The Cummins/Onan QSL9-G2 is a 8.9 L 6-cylinder turbocharged and cac engine rated at 1800 rpm, producing up to 271.5 kW. It powers generator sets from Cummins/Onan and MQ Power, including the DSHAA 60 Hz, DSHAC, 1200 Amp Diesel Studio Generator and 1400 Amp Diesel Studio Generator. It holds 26.5 L (7.0 gal) of oil and 29.5 L (7.8 gal) of coolant.
Also known as: Cummins, Inc QSL9-G2
Part of the Cummins/Onan QSL9 engine family — 12 variants share parts & fitment.
| Oil capacity | 26.5 L |
|---|---|
| Coolant capacity | 29.5 L |
| Displacement | 8.9 L |
| Cylinders | 6 |
| Aspiration | Turbocharged and CAC |
| Rated speed | 1800 rpm |
| Gross power | 271 kW |
Shared across brands: Cummins/Onan, MQ Power
How to read your Cummins/Onan engine serial & model number →
Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan QSL9-G2.
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Replaceable, Paper insert | — | 100 hr | ||
| Fuel filter | Spin-on type | — | 100 hr | ||
| Oil filter | Full flow, spin-on | — | 100 hr | ||
| Battery | 2 x 750 cca | — | 100 hr | ||
| Belt | Mechanical Fan Drive | — | 100 hr | ||
| Coolant | 29.5 L | — | |||
| Oil | 26.5 L | — | |||
| Spark plug | N/A | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Other | Alternator cooling air flow | 41.3 | m3/min | |
| Other | Alternator excitation current - full load | 2.2 | amps | |
| Other | Alternator excitation current - no load | 0.5 | amps | |
| Other | Combustion air flow - standby | 20.9 | m3/min | standby rating |
| Other | Compression ratio | 16.8:1 | ||
| Other | Cooling system air flow | 248 | m3/min | standard set-mounted radiator |
| Other | Cycle cranking - number of starting cycles | 1 to 7 | cycles | |
| Other | Exhaust flow at set rated load - standby | 33.3 | m3/min | standby rating |
| Other | Fault current regulation (max output current on any phase under fault) | 3 | times rated current | single and three phase faults |
| Other | Frequency regulation | Isochronous | ||
| Other | Full load acceptance - frequency dip / recovery time | 12.6% / 3.7 | % / seconds | NFPA 110 single step load |
| Other | Full load acceptance - voltage dip / recovery time | 29.1% / 3.2 | % / seconds | NFPA 110 single step load |
| Other | Full load rejection - frequency rise / recovery time | 3.9% / 2.9 | % / seconds | load rejection |
| Other | Full load rejection - voltage rise / recovery time | 18.4% / 1.5 | % / seconds | load rejection |
| Other | Governor regulation class | ISO 8528 Part 1 Class G3 | ||
| Other | Ground fault warning (optional) sensing range | 100-1200 | amps, time delay 0-1 s | 600 VAC class, solid ground |
| Other | Maximum air cleaner restriction with clean filter | 3.7 | kPa | |
| Other | Maximum surge power | 233 | kW | PTS test |
| Other | Motor starting kVA at 90% sustained voltage - PMG excitation | 920 | kVA | PTS test |
| Other | Motor starting kVA at 90% sustained voltage - shunt excitation | 770 | kVA | PTS test |
| Other | Over current shutdown (51) | >110 and <175 | % of rating | |
| Other | Over current warning | >110 for >60 s, or >400 for >1 s | % of rating | |
| Other | Over frequency shutdown/warning (81o) | 0-10 | Hz above nominal, 0-20 s time delay | default disabled |
| Other | Over load (kW) warning default | 105 | % of rated kW, 60 s delay | range 50-140%, 0-120 s |
| Other | Random frequency variation | ± 0.25 | % | |
| Other | Reverse Var shutdown default | 0.2 | per unit, 10 s delay | threshold 0.15-0.50, delay 10-60 s |
| Other | Reverse power shutdown (32) default | 10 | % of standby kW rating, 3 s delay | range 5-20%, delay 1-15 s |
| Other | Short circuit shutdown | >175 | % of rating | |
| Other | Time delay start | 0-300 | seconds | default 0 s |
| Other | Time delay stop (cool down) | 0-600 | seconds | default 0 s |
| Other | Total heat rejection - standby | 7.8 | MJ/min | standby rating |
| Other | Under frequency shutdown (81u) default | 6 | Hz below nominal, 10 s time delay | adjustable 0-10 Hz, 0-20 s |
