The Atlas Copco QAS 125 JD T4F generators are prime power, multi-voltage, sound attenuated, mobile generators. They are powered by a John Deere T4 Final liquid-cooled, four-cylinder diesel engine.

The units consist of an alternator, diesel engine, cooling system, electrical distribution and control systems - all enclosed within a sound attenuated enclosure fabricated from powder coated steel with zinc rich primer. 6000 hour salt spray tested. A broad range of undercarriage formats and options are available. Special attention has been given to the overall product quality, user friendliness, ease of serviceability, and economical operation to ensure best in class total cost of ownership.

All QAS generators include the latest Tier 4 Final engine and have a footprint that is up to 20 percent smaller than the previous generation. The starting mechanism ensures that stable power is achieved in less than six seconds.

View and/or Download QAS 125 JD T4F: Datasheet / Brochure



  • Compact, sound attenuated, corrosion resistant, with single point lifting and 110% fluid containment
  • Available as a skid mounted unit with forklift pockets, or on a single axel trailer
  • Heavy Duty alternator with AREP excilation and marine grade protection
  • "DeepSea" controller
  • Single side servicing with long run filters and 500 hour service intervals
  • Extremely reliable and durable John Deere 4045 engine with DOC & SCR after-treatment and 5 year limited warranty
  • Identical enclosures and maintenance points between both models
  • Emergency Stop
  • Remote Start / Stop


  • Extremely durable and environmentally sensitive designed to be used for everything from the oil patch to special event power
  • Versatility, giving you the flexibility to match your machine to the correct application
  • Start-up power for the most demanding sites with 300% over load starting capabilites
  • Reliable and intuitive controls for ease of use and diagnostic capabilities
  • Heavy duty oil, air and fuel filters extend themaintenance interval to 500 hours for reduced total cost of ownership
  • Reduces maintenance costs with long intervals easy access for mechanics
  • Proven engine platform with high reliability, a simple maintenance free Diesel Oxidization Catalyst onlyafter treatment
  • Reduces stock of service kits and inventory of parts withrental ROI kept in mind
  • External, recessed emergency stop for increased safety
  • Allows connection as a critical back-up unit via a 2 wire dry contact connection in the distribution panel


Performance  Units QAS 95 JD 
Frequency  Hz  60 
Rated prime power 3ø 600V  kW/kVA  100 / 125 
Rated standby power 3ø 600V  kW/kVA  110 / 137
3ø Power factor    0.8 
3ø Voltage in 600V switch position (series star w/neutral)  600Y / 347 
Amp capacity @600V  120
3ø Voltage in 480V switch position (series star w/neutral)  480Y / 277 
Amp capacity @480V  120
3ø Voltage in 240V switch position (parallel star w/neutral)  240YY / 139 
Amp capacity @240V  240
3ø Voltage in 208V switch position (parallel star w/neutral)  208YY / 120 
Amp capacity @208V  240
Rated prime power 1ø  kW/kVA  52 / 52
1ø Power factor   
1ø Voltage in 120-240V switch position (Zig-Zag)  240 / 120 
Amp Capacity @240V  216
Amp Capacity @120V  216 x 2 
Main breaker - Rated Current in  400 
Power distribution - Terminal board    5 Wire (L1, L2, L3, N, Ground) 
Terminal board connections    Bare Wire Terminals 
Maximum terminal cable size    350MCM 
Convenience receptacles    2 x NEMA 5-20R 

& 2 x 125/250V 50A CS6364 

Max. sound pressure level (LPA) @23' @75% Load 

dB(A)  72
Fuel consumption  Units QAS 95 JD

Fuel tank capacity UN31A



Fuel consumption at full load (PRP)

gal / h


Fuel autonomy considering 90% of fuel capacity



Alternator   QAS 125 JD
Model   Leroy Somer 44.3 S5

Excitation system


AREP (auxiliary winding)

Automatic voltage regulator (+/-0.25%)   Leroy Somer R438
Insulation   Class H

Engine  Units QAS 125 JD
Model    John Deere 4045 HFG04 
US EPA Family    HJDXL0.4.5311
US EPA Tier    Tier 4 Final
Displacement  L 4.5 
Cylinders    4
Continuous engine output  hp 157
Gross engine power output  hp 172
Speed  rpm 1800
Engine control    ECU
Aspiration   Turbo w/ Intercooler
Engine oil capacity  US gal 5.4
Engine coolant capacity  US gal 2.25
Max. ambient temperature (@Sea Level)  ºF  122
Min. starting temperature (w/o Cold weather options)  ºF  0
Minimum starting temperature (w/Cold weather options)  ºF  -4
Electrical system (Negative ground)  V 12
Engine alternator output  A 90
Battery Capacity (Cold Cranking Amps)  A 1100

Applications & Use Cases


Construction site with QAS 40 and XAS 97

Generators can supply power to temporary structures and construction equipment that require electricity to operate. The QAS 125 Portable Generator is suitable for less complex projects such as small road construction, single family houses, and low-rise apartments.


Winter campaign light tower and portable generator top banner

Outdoor events such as festivals, sporting events, and the like depend on high-performing generators to keep the function running smoothly. Easy-to-use interface and water-resistant design ensure inclement weather or poor handling will not impede the event.


QAS 150 ESF mobile diesel generator

Natural disasters and inclement weather are the main causes of power outages. Protect yourself against an outage with our QAS 125 Generator. With an intuitive system controller, you have advanced warning and alert parameters for added safety.

Applications & Use Cases

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