Cummins/Onan 6CTA8.3 — Specs, Engine, Parts & Maintenance

Specifications

Fuel	diesel
Frequency	50.0 Hz
Standby power	160 kW
Standby kVA	200
Prime power	146 kW
Oil capacity	23.8 L
Coolant capacity	12.3 L
Max ambient	55.0 °C
Dimensions (L×W×H)	1417×831×1255 mm
Dry weight	702 kg

Engine

Cummins/Onan 6CTA8.3-G2

Oil capacity	23.8 L
Coolant capacity	28.4 L
Displacement	8.3 L
Aspiration	Turbocharged, Jacket Water Aftercooled (JWAC)
Rated speed	1500 rpm

Filters for the Cummins/Onan 6CTA8.3-G2

Engine-mounted filters the filter manufacturers list for this engine family. These come from the engine, not from this generator set’s own parts list, so confirm against your serial number before ordering.

System	Filter	Description	Cross-references
Oil filter	P553000	Lube Filter, Spin-On Full Flow	CUMMINS 3318853, CUMMINS 3825970, NAPA 1748, NAPA 1748XD	FridayParts $125.00
Oil filter	P553548	Lube Filter, Spin-On Combination	CUMMINS 3919562, CUMMINS 3973686, BALDWIN BD324, LOESING 025227	KuduParts $48.00 FridayParts $49.99
Fuel filter	P550440	Fuel Filter, Spin-On Secondary	CUMMINS 3831063, CUMMINS 3890707, NAPA 3358, BALDWIN BF788	FridayParts $356.80
Fuel filter	P550974	Fuel Filter, In-Line	CUMMINS 3826094, NAPA 3270, BLAW KNOX 0016481600, PERKINS 102601	FridayParts $356.80
Fuel / water separator	P551329	Fuel Filter, Water Separator Spin-On Twist&Drain	CUMMINS 11E170210, CUMMINS 3890063, NAPA 3357, BALDWIN BF1280	FridayParts $151.00
Fuel / water separator	P558000	Fuel Filter, Water Separator Spin-On Twist&Drain	CUMMINS 3308638, CUMMINS 3308683, NAPA 3405, NAPA 3693	KuduParts $24.00 FridayParts $25.66
Coolant filter	P554071	Coolant Filter, Spin-On	CUMMINS 209604, CUMMINS 209606, NAPA 4071, WALGAHN-MOTORENTECHN 00811412	FridayParts $397.60
Coolant filter	P552072	Coolant Filter, Spin-On Sca Plus	CUMMINS 3100305, CUMMINS 3300900, NAPA 4072, IMPERIAL 04WF2072	buy

Same engine, other brands

1 brand

The Cummins/Onan 6CTA8.3-G2 in this set also powers 1 generator set sold under 1 other brand. Service parts and maintenance intervals for the engine are shared; enclosure, alternator, controller and ratings are not.

Brand	Models
AKSA	APD220C-6

Maintenance & consumables

for the Cummins/Onan 6CTA8.3-G2

Item	Capacity	Part #	Interval
Air filter		—	500 hr
Fuel filter		—	500 hr
Oil filter		—	500 hr
Battery		—	1000 hr
Belt		—	1000 hr
Coolant	36.0 liters	—
Oil	150.0 liters	—	1000 hr
Spark plug		—	1000 hr

