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Cummins/Onan QST30 Engine

The Cummins/Onan QST30 is a 30.5 L 12-cylinder turbocharged and aftercooled engine rated at 2100 rpm, producing up to 1119 kW. It powers generator sets from AKSA and Cummins/Onan, including the AC1026, AC1130, AC880 and CFP30E-F10. It holds 76 L (20.1 gal) of oil and 85 L (22.5 gal) of coolant.

Also known as: CUMMINS QST30, QST30

Part of the Cummins/Onan QST30 engine family — 7 variants share parts & fitment.

30.5 L

Displacement

Cylinders

2100 rpm

Rated speed

1119 kW

Gross power

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Fault codes Procedures Wiring

Engine specifications

Oil capacity	76.0 L
Coolant capacity	85.0 L
Displacement	30.5 L
Cylinders	12
Aspiration	Turbocharged and Aftercooled
Rated speed	2100 rpm
Gross power	1119 kW

Generator sets powered by this engine

Shared across brands: AKSA, Cummins/Onan

AKSA AC1026AKSA AC1130AKSA AC880Cummins/Onan CFP30E-F10Cummins/Onan CFP30EVS-F10Cummins/Onan DFHA Cummins/Onan DFHB Cummins/Onan DFHC Cummins/Onan DFHD Cummins/Onan DQFAA Cummins/Onan DQFAB Cummins/Onan DQFAC Cummins/Onan DQFAD Cummins/Onan PCC 3100 Cummins/Onan QST30 series

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

Troubleshooting

Fault codes

Code	Meaning	Remedy
RAIN	Rain	Repair as soon as convenient
SOE	System Over-ride Event
0	Check electronic engine controls (fault code lamp)

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

Common problems

Warning lamp lights. MESSAGE: WEAK BATTERY 232 − WARNING 232
Fix: Discharged or defective battery. See Warning message 230, LOW DC VOLTAGE.
Warning lamp lights. MESSAGE: LOW FUEL DAY 240 − WARNING 240
Fix: Check fuel supply and replenish as required.
Warning lamp lights. MESSAGE: LOW FUEL 241 − WARNING 241
Fix: Check fuel supply and replenish as required.
Warning lamp lights. MESSAGE: LOW DC VOLTAGE 230 − WARNING 230
Fix: A. Discharged or defective battery. Check the battery charger fuse. Recharge or replace the battery. b. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. c. Contact an authorized service center if none of the above.
Warning lamp lights. MESSAGE: HIGH DC VOLTAGE 231 − WARNING 231
Fix: Contact an authorized service center.
Warning lamp lights.
Fix: Indicates battery voltage is below 24 VDC. a. Discharged or defective battery. Check the battery charger fuse. Recharge or replace the battery. b. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. c. Contact an authorized service center if none of the above.
Shutdown lamp lights. MESSAGE: MAG PICKUP 220 − SHUTDOWN 220
Cause: Indicates mag pickup speed indication is not being sensed or does not match generator set output frequency.
Fix: A. Restart and check RPM on the digital display. b. Contact an authorized service center.
Shutdown lamp lights. MESSAGE: FAIL TO CRANK 221 − SHUTDOWN 221
Fix: A. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. b. Discharged or defective battery. Recharge or replace the battery. c. Contact an authorized service center for service of starter and starting system.
Shutdown lamp lights. MESSAGE: EEPROM ERROR 250 − SHUTDOWN 250
Fix: Indicates PCC memory error. Data corruption of critical operating parameters. Contact an authorized service center.
Shutdown lamp lights. Engine will not crank. MESSAGE: OVERCRANK 222 − SHUTDOWN 222
Fix: A. Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. b. Check for dirty fuel filter and replace if necessary. c. Check for dirty or plugged air filter and replace if necessary. d. Reset the control and restart after correcting the problem. Contact an authorized service center if none of the above.
Shutdown lamp lights. Engine will not crank. MESSAGE: FAIL TO CRANK 221 − SHUTDOWN FAIL TO CRANK 221 - SHUTDOWN
Fix: A. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. b. Discharged or defective battery. Recharge or replace the battery. c. Contact an authorized service center for service of starter and starting system.
Shutdown lamp lights. Engine stops cranking. MESSAGE: OVERCRANK 222 − SHUTDOWN OVERCRANK 222
Fix: A. Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. b. Check for dirty fuel filter and replace if necessary. c. Check for dirty or plugged air filter and replace if necessary. d. Reset the control and restart after correcting the problem. Contact an authorized service center if none of the above.
Shutdown lamp lights. Engine runs and then shuts down. MESSAGE: OVERSPEED 223 − SHUTDOWN 223
Fix: Contact an authorized service center.
Shutdown lamp lights.
Fix: Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary.
Engine shuts down and will not crank. 102
Fix: Indicates local or remote Emergency Stop. To reset the local Emergency Stop button : Pull the button out or turn the switch clockwise (button with arrow) and allow it to pop out. Move the Run/Off/Auto switch to Off. Press the Reset switch. Select Run or Auto, as required.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan QST30.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	Dry replaceable element		D041-2		eBay
Fuel filter	Water/Fuel Filter Wrench		3376807		Amazon eBay
Oil filter			3825142	2000 hr	Amazon eBay
Battery			—	2000 hr
Belt	Belt		ST669	500 hr	Amazon eBay $204.59
Coolant	High ambient radiator	167.0 L	—	6000 hr
Coolant filter	Coolant Filter		—	1000 hr
Oil		132.0 l	—	2000 hr
Spark plug			—	1000 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Air cleaner restriction indicator	Check	8 hr		Where fitted; if indicator shows red replace elements and reset indicator
Battery connections	Check	8 hr		Connections secure; battery area free from tools and other items
Bedframe/enclosure fluid containment	Drain	8 hr		Where fitted
Control panel operation	Test	8 hr		System performs a control panel test on initial activation
Engine oil level	Check	8 hr		Check with engine stationary; top up to engine specifications
Exhaust components, hardware and condensation trap	Check	8 hr		Drain condensation into a suitable container
Fuel level in tank	Check	8 hr		Add fuel if low; full tank reduces condensation
Fuel lines and hoses	Check	8 hr		Check before starting and again with generator set running
Fuel system primary filter/water separator	Drain	8 hr		Drain one cup or more to remove water and sediment
Generator set enclosure	Check	8 hr		Walk-around inspection; no inlets/outlets covered
Radiator coolant level (water jacket & LTA)	Check	8 hr		Top up with Cummins recommended coolant mix
Charge alternator	Check	50 hr		Check visually and audibly with generator set running
Coolant lines and radiator hoses	Check	50 hr	6 mo	Visually check for leaks, worn or damaged hoses
Cooling fan blades	Inspect	50 hr		Visually through guarding for wear or damage
Crankcase breather tube/collector	Drain	50 hr		Check for condensed oil
Drive belt condition and tension	Check	50 hr		Visually check for evidence of wear or slippage
Engine coolant heater	Check	50 hr		Check heater has power and is running
Battery	Check	100 hr	1 mo	Check electrolyte level at least every month or 100 hours, whichever occurs first
Air cleaner housing	Clean	250 hr	6 mo
Air intake system leaks	Inspect	250 hr	6 mo	Visually and audibly inspect for signs of wear or damage
All hardware (fittings, clamps, fasteners)	Check	250 hr	6 mo
Anti-freeze and DCA concentration	Check	250 hr	6 mo
Battery electrolyte level	Check	250 hr	6 mo
Coolant filter	Replace	250 hr	6 mo	Change service coolant filter at every oil and filter change interval
Cooling fan	Check	250 hr	6 mo	Check for cracks, loose rivets, bent or loose blades
Crankcase Oil and Filter	Change	250 hr	12 mo	Footnote X6: If genset is used for standby applications, change oil every 12 months or 250 hours, whichever comes first
Crankcase breather tube	Clean	250 hr	6 mo	Check internally for obstructions or sludge
Drive belts	Check	250 hr	6 mo	Replace if cracked or frayed
Electrical connections (battery, starter motor and alternator)	Check	250 hr	6 mo
Emergency Stop Button operation	Test	250 hr	6 mo	With generator set running press the Emergency Stop button; check all systems before resetting
Engine ground	Check	250 hr	6 mo	Clean as necessary
Engine steam clean	Clean	250 hr	6 mo
Fan drive idler pivot arm assembly	Lubricate	250 hr	6 mo	Lubricate until grease appears from under the cap
Fuel filter (spin-on)	Replace	250 hr	6 mo	Whichever comes first
Fuel lift pump inlet screen / prefilter	Clean	250 hr	6 mo	Clean with compressed air or replace
Fuel system secondary filter	Replace	250 hr	6 mo
Lubricating oil and filters	Change	250 hr	6 mo	Whichever comes first; generator drives 250 hours or 12 months
Lubricating oil and filters	Replace	250 hr	6 mo
Radiator air flow	Check	250 hr	6 mo	Inspect radiator through guarding for blockage and debris
Starting motor	Check	250 hr	6 mo

