Atlas Copco Oil Lubricated Rotary Screw Air Compressor

Model GA11 – 30+ (GA11-30+ and GA15-26)

Standard Scope of Supply

The GA 11-30+ is a state-of-the-art air- or water cooled, silenced, rotary compressor with extended monitoring capabilities. They are industry leading in free air delivery and specific energy requirement, setting the standard in the oil-injected rotary screw air compressor technology.

The compressor package includes a direct driven, superior rotary screw compression element, driven by a high efficient, totally enclosed fan cooled motor, an integrated lubrication and cooling system and an integrated oil/water separator built into a sound-insulated bodywork where noise levels are minimized. The silencing enclosure allows the possibility to have a workplace compressor next to the point of use, minimizing the installation costs and maximizing energy efficiency.

These compressors are equipped with the Atlas Copco Elektronikon® Graphic controller, to control and monitor the compressor in the most efficient and reliable way.

GA11-30+ Full Feature

The GA 11-30+ Full Feature are additionally provided with an air dryer which removes moisture from the compressed air by cooling the air to near freezing point and automatically draining the condensate.

Designed for extreme running conditions

The GA has been designed to operate continuously in the most extreme running conditions. All rotating components are totally enclosed and protected against contamination to ensure long and reliable operation. The compressor cooling system is sized to run perfectly in ambient temperatures up to 46°C/115°F and high ambient versions up to 55°C/131°F.

Superior efficiency ensuring lowest operating costs

Designed to meet the highest levels of reliability, energy efficiency and air quality, the compressor package includes following main features:


Heavy duty oil filtration system
oilAssuring continuous uptime, the compressor is delivered with a 12 micron oil filtration system for extremely clean oil. This ensures maximum reliability, long service intervals and lifetime

  • Long lifetime of internal components
  • Long service intervals and easily accessible
  • Protecting the compressor element, bearings and gears in the harshest operating conditions

Peace of mind using intelligent controls

elektronikonThe Atlas Copco Elektronikon® compressor control and monitoring system uses advanced algorithms for maximum reliability. The controller can handle 32 languages facilitating communication

  • Elektronikon® Graphic installed as standard, which can save energy with features like dual pressure band and week-timer functionality
  • Comprehensive, pro-active maintenance display
  • User-friendly, intuitive navigation system

Forced cooling of electrical cubicle

coolingAll cubicles are equipped with an electrical cubicle fan, including a filter, ensures the optimal working temperature

  • Extra filtration eliminates environment dust in the electrical cabinet, to increase the components lifetime
  • Extra cooling of the cubicle keeps the temperature low, having the electrical components working in optimal temperatures


State-of-the-art rotary screw element
screw_elementPatented, in-house designed oil injected rotary screw elements with the latest Atlas Copco asymmetric rotor profile designed for the optimum combination of maximized free air delivery for the lowest power consumption

  • Extended lifetime
  • Precise oil injection for the highest performance at the lowest element temperatures and minimal losses
  • Designed for low wear and tear, thanks to the selection of high quality materials

Most efficient transmission and drive system

All compressors are equipped with a Y/D starter, to lower transmission losses and smooth starting


  • IE3 Efficiency class (50Hz)
  • NEMA PREMIUM Efficiency (60Hz)
  • Maintenance free, eXtreme duty gearbox drive resulting in lower drive end bearing temperature and longer bearing lifetime
  • Direct gear-driven high performing element eliminating coupling losses and maintenance
  • TEFC, IP55 Leroy Somer motor enclosure
  • Class F insulation, B temperature rise


Heavy duty air inlet filter
To protect the compressor components from wear, even in the harshest environments, a heavy duty air inlet filter is integrated in the package, ensuring

  • Long lifetime of internal components
  • Two steps of dust removal
  • Premium filtration of particles > 3µm with an efficiency of 99.9%
  • Long service intervals
  • Equipped with differential pressure service indicator as standard

Protecting your production process

The integrated high efficient cooling system with air/oil separator ensures a low residual oil content in the, free of liquid condensate, compressed air

  • Separate oil- and after cooler, to optimize the cooling for both media, resulting in low air outlet temperatures and less oil carry-over
  • EWD330M no-loss drain installed as standard to remove condensate (no corrosion due to free condensate) effectively without wasting compressed air

Minimized installation work

The compressor packages are completely pre-wired and assembled to minimize the installation work onsite.

