the following in this table.
12OVERVOLTAGE FAULT—CODE NO. 12(The controller is not able to regulate to rated voltage)See an authorized Onan dealer.
13UNDERVOLTAGE FAULT—CODE NO. 13(The controller is not able to regulate to rated voltage)Turn OFF the line circuit breaker on the operator’s console. If the genset now runs, run it with fewer connected loads.
14OVERFREQUENCY FAULT—CODE NO. 14(The controller is not able to regulate to rated frequency)1. Prime the engine fuel system by holding the control switch at Stop for one minute. (There may be air in the fuel system.) 2. Check for a tripped genset circuit breaker, reset it if necessary, and run with fewer connected loads.
15UNDERFREQUENCY FAULT—CODE NO. 15(The controller is not able to regulate to rated frequency)1. Turn OFF the line circuit breaker on the operator’s console. If the genset now runs, run it with fewer connected loads. 2. Prime the engine fuel system by holding the control switch at Stop for one minute. (There may be air in the fuel system.)
21STARTER SOLENOID CIRCUIT PROTECTION FAULT—CODE NO. 21(The controller sensed a starter control circuit short)See an authorized Onan dealer.
22GOVERNOR ACTUATOR OVERLOAD FAULT—CODE NO. 22(The duration of operation at or near full-duty cycle was beyond the design limit)1. Reduce the number of appliances running at the same time. 2. Replace the engine air filter and clean the spark-arrest muffler. 3. Replace the engine fuel filter.
23LOW OIL PRESSURE CUTOFF SWITCH FAULT—CODE NO. 23(The controller sensed a defective switch)See an authorized Onan dealer. Also see BYPASSABLE FAULTS (Page 20).
24COOLANT TEMPERATURE SENDER FAULT—CODE NO. 24(The controller sensed a defective sender)See an authorized Onan dealer. Also see BYPASSABLE FAULTS (Page 20).
27QUADRATURE SENSE FAULT—CODE NO. 27(The controller was unable to sense the required parameter)See an authorized Onan dealer.
28AC OUTPUT SENSE FAULT—CODE NO. 28(The controller was unable to sense the required parameter)See an authorized Onan dealer.
1The status indicator light is dead (There is no response to the control switch)1. Try starting the genset at the operator’s console if it does not start at the remote panel. 2. Check whether Fuse F1 is blown. If it is, first check the battery connections for proper polarity: battery positive (+) to genset positive (+) and battery negative (–) to genset negative (–). If necessary, reconnect the battery cables properly and replace the fuse. (The control circuit is designed so that the fuse will blow if battery polarity is wrong.) 3. Clean and tighten the positive (+) and negative (–) battery cable connections at the battery and at the genset. 4. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations.
CODE NO. 29HIGH BATTERY VOLTAGE FAULT—The controller sensed battery system voltage greater than 19 volts1. Check battery bank connections and reconnect if necessary so that the 12 volt batteries serving the genset are connected in parallel (12 volt) rather than in series (24 volt). 2. Select a lower battery booster charge rate.
CODE NO. 35CONTROL CARD FAULT—There was a memory error in the microprocessor during self-testSee an authorized Onan dealer.
CODE NO. 36ENGINE STOPPED FAULT—The genset stopped without a command from the controller1. Check the fuel level and refill as necessary. 2. Prime the engine fuel system by holding the control switch at Stop for one minute. 3. Check the engine air filter and remove any blockage. 4. Check for mechanical damage. 5. Check for fuel (air) leaks at all fuel fittings and tighten as necessary. 6. Replace the fuel filter.
CODE NO. 37INVALID GENSET CONFIGURATION—There was a memory error in the microprocessor during self-testSee an authorized Onan dealer.
CODE NO. 38FIELD OVERCURRENT—Too many low-power-factor-causing loads were connected1. Reduce the number of air conditioners running at the same time (and other appliances that cause low power factor). 2. Have the air conditioners and other appliances checked for proper operation. (A locked compressor rotor can cause very low power factor.)
CODE NO. 45SPEED SENSE FAULT—The controller failed to sense quadrature frequency and voltage during crankingSee an authorized Onan dealer.