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Actuator maximum range	0 - 21	mm
Clearance	Actuator position fault threshold	1.5	mm	more than commanded position
Clearance	Compressor impeller radial clearance (HX60) (max)	0.46	mm [0.018 in]
Clearance	Compressor impeller radial clearance (HX60) (min)	0.15	mm [0.006 in]
Clearance	Crankshaft end clearance (max)	0.32	mm [0.013 in]
Clearance	Crankshaft end clearance (min)	0.14	mm [0.006 in]
Clearance	Exhaust pipe clearance from combustible wall or partition	12	inches (305 mm)
Clearance	Fan hub bearing end clearance (max)	0.15	mm [0.006 in]
Clearance	Fan hub bearing end clearance (min)	0.03	mm [0.001 in]
Clearance	Float switch lift below C-clip stop	1/8	inch (3 mm)
Clearance	Fuel line minimum clearance from electrical wiring	1/2	inch (12.7 mm)
Clearance	Fuel line minimum clearance from hot exhaust parts	2	inch (51 mm)
Clearance	Fuel rack position range	0 - 21	mm
Clearance	Generator/engine angular alignment T.I.R. (max)	.001	inch per inch of radius (center of shaft to indicator axis)	dial indicator at bolt circle diameter
Clearance	Left/right actuator fault threshold (more than this from commanded position)	1.5	mm
Clearance	Turbine wheel radial clearance (HX60) (max)	0.53	mm [0.021 in]
Clearance	Turbine wheel radial clearance (HX60) (min)	0.20	mm [0.008 in]
Clearance	Turbocharger (Holset HX60) shaft end clearance (max)	0.10	mm [0.004 in]
Clearance	Turbocharger (Holset HX60) shaft end clearance (min)	0.03	mm [0.001 in]
Clearance	Vibration isolator base elevation difference (max)	0.25	inch (6 mm)	shimmed or grouted, flat and level surface
Clearance	Vibration isolator top plate clearance (nominal)	0.25	inch (6 mm)	level, genset installed
Gap	Fuel rack travel (rack test)	0 to 19	mm	rack test
Gap	Governor actuator position fault threshold	more than 1.5 from commanded position	mm (actuator range 0-21 mm)
Other	Air compressor discharge line carbon deposit (max)	2	mm [1/16 in]
Other	All continuity checks - OK (no open circuit) if	less than 10	ohms	continuity check
Other	Battery electrolyte specific gravity (charge threshold)	1.215		charge battery if below this reading
Other	Battery electrolyte specific gravity (fully charged)	1.260		corrected to 80°F (27°C)
Other	Battery electrolyte specific gravity (fully charged, corrected)	1.260	SG	at 25 °C (77 °F)
Other	Battery electrolyte specific gravity - charge battery if reading is below	1.215	SG	at 25 °C (77 °F)
Other	Bearing grease quantity	81	ml
Other	Compression ratio	14.7:1
Other	Cycle crank crank and rest time	7 to 20	seconds
Other	Cycle crank number of cycles	3, 4, or 5
Other	ESS circuits shorts to ground - OK (no short circuits) if	more than 10	kohms	shorts to ground
Other	Engine torque adjustment range	0% to +1%	duty cycle units	approximately 0% to +2% engine horsepower
Other	Frequency adjustment range	±5%	%	genset running
Other	Frequency regulation	Isochronous
Other	GOV RAMP adjustment range	0 through 10	seconds
Other	Generator insulation resistance (frame HC6)	5.0 - 1.0	MEG	500 VDC megger setting
Other	Generator insulation resistance (frame P7)	10.0 - 1.0	MEG	500 VDC megger setting
Other	Generator set operating incline limit	+/- 2.5	degrees
Other	Governor duty cycle range	25 - 93	%
Other	Governor regulation class	ISO 8528 Part 1 Class G3
Other	Magnetic Pickup proximity to gear teeth	0.71 - 1.07	mm	Approx. 1/2 to 3/4 turn
Other	Maximum intake restriction with heavy duty air cleaner, clean filter element	305	mm H2O [12 in H2O]
Other	Maximum intake restriction with heavy duty air cleaner, dirty filter element	635	mm H2O [25 in H2O]
Other	Polarization Index (PI) acceptance ratio	2 or greater	ratio (10 min megohms / 1 min megohms)	new and in-service sets
Other	Pressure sensing line nominal size inside diameter	1/2	in. (12.7 mm)	connected between the transducer (located under the FPDP) and the pump discharge flange and the discharge check valve
Other	REG VHZ adjustment range	1 through 50 (normal range 7 through 21)
Other	Rack position test voltage (disconnect fuel pump)	1.3 ±.25 to 4.5 ±.25	VDC	racks moved to 0mm
Other	Rack test position range	0 to 19	mm
Other	Specific gravity at end of charge (ambient frequently above 32 °C / 90 °F)	1.240 - 1.260	SG
Other	Specific gravity at end of charge (ambient normally below 32 °C / 90 °F)	1.270 - 1.290	SG
Other	Specific gravity correction	0.007	SG points	subtract for every 10 °C (18 °F) above 25 °C (77 °F); add for every 10 °C below
Other	Specific gravity for filling new cells (ambient frequently above 32 °C / 90 °F)	1.240	SG
Other	Specific gravity for filling new cells (ambient normally below 32 °C / 90 °F)	1.270	SG
Other	Start delay adjustment range	0 to 300	seconds	remote starting in Auto mode
Other	Start delay adjustment range (Auto mode remote start)	0 to 300	seconds
Other	Stop delay adjustment range	0 to 600	seconds	remote stopping in Auto mode
Other	Stop delay adjustment range (Auto mode remote stop)	0 to 600	seconds