| Pressure | BMEP at set rated load - prime | 1816 | kPa | prime rating |
| Pressure | BMEP at set rated load - standby | 1979 | kPa | standby rating |
| Pressure | Maximum back pressure | 10.2 | kPa (41.0 in H2O) | |
| Pressure | Maximum exhaust back pressure | 10.2 | kPa | |
| Pressure | Maximum fuel inlet restriction | 152.4 | mm Hg | |
| Pressure | Maximum fuel return restriction | 254.0 | mm Hg | |
| Pressure | Maximum inlet restriction | 152.4 | mm Hg (6.0 in Hg) | |
| Pressure | Maximum return restriction | 254.0 | mm Hg (10.0 in Hg) | |
| Resistance | Alternator rotor resistance | 2.0 | ohms | at 20 deg C |
| Resistance | Alternator stator resistance | 0.0128 | ohms per phase | at 20 deg C |
| Speed | Alternator maximum speed | 2250 | rpm | |
| Speed | Engine overspeed limit | 2100 +/- 50 | rpm | |
| Speed | Isochronous governing, steady state load no load to full load | +/-0.25 | % | |
| Speed | Over speed shutdown (default setting) | 115 | % of nominal | |
| Speed | Overspeed limit | 2100 ± 50 | rpm | |
| Speed | Overspeed shutdown default | 115 | % of nominal | |
| Speed | Random frequency variation (PTS test) | +/-0.25 | % | |
| Speed | Rated speed | 1800 | rpm | |
| Temperature | Battery charger ambient temperature operation at full rated output | -20 to 45 | deg C | full rated output |
| Temperature | Control operating ambient temperature range | -40 to +70 | deg C | |
| Temperature | Cooling system ambient design - prime | 48 | deg C | standard set-mounted radiator, non-seismic |
| Temperature | Cooling system ambient design - standby | 52 | deg C | standard set-mounted radiator, non-seismic |
| Temperature | Exhaust temperature | 600 | °C (1110 °F) | standby at set rated load |
| Temperature | Exhaust temperature at set rated load - prime | 572 | deg C | prime rating |
| Temperature | Exhaust temperature at set rated load - standby | 600 | deg C | standby rating |
| Temperature | Standard temperature rise | 150 | °C | Standby at 40 °C ambient |
| Torque | Piston speed | 8.7 | m/s | 1800 rpm |
| Voltage | Alternator voltage adjustment (operator) | +/-5 | % |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Fuel | No. 2 diesel fuel | Direct injection, number 2 diesel fuel | |||
| Fuel | Number 2 diesel fuel | Direct injection fuel system |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Code | Name | Meaning | Severity | Action |
|---|---|---|---|---|
| - | Reverse Var shutdown | Shutdown level adjustable: threshold 0.15-0.50 per unit, delay 10-60 seconds. | Shutdown | Defaults 0.20, 10 seconds. |
| 27 | Low AC voltage shutdown | Voltage on any phase has dropped below a preset value; adjustable 50-95% of reference voltage, time delay 2-10 s; default 85% for 10 seconds | Shutdown | Default 85% for 10 seconds; function tracks reference voltage. |
| 32 | Reverse power shutdown | Adjustment range 5-20% of standby kW rating, delay 1-15 seconds; default 10%, 3 seconds | Shutdown | Defaults 10%, 3 seconds. |
| 51 | Over current shutdown | Output current on any phase more than 110%, less than 175% of rating and approaching thermal damage point of alternator. | Shutdown | Control includes algorithms to protect alternator from repeated over current conditions over a short period. |
| 59 | High AC voltage shutdown | Output voltage on any phase exceeds preset values; time to trip inversely proportional to amount above threshold. Adjustable 105-125% of nominal, time delay 0.25-10 s. | Shutdown | Default 110% for 10 seconds. |
| 81o | Over frequency shutdown/warning | Adjustable 0-10 Hz above nominal frequency, time delay 0-20 seconds. | Defaults: disabled. | |
| 81u | Under frequency shutdown | Generator set output frequency cannot be maintained; adjustable 0-10 Hz below nominal governor set point, 0-20 s delay. | Shutdown | Default 6 Hz, 10 seconds. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
⚠ If the first 3 letters are PJP, start the search with PJ only.
