HomeCummins/OnanCummins/Onan D

Cummins/Onan D Generator Set

The Cummins/Onan D is a 23 kW Gasoline prime generator set powered by a Ford Model SNNN-6006 engine. It is available at 120 V and 208 V, 3-phase and 60 Hz. It holds 60 L (15.9 gal) of coolant.

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Document types

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

Specifications

FuelGasoline
Frequency60.0 Hz
Prime power23 kW
Voltage options120 V, 208 V
Phase3
Coolant capacity60 L

Maintenance & consumables

for the Ford Model SNNN-6006
ItemSpecCapacityPart #Interval
Air filter50 hr find
Fuel filter find
Oil filter50 hr find
Belt2500 hr find
Coolant
Coolant filter find
Oil

Common questions

What engine does the Cummins/Onan D use?

The Cummins/Onan D is powered by the Ford Model SNNN-6006 engine.

What fuel does the Cummins/Onan D use?

The Cummins/Onan D runs on Gasoline.

Troubleshooting

49

Symptoms & remedies

SymptomCauseRemedy
Engine runs but current does not build upPoor brush contact. Open circuit, Short circuit, or ground in generator.See that brushes seat well, are free in holders, are not worn too short, and have good spring tension. See GENERATOR, replace part necessary.
Current steady but engine not misfiringSpeed too low. Poor commutation or brush contact. Loose connections. Fluctuating load.Adjust governor to correct speed. Tighten connections. Correct any abnormal load condition causing trouble.
Engine overheatingOverloaded.Reduce load.
Voltage drops under heavy loadEngine lacks power. Poor compression. Faulty carburetion. Restricted air cleaner. Excessive choking. Carbon in cylinders. Restricted exhaust line.See remedies for engine missing under heavy load. Tighten cylinder head and spark plugs. If still not corrected, grind the valves. Replace piston rings, if necessary. Check the fuel system. Clean, adjust or replace parts necessary. Clean and refill. See that choke opens properly. Remove carbon. Clean or increase the size.
Engine misfires at light loadCarburetor idle adjustment set wrong or clogged. Spark plug gaps too narrow. Intake air leak. Faulty ignition. Uneven compression.Adjust to correct gap. Tighten or replace gaskets. Clean, adjust, or replace breaker points, plugs, condenser, coils, etc., or retime ignition. Tighten cylinder head and spark plugs. If still not corrected, grind valves. Replace piston rings, if necessary. Worn intake valve stems. Replace valves.
Engine misfires at heavy loadSpark plugs defective. Faulty ignition.Replace. Clean, adjust, or replace breaker points, plugs, condenser, coil, etc., or retime ignition.
Engine backfires at carburetorLean fuel mixture. Clogged fuel screen. Intake air leak.Clean carburetor. Clean screen. Replace flange gaskets, tighten carburet. Poor fuel. Refill with good, fresh fuel. Spark too late. Retime ignition. Spark plug wires crossed. Install wires correctly. Intake valves leaking. Grind or replace.
Excessive oil consumption, light blue smoky exhaustPoor compression, usually due to leaking valves.Tighten cylinder head and plugs. If still not corrected, grind or replace valves. Oil leaks from engine or connections. This does not cause smoky exhaust. Tighten screws and connections. Oil too light or diluted. Drain, refill with correct oil. Too large bearing clearance. Replace. Oil pressure too high. Refer to symptoms of high oil pressure for remedies. Engine misfires. Refer to symptoms of engine misfires. Faulty ignition. Clean, adjust, or replace breaker points, plugs, condenser, coil, etc., or retime ignition. Unit operated at light or no load for long periods. No remedy needed. Too much oil. Drain excess oil.
Black, smoky exhaust, excessive fuel consumption, fouling of spark plugs with black soot. Possible lack of power under heavy loadFuel mixture too rich.Adjust choke. Install needed carburetor parts, adjust float level. Choke not open. See that choke opens properly. Dirty air cleaner. Clean, refill to proper level.
Large speed droop on engine.AVR UFRO protection activated.Check that the speed droop from no load to full load is no greater than 4%. Check AVR LED, if LIT, increase engine speed.
Unbalanced load.Check voltage and load current on all phases. If unbalanced, redistribute the load more evenly across the phases.
Parallel droop circuit incorrectly adjusted, or requires shorting switch for single running.The droop circuit will give additional voltage droop of -3% at full load 0.8 pf. For single running machines this can be removed by fitting a shorting switch across the droop CT input, (S1 – S2), on the AVR. (Pre 1989 machines, short across the burden resistor in the terminal box).
Voltage drop between machine and load, due to I2R losses in supply cable.Check the voltage at both ends of the cable run at full load. Differences in voltage levels indicates a volts drop along the cable. In severe cases, a larger diameter cable is required.
Improved regulation equipment reversed.Reverse the secondary leads on the transformer, and re-test on load.
Fault on main rectifier or excitation windings.Check the no-load excitation volts across AVR X+ (F1) and XX- (F2). Compare with the D.C. voltages as listed in Test Method A Section 3. If much higher than listed, carry out Test Method A.
AVR Under frequency protection circuit, (UFRO), activated.Check AVR LED, if lit, UFRO is activated, (engine speed is low). Check engine speed and adjust to correct nominal speed, (or frequency).