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Coolant	50/50 mixture of fully formulated coolant and DCA4 (or equivalent); premixed fully formulated coolant or 50/50 mix of high-quality distilled/deionized water and fully formulated concentrated antifreeze	Cummins Engineering Standard 14603; Fleetguard coolants containing DCA4 recommended			Either ethylene glycol or propylene glycol; fill to bottom of filler neck
Coolant	50/50 ethylene glycol antifreeze and water (40 to 60% working range)	TMC RP 329 (ethylene glycol) or TMC RP 330 (propylene glycol)	above -36°C	85.0 L	50/50 mixture gives -36 C [-34 F] freeze point and 110 C [228 F] boiling point. Use Fleetguard Compleat. Engine only capacity 85 liters [22.4 U.S. gal].
Engine oil	15W-40 (multigrade)	API CF-4, CG-4, CF-4/SG, or CG-4/SH		76.0 L	Nominal ash content 1 to 1.5 percent mass. 132 L [35 U.S. gal] oil pan option. Special break-in oils not recommended.
Engine oil	High-quality multi-viscosity lubricating oil such as Cummins Premium Blue or equivalent				Consult authorized distributor for correct lubricating oil specifications for operating conditions
Fuel	ASTM No. 2 diesel fuel				Cummins engines normally use ASTM No. 2 diesel fuel and will operate on alternate diesel fuels within the specifications shown in the Cummins engine Operation and Maintenance Manual. Never use galvanized or copper fuel lines, fittings or fuel tanks.
Fuel	ASTM No. 2D diesel				No. 1D acceptable below 0 C [32 F] blended with No. 2D. Viscosity must be kept above 1.3 cSt at 40 C [104 F].
Fuel	ASTM No. 2D diesel fuel, minimum Cetane number 40	ASTM No. 2D; BS 2869:2010+A1:2011 acceptable alternative			Cetane numbers higher than 40 often needed at high altitudes or extremely low ambient temperatures
Fuel	Number 2 diesel				Direct injection, number 2 diesel fuel; fuel filter; automatic electric fuel shutoff
Fuel	Number 2 diesel fuel				Direct injection
Fuel	number 2 diesel fuel				Direct injection
Grease	Kluber, type ASONIC GHY72			75.0 grams	P7 generator bearing re-lubrication grease; must be filled with same type used at manufacture and MUST NOT be mixed with any other type.
Grease	Lithium based grease, Mobilux No. 2 or Shell Alvania R3		-30°C to 120°C	2.74 oz (81 ml)	Generator end bearing lubrication; grease divided equally between bearing, bearing cap cavity and bearing cartridge cavity
Other	DCA4 supplemental coolant additive				Recommended concentration 1.5 units per 3.8 liters [1 U.S. gal]; never below 1.2 or above 3 units. Reduce DCA4 by one-third if Methoxy Propanol antifreeze is used.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Fault codes