Service intervals

Item	Action	Hours	Months	Notes
Air Cleaner	Inspect	250 hr	3 mo	Every 8,000 km [5,000 mi]
Air Cleaner Service Indicator	Check	250 hr	3 mo
Air Intake System Piping	Inspect	250 hr	3 mo
Antifreeze	Check	500 hr	6 mo	Every 8,000 km [5,000 mi]
Belt Tension	Check	250 hr	3 mo	Every 8,000 km [5,000 mi]
Belt Tensioner Bearing	Inspect	250 hr	3 mo	Every 8,000 km [5,000 mi]
Charge Air Cooler	Clean	250 hr	3 mo
Coolant Filter	Replace	500 hr	6 mo	Every 8,000 km [5,000 mi]
Cooling System Condition	Check	250 hr	3 mo
Damper	Inspect	250 hr	3 mo	Every 8,000 km [5,000 mi]
Electrical Components	Inspect	250 hr	3 mo
Engine Coolant Heater	Check	250 hr	3 mo
Engine Mounting Bolts	Check	250 hr	3 mo
Fan Hub	Inspect	250 hr	3 mo	Every 8,000 km [5,000 mi]
Fuel Filter (Spin-on Type)	Change	250 hr	3 mo
Fuel Pump	Check	250 hr	3 mo
Heat Exchanger Zinc Plug	Inspect	250 hr	3 mo
Hose Condition	Check	250 hr	3 mo	Every Three Months or 250 Hours
Intake System	Inspect	250 hr	3 mo	Every 8,000 km [5,000 mi]
Lube Filter	Replace	500 hr	6 mo	Every 8,000 km [5,000 mi]
Lube Oil	Change	500 hr	6 mo	Every 8,000 km [5,000 mi]
Lubricating Oil and Filters	Change	250 hr	3 mo
Output Shafts	Lubricate	250 hr	3 mo	Lubrication of output/drive shafts
Turbocharger Mounting Nuts	Check	250 hr	3 mo
Valve Lash Clearance	Adjust	1000 hr	12 mo	Every 8,000 km [5,000 mi]
Coolant Filter	Change	500 hr	6 mo
Cooling System	Drain	500 hr	6 mo	Drain and flush cooling system; Every Six Months or 500 Hours
Fuel Filter	Replace	500 hr	6 mo	Every 16,000 km [10,000 mi]
Fuel Supply Lines	Other	500 hr	6 mo	Vent fuel supply lines
Injection Pump	Other	500 hr	6 mo	Vent injection pump
Air Compressor	Inspect	1000 hr	12 mo	Every 33,000 km [20,000 mi]
Drive Belt, Tensioner Bearing and Belt Tension	Check	1000 hr	12 mo
Overspeed Switch Operation	Check	1000 hr	12 mo	Every Year or 1000 Hours
Valve Lash	Adjust	1000 hr		After 1000 hours; contact an authorized service center for service
Antifreeze	Change	2000 hr	24 mo	Every 64,000 km [40,000 mi]; coolant mixtures with water pump lubricants and corrosion inhibitors
Coolant	Change	2000 hr	24 mo	Every 64,000 km [40,000 mi]; flush system
Engine	Clean	2000 hr	24 mo	Engine steam cleaning
Turbocharger	Inspect	2000 hr	24 mo	Every Two Years or 2000 Hours
Viscous Damper	Inspect	2000 hr	24 mo
Water Pump	Inspect	2000 hr	24 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	Air compressor discharge total carbon deposit (clean if exceeded)	2	mm [1/16-inch]
Clearance	Fan hub maximum end play	0.15	mm [0.006 in]
Clearance	Thermostat fully open clearance between flow valve and flange	41.5	mm	minimum
Clearance	Turbocharger axial clearance MAX	0.093	mm
Clearance	Turbocharger axial clearance MIN	0.038	mm
Clearance	Turbocharger radial bearing clearance MAX	0.46	mm
Clearance	Turbocharger radial bearing clearance MIN	0.30	mm
Clearance	Vibration damper index line misalignment (replace if exceeded)	1.59	mm [1/16 inch]
Gap	Overspeed switch air gap	0.005 in. / 0.13 mm	in / mm
Gap	Tensioner spring case to tensioner arm clearance (replace if exceeded)	3	mm
Gap	Turbocharger wastegate actuator rod travel	0.33 to 1.27	mm	applied 200 kPa [29 psi]
Other	Drive belt maximum deflection	9.5 to 12.7	mm [3/8 to 1/2 inch]	at longest span
Other	Drive belt tension gauge value	80 to 110	lbs	using Cummins belt tension gauge ST-1293
Other	Generator voltage adjustment range via rheostat R21	+/-3 percent of rated nameplate voltage	percent
Other	LOP and HET fault time delay following starter disconnect	about 10 seconds	seconds
Other	Over/under voltage module time delay (to prevent nuisance tripping)	25 percent, or approximately 2.5 seconds	percent / seconds
Other	Overcrank limit (three 15-second cranking cycles with two 15-second rest periods)	75 seconds	seconds
Other	Overspeed module time delay	typically one second	seconds
Other	Time delayed start / time delayed stop adjustment range	1 to 15 seconds (start); 1 to 15 seconds (stop); cool-down 3-5 minutes recommended	seconds / minutes
Pressure	Idle Oil Pressure	10-30	psi	idle
Pressure	Idle Oil Pressure Shutdown Limit	8	psi	idle
Pressure	Idle Oil Pressure Warning Limit	12	psi	idle
Pressure	Low oil pressure shutdown setpoint	14 psi (97 kPa)	psi (kPa)	shutdown
Pressure	Lubricating oil pressure at low idle (minimum allowable)	69	kPa [10 psi]	low idle
Pressure	Lubricating oil pressure at rated speed (minimum allowable)	207	kPa [80 psi]	rated speed
Pressure	Lubricating oil pressure range at rated	276-414	kPa	at rated
Pressure	Max. Allowable Exhaust Back Pressure	41	in. H2O
Pressure	Max. Fuel Inlet Restriction	4	in. Hg (13.5 kPa)
Pressure	Max. Fuel Return Restriction	10	in. Hg (33.8 kPa)
Pressure	Max. Fuel Return Restriction	20	in. Hg (67.6 kPa)
Pressure	Maximum allowable exhaust back pressure	75	mm Hg [3.0 in. Hg]
Pressure	Maximum allowable fuel inlet restriction	101.6	mm-hg	low/high idle
Pressure	Maximum allowable intake restriction, dirty air filter	508	mm H2O [20.0 in. H2O]	naturally aspirated
Pressure	Maximum allowable intake restriction, dirty air filter	635	mm H2O [25.0 in. H2O]	turbocharged
Pressure	Maximum allowable restriction to pump, dirty filter	95	mm Hg [8.75 in. Hg]
Pressure	Maximum fuel drain line restriction	69	kPa	engine at rated speed and no load
Pressure	Minimum allowable pressure cap	50	kPa [7.0 psi]
Pressure	Minimum lubricating oil pressure	207	kPa	high idle rpm
Pressure	Minimum lubricating oil pressure	69	kPa	low idle (675 to 725 rpm)
Pressure	Normal Oil Pressure	40-70	psi	normal
Pressure	Oil Pressure Shutdown Limit	15	psi	normal
Pressure	Oil Pressure Warning Limit	20	psi	normal
Pressure	Pre-low oil pressure alarm setpoint	20 psi (138 kPa) or less	psi (kPa)	pre-alarm
Resistance	Circuit breaker insulation resistance (between each pole and to ground)	less than 100,000 ohms indicates a ground	ohm
Resistance	Mag pick-up (speed sensor) resistance	265	Ohms	good sensor
Resistance	Maximum resistance of starting circuit	0.002	Ohms	12V
Resistance	Maximum resistance of starting circuit	0.004	Ohms	24V
Resistance	Permanent magnet exciter stator resistance	4.4	ohms line-to-line
Resistance	Table 5-1 EXCITER ROTOR column	0.016	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER ROTOR column	0.022	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER ROTOR column	0.025	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER ROTOR column	0.047	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER ROTOR column	0.062	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER ROTOR column	0.071	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER ROTOR column	0.11	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER STATOR column	0.67	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER STATOR column	0.8	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER STATOR column	1.1	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER STATOR column	1.3	ohm	approximate, at 68 F (20 C) +/-10%
Resistance	Table 5-1 EXCITER STATOR column	1.7	ohm	approximate, at 68 F (20 C) +/-10%