Engine fault or engine governor unable to respond, (speed drop too low).Check performance of engine during application of load. Check if AVR LED is lit during motor starting. Check if AVR ‘DIP’ or ‘DWELL’ engine relief circuits are activated. Adjust as necessary. (See AVR instruction sheet for details).
Parallel droop circuit incorrectly set.Too much droop will increase voltage dips when motor starting. Fit shorting switch for single running Generators. (See parallel section 6).
Load surges exceed 2.5 times the full load current.Check load surges with a clip-on ammeter. Voltage dip may be excessive if the current exceeds 2.5 times full load. Refer to factory for motor starting calculations.
AVR 'Stability' control incorrectly adjusted.Set AVR ‘Stability’ control for optimum performance. Adjust anticlockwise until voltage is unstable, then slightly clockwise until stable.
Fault on windings or rotating rectifier.Any fault in this area will appear as high excitation voltage across X+ (F1) and XX- (F2), higher than figures listed in Section 3. Complete Test Method A Section 3.
AVR UFRO and/or engine relief circuit activated during motor starting.Check performance of engine during application of load. Check if AVR LED is lit during motor starting. Check if AVR ‘DIP’ or ‘DWELL’ engine relief circuits are activated. Adjust as necessary. See AVR instructions for details.
Faulty AVR.Replace and re-test on load.
Voltage drop between Generator and load, due to I2R losses in the cable.This will be worse during current surges (motor starting etc). Check the voltage at both ends of the cable run at full load. Differences in voltage levels indicates a volts drop along the cable. In severe cases, a larger diameter cable is required.
Motor contactors dropping out during starting.Large current surges, Voltage dips greater than 30%. All symptoms and remedies in this section may apply to this problem. Refer to factory for typical voltage dips.
Engine speed low.Under frequency protection (UFRO) circuit activated.Check AVR LED. If lit, UFRO is activated, indicating low speed. Check speed with tachometer. Adjust governor control to nominal speed, or up to maximum (+4%) of nominal speed.
AVR 'VOLTS' adjust, or external hand trimmer control incorrectly set.Adjust voltage on AVR 'volts' trim, or remote trimmer. Ensure that speed is correct, and UFRO is OFF.
Voltmeter faulty or sticking.Check and verify voltage across machine output terminals, with a Multimeter.
Fault in AVR.Replace AVR and re- test.
Loose, broken or corroded connections.Check the wiring for poor connections. Repair or replace where necessary.
Fault on power supply from main stator.See item 11, previous test under 'No voltage, at no load'.
Sensing supply from Main Stator to AVR open circuit or too low.Check sensing supply voltage, as per Test Method A, Section 3, (item 13).
AVR 'VOLTS' control or hand trimmer incorrectly set.Adjust as necessary. Ensure that the engine speed is correct first.
Sensing supply transformer or sensing module (PCB), faulty.AVR sensing supply circuit via dropper transformer, (4 or 6 wire Generators), or sensing PCB. Check sensing supply as per Test Method A, Section 3, (item 13).
Burden resistor, fitted in AVR sensing supply, corroded or open circuit.(Pre 1987 Generators only.) A fault on the burden resistor can create a high voltage condition. Check tapping bands for corrosion/poor contact. Normal resistance value 215 ohms.
AVR faulty.Replace AVR and re-test.
Engine governor unstable (hunting).Check for speed instability with a frequency meter, or tachometer. Sometimes this problem will clear when a load is applied to the engine.
AVR Stability settings.Check AVR stability links, adjust stability potentiometer.
Loose or corroded connections.Intermittent voltage fluctuations can be created by poor connections. Check auxiliary and AVR terminals.
Intermittent earth (low insulation resistance).Megger all windings, (see section 2), including Exciter Stator, low insulation resistance can effect the AVR.
Voltmeter faulty/unstable.Panel mounted voltmeters are sensitive to vibration. Check and verify readings.
Single-phase loads (phase - neutral) unevenly distributed over the three phases.Check current in each phase with clip-on ammeter. The full load rated current must NOT be exceeded on any individual phase. Re-distribute load if necessary.
Leading Power Factor load created by power factor correction capacitors.Isolate the power factor correction capacitors until sufficient inductive load has been applied. (See Power Factors, Section 2).
Fluctuations in load current, (motor starting, or reciprocating loads).Check the load current on a stable supply, i.e. mains, or separately excite the machine. A variable D.C. supply is required for on load separate excitation tests. (See test method A, section 3).
Non linear load creating waveform distortion.Use Permanent Magnet Generator (PMG), powered AVR control system.
AVR stability incorrectly adjusted.Adjust AVR, until voltage stabilises.
Leading Power Factor load (capacitor banks).Check excitation volts across X+, (F1) and XX- (F2). A leading power factor will give an abnormally LOW DC excitation. Remove power factor correction capacitors from system at low load (see Power Factors Section 2).
Parallel droop current transformers reversed.Check for droop reversal. (See section 6, parallel operation).
Burden resistor incorrectly set across improved regulation transformer.(Pre 1989 machines only). Reduce the amount of resistance across the improved regulation transformer until