Code	Name	Meaning	Severity	Action
101	IDLE MODE	Indicates the engine is operating in idle mode. Grounding the engine idle input causes generator build-up to be inhibited and the engine to be governed at 800 RPM.	Warning	When ground is removed from the input, the genset returns to normal speed and voltage.
102	EMERGENCY STOP	Local or remote Emergency Stop activated.	Shutdown	Turn switch clockwise to pop out (local); move Run/Off/Auto to Off; press Reset; select Run or Auto.
111	Internal ECM Failure	Internal ECM Failure	Shutdown
1131	Battle Short Active	Control is in Battle Short mode (bypasses several fault shutdowns).	Warning	If possible, investigate any fault codes being bypassed.
115	No engine speed signal detected	No engine speed signal detected between pins 21 and 22 of Engine Harness Connector.	Shutdown	Engine is shut down and cannot be run. Common Alarm output is energized.
121	Engine Magnetic Crankshaft Speed or Position Lost One of Two Signals	Engine Magnetic Crankshaft Speed or Position Lost One of Two Signals	Warning
1312	Configurable Input # 2	Optional customer configurable input fault.	Info	Check the Input # requirements and correct if possible.
1317	Configurable Input # 13	Optional customer configurable input fault.	Info	Check the Input # requirements and correct if possible.
1318	Configurable Input # 14	Optional customer configurable input fault.	Info	Check the Input # requirements and correct if possible.
135	High voltage at engine oil pressure sensor signal	High voltage detected at engine oil pressure sensor signal pin 12 of Engine Harness ECM Connector.	Warning	No effect on performance. Common Warning output is energized.
141	Low voltage at engine oil pressure sensor signal	Low voltage detected at engine oil pressure sensor signal pin 12 of Engine Harness ECM Connector.	Warning	See code 415 procedure.
1416	Fail To Shutdown	Records a bypassed shutdown fault while the generator set was in Battle Short mode.	Warning	Troubleshoot the shutdown fault causing the bypassed shutdown.
142	Oil Overpressure	Oil Overpressure	Warning
143	Low oil pressure warning	Engine oil pressure has dropped below the warning trip point.	Warning	No effect on performance. Common Warning output is energized. Pre-low Oil Pressure relay driver is energized.
1433	Local Emergency Stop	A local Emergency Stop has been activated.	Shutdown	De-activate the Emergency Stop button; press Stop; press Reset; select desired operating mode; check the Emergency Stop button works correctly.
1434	Remote Emergency Stop	A remote Emergency Stop has been activated.	Shutdown	De-activate the Emergency Stop button; press Stop; press Reset; select desired operating mode; check the Emergency Stop button works correctly.
1435	Low Coolant Temperature	Engine coolant heater is not operating or not circulating coolant; occurs when coolant temperature is 21 °C (70 °F) or lower.	Warning	Check coolant heater power supply, blown fuse or disconnected heater cable; look for coolant leaks; check coolant level and replenish.
1438	Fail To Crank	Possible fault with the control, speed sensing, or starting system.	Shutdown	See code 441 for corrective action; ensure the Emergency Stop button is disengaged.
1439	Low Day Tank Fuel Switch	Day tank fuel supply is running low.	Warning	Look for possible fuel leaks and repair; check for low fuel level and replenish.
144	High voltage at engine coolant temperature sensor signal	High voltage detected at engine coolant temperature sensor signal pin 14 of Engine Harness ECM Connector.	Warning	Review fault code 151 correction list for possible causes.
1441	Low Fuel Level	Fuel level has gone below the threshold setting for low fuel level against the time setting.	Warning	Look for possible fuel leaks and repair; check for low fuel level and replenish.
1442	Weak Battery	During cranking battery voltage is at or below the weak battery warning trip point for a time greater than or equal to the weak battery set time.	Warning	See code 441.
1443	Dead Battery	During cranking battery voltage dropped below the operating voltage of the control, resetting the control; after three consecutive resets this code becomes active.	Shutdown	See code 441.
1444	Overload	Overload	Warning
1445	Short Circuit	Short Circuit	Shutdown
1446	High AC Voltage	High AC Voltage	Shutdown
1447	Low AC Voltage	Low AC Voltage	Shutdown
1448	Under Frequency	Generator set frequency has dropped below 90% of nominal for approximately ten seconds.	Shutdown	Check the fuel supply; check the air intake supply; check the load and correct any overload.
1449	Over Frequency	Generator set frequency has exceeded the Over Frequency threshold for the set time parameter.	Warning	Check the fuel supply; check the air intake supply; check the load and correct any overload.
145	Low voltage at engine coolant temperature sensor signal	Low voltage detected at engine coolant temperature sensor signal pin 14 of Engine Harness ECM Connector.	Warning	No effect on performance. Common Warning output is energized.
1452	Genset Breaker Fail To Close	Genset Breaker Fail To Close	Warning
1453	Genset Breaker Fail To Open	Genset Breaker Fail To Open	Warning
1455	Utility Breaker Position Contact	Utility Breaker Position Contact	Warning
1456	Bus Out Of Synchronizer Range	Bus Out Of Synchronizer Range	Warning
1457	Fail To Synchronize	Fail To Synchronize	Warning
1459	Reverse Power	Reverse Power	Shutdown
146	Pre-High Engine Coolant Temperature	Engine operating near cooling system capacity.	Warning	Review fault code 151 correction list for possible causes.
1461	Loss of Field (Reverse kVAR)	Loss of Field (Reverse kVAR)	Shutdown
1463	Not In Auto	Not In Auto	Info
1465	Ready To Load	Ready To Load	Info
1469	Speed/Hz Mismatch	Speed/Hz Mismatch	Shutdown
1471	Over Current	Over Current	Warning
1472	Over Current	Over Current	Shutdown
151	High coolant temperature shutdown	Engine has overheated (coolant temperature above shutdown trip point or coolant level is low).	Shutdown	Engine will shut down. Common Alarm output is energized. High Coolant Temperature relay driver is energized.
155	High Intake Manf 1 Temp	Engine has overheated (intake manifold temperature above shutdown trip point).	Shutdown	Review fault code 151 correction list for possible causes.
171	Fuel pump rack position fault	One or both of the left bank or right bank fuel pump racks is not at the commanded position.	Warning	Performance could be sluggish or slow to respond. Common Warning output is energized.
1852	Pre-High H2O In Fuel	Water in the fuel is above normal and has reached the warning trip point.	Warning	Check fuel in tank (local or remote); drain and re-fill if necessary.
196	Low Coolant 1 Level	Engine coolant level has fallen below the trip point.	Warning	Check for coolant leaks and level; replenish if low; reset the control and restart.
197	Low Coolant Level	Engine coolant level has fallen below the trip point.	Warning	Check for coolant leaks and level; replenish if low; reset the control and restart.
1999	Maximum Parallel Time	Maximum Parallel Time	Warning
200	LOW OIL PRESSURE	Indicates engine oil pressure has dropped to an unacceptable level.	Warning	If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow the 201-SHUTDOWN procedure. To check oil pressure, access the Oil Pressure menu prior to clearing the fault.
201	LOW OIL PRESSURE	Indicates engine oil pressure has dropped below the shutdown trip point.	Shutdown	Check oil level, lines and filters; reset control and restart.
204	OIL PRESS SENDER	Oil pressure sender out of working range.	Warning	Check that the oil pressure sender is properly connected.
210	LOW COOLANT TEMP	Warning occurs when engine coolant temperature is 70°F (21°C) or lower, indicating the engine coolant heater is not operating or is not circulating coolant.	Warning	Check for coolant heater not connected to power supply (blown fuse or disconnected cord); check for low coolant level and replenish; check for open heater element (check current draw).
211	HIGH COOLANT TEMP	Indicates the engine coolant temperature is getting close to the recommended maximum temperature limit: 215°F (102°C) standby or 207°F (97°C) prime.	Warning	Reduce load; check air inlets/outlets for obstructions.
212	HIGH COOLANT TEMP	Indicates engine has overheated (coolant temperature above the shutdown trip point: 223°F (106°C) standby or 215°F (102°C) prime).	Shutdown	Check for obstructions to cooling airflow. Check fan belt. Reset control and restart after correcting problem.
213	COOLANT SENDER	Resistance of coolant temperature sender out of range.	Warning	Contact an authorized service center.
214	LOW COOLANT LVL	Indicates engine coolant level has fallen below the trip point.	Warning	Check coolant level and replenish; look for leaks.
215	LOW COOLANT LVL	Indicates engine coolant level has fallen below the trip point. LOW COOLANT LVL Shutdown will not occur if genset is in Idle mode (low coolant warning only).	Shutdown	Check coolant level and replenish. Look for leaks. Reset control and restart.
220	MAG PICKUP	Mag pickup speed indication not sensed or does not match genset output frequency.	Shutdown	Restart and check RPM. Check wires and MPU adjustment.
221	FAIL TO CRANK	Possible fault with control or starting system.	Shutdown	Check fuse F3 on the Engine Interface board; check for poor battery cable connections; recharge or replace a discharged or defective battery.
222	OVERCRANK	Possible fuel system problem.	Shutdown	Check fuel supply, fuel filter and air filter.
223	OVERSPEED	Indicates engine has exceeded normal operating speed (115% ±1% of nominal). Engine runs and then shuts down.	Shutdown	Perform rack position fault/test; check governor output module A38 and digital board A32.
224	FAIL TO SYNCHRONIZE	The generator set has not synchronized to the system bus within the allowable time frame.		Check the governor system stability and adjust governing and synchronizer parameters as required. Check for fuel system problems which can cause engine instability. Synchronizing time can be improved by widening the synchronizing window and reducing the acceptance time delay.
226	FAIL TO CLOSE	Indicates that the paralleling breaker has been given a signal to close, but has not closed properly.		Verify that the charging mechanism of the paralleling breaker is functioning properly. Check the close signal to the breaker. Verify that the auxiliary contact signals from the breaker to the PowerCommand control are operational.
228	Low Coolant Pressure	Low Coolant Pressure	Shutdown
230	LOW DC VOLTAGE	Indicates battery voltage is below 10 VDC.	Warning	Recharge or replace the battery. Check the battery charger fuse. Clean and tighten or replace the battery cable terminals and cables. Check the engine DC alternator; replace if normal charging voltage is not obtained.
231	HIGH DC VOLTAGE	Indicates battery voltage exceeds 32 VDC.	Warning	Lower battery charger float level.
232	WEAK BATTERY	Indicates battery voltage drops below 60% of nominal for two seconds, during starting.	Warning	See warning 230 Low DC Voltage; recharge or replace battery.
2335	AC Voltage Sensing Lost (Excitation Fault)	Excitation Fault (Loss of Voltage Sense)	Shutdown	Critical shutdown fault - suspends Battle Short mode.
234	Engine overspeed	Overspeed	Shutdown	Fuel shutoff valves are de-energized (valves closed). Common Alarm output is energized. Overspeed relay driver is energized.
2342	Too Long In Idle	Too Long In Idle	Warning
235	Low Coolant Level	Low Coolant Level input is active and threshold response is set to Shutdown.	Shutdown	Allow engine to cool completely; check for coolant leaks and level; replenish if low; reset control and restart.
236	Both Engine Speed Signals Lost	Both Engine Speed Signals Lost	Shutdown
240	LOW FUEL-DAY	Indicates day tank fuel supply is running low.	Warning	Check fuel supply and replenish.
241	LOW FUEL	Indicates fuel supply is running low.	Warning	Check fuel supply and replenish.
250	EEPROM ERROR	PCC memory error; data corruption of critical operating parameters.	Shutdown	Perform the initial start setup procedure. If the set shuts down on the same EEPROM ERROR message, replace the digital board (A32).
251	EEPROM ERROR	PCC memory error; data corruption of non-critical operating parameters.	Warning	Perform the adjustment procedures, save the adjustments and reset the control. If the error persists perform the calibration procedures. If the error still persists replace the digital board (A32).
252	EEPROM ERROR	PCC memory error; data corruption of non-critical operating parameters.	Warning	Verify values/choices and repeat the save operation; reset; if persists replace A32.
253	Oil Level Low	Oil Level Low	Shutdown