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		Refer to Cummins engine Operation and Maintenance Manual for coolant recommendations/specifications			Balanced coolant mixture of water, antifreeze and coolant additives.
Coolant	50-percent water and 50-percent ethylene glycol-base antifreeze		above -37°C	22.2 litre	Protects the engine to -37°C [-34°F] year-around; coolant water capacity (engine side) 22.2 Litre; use Fleetguard coolant test kit CC2602 to check SCA
Coolant	50 percent water / 50 percent ethylene-glycol antifreeze	DCA4 supplemental coolant additive	above -34°C	11.4 litres [12.0 U.S. Qts] (6C8.3, 6CT8.3); 12.3 litres [13.0 U.S. Qts] (6CTA8.3)	Never exceed 70/30 antifreeze/water mix; never use 100 percent antifreeze; 50/50 mix protects to -34F (DCA4 one unit per 3.8 litres [1.00 U.S. gallon] initial charge)
Engine oil		Refer to Cummins engine Operation and Maintenance Manual for lubricating oil classification			Gensets are shipped with oil added.
Engine oil	15W-40 multiviscosity	Cummins Premium Blue or its equivalent		23.8 litre	Total system capacity 23.8 litre; no change in oil viscosity or type is needed for new or newly rebuilt engines
Engine oil	5W-20 or 5W-30 synthetic CC/CD		below -23°C		Arctic operation: for ambient temperatures consistently below -23C [-10F] with no means to keep engine warm
Engine oil	SAE 15W-40	API CE (CC/CD or CD/SF where CE unavailable); Cummins Premium Blue		22.4 litres [23.7 U.S. quarts] total including filter	Sulfated ash limit 1.0 mass percent suggested; must not exceed 1.85 mass percent
Fuel	ASTM No. 2 D diesel	ASTM No. 2 D; blends of No. 2 D and No. 1 D below 0C [32F]			Do not mix gasoline or alcohol with diesel fuel; fuel viscosity must stay above 1.3 cSt
Fuel	Diesel				Do not use zinc coated or copper fuel lines with diesel fuel.
Fuel	Number 2 Diesel	ASTM no. 2D			Use only number 2 diesel fuel; do not mix gasoline, alcohol, or gasohol with diesel fuel
Other	Starting battery electrolyte specific gravity			1.26 specific gravity	1.225 specific gravity recommended where ambient temperature is consistently above 95 F (35 C) to reduce electrolyte loss