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

Parts

37
Part #DescriptionQtySystem
018102000/18 10 Micron1Filter elements PartsGeek
018302000/18 30 Micron (standard)1Filter elements PartsGeek
01860S2000/18 60 Micron, stainless steel1Filter elements PartsGeek
129698-77190BRACKET3Bracket PartsGeek
1552267G-C21Connector PartsGeek
1552269G-C71Connector PartsGeek
280BHAND WHEEL1Handle PartsGeek
411294FOBall or Tapered Roller Bearing6Bearing PartsGeek
434198FOBall or Tapered Roller Bearing1Bearing PartsGeek
437425FOBall or Tapered Roller Bearing1Bearing PartsGeek
5395259Crankshaft Rear Oil Seal Installation KitSeal PartsGeek
5395330Crankshaft Rear Oil Seal Removal KitSeal PartsGeek
786ASPACER1Spacer PartsGeek
AA519RFUEL SCREEN IN SEDIMENT BOWLFuel filter PartsGeek
AN500T0007STARTER MOTOR (w/ pad terminal)Starter PartsGeek
AR26350OIL FILTEROil filter PartsGeek FridayParts $18.99
C072754Sensors, C18 & C13Sensor PartsGeek
P0005255Fuel level gaugeFuel filter PartsGeek
S12/PAuto / Manual Transfer, Source 2-1 / 1-2Transfer PartsGeek
S13/PCommit / No Commit Transfer to Source 2Commit transfer PartsGeek
26100BPan, 24 hr. containment1Service part / kit PartsGeek
3E3361J-C31Service part / kit PartsGeek
437-4129J-C141Service part / kit PartsGeek
4389-4758-4679Static Rotor Amp Draw Test Results - Model A, B, C, D, E, F, G, HService part / kit PartsGeek
4390-4760Static Rotor Amp Draw Test Results - Model A, B, C, D, E, F, G, HService part / kit PartsGeek
4456-4759Static Rotor Amp Draw Test Results - Model A, B, C, D, E, F, G, HService part / kit PartsGeek
453.08Inlet Manifold Assembly – identified ‘B’Service part / kit PartsGeek
960-0135Service part / kit PartsGeek
C121122 C123Service part / kit PartsGeek
FPS-KIT-06Replacement Memory Pack1Service part / kit PartsGeek
FPS210S02220V@50Hz w/ fuel conditioner w/ metal heat deflector1Service part / kit PartsGeek
FPS210S06Reverso 220V@50Hz Separ w/ metal heat deflector1Service part / kit PartsGeek
FPS210S36220V@50Hz w/ fuel conditioner1Service part / kit PartsGeek
FPS210S38Reverso 220V@50Hz Separ1Service part / kit PartsGeek
P0001006EVC menu displayService part / kit PartsGeek
P0001315Fault handling displayService part / kit PartsGeek
T1T2TOTTI] TSTI2ZT4 «©T9 «T5777 73. 10Service 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
Prime
Standby

Available documents

Operator's manual — TD FAULT MAN GB JULY 2009 GB (Cummins/Onan)Parts manual — 0932-0112 Onan Post-Sale Literature Index (07-1998) (Cummins/Onan)Parts manual — 903-0206 Onan DB DC DM Series Parts 440-600KW Spec A-B (7-1988) (Cummins/Onan)Parts manual — 903-0207 Onan DB DC DM 620KW-900KW Genset Parts manual (08-1988) (Cummins/Onan)Parts manual — 903-0208 Onan DB DC DM Series 900-1250KW Genset Parts manual (08-1988) (Cummins/Onan)Parts manual — 982-0600 Onan DV Series Installation Manual (2-1985) (Cummins/Onan)Service manual — 903-0000 Onan 6GO-F 5GO-F Genset Instruction & Parts manual (09-1949) (Cummins/Onan)Service manual — 904-0000 Onan 10EL Genset Instruction & Parts manual (10-1948) (Cummins/Onan)Service manual — 960-0510B Onan DGBB thru DGFC Series Service Manual (10-1998) (Cummins/Onan)