Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Battery | 12 | — | |||
| Coolant | -45 | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
The Cummins/Onan qsb7g5nr3 is a 6.7 L 6-cylinder turbocharged and air-to-air after-cooled engine rated at 1800 rpm, producing up to 242 kW. It powers generator sets from Cummins/Onan, including the C125 D6D, C150 D6D, C175 D6 and C200 D6. It holds 17.5 L (4.6 gal) of oil and 23 L (6.1 gal) of coolant.
Also known as: cummins qsb7g5nr3
| Oil capacity | 17.5 L |
|---|---|
| Coolant capacity | 23.0 L |
| Displacement | 6.7 L |
| Cylinders | 6 |
| Aspiration | Turbocharged and air-to-air after-cooled |
| Rated speed | 1800 rpm |
| Gross power | 242 kW |
How to read your Cummins/Onan engine serial & model number →
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Battery | 12 | — | |||
| Coolant | -45 | — |
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 | AC waveform Total Harmonic Distortion (THDV) | < 5% no load to full linear load, < 3% for any single harmonic | % | |
| Other | AC waveform total harmonic distortion | < 5% no load to full linear load, < 3% for any single harmonic | % | |
| Other | BMEP at set rated load | 2276 (330) / 2063 (299) | kPa (psi) | standby / prime |
| Other | Combustion Air | 15.86 (560) / 15.38 (543) | m3/min (scfm) | standby / prime |
| Other | Compression ratio | 17.2:1 | ||
| Other | Governor regulation class | ISO 8528 Part 1 Class G3 | ||
| Other | Governor regulation class | ISO8528 Part 1 Class G3 | ||
| Other | Random frequency variation | ± 0.50 | % | |
| Other | Telephone Influence Factor (TIF) | < 50 | per NEMA MG1-22.43 | |
| Other | Telephone harmonic factor (THF) | < 3 | ||
| Other | Telephone influence factor (TIF) | < 50 per NEMA MG1-22.43 | ||
| Pressure | Actual Exhaust Back Pressure with CPG Sound level 2 Enclosure Muffler | 10 (40.19) / 9.9 (39.78) | kPa (in H2O) | standby / prime |
| Pressure | Actual Exhaust Back Pressure with CPG Weather Enclosure Muffler | 8.4 (33.76) / 7.8 (31.47) | kPa (in H2O) | standby / prime |
| Pressure | Maximum Air Cleaner Restriction with Clean Filter | 3.7 (15) | kPa (in H2O) | clean filter |
| Pressure | Maximum Back Pressure | 10 (40.19) | kPa (in H2O) | standby and prime ratings |
| Pressure | Maximum Cooling Air Flow Static Restriction | 0.12 (0.5) | kPa (in H2O) | |
| Pressure | Maximum Fuel Inlet Restriction with Clean Filter | 127 (5.0) | mm Hg (in Hg) | clean filter |
| Pressure | Maximum air cleaner restriction | 3.7 | kPa | |
| Pressure | Maximum air cleaner restriction with clean filter | 3.7 | kPa | with clean filter |
| Pressure | Maximum back pressure | 10 | kPa | |
| Pressure | Maximum cooling air flow static restriction | 0.12 | kPa | |
| Pressure | Maximum fuel inlet restriction with clean filter | 127 | mm Hg | with clean filter |
| Pressure | Maximum return restriction | 152 | mm Hg | |
| Speed | Frequency regulation | Isochronous | ||
| Speed | Overspeed limit | 2100 | rpm | |
| Speed | Overspeed limit | 2250 | rpm | |
| Speed | Piston Speed | 7.44 (1464) | m/s (ft/min) | |
| Speed | Random frequency variation | ± 0.25 | % | |
| Speed | Random frequency variation | ± 0.25% | % | |
| Speed | Rated Speed | 1800 | rpm | |
| Temperature | Exhaust Temperature | 512.22 (954) / 484.44 (904) | °C (°F) | standby / prime at set rated load |
| Temperature | Maximum Temperature Rise above 40 °C Ambient (single phase) | 120 | °C | 40 °C ambient |
| Temperature | Maximum Temperature Rise above 40 °C Ambient (three phase, BB94-2/BB95-2/BB92-2/BB85-2/BB93-2) | 105 | °C | 40 °C ambient |
| Temperature | Standard temperature rise | 150 | °C | Standby at 40 °C ambient |
| Voltage | Random voltage variation | ± 0.5 | % | |
| Voltage | Random voltage variation | ± 0.5% | % | |
| Voltage | Random voltage variation | ± 1.0 | % | |
| Voltage | Voltage regulation, no load to full load | ± 1% | % | |
| Voltage | Voltage regulation, no load to full load | ± 1.0 | % | no load to full load |
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 | Number 2 diesel fuel | Direct injection; single element, 10 micron filtration, spin-on fuel filter with water separator; automatic electric fuel shutoff |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
The Cummins/Onan qsb7g5nr3 engine has an oil capacity of 17.5 liters.
The Cummins/Onan qsb7g5nr3 has a displacement of 6.7 liters with 6 cylinders.
The Cummins/Onan qsb7g5nr3 powers 8 generator set(s), including Cummins/Onan C125 D6D, Cummins/Onan C150 D6D, Cummins/Onan C175 D6, Cummins/Onan C200 D6, Cummins/Onan DSGAA.