Light Commercial Diesel
125kW liquid-cooled standby generator, Diesel. Clinics, restaurants, data closets, cold storage, multi-tenant retail and small industrial.
The C125D6D is a diesel standby set, supplied open with no enclosure, so it is intended for a generator room, roof well, or a yard where you provide your own housing. It weighs 2586 lb and measures 113 x 40 x 56 inches.
Diesel gives you the highest power density and fuel you can store on site, independent of the gas utility - the usual choice when the load is large, the runtime requirement is fixed, or code requires on-site fuel.
Units at this size are specified against your electrical service, switchgear and fuel arrangement, so they are quoted per project rather than listed at a shelf price.
The five items above are part of the installation quote, not the equipment price.
Reserve this unit — (214) 957-4307Refundable deposit · locks this price 90 days · schedules your free survey · applies 100% to final invoice
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| Model | Cummins C125D6D |
|---|---|
| Rated output | 125 kW |
| Fuel | Diesel |
| Cooling | Liquid-cooled |
| Enclosure | Open — no enclosure |
| Weight | 2586 lb |
| Dimensions (L×W×H) | 113 x 40 x 56 in |
| Voltage configurations | 120/240 1Ph |
| Extreme cold package | Available as an upgrade |
| Transfer switch | Sold separately, sized to your service |
| Application | commercial |
| Standby rating | 125 kW / 156 kVA |
| Prime rating | 113 kW / 141 kVA |
| Engine | QSB7-G5 |
| Alternator | UC3E |
| Emissions | EPA Tier 3 |
| Enclosure options | Available open, or in a Sound Attenuated Enclosure Level 1 or Level 2. A Level 1 to Level 2 upgrade kit exists. |
| Rated speed | 1800 rpm |
| Controller | PowerCommand 1.1 |
| Certifications | NFPA 110 Level 1 compliance, FCC 47 CFR part 15 class A and B |
| Warranty | 2 year / 400 hour base warranty. 3 year and 5 year standby warranty options are available. |
This model ships in a single factory configuration.
| Part number | Voltage | Phase | Price |
|---|---|---|---|
| A060A344 | 120/240 | 1Ph | — |
This model is quoted directly rather than listed. Part numbers are shown so you can confirm exactly what you are being quoted.
Built in
Diesel is stored on site, so the set is independent of the gas utility entirely. For a clinic, a restaurant, cold storage or a data closet that independence is usually the whole reason for choosing diesel.
Half the engine speed of a residential air-cooled unit. Fewer revolutions per running hour is why these are specified where the set may run for days rather than minutes.
Digital governing, voltage regulation, alarm and status monitoring, with auto-shutdown on fault detection and NFPA 110 Level 1 compliance.
Diesel degrades, absorbs water and grows biological contamination if it sits. A set that runs rarely needs its fuel maintained, not just topped up — which is part of what a service visit covers.
Accessories and maintenance parts for this unit →
Specifications on this page are taken from the Cummins published specification sheet for
the air-cooled Connect range.
Download it from Cummins →
Pairs with
The switch is sized to your electrical service, not to the generator. These are the families that typically apply at this output — we confirm the exact one at the survey.
The C125D6D is quoted per project rather than listed at a shelf price. Units at this size are specified against your electrical service, switchgear and fuel arrangement, so a shelf number would be meaningless. Tell us the application and we will put equipment and installation in writing together.
Commercial standby power for facilities with substantial motor and HVAC load. Final confirmation comes from a load calculation against your actual panel, which we do at the survey.
Yes. A standby generator cannot be code-compliantly connected without an automatic transfer switch - it is what keeps your generator from backfeeding the utility line and endangering line crews. The switch is sized to your electrical service, not to the generator, so we confirm your service size at the survey before specifying it.
Availability changes weekly. A refundable deposit reserves a specific unit and locks the equipment price for 90 days, which is the practical way to hold one while the survey and permit work happen. If we cannot source it in a reasonable window, you get the deposit back.
Compare
Liquid-cooled · Diesel
Units at this size are specified against your electrical service, switchgear and fuel arrangement, so they are quoted per project rather than listed at a shelf price.
View detailsLiquid-cooled · Diesel
Units at this size are specified against your electrical service, switchgear and fuel arrangement, so they are quoted per project rather than listed at a shelf price.
View detailsLiquid-cooled · Diesel
Units at this size are specified against your electrical service, switchgear and fuel arrangement, so they are quoted per project rather than listed at a shelf price.
View detailsThis model is quoted directly. Tell us the application and we will put equipment and installation in writing together.