⚠ If the catalog number starts with N, skip the N and begin the search with the second letter.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Voltage | Phase | Connection | Leads | Notes |
|---|---|---|---|---|
| 120/208 | 3 | three phase reconnectable | 12 | |
| 120/208 thru 139/240 | three phase | Broad range | 12 | 150 deg C rise rating 230 kW / 288 kVA per ADS-212 |
| 120/240 | 1 | single phase non-reconnectable | 4 | Double delta, 4 lead |
| 120/240 | single phase | Double delta | 4 | 125 deg C rise rating 175/219 kW/kVA; 105 deg C rise rating 157/196 kW/kVA |
| 120/241 | 1 | single phase non-reconnectable | ||
| 127/220 | 1 | single phase non-reconnectable | ||
| 139/240 | 1 | single phase non-reconnectable | ||
| 220/380 | 3 | three phase reconnectable | 12 | |
| 240/416 | 3 | three phase reconnectable | 12 | |
| 240/416 thru 277/480 | three phase | Broad range | 12 | 150 deg C rise rating 255 kW / 319 kVA |
| 254/440 | 3 | three phase reconnectable | 12 | |
| 277/480 | 3 | three phase reconnectable | 12 | |
| 347/600 | 3 | three phase reconnectable | 12 | Lower broad range |
| 347/600 | three phase | Upper broad range (LBR) | 6 | 150 deg C rise rating 230 kW / 288 kVA; lower broad range 110/190 thru 120/208, 220/380 thru 240/416 |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Part # | Description | Category |
|---|---|---|
| 4021518 | Alternator Manual | Alternator |
| 431PSL6206 | Marathon Magna Plus / 431PSL6206 | Alternator |
| PI144D1 | Alternator Model | Alternator |
| UC274C | Alternator Model | Alternator |
| UC274K | Alternator Model | Alternator |
| 0518-0548-15 | Clamp | Clamp |
| 0518-0548-22 | Clamp | Clamp |
| 0518-0548-29 | Clamp | Clamp |
| 0518-0548-35 | Clamp | Clamp |
| A056F113 | Clamp | Clamp |
| QSL9-G2 | Cummins / QSL9-G2 | Engine |
| A052T655 | Gasket | Gasket |
| A047A980 | Heater, Blanket | Heater |
| A045P359 | Hose, DEF | Hose |
| A045P417 | Hose, DEF | Hose |
| A051B439 | Hose, DEF | Hose |
| 1000A | LCD Ammeter | Service part / kit |
| A030X751 | Box | Service part / kit |
| A030Y642 | Hinge | Service part / kit |
| A031A954 | Panel, Enclosure | Service part / kit |
| A034N673 | Grill, Enclosure | Service part / kit |
| A034N943 | Bolt, Carriage | Service part / kit |
| A034P011 | Bolt, Carriage | Service part / kit |
| A034P012 | Washer, Flat | Service part / kit |
| A034P026 | Screw, Hex Flange Head | Service part / kit |
| A034P039 | Nut | Service part / kit |
| A034P108 | Screw, Hex Flange Head | Service part / kit |
| A035H898 | Screw, Hex Head | Service part / kit |
| A035P345 | Lead, Electrical | Service part / kit |
| A041D550 | Header, Door | Service part / kit |
| A041E195 | Panel, Enclosure | Service part / kit |
| A041E396 | Panel, Enclosure | Service part / kit |
| A041E596 | Header, Door | Service part / kit |
| A041E928 | Post, Enclosure | Service part / kit |
| A041M317 | Door, Control | Service part / kit |
| A041S526 | Insulation, Door | Service part / kit |
| A046F214 | Panel, Enclosure | Service part / kit |
| A046F238 | Panel, Enclosure | Service part / kit |
| A047V570 | Panel, Window | Service part / kit |
| A052S411 | Latch | Service part / kit |
| A053J589 | Screw, Hex Head | Service part / kit |
| A053J591 | Screw, Hex Head | Service part / kit |
| A053T433 | Padlock, Attachment | Service part / kit |
| A055G556 | Screw, Socket Head | Service part / kit |
| A056C784 | Latch, Mechanical | Service part / kit |
| A056H470 | Hinge | Service part / kit |
| A056M306 | Bolt, Carriage | Service part / kit |
| A063L015 | Door, Enclosure | Service part / kit |
| A063L064 | Header, Door | Service part / kit |
| A063L069 | Header, Door | Service part / kit |
| A063L072 | Panel, Enclosure | Service part / kit |
| A063L080 | Panel, Enclosure | Service part / kit |
| A064U218 | Cover, Electrical Connector | Service part / kit |
| A072Y708 | Door, Enclosure | Service part / kit |
| A072Y709 | Panel, Enclosure | Service part / kit |
| V2403-M-E3BG | Engine Model | Service part / kit |
| A045J792 | Pump, Doser (See Page 70 for Components) | Pump |
| 0821-0016 | Screw, Locking | Screw |
| 0821-0029 | Screw, Locking | Screw |
| 0821-6002-03 | Screw, Hex Head | Screw |
| 0821-6003-01 | Screw, Hex Head | Screw |
| A030Y648 | Edging, Seal | Seal |
| A047V572 | Seal, Weather | Seal |
| A054S414 | Seal, Door | Seal |
| A054S416 | Seal, Door | Seal |
| A046D072 | Strap, Tank | Strap |
| A049G884 | Tank, DEF Complete (Includes Header and Heated Blanket) (See Page 66 for Components) | Tank |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
The Cummins/Onan QSL9-G2 engine has an oil capacity of 26.5 liters.
The Cummins/Onan QSL9-G2 has a displacement of 8.9 liters with 6 cylinders.
The Cummins/Onan QSL9-G2 powers 6 generator set(s), including Cummins/Onan DSHAA 60 Hz, Cummins/Onan DSHAC, MQ Power 1200 Amp Diesel Studio Generator, MQ Power 1400 Amp Diesel Studio Generator, MQ Power 1800 Amp Diesel Studio Generator.
A commonly reported issue on generators using the Cummins/Onan QSL9-G2 is: Over Current.