HomeCummins/OnanCummins/Onan DQCB

Cummins/Onan DQCB Generator Set

The Cummins/Onan DQCB is a 750 kW (938 kVA) Diesel standby generator set powered by a Cummins/Onan QSK23 engine. It is available at 110/190 V, 127/220 V, 230/380 V, 277/480 V, 115/200 V, 139/240 V, 240/416 V, 347/600 V and 120/208 V, A (U), B (V), C (W), 60 Hz and rated 600 A. It holds about 12 L (3.2 gal) of oil and 109.5 L (28.9 gal) of coolant, with a maximum ambient rating of 50 °C. Starting uses 1 group-6 battery rated 1400 CCA at 24 V. The set measures 4395.4×1855.5×2065.7 mm (173.0×73.1×81.3 in), weighs about 6075 kg (13393 lb) and produces 75 dBA at 7 m. An integrated tank holds 120 L (31.7 gal), roughly 8 hours of runtime.

750 kW
Standby
23.0 L
Displacement
12.0 L
Oil capacity
2
Document types

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

Typical fuel consumption for 600–605 kW Diesel generators →

Compare with other 600–605 kW Diesel generators →

Service parts for the DQCB

Grouped by system, with how many of each the parts manual calls for.

Air intake

1 required

Fuel system

1 required
FS1006Fuel filter$29.99eBay

Oil system

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

FuelDiesel
Frequency60.0 Hz
Standby power750 kW
Standby kVA938
Prime power680 kW
EmissionsA−N
ControllerPowerCommand, PowerCommand 2100
Oil capacity12.0 L
AlternatorStamford/AvK HC634 (4-pole, Class F insulation)
Voltage options110/190 V, 127/220 V, 230/380 V, 277/480 V, 115/200 V, 139/240 V, 240/416 V, 347/600 V, 120/208 V
PhaseA (U), B (V), C (W)
Rated current600 A
Power factor0.8
Circuit breaker600 A
Battery group6L
Battery cranking1400 CCA
Battery voltage24 V
Battery quantity1
Coolant capacity109.5 L
Max ambient50 °C
Dimensions (L×W×H)4395×1855×2065 mm
Dry weight6075 kg
Wet weight6337 kg
Sound level75.0 dBA @ 7 m
Fuel tank120.0 L
Tank runtime8 hr

Engine

Cummins/Onan QSK23
Oil capacity12.0 L
Coolant capacity12.0 L
Displacement23.0 L
AspirationTurbocharged
Rated speed1500 rpm

Maintenance & consumables

for the Cummins/Onan QSK23
ItemSpecCapacityPart #Interval
Air filterAF25544AF25544 Amazon $1537.19 eBay $285.93
Fuel filter(1) primary element AF25544; (1) secondary element AF25545, (2) Cummins Filtration FS1006500 hr
Fuel filterFS1006FS1006 Amazon $33.95 eBay $29.99
Oil filterCummins QuickServe® CommitmentLF9325250 hr Amazon eBay $127.04 KuduParts $74.00
Battery24V, 1400 CCA, 460 minutes reserve capacity500 hr
BeltSteel, flanged; Stainless steel flex, NPT15000 hr
CoolantAntifreeze 50/50 (Ethylene glycol)24000 hr
Coolant filterCummins Filtration WF2076500 hr
OilCummins QuickServe® Commitment250 hr
Spark plug500 hr

Common questions

What size generator is the Cummins/Onan DQCB?

The Cummins/Onan DQCB is rated 750 kW standby (938.0 kVA).

What engine is in the Cummins/Onan DQCB?

The Cummins/Onan DQCB is powered by the Cummins/Onan QSK23 engine.

What kind of fuel does the Cummins/Onan DQCB run on?

The Cummins/Onan DQCB runs on Diesel.

What's the oil capacity on a Cummins/Onan DQCB?

The Cummins/Onan QSK23 engine in the Cummins/Onan DQCB has an oil capacity of 12.0 liters.

What alternator does the Cummins/Onan DQCB use?

The Cummins/Onan DQCB uses a Stamford/AvK HC634 alternator. It has 4 poles. Insulation class F.

Which oil filter part number does the Cummins/Onan DQCB take?

The Cummins/Onan DQCB uses oil filter part number LF9325.

What fuel filter does the Cummins/Onan DQCB use?

The Cummins/Onan DQCB uses fuel filter part number FS1006.

What air filter does the Cummins/Onan DQCB use?

The Cummins/Onan DQCB uses air filter part number AF25544.

Troubleshooting

6

Fault codes

CodeMeaning
121Speed Signal Lost
135Oil Pressure Sensor High
141Oil Pressure Sensor Low
143Pre-Low Oil Pressure Sensor
144Coolant Temperature Sensor High
145Coolant Temperature Sensor Low

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan DQCB troubleshooting guide (53 entries) →

Parts

14
Part #DescriptionQtySystem
501-0876Line, Fuel Cooler Return (Bearward Cooling System, not shown)1Hose Amazon eBay
501-0877Line, Fuel Supply (Engine Accessories group)1Hose Amazon eBay
501-0892Line, Fuel Cooler Supply (Bearward Cooling System, not shown)1Hose Amazon eBay
503-1675Hose, Reducer (Air Cleaner group)1Hose Amazon eBay
503-2754-01Hose, Oil1Hose Amazon eBay
A053A190Hose, Oil (Valve group)1Hose Amazon eBay
A055E534Switch, Level (low coolant level warning)1Sensor Amazon eBay
A059Z452Seal, O Ring (Valve group)1Seal Amazon eBay
AF2559300Element, Replacement (Cummins Filtration Part Number)1Air filter Amazon eBay
140-1548Indicator, Service2Service part / kit Amazon $29.99 eBay $49.99
204-009Acronyms and AbbreviationsService part / kit Amazon eBay
3822735Plastic bead blasting media1Service part / kit Amazon eBay
4021375QSK23 Troubleshooting and Repair Manual1Service part / kit Amazon eBay
KS-E368RHead OfficeService 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

RatingLoadL/hgal/h
Prime138.236.5
Prime25%56.815.0
Prime50%94.625.0
Prime60%12.03.2
Prime100%181.748.0
Standby25%60.616.0
Standby50%12.03.2
Standby75%151.440.0
Standby100%193.151.0

Available documents

Spec sheet — Cummins-750-kW-DQCB QSK23 (Cummins/Onan)Spec sheet — s-1551 (Cummins/Onan)Parts manual — 0961-0204 I17 201605 (Cummins/Onan)Parts manual — A056J197 I12 202505 (Cummins/Onan)
Full service, cheapest listings

Priced items from this model's own parts manual.

Air filter AF25544$285.93
Fuel filter FS1006$29.99
Oil filter LF9325$127.04
3 priced items$442.96