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Aligning Generator with Engine adjustment

⚠ Accidental starting during this procedure presents a hazard of severe personal injury or death; disconnect negative battery cable first

Tools: Dial indicator, Shims

Fasten a dial indicator to the generator shaft or cooling fan with the point on the capscrew head or drive disc flat.
Bar the engine over clockwise one revolution; record the total indicator reading (T.I.R.).
Measure distance from generator shaft center to indicator point and from flex discs to mounting bolt center.
Compute shim change: multiply distance ratio by one half the T.I.R.
Keep T.I.R. not more than .001 inch for each inch of radius.
If axial runout is excessive, rotate drive discs 180 degrees (or 30/60/90 degrees) and retorque.

Analog Meter Calibration adjustment

Select >> from Main Menu, proceed to A−C VOLTS ADJ TO menu.
Start generator set and allow to reach normal operating speed.
Calibrate analog Voltmeter to digitally displayed value.
Calibrate analog % Amps meter to digitally displayed value.
Calibrate analog % Load meter to digitally displayed value.
Calibrate analog Frequency meter to digitally displayed value.
SAVE, then EXIT.

Angular Alignment Procedure adjustment

⚠ Accidental starting during this procedure presents the hazard of severe personal injury or death; disconnect the negative (-) battery cable(s) first.

⚠ Do not bar engine over by prying on fan blade; this may damage the blade and cause sudden blade failure.

Tools: dial indicator, shims, wrenches

Disconnect the negative (-) battery cable(s) before beginning.
Fasten a dial indicator to the generator shaft or cooling fan with the sensing point on the capscrew head or flat surface of the drive disc at bolt circle diameter.
Bar the engine over clockwise as viewed from engine flywheel; do not allow it to roll back on compression at the end of travel.
Total indicator reading (T.I.R.) is the sum of maximum positive and negative readings over one revolution.
Compare distance from generator shaft center to indicator point with distance from flex discs to generator mounting bolt center to get a ratio.
Multiply the ratio by one half the T.I.R. to determine the amount of shims to add or remove under the mounting feet.

Axial Alignment Procedure adjustment

Tools: dial indicator, dial indicator holding device with magnetic base or clamp, capscrew tools, torque wrench

Check axial misalignment only when an objectionable vibration is present.
Fasten a dial indicator to skid base, engine block, or generator shell so the sensing point rests on the generator shaft hub.
Bar the engine over clockwise as viewed from engine flywheel through a couple of rotations.
Record indicator readings in eight equally spaced points around the shaft diameter to obtain a T.I.R. for axial shaft misalignment.
To correct out-of-tolerance T.I.R., remove the capscrews connecting drive discs and flywheel and mark the discs and flywheel relative to each other.
Rotate engine or generator so drive disc holes are repositioned 180 degrees from original location; reinstall and retorque capscrews.
If runout is unchanged, rotate discs to 30, 60 or 90 degrees from original location.
If T.I.R. does not improve, inspect the flywheel pilot and drive disc runouts more closely.

Cooling Fan Drive Belt Adjustment - Back Side Idler System adjustment

⚠ Do NOT tighten the inner jam nut excessively; the spring retainer will bend and the control rod will fail.

⚠ The fan belt idler is under tension. Do NOT allow your hands between the idler and belt or fan hub.