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
121	Speed Signal Lost		Shutdown
135	Oil Pressure Sensor H		Warning
141	Oil Pressure Sensor L		Warning
143	Pre-Low Oil Pres		Warning	Indicates engine oil pressure has dropped below the warning trip point. If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow code 415 procedure.
144	Coolant Sensor High		Warning
145	Coolant Sensor Low		Warning
146	Pre-High Coolant Temp		Warning	Indicates engine is operating near cooling system capacity. Increase in load or higher ambient temperature may cause High Coolant Temp (151) shutdown. Review 151 correction list for other possible causes.
151	High Coolant Temp		Shutdown	Allow engine to cool down completely. Check coolant level and replenish if low; look for leaks and repair. Check for obstructions to cooling airflow. Check fan belt and repair or tighten. Check blower fan and circulation pumps. Reset control and restart.
197	Low Coolant Level		Warning	Indicates engine coolant level has fallen below warning trip point. If generator is powering critical loads and cannot be shut down, wait until next shutdown period, then follow code 235 procedure. If engine can be stopped, follow code 235 procedure.
212	Oil Temp Sensor H		Warning
213	Oil Temp Sensor L		Warning
234	Overspeed		Shutdown
235	Low Coolant Level		Shutdown	Allow engine to cool down completely. Check coolant level and replenish if low; look for possible coolant leakage points and repair. Reset control and restart.
359	Fail To Start		Shutdown	Indicates possible fuel system or air induction problem. Check for empty fuel tank, fuel leaks, or plugged fuel lines. Check for dirty fuel filter and replace if necessary. Check for dirty or plugged air filter and replace if necessary. Reset control and restart.
415	Low Oil Pressure		Shutdown	Indicates engine oil pressure has dropped below shutdown trip point. Check oil level. If oil level is low, replenish. Reset control and restart.
421	Oil Temp		Warning	Indicates engine has begun to overheat. If generator is powering non-critical and critical loads and cannot be shut down: reduce load if possible; check air inlets and outlets and remove obstructions. If engine can be stopped, follow code 151 procedure and check engine oil level.
441	Low Bat Voltage		Warning	Indicates battery voltage supply to control is approaching a low level. Check battery charger fuse. Recharge or replace battery. Clean battery cable terminals and tighten all connections. Check battery charge voltage float level if applicable.
442	High Bat Voltage		Warning	Indicates battery voltage supply to control is approaching a high level. Check float level on battery charger if applicable (lower float level).
1122	Rated/Idle Trans		Info
1123	Shutdown After Battle Short		Shutdown
1124	Delayed Shutdown		Warning
1131	Battle Sh Active		Warning
1311	Customer Input #1			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1312	Customer Input #2			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1317	Customer Input #3			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1318	Customer Input #4			Nature of fault is optional customer selection. Example inputs: Low Fuel Day Tank, Water In Fuel, Ground Fault, Low Starting Hydraulic Pressure, Low Starting Air Pressure, etc. Programmable via service tool.
1334	Crit Scaler Out Of Range		Shutdown
1335	Noncrit Scaler Out Of Range		Warning
1337	No Message		Info
1416	Fail To Shutdown		Warning
1417	Powr Down Error		Warning	Indicates controller cannot power down because of unknown condition. Possible drain on battery. Contact an authorized service center for service.
1433	Emergency Stop		Shutdown	Indicates local Emergency Stop. To reset: Pull button out; move O/Manual/Auto switch to O; press front panel Fault Acknowledge/Reset button; return switch to desired position.
1434	Remote E-Stop		Shutdown	Indicates remote Emergency Stop. See code 1433 to reset.
1435	Low Coolant Temp		Warning	Indicates engine coolant heater is not operating or is not circulating coolant. Check coolant heater power supply for blown fuse or disconnected cord; check for low coolant level and replenish; look for coolant leaks and repair.
1438	Fail To Crank		Shutdown	Indicates possible fault with control, speed sensing or starting system. See code 441 for corrective action.
1442	Weak Battery		Warning	Indicates during cranking battery voltage is at or below weak battery warning trip point for time greater than or equal to weak battery set time. See code 441 for corrective action.
1443	Battery Failed		Shutdown	Dead battery – engine will not start. See code 441 for corrective action.
1444	KW Overload		Warning
1445	Short Circuit		Shutdown
1446	High AC Voltage		Shutdown
1447	Low AC Voltage		Shutdown
1448	Under Frequency		Shutdown
1449	Over Frequency		Warning
1452	Gen CB Not Close		Warning
1453	Gen CB Not Open		Warning
1459	Reverse Power		Shutdown
1461	Loss Of Field		Shutdown
1466	Modem Failure		Warning
1468	Network Error		Warning
1469	Speed/Hz Match		Shutdown
1471	Over Current		Warning
1472	Over Current		Shutdown
2327	PTC Fault		Warning
2329	Low S1 Frequency		Warning
2331	Low S1 Voltage		Warning
2335	Excitation Fault		Shutdown
2336	Memory Error		Shutdown
2337	Pwr Tran Disabled		Warning
2338	Pwr Tran Failure		Warning
2339	Pwr Down Enabled		Warning
2341	High Control Temp		Warning
2342	Too Long In Idle (10 min.)		Warning	Indicates genset has been in Idle mode too long (10 minutes maximum).
2358	High S1 Voltage		Warning
2396	S1 CB Not Close		Warning
2397	S1 CB Not Open		Warning
2966	PTC Timeout		Warning
2967	Governor Fault		Warning
2968	AVR Fault		Warning
2969	LON Failure		Warning
2972	Field Overload		Shutdown
FAULT 1	Fault 1 (Detector-12)	Red undedicated fault; may be programmed as timed or non-timed shutdown or fault light only (normally factory set for timed shutdown)	Shutdown	Refer to Tests and Adjustments section and perform necessary adjustments
FAULT 2	Fault 2 (Detector-12)	Red fault, same features as Fault 1 (normally factory set for non-timed shutdown)	Shutdown	Refer to Tests and Adjustments section and perform necessary adjustments
HI ENG TEMP	High Engine Temperature	Red lamp; engine shutdown because coolant temperature rose above 215 F (102 C); not operable if coolant level too low	Shutdown	Maintain adequate coolant level; check coolant level and temperature gauge; replace switch S2, thermostat, or tighten fan belt as needed
LO FUEL	Low Fuel (Detector-12)	Yellow lamp; fuel supply marginally low (if equipped)	Warning	Replenish fuel supply
LO OIL PRES	Low Oil Pressure	Red lamp; engine shutdown because oil pressure dropped below 14 psi (97 kPa); fault inhibited during cranking and time delayed about 10 seconds after starter disconnect	Shutdown	Check oil level; monitor oil pressure gauge; replace switch S1 if gauge reading within normal range
LOW ENG TEMP	Low Engine Temperature (Detector-12)	Yellow lamp; engine water jacket temperature 70 F (21 C) or lower; indicates possible inoperative coolant heater	Warning	Check coolant heater; lamp should extinguish after engine warms up
OVERCRANK	Overcrank	Red lamp; starter locked out because of excessive cranking time; limits cranking to 75 seconds (three 15-second cranking cycles with two 15-second rest periods)	Shutdown	Press Reset switch (S11) to clear the fault before attempting to restart
OVERSPEED	Overspeed	Red lamp; engine shutdown due to excessive speed; factory set approximately 2100 r/min (60 Hz units) or 1850 r/min (50 Hz units)	Shutdown	Adjust or replace overspeed switch/module; reset before restarting
PRE Hi ENG TEMP	Pre-High Engine Temperature (Detector-7)	Yellow lamp; engine temperature marginally high, 205 F (97 C) or higher	Warning	Find and correct cause as soon as possible
PRE HI OIL TEMP	Pre-High Oil Temperature (Detector-12)	Yellow lamp; engine temperature marginally high	Warning