Symptoms & remedies

SymptomCauseRemedy
DO NOT MAINTAIN A CHARGE(The battery, battery connections or charging system are in marginal condition)1. Clean and tighten the positive (+) and negative (–) battery cable connections at the battery and at the genset. 2. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations.
THE ENGINE CRANKS BUT DOES NOT START(Fuel delivery is marginal)1. Check the fuel level and refill as necessary. 2. Prime the engine fuel system by holding the control switch at Stop for one minute. 3. Check the engine air filter and remove any blockage. 4. Check for fuel (air) leaks at all fuel fittings and tighten as necessary. 5. Replace the fuel filter.
THE STARTER ENGAGES AND DISENGAGES(Cranking voltage dips below 6 volts because of low battery charge or poor connections)1. Have the vehicle propulsion engine running while trying to start the genset. (The battery charging alternator may be able to maintain starting voltage high enough to get the genset started.) 2. Clean and tighten the positive (+) and negative (–) battery cable connections at the battery and at the genset. 3. Recharge or replace the battery. Refer to the battery manufacturer’s recommendations.
THERE IS NO POWER WHEN THE GENSET IS RUNNING(A line circuit breaker is OFF, tripped or malfunctioning)1. Reset or turn ON the line circuit breaker on the genset. See RESETTING CIRCUIT BREAKERS (Page 9). 2. Reset or turn ON any other circuit breaker in the power supply system.
Generator voltage is deadGenerator electrical output connections must be made by a trained and experienced electrician in accordance with applicable codes. The genset must not be connected to the public utility or any other source of electrical power. An approved switching device must be used to prevent interconnections.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.