Tools: Socket and breaker bar

The fan belt must be installed and under fan idler arm spring tension.
Turn the adjusting screw until the end of the slot on the lower control rod end touches the spacer.
Note that one of the nuts has left-hand threads.
Hold the adjusting screw and tighten the two jam nuts.
For control rod with spring, turn the inner jam nut until spring retainer washers touch the cylinder.
Hold the inner jam nut and tighten the outer jam nut.

Crosshead Adjustment adjustment

⚠ The adjusting screw must not turn when the lock nut is tightened.

Tools: Torque wrench, Torque wrench adapter ST669

Adjust crossheads before adjusting valves, on the cylinder with both valves closed.
Loosen the crosshead adjusting screw locknuts on intake and exhaust.
Turn the adjusting screw out at least one turn.
Hold the crosshead down against its guide.
Turn the adjusting screw in until it touches the valve stem top without raising the crosshead.
Hold the screw and tighten the locknut to the specified torque.
Torque value with adapter ST669: 45 N-m [35 ft-lb].
Torque value without adapter: 60 N-m [45 ft-lb].

Day Tank Controller Conversion 240 VAC to 120 VAC adjustment

Remove the two jumpers between terminals TB1-6 and TB1-7 and connect one between TB1-5 and TB1-6 and the other between TB1-7 and TB1-8.
Move selector switch S103 on the control PCB to the up position for 120V.
On the control transformer, remove the two jumpers between terminals H2 and H3 and connect one between H1 and H3 and the other between H2 and H4.

Digital Ammeter Display Calibration adjustment

Tools: calibrated ammeter

Select >> from Main Menu, proceed to AMPS L1 menu.
With generator set OFF, attach calibrated ammeter to L1.
Start generator set and allow to reach normal operating speed.
Load generator set to maximum rated kVA at rated voltage.
Calibrate AMPS L1 reading to agree with calibrated ammeter.
Repeat steps 17 through 20 for L2 and L3.
Select EXIT if no calibration; SAVE then EXIT if calibration made.

Digital Coolant Temperature Display Calibration adjustment

Tools: precision resistor (engine sensor calibration tool)

With generator set OFF, replace coolant temperature sender with precision resistor in calibration tool.
Select >> from Main Menu, proceed to COOLANT TEMP L menu.
Calibrate temperature reading to match calibration tool.
Repeat step 32 for COOLANT TEMP R if engine uses two sensors.
Select EXIT if no calibration; SAVE then EXIT if calibration made.

Digital Power Factor Display Calibration adjustment

Tools: power factor meter

Select >> from Main Menu, proceed to PF1 menu.
With generator set OFF, attach power factor meter to L1.
Start generator set and allow to reach normal operating speed.
Load generator set to maximum rated kVA at rated voltage.
Calibrate PF1 reading to agree with power factor meter.
Repeat steps 24 through 27 for L2 and L3.
Select EXIT if no calibration; SAVE then EXIT if calibration made.

Digital Voltage Display Calibration adjustment

Tools: calibrated frequency/voltmeter

Select >> from Main Menu, proceed to VOLTS L12 menu.
With generator set OFF, attach calibrated frequency/voltmeter to AC output L1 to L2.
Start generator set and allow to reach normal operating speed.
Calibrate VOLTS L12 reading to agree with calibrated voltmeter.
Shut generator set OFF.
Repeat steps 10 through 13 for L23 and L31.
Select EXIT if no calibration; SAVE then EXIT if calibration made.

Engine Torque Adjustment adjustment

⚠ Calibration and adjustment must be performed by technically qualified personnel only

Tools: Calibrated instruments

Select >> from the Main Menu to proceed to the Torque Adjust %DC menu.
Start the generator set and allow it to reach normal operating speed.
Load the generator set to maximum rated kVA at rated voltage.
Adjust the torque limit up or down to achieve proper frequency under maximum load.
Select SAVE to retain the adjustment.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

Connection	Leads	Notes
Connector A, pin 12	Oil Pressure Sensor Signal
Connector A, pin 14	Coolant Temperature Signal
Connector A, pin 21	ESS + Signal	Engine Speed Sensor
Connector A, pin 22	ESS - Signal	Engine Speed Sensor
Connector A, pin 39/40	Fuel Shutoff Supply +24VDC (left bank pin 39, right bank pin 40)
Connector A, pins 31-34	DSR (31), RXD (32), TXD (33), DTR (34)	Datalink connector
Connector B, NC pins	4, 5, 22, 23, 40	No connection
Connector B, pin 1	Alarm Reset Signal	Customer supplied switch; grounds to reset alarms/warnings and inactive fault codes
Connector B, pin 10	Common Warning Relay Output (N/O)
Connector B, pin 11	Speed Adjust +5VDC Supply	Remote speed adjust potentiometer
Connector B, pin 12	Speed Adjust Signal	Potentiometer center wiper; 500 to 5000 ohms
Connector B, pin 13	Speed Adjust Return
Connector B, pin 14	Coolant Temperature Meter Driver	0-1mA meter output
Connector B, pin 15	Speed Bias Reference Supply (7.75VDC)
Connector B, pin 16	Speed Bias Input (Woodward)
Connector B, pin 17	Speed Bias Reference Supply (5.0VDC)
Connector B, pin 18	Speed Bias Input (Barber-Colman)
Connector B, pin 19	Shield
Connector B, pin 2	Alternate Frequency Signal	Customer supplied switch; ground to select alternate frequency
Connector B, pin 21	Tachometer Meter Driver	0-1mA meter output
Connector B, pin 24	Run Signal (switched B+)	Customer supplied Run/Stop input, 24VDC
Connector B, pin 3	Idle/Rated Signal	Ground to select idle speed mode
Connector B, pin 30	Ground
Connector B, pin 35	High Coolant Temperature Relay Driver	Rated 200mA max at 24VDC
Connector B, pin 36	Low Oil Pressure Relay Driver	Rated 200mA max at 24VDC
Connector B, pin 37	Engine Overspeed Relay Driver	Rated 200mA max at 24VDC
Connector B, pin 38	Pre-High Coolant Temperature Relay Driver	Rated 200mA max at 24VDC
Connector B, pin 39	Pre-Low Oil Pressure Relay Driver	Rated 200mA max at 24VDC
Connector B, pin 6	Oil Pressure Meter Driver	0-1mA meter output
Connector B, pin 7	Common Alarm Shutdown Relay Return