Showing the first 80 of 83 codes.

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

Procedures

Adjust Valve Lash Clearance adjustment

⚠ Be sure to disengage the engine timing pin after locating top dead center to prevent damage to the engine timing pin.

Tools: Engine barring gear, Feeler gauge

Remove the air crossover tube, support clamps, hose clamp, and wastegate sensing line.
Remove the crankcase vent tube and remove the valve cover.
Locate top dead center for cylinder No. 1 by rotating the crankshaft while pressing on the engine timing pin.
Check/adjust the valves indicated for STEP A (I = intake; E = exhaust).
Tighten the rocker lever locknut and recheck valve clearance. Torque: 24 N•m [212 in-lb].
Disengage the timing pin; mark the vibration damper and rotate the crankshaft 360 degrees.
Set the valves indicated for STEP B; tighten the locknut and recheck the clearance.
Install a new rubber seal in the valve cover and new sealing o-rings on the capscrews.
Install the valve cover, wastegate sensing tube, and crankcase vent tube.

Adjusting Values/Parameters adjustment

⚠ If Home button or Previous Main Menu button is pressed before pressing save symbol, changes are not saved.

Press button next to symbol in display until + and − symbols are displayed.
Press button next to arrow symbols to move to numeric character to change.
Press button next to + symbol to increase value or select parameter.
Press button next to − symbol to decrease value or select parameter.
After adjusting values/selecting parameters, press symbol to save changes.