Parts

97
Part #DescriptionQtySystem
054-01Hose, Intake1Hose PartsGeek
054-02Hose, Intake1Hose PartsGeek
12.0HDCAD42345AENGINEEngine PartsGeek
140-3050Cleaner Assy, Air (Includes1Air filter PartsGeek
140-3071Element, Air Cleaner1Air filter PartsGeek FridayParts $16.50
140-3072Cover, Air Cleaner1Air filter PartsGeek
149-2513Filter, Fuel1Fuel filter Amazon eBay $36.95 PartsGeek
149-2605Line, Fuel Filter1Fuel filter PartsGeek
149-2790Pump, Fuel1Pump PartsGeek FridayParts $24.89
154-2800Gasket, Exhaust Manifold2Gasket PartsGeek
184-0010Gasket1Gasket PartsGeek
187-1000Filter, Oil1Oil filter PartsGeek FridayParts $20.19
187-1021Stud, Injection Pump (20mm)6Pump PartsGeek
187-1022*Cup, Sealing (44.5mm Dia)1Seal PartsGeek
187-1023*Cup, Sealing (22mm Dia.)1Seal PartsGeek
187-1032Seal, Lead2Seal PartsGeek
187-1036Gasket, Set Screw2Gasket PartsGeek
187-1038Cup, Sealing (12mm Dia.)1Seal PartsGeek
187-1041Seal, Crankshaft Front Oil1Seal PartsGeek
187-1042Seal, Crank Rear Oil1Seal PartsGeek
187-1043Clip, Fuel Hose2Hose PartsGeek
187-1045Cup, Sealing (16mm Dia.)1Seal PartsGeek
187-1059Gasket6Gasket PartsGeek
187-1061Shield, Nozzle Heat3Injector PartsGeek
187-1062Seal, Valve6Seal PartsGeek
187-1065Gasket, Oil Fill Cap1Gasket PartsGeek
187-1066Clip, Hose1Hose PartsGeek
187-1068Gasket3Gasket PartsGeek
187-1107Spring, Nozzle3Injector PartsGeek
187-1131Clip, Hose2Hose PartsGeek
187-1136Gasket, Nozzle Holder3Gasket PartsGeek
187-1137Gasket, Heat Shield3Gasket PartsGeek
187-1140Stud, Oil Filter1Oil filter PartsGeek
187-1143Stud, Injection Pump Housing1Pump PartsGeek
187-1150Cup, Bush Sealing (10mm Dia.)1Seal PartsGeek
187-1162Pump Assy, Injection1Pump PartsGeek
187-1180Plate, Lever Pump Link1Pump PartsGeek
187-1191Cup, Sealing (8mm)1Seal PartsGeek
187-1194Gasket, Exhaust Manifold1Gasket PartsGeek
187-1197*Pump, Oil1Pump PartsGeek
187-1201Gasket, Cylinder Head1Gasket PartsGeek
187-1212Cord, Glow Plug1Glow plug PartsGeek
187-1215Hose, Fuel Feed Leakoff1Hose PartsGeek
187-1219Gasket, Exhaust Manifold1Gasket PartsGeek
187-1222Pump Assy, Oil (Includes Parts1Pump PartsGeek
187-1229Gasket, Governor Lever Cover1Gasket PartsGeek
187-1240Gasket, Cylinder Head Cover1Gasket PartsGeek
187-1249Nozzle Assy, Injection (See3Injector PartsGeek
187-1273Gear, Injection Pump & Valve1Pump PartsGeek
187-1276Hose, PCV1Hose PartsGeek
187-1277Hose, PCV1Hose PartsGeek
187-1278Hose, PCV1Hose PartsGeek
187-1286Cup, Sealing (35mm Dia.)4Seal PartsGeek
187-1287Cover, Injection Pump Housing1Pump PartsGeek
187-1289Plug, Glow (HR1)3Glow plug Amazon eBay PartsGeek
187-1307Stud, Injection Pump Housing1Pump PartsGeek
187-1310Stud, Water Pump1Pump PartsGeek
187-1331Clip, Fuel Pump Lead Wire1Pump PartsGeek
187-1334Gasket, Plug1Gasket PartsGeek
187-1335Gasket, Plug1Gasket PartsGeek
187-1341Dowel, Oil Pump2Pump PartsGeek
187-1342Wire, Lead Seal2Seal PartsGeek
187-1346Nozzle3Injector PartsGeek
193-0318Sender, Water Temperature (E2)1Sensor PartsGeek
300-1200DC ConverterAir filter PartsGeek
332-1554Clamp, Hose2Hose PartsGeek
403-3859Seal, Oil Drain2Seal PartsGeek
403-4219Seal, Radiator Drain1Seal PartsGeek
502-1299Connector, Hose1Hose PartsGeek
502-1306Connector, Hose1Hose PartsGeek
503-0365Clamp, Hose1Hose PartsGeek
503-0685Clamp, Hose2Hose PartsGeek
503-1138Clamp, Hose1Hose PartsGeek
503-1141Band, Hose Clamp2Hose PartsGeek
503-1148Band, Hose Clamp1Hose PartsGeek
503-1959Hose, Cooling Over Flow1Hose PartsGeek
503-2053Hose, Intake1Hose PartsGeek
503-2055Hose, Engine (Out)1Hose PartsGeek
503-2059Hose, Overflow1Hose PartsGeek
503-2060Hose, Air Bleed1Hose PartsGeek
503-2435Hose, Air1Hose PartsGeek
503-2436Hose, Air1Hose PartsGeek
503-2446Hose, Intake1Hose PartsGeek
580-01Line, Fuel Injection Pump1Pump PartsGeek
585-04Bracket, Fuel Filter1Fuel filter PartsGeek
746-01Seal, Fan (460mm)1Seal PartsGeek
746-02Base, Air Cleaner − Tie Rod2Air filter PartsGeek
872-02Band, Hose Clamp4Hose PartsGeek
951-09Clamp, Hose1Hose PartsGeek
951-12Clamp, Hose1Hose PartsGeek
951-35Clamp, Hose1Hose PartsGeek
1000-1500Electric Frying Pan or Wok1200Service part / kit PartsGeek
1400-2000Battery Charger Up to 3000 DC ConverterService part / kit PartsGeek
600-1000Microwave Oven1Service part / kit PartsGeek
981-0165Service part / kit PartsGeek
981-0525Service part / kit PartsGeek
981-0632Service part / kit PartsGeek

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Fuel consumption

RatingLoadL/hgal/h
Full-load5.031.1
Full-load100%4.16
Half-load2.340.62
Half-load50%2.34
No-load0.41
Prime
Standby

Available documents

Installation manual — 981-0638 Onan HDCAC HDCAD Installation Manual (11-2003) (Cummins/Onan)Parts manual — 981-0275 Onan HDCAC HDCAD (spec A-D) Diesel Mobile Genset Parts manual (08-2012) (Cummins/Onan)Parts manual — F-1106A Cummins-Onan post-1990 Accessories & Service Support Catalog (02-2002) (Cummins/Onan)Service manual — 981-0165 Onan HDCAC HDCAD Diesel Mobile Genset Operator's manual (09-2001)Service manual — 981-0171 Onan HDCAC HDCAD Operator's Manual (11-2003)Service manual — 981-0632 Onan HDCAC HDCAD Diesel Mobile Genset Installation manual (09-2001) (Cummins/Onan)