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Cummins/Onan QST30 family

300

Part #	Description	Category
100-025-001	Air Filter	Air filter
100-029-001	AIR FILTER	Air filter
1007973	Air	Air filter
110331287	Air, Primary	Air filter
110337797	Air, Secondary	Air filter
110337854	Air, Secondary	Air filter
11033838	Air	Air filter
110338381	Air	Air filter
11110175	Air, Primary Magnum RS	Air filter
11110176	Air, Secondary Magnum RS	Air filter
1132848	Air, Primary	Air filter
140-3288-02	Cleaner, Air	Air filter
14589	PLATE CAMSHAFT LOCATING	Air filter
2165039	Air	Air filter
2165059	Air, Primary	Air filter
2339823	Air	Air filter
266787	Air, Primary	Air filter
267953	Air, Secondary	Air filter
26815	Air	Air filter
27407	Air	Air filter
279245	Air, Secondary	Air filter
3044713	Air	Air filter
3214300100	Compressor Air	Air filter
3214300300	Air, Primary	Air filter
3214300800	Air, Primary	Air filter
3214303600	Air, Primary	Air filter
3214304100	Air, Primary	Air filter
3214305300	Air, Secondary	Air filter
3214306500	Air, Secondary	Air filter
3214306800	Air, Primary	Air filter
3214308700	Compressor Air	Air filter
3388840M2	Cab Air	Air filter
3632350M1	Air, Secondary	Air filter
3901475M1	Relevage / Lift Kraftheber	Air filter
3901476M1	Relevage / Lift Kraftheber	Air filter
3901477M1	Relevage / Lift Kraftheber	Air filter
3901478M1	Relevage / Lift Kraftheber	Air filter
3902782M1	Air	Air filter
4144966	Air, Secondary	Air filter
4271467M1	Air, Primary Magnum RS	Air filter
4271468M1	Air, Secondary Magnum RS	Air filter
4319256	Air, Secondary	Air filter
4319257	Air, Primary	Air filter
49931583	Air	Air filter
5016603M1	Air	Air filter
5016604M1	Air	Air filter
609374	Air, Secondary	Air filter
663856	Air, Primary	Air filter
6I2503	Air, Magnum RS	Air filter
700274	Air, Secondary	Air filter
700282	Air, Primary	Air filter
701165	Air, Primary	Air filter
70185128	Air	Air filter
70185824	Air	Air filter
70197588	Air, Secondary	Air filter
70235449	Air	Air filter
70235863	Air	Air filter
70237395	Air	Air filter
70239518	Air	Air filter
70243163	Air	Air filter
70244728	Air	Air filter
702455	Air, Primary	Air filter
702463	Air, Secondary	Air filter
70257024	Air, Primary	Air filter
70257029	Air, Secondary	Air filter
70257597	Air	Air filter
70259793	Air, Secondary	Air filter
70263434	Air, Primary	Air filter
70263435	Air, Secondary	Air filter
70264113	Air, Secondary	Air filter
70264114	Air, Primary	Air filter
70264115	Air, Primary	Air filter
70264740	Air	Air filter
70264744	Air, Primary	Air filter
70264745	Air, Secondary	Air filter
70266786	Air, Primary	Air filter
70267953	Air, Secondary	Air filter
70267962	Air, Secondary	Air filter
70269244	Air, Primary	Air filter
70269245	Air, Secondary	Air filter
70569300	Cab Air	Air filter
70620717	Air	Air filter
70622893	Air	Air filter
70632707	Air	Air filter
70634446	Air	Air filter
70638414	Air	Air filter
70638731	Air	Air filter
70659387	Air, Primary	Air filter
70662477	Air, Secondary	Air filter
70662609	Air, Secondary	Air filter
70671838	Air, Primary	Air filter
70671839	Air, Secondary	Air filter
70684733	Air, Primary	Air filter
70684734	Air, Primary	Air filter
71004652	Air	Air filter
71167808	Air	Air filter
72083768	Air, Secondary	Air filter
72083771	Air, Primary	Air filter
72097035	Air	Air filter
72097371	Air	Air filter
72097407	Air	Air filter
72162545	Air, Primary	Air filter
72163296	Air, Secondary	Air filter
72257812	Air	Air filter
73040631	Air	Air filter
73042190	Air	Air filter
73046858	Air	Air filter
73622243	Air, Primary	Air filter
74052520	Air	Air filter
74059292	Air	Air filter
74379069	Air	Air filter
74993158	Air	Air filter
74996245	Air	Air filter
74997568	Air	Air filter
79011386	Air, Primary	Air filter
79011387	Air, Secondary	Air filter
8022345	Air, Panel	Air filter
8422800	Air, Primary	Air filter
AF1601M	Air	Air filter
AF1638	Air, Primary	Air filter
AF1639	Air, Secondary	Air filter
AF1658K	Air	Air filter
AF1686	Air, Panel	Air filter
AF1695	Cab Air	Air filter
AF1727	Air, Panel	Air filter
AF1733K	Air, Primary	Air filter
AF1735K	Air, Primary	Air filter
AF1767	Air, Secondary	Air filter
AF1768M	Air, Primary	Air filter
AF1791	Air	Air filter
AF1830KM	Air, Primary	Air filter
AF1839	Air, Secondary	Air filter
AF1840	Air	Air filter
AF1841	Air, Secondary	Air filter
AF1842	Air, Secondary	Air filter
AF1843	Air, Secondary	Air filter
AF1887M	Air	Air filter
AF1917M	Air, Primary	Air filter
AF1934MAND	Air	Air filter
AF1935M	Air	Air filter
AF1972	Air	Air filter
AF250	Crankcase Breather	Air filter
AF25057	Air	Air filter
AF25064	Air	Air filter
AF25065	Air, Primary	Air filter
AF25067	Air	Air filter
AF25129M	Air, Magnum RS	Air filter
AF25352	Air	Air filter
AF25376	Air	Air filter
AF25425	Air	Air filter
AF25454	Air, Primary Magnum RS	Air filter
AF25468	Air, Secondary Magnum RS	Air filter
AF25481	Air, Primary	Air filter
AF25491	Air, Secondary Magnum RS	Air filter
AF25558	Air, Secondary	Air filter
AF25617	Air, Primary	Air filter
AF25618	Air, Secondary Magnum RS	Air filter
AF25723	Air	Air filter
AF25724	Air	Air filter
AF25729	Air	Air filter
AF25730	Air	Air filter
AF25748	Air filter	Air filter
AF25749	Air filter	Air filter
AF25849	Cab Air	Air filter
AF25964	Air, Primary Magnum RS	Air filter
AF263	Air	Air filter
AF26393	Air	Air filter
AF26394	Air	Air filter
AF26395	Air	Air filter
AF26396	Air	Air filter
AF26398	Air	Air filter
AF26399	Air, Primary	Air filter
AF26400	Air, Secondary	Air filter
AF26401	Air	Air filter
AF26402	Air	Air filter
AF289	Air filter	Air filter
AF291	Air	Air filter
AF303	Air	Air filter
AF303AND	Air, Primary	Air filter
AF335M	Air, Primary	Air filter
AF338	Air, Secondary	Air filter
AF349	Air, Primary	Air filter
AF349M	Air	Air filter
AF350K	Air	Air filter
AF350KM	Air	Air filter
AF351K	Air	Air filter
AF351KM	Air	Air filter
AF353KM	Air	Air filter
AF362	Air	Air filter
AF4058	Air, Primary	Air filter
AF4059K	Air	Air filter
AF4060	Air, Primary	Air filter
AF4066	Air	Air filter
AF4067	Air	Air filter
AF409K	Air	Air filter
AF4100	FILTER, AF PKG - AF4100	Air filter
AF4103	Air, Secondary	Air filter
AF4124	Air	Air filter
AF4135	Air	Air filter
AF4150	Air, Secondary	Air filter
AF4164K	Air, Primary	Air filter
AF4165	Air, Secondary	Air filter
AF417K	Air	Air filter
AF418	Air, Primary	Air filter
AF418M	Air, Primary	Air filter
AF424	Air filter	Air filter
AF424M	Air, Primary	Air filter
AF427M	Air	Air filter
AF434KM	Air, Primary	Air filter
AF435KM	Air	Air filter
AF436M	Air	Air filter
AF437K	Air	Air filter
AF448	Air	Air filter
AF4521	Air, Secondary	Air filter
AF4522	Air, Secondary	Air filter
AF4523	Air filter	Air filter
AF453	Air	Air filter
AF4553M	Air, Primary	Air filter
AF4554M	Air, Secondary	Air filter
AF456	Air filter	Air filter
AF4567	Air filter	Air filter
AF4581	Air filter	Air filter
AF4589	Air	Air filter
AF459	Air	Air filter
AF461	Air	Air filter
AF4626	Air, Secondary	Air filter
AF4713	Air filter	Air filter
AF471M	Air, Secondary	Air filter
AF472AND	Air	Air filter
AF472M	Air, Primary	Air filter
AF4734	Air, Secondary	Air filter
AF4748K	Air, Primary	Air filter
AF4754	Air, Primary	Air filter
AF4755	Air, Secondary	Air filter
AF4757	Air	Air filter
AF4758KM	Air	Air filter
AF4807	Air, Panel	Air filter
AF4828	Air, Secondary	Air filter
AF4838AND	Air	Air filter
AF486K	Air, Primary	Air filter
AF487	Air, Secondary	Air filter
AF4896	Air	Air filter
AF490M	Air, Secondary	Air filter
AF491	Air	Air filter
AF492	Air	Air filter
AF493	Air	Air filter
AF4994	Air, Secondary	Air filter
AF804M	Air, Secondary	Air filter
AF819KM	Air	Air filter
AF820M	Air, Secondary	Air filter
AF821M	Air, Primary	Air filter
AF835K	Air	Air filter
AF843	Air	Air filter
AF886M	Air	Air filter
AF929	Air, Secondary	Air filter
AF937	Air, Secondary	Air filter
AF939	Air, Primary	Air filter
AF940K	Air	Air filter
AF955	Air filter	Air filter
AF956M	Air filter	Air filter
AF964	Air, Primary	Air filter
AF979M	Air, Primary	Air filter
AF987	Air, Secondary	Air filter
AF988	Air, Secondary	Air filter
AF990	Air	Air filter
AF991	Air	Air filter
AH1198	Air	Air filter
C30810	Air	Air filter
CF810	Air	Air filter
P122115	Air, Panel	Air filter
P122425	Air, Secondary	Air filter
P126318	Air, Primary	Air filter
s9001039	Air Cleaner Precleaner	Air filter
3377193	Battery Tester	Battery tester
08a00029	Drive Belt, Cooling Fan	Belt
100-028-001	Coolant Filter	Belt
100-031-001	BELT	Belt
13800007	Drive Belt, Alternator	Belt
3822524	Use on v-belts ( 3/8 to 7/8) and v-ribbed belts with 5 ribs or less.	Belt
3822525	Use on v-beits larger than 7/8 in. and v-ribbed belts with 6 or more ribs.	Belt
A40-TB1-2	SWITCHED B+	Belt
A40-TB1-4	GROUND	Belt
A40-TB1-7	COMMON ALARM	Belt
ST669	water pump type grease listed below, or its equivalent	Belt
01a0028	Bolts, coupling	Bolt
3825183	INSITE™ cable	Cable
49400361	Common Alarm Circuit	Common alarm circuit
49400355	Common Warning Circuit	Common warning circuit
3621208	B Connector DRC26-40SB-LO11	Connector
3656990	Connector Socket 0462-201-20141	Connector
3657034	Cavity Plugs 0413-204-2005	Connector
3822917	Female 3822917	Connector
3823995	Weatherpack Deutsch/Metri-Pac Male 3823993	Connector
3823996	Weatherpack Deutsch/Metri-Pac Male 3823994	Connector
3824811	Test lead for 9-pin Deutsch connector	Connector
3824812	Weatherpack Deutsch Female 3824811	Connector
1076751M1	Water, Spin-On	Coolant filter
16998304	Water, Spin-On	Coolant filter
28043	Coolant	Coolant filter
3315116	Cummins Part No. DCA4 Units	Coolant filter