Electric Governor Calibration Checks adjustment

Tools: Frequency meter or tachometer

Start the generator set.
Set no-load speed for desired droop (isochronous 60.0 Hz/1800 r/min).
With no load, turn GAIN clockwise until actuator lever oscillates; reduce until stable.
Reduce GAIN one division, then turn fully clockwise while observing lever.
Turn I adjustment counterclockwise until lever stable; it should oscillate up to 3 times.
Apply and remove loads to check response; recalibrate if unsatisfactory.

Electric Governor Preliminary Adjustments adjustment

Tools: Screwdriver

Set frequency adjust (engine speed) potentiometer to mid position and tighten locking nut.
Set I potentiometer one division from zero.
Set Gain potentiometer at the third division from zero.
For isochronous operation turn Droop potentiometer fully counterclockwise.
Turn droop screw to approximately 40 for 3 percent droop.
Turn droop screw to approximately 80 for 5 percent droop.

Fuel Pump Control: Convert 120 VAC to 240 VAC adjustment

Remove jumpers between TB1-5/TB1-6 and TB1-7/TB1-8; connect two jumpers between TB1-6 and TB1-7.
Move selector switch S103 on control PCB to down position for 240 VAC.
If equipped with a transformer, remove jumpers between H1/H3 and H2/H4 and connect two jumpers between H2 and H3.
Attach a tag to the control box indicating the supply voltage.

Fuel Pump Control: Convert 240 VAC to 120 VAC adjustment

Remove jumpers between TB1-6/TB1-7; connect one jumper TB1-5 to TB1-6 and one TB1-7 to TB1-8.
Move selector switch S103 on control PCB to up position for 120V.
If equipped with a transformer, remove jumpers between H2/H3 and connect one between H1-H3 and one between H2-H4.

Idle Speed - Adjustment adjustment

Tools: Screwdriver, Tachometer, 13, 19 and 10 mm wrenches

Industrial: loosen locknut and back out the bumper spring screw.
Speed should drop 20-30 rpm as the screw is backed out.
Loosen locknut; set idle screw 20-30 rpm less than desired speed.
Turn idle screw counterclockwise to decrease rpm; clockwise to increase.
Turn bumper spring screw in until desired idle speed is obtained.
Tighten the locknut.
Automotive: loosen locknut and turn screw counterclockwise to raise rpm, clockwise to decrease.

Mechanical Governor Speed Adjustment adjustment

Tools: Frequency meter or tachometer, Wrench

Use the frequency control meter (if equipped) or an accurate tachometer.
Loosen the speed adjustment screw locknut.
Start set, warm to operating temperature, then apply full rated load.
Adjust speed adjust screw in or out to reach required speed (60 Hz - 1800 r/min, 50 Hz - 1500 r/min).
Hold screw at proper setting and retighten locknut.
Remove and apply loads to check response; readjust if necessary.

Overspeed Setpoint Adjustment and Testing adjustment

⚠ Do not exceed 120% of rated speed.

Tools: Signal generator (0.25 to 120 VAC RMS)

Lower the cover on the engine's local control panel.
Disconnect the engine speed sensor signal from PICK-UP terminals 1 and 2.
Connect a signal generator capable of providing 0.25 to 120 VAC RMS proportional to the engine's rated speed.
Remove the calibrating screw cover from the electronic overspeed switch.
Turn the potentiometer screw clockwise to increase trip speed, counter-clockwise to reduce trip speed.
Adjust until the OVERSPEED light is just illuminated at the desired setpoint.
Replace the screw cover, disconnect the signal generator, reset the light, and reconnect the speed sensor input.

Valves - Adjustment adjustment

⚠ Be sure to disengage the engine timing pin after locating TDC

Tools: Screwdriver, 13, 14, 15 and 18 mm wrenches, Feeler gauge, Barring gear Part No. 3904682

Remove air crossover tube, support clamps and crankcase vent tube.
Remove the valve cover.
Locate Top Dead Center for cylinder number 1 using barring gear and timing pin.
Check/set valves with engine cold, below 60C [140F].
Adjust the valves indicated for STEP A (intake then exhaust).
Tighten locknut to 24 Nm [18 ft-lb] and re-check valve lash.
Rotate crankshaft 360 degrees; be sure timing pin is disengaged.
Set the valves indicated for STEP B; tighten locknuts to 24 Nm [18 ft-lb].

Voltage Regulator Adjustment adjustment

⚠ Seated voltage regulator potentiometers are factory calibrated; further adjustments only by qualified service representative.

Tools: Screwdriver

Adjust voltage control rheostat R21 (if available) to mid position.
Open control panel doors to gain access to voltage regulator.
With set operating and voltage monitored, adjust Volts potentiometer to desired voltage.
Perform fine voltage adjustment (+/-3 percent) with rheostat R21, retighten locking nut.
Stop and restart generator set to confirm proper operation.