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the oil capacity of the Cummins/Onan QST30?

The Cummins/Onan QST30 engine has an oil capacity of 76.0 liters.

What is the displacement of the Cummins/Onan QST30?

The Cummins/Onan QST30 has a displacement of 30.5 liters with 12 cylinders.

Which generators use the Cummins/Onan QST30 engine?

The Cummins/Onan QST30 powers 15 generator set(s), including AKSA AC1026, AKSA AC1130, AKSA AC880, Cummins/Onan CFP30E-F10, Cummins/Onan CFP30EVS-F10.

How often should you change the oil in the Cummins/Onan QST30?

The Cummins/Onan QST30 oil change interval is every 2000 hours.

What is a common problem with the Cummins/Onan QST30 engine?

A commonly reported issue on generators using the Cummins/Onan QST30 is: Warning lamp lights. MESSAGE: WEAK BATTERY 232 − WARNING. Fix: Discharged or defective battery. See Warning message 230, LOW DC VOLTAGE..

Cummins/Onan QST30 Engine

Engine specifications

Generator sets powered by this engine

Troubleshooting

Fault codes

Common problems

Maintenance schedule

Repair guides

Service intervals

Service specifications

Recommended fluids

Fault codes

Procedures

Voltage reconnection

Parts cataloged across the Cummins/Onan QST30 family

Common questions