Battery Testing - Check Specific Gravity diagnostic

⚠ Batteries can emit explosive gases. Always ventilate the compartment before servicing the batteries.

⚠ Acid is extremely dangerous.

Tools: Hydrometer, Refractometer

Use a hydrometer to measure the specific gravity of each cell.
Check the battery fluid column in the refractometer to determine the state of charge of each battery cell.
If charge is low, charge the batteries.
Replace the battery if it will not charge to the manufacturer's specifications.

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

Voltage	Phase	Notes
110/190	3
110/220	1
115/220	3
115/230	1	Generator voltage connections (reconnectable type only) per Figure 5-20; single phase double delta connection will reduce set rating and may not work with 3-phase meters
120/208	3
120/240	1
127/220	3
139/240	3
220/380	3
220/480	3
230/400	3
240/416	3
240/480	1
254/440	3
277/480	3

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

Common questions

What is the power rating of the Cummins/Onan 6CTA8.3?

The Cummins/Onan 6CTA8.3 is rated 160 kW standby (200.0 kVA).

Which engine powers the Cummins/Onan 6CTA8.3?

The Cummins/Onan 6CTA8.3 is powered by the Cummins/Onan 6CTA8.3-G2 engine.

What kind of fuel does the Cummins/Onan 6CTA8.3 run on?

The Cummins/Onan 6CTA8.3 runs on diesel.

What's the oil capacity on a Cummins/Onan 6CTA8.3?

The Cummins/Onan 6CTA8.3-G2 engine in the Cummins/Onan 6CTA8.3 has an oil capacity of 23.8 liters.

What is the cooling system capacity of the Cummins/Onan 6CTA8.3?

The Cummins/Onan 6CTA8.3 cooling system holds 12.3 liters (3.2 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.

What is the prime power rating of the Cummins/Onan 6CTA8.3?

The Cummins/Onan 6CTA8.3 is rated 146 kW prime (182 kVA), against 160 kW standby.

What is the dry weight of the Cummins/Onan 6CTA8.3?

The Cummins/Onan 6CTA8.3 has a dry weight of 702 kg (1547 lb).

Troubleshooting

Fault codes

Code	Meaning
31	Engine will not shut off
38	Excessive engine moisture
86	Excessive fuel consumption
387	Excessive vibration
80	Exhaust smoke excessive under load
338	Knock

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan 6CTA8.3 troubleshooting guide (8 entries) →

Parts

Part #	Description	Qty	System
098-4500	Decal	2	Label	eBay
098-4730	Label, Warning	4	Label	eBay
098-4732	Label, Warning	1	Label	eBay
098-5429	Label, Coolant Fill	1	Label	eBay
098-7868	Label	1	Label	eBay
098-7902-03	Label, Logo	2	Label	eBay
128-0154-01	Insulation, Foam	1	Insulation	eBay
128-0154-02	Insulation, Foam	1	Insulation	eBay
155-3150-04	Muffler, Critical	1	Muffler	Amazon eBay
155-3164-01	Pipe, Exhaust	1	Pipe	Amazon eBay
155-3164-05	Muffler, Critical	1	Muffler	Amazon eBay
155-3238	Cover, Exhaust	3	Cover	eBay
20090	Fire Pump Packages	6	Pump	eBay FridayParts $22.17
319-2653	Window, Control (If Equipped)	1	Window	Amazon eBay
405-5744	Post, Housing - Center	4	Post	Amazon eBay
405-5832	Door, Housing	6	Door	Amazon eBay
405-5908	Panel, Side - Radiator Housing	2	Panel	Amazon eBay
405-5909	Panel, Front - Radiator Housing	1	Panel	eBay
405-5915	Angle, Roof	1	Angle	eBay
405-5916	Post, Corner - Housing	2	Post	Amazon eBay
405-5917	Panel, End - Roof	2	Panel	Amazon eBay
405-5926	Roof	1	Roof	eBay
406-0831	Hinge, Door	14	Hinge	Amazon eBay
406-0972-01	Latch, Door	7	Latch	eBay
502-0047	Nipple, Pipe (1/4)	1	Nipple	Amazon eBay
502-0827	Fitting, Hose – Barbed (1/2” ID Pipe to 3/4” ID Hose)	2	Hose	Amazon eBay
503-0276	Hose, Breather	-1	Hose	eBay
503-0446	Clamp, Hose	2	Hose	Amazon eBay
503-0889	Hose, Breather	1	Hose	Amazon eBay
503-1134	Clamp, Hose	1	Clamp	Amazon eBay
503-1137	Clamp, Hose	1	Clamp	Amazon eBay $9.95
503-2079	Hose - Bulk (Order by the Foot - 5 Feet Required)	-1	Hose	eBay
526-0333	Washer, Flat	1	Washer	eBay
526-0451	Washer, Flat - Stainless Steel (M8)	2	Washer	Amazon eBay
800-2072	Screw, Cap - Hex Head (M8 x 1.25 x 100)	1	Screw	Amazon eBay
821-6006-01	Screw, Hex Head (M6 x 16)	2	Screw	eBay
870-0504	Nut, Captive Floating (M6 x 1.0)	2	Nut	Amazon eBay
895-0363	Bumper, Door	14	Bumper	Amazon eBay
A028Z105	Sender, Low Coolant	1	Sender	Amazon eBay
A052K226	Hose	2	Hose	eBay
FS1251	Fuel Filter	1	Fuel filter	Amazon eBay $119.92 NAPA $23.51
LF9009	Lube Filter	1	Oil filter	Amazon eBay $110.91 NAPA $70.33 FridayParts $125.00
RU5045	Air Cleaner	1	Air filter	Amazon eBay $26.95 NAPA $101.05
V70509	Lube Oil	4 Gal.	Fluid	Amazon eBay
WF2072	Coolant Filter	1	Coolant filter	Amazon eBay $20.95 NAPA $29.33
155-2305	Clamp, Muffler	1	Service part / kit	Amazon eBay
155-2570	Clamp, V-Band	1	Service part / kit	Amazon eBay
502-0153	Plug, Hex Head	1	Service part / kit	Amazon eBay NAPA $222.77
504-0011	Valve, Shutoff (1/2”)	1	Service part / kit	Amazon eBay $59.95
505-0117	Bushing, Reducer - Flush, Brass (1/2' NPT x3/8° NPT)	1	Service part / kit	Amazon eBay
818-0237-01	Rivet, Pop (1/8)	6	Service part / kit	Amazon eBay
821-6003-02	Screw, Cap - Hex Head (M8 x 1.25 x 25mm)	2	Service part / kit	Amazon eBay

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

Rating	Load	L/h	gal/h
Prime		51.0	13.0
Prime	100%	40.0	10.6
Standby	100%	45.0	11.9

Available documents

Engine spec — 0043216 (Cummins/Onan)Engine spec — 0057290 (Cummins/Onan)Engine spec — 4000073 0703 (Cummins/Onan)Engine spec — 4000137 (Cummins/Onan)Engine spec — fr90216 (Cummins/Onan)Engine spec — fr9754 (Cummins/Onan)Spec sheet — 6CTA8.3-G2 (Cummins/Onan)Spec sheet — 6CTA83-G2 1 (Cummins/Onan)Spec sheet — fr90413 (Cummins/Onan)Spec sheet — fr90608 (Cummins/Onan)Spec sheet — fr90726 (Cummins/Onan)Operator's manual — Cummins-DGBB-DGBC-DGCA-DGCB-DGCG-DGFA-DGFB-DGFC-DGFS-operator-manual (Cummins/Onan)Reference — CUMMINS-GENERATOR-ENGINES-CATALOG (Cummins/Onan)Reference — Motopompe antincendio (Compagnia Tecnica Motori)Owner's manual — 0057258 (Cummins/Onan)Owner's manual — Cummins Diesel C Series Manual 1988 (2) (Cummins/Onan)Parts manual — 6cfparts (Cummins/Onan)Parts manual — 960-0205B Onan Power Command Control Parts (1-1999) (Cummins/Onan)Parts manual — 960-0211 Onan DGDA DGFA Series Parts Manual (12-1998) (Cummins/Onan)Parts manual — 960-0215 Cummins DGDH DGEB DGFK Serise Parts Manual (6-2010) (Cummins/Onan)Parts manual — 960-0297 Cummins DGFA DGFB DGFC DGFS Parts Manual (8-2016) (Cummins/Onan)Parts manual — cummins-midrange-catalog-2014-lr (Cummins/Onan)Parts manual — l20287 (Haldex / FPT Industrial)Service manual — 904-0501 Onan 4BT 6BT 6CT 6CTA Series Genset Service manual 04-1989 text (Cummins/Onan)Service manual — 960-0618D Cummins DGBB DGCA DGEA DGFA Series Installation Manual (10-2001) (Cummins/Onan)Service manual — 960-0628D Cummins DGB DGC DGF Series Installation Manual (2-2004) (Cummins/Onan)

This page was generated from the 26 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.

Cummins/Onan 6CTA8.3 Generator Set

Specifications

Engine

Filters for the Cummins/Onan 6CTA8.3-G2

Same engine, other brands

Maintenance & consumables

Service intervals

Service specifications

Recommended fluids

Fault codes

Procedures

Voltage reconnection

Common questions

Troubleshooting

Fault codes

Repair guides

Parts

Fuel consumption

Available documents