  • Easy ducting installation due to cool canopy concept (single cooling air inlet/outlet location)
  • Integrated refrigerant dryer (FF compressors), mechanically and electrically connected (no extra power supply required)

Working principle


The air system

The air is drawn into the compressor through the inlet filter (1) and is compressed in the oil injected rotary screw compression element (3) via the air intake (load-unload) valve (2).

Lubrication fluid is injected into the air and the air / oil mixture passes through a non-return valve (4) to the oil separator element (5).

The air then passes through a minimum pressure valve (6) and is cooled by an air- or water cooled after cooler (7).

The condensed moisture is removed by an integrated low pressure drop moisture separator and electronic condensate drain (9) and the compressed air is released to the main piping.

The oil system

Lubrication fluid contained in the oil receiver (5) flows under differential pressure to a thermostatic bypass valve (13), air- or water cooled oil cooler (12), high efficiency oil filter (14) and oil stop valve (15) before being injected into the compression element (3) where it cools, seals and lubricates the compression process.

The high efficiency oil filter (14) provides superior filtration compared to conventional filters resulting in cleaner lubricant. The thermostatic bypass valve (13) ensures that the compressor quickly reaches optimum operating temperature on start-up and maintains temperature during periods of low load by allowing cold lubricant to bypass the oil cooler.

A low noise radial cooling fan (for air cooled compressors) provides cooling air to the oil cooler (12) and after cooler (7), ensuring satisfactory running temperatures as well as ventilating the compressor enclosure.

Control system

To control these compressors, they are as standard equipped with a control cubicle containing:

  • Fan motor overload relay(s)
  • Motor Y/D starter with overload relay
  • Transformers
  • Plexiglass screen protection (in case copper bars are exposed)
  • Start-stop button and isolator switch
  • Elektronikon® Graphic control, regulation, safety and indication panel
  • All wiring

Elektronikon® Graphic with compressor visualization:

Graphic_ControllerThe next-generation Elektronikon® operating system offers a wide variety of control and monitoring features that allow you to increase your compressor’s efficiency and reliability thanks to the many embedded advanced control algorithms.

Thanks to the built in clock function, also a timer based start/stop function and the dual pressure band functionality will increase the savings generated with the Elektronikon® Graphic controller.

DisplayThe compressor controller comes with a graphical 3.5 inch high definition colour display with clear pictograms and self-explaining navigation and has the possibility to switch between 32 different languages for operators ease of use.

As standard, this module offers an internet based compressor visualization using the Ethernet (hard wired) connection. When connected to a wireless network, the same visualization is available through iOS or Android operated mobile devices.

Standard scope of supply

  • Structural base frame with integrated forklift slots
  • Sound enclosure for indoor use, even at point of use
  • Heavy duty air inlet filter, with differential pressure indicator
  • Air intake valve for load/unload control
  • High efficient, TEFC (IP55) main drive motor
  • A maintenance free, eXtreme duty gearbox drive
  • State-of-the-art, single stage oil injected rotary screw compressor element
  • Integrated oil circuit with heavy duty oil filters
  • Elektronikon® control and monitoring system
  • All alarm and safety devices connected to the controller
  • All piping connections located at convenient locations
  • EMC compliant, pre-wired control panel with integrated Y/D starter
  • After cooler with integrated water separator for 100% condensate removal
  • Oil and aftercooler, with radial fan rotating at low speed
  • Air/oil separator with 3 step separation process for low residual oil content (< 2 ppm) in the compressed air
  • Integrated safety valve on air/oil separator
  • Roto-Inject Fluid (50Hz) / Roto-Xtend Duty (60Hz) oil
  • Remote monitoring and connectivity


Design Features

Optimum cooling module for environments up to 46°C / 115°F

Ultimate reliability in the most extreme operating conditions,
guaranteeing extended lifetime

High efficient (IE3 or NEMA PREMIUM) main drive motor (TEFC) driving the most efficient compressor element

Excellent efficiency for the
lowest energy consumption.
Resistant to the harshest atmospheric contaminants

A maintenance free, eXtreme duty gearbox drive

Low drive maintenance cost
Lower drive end bearing temperatures resulting in longer bearing lifetimes

Meticulous selection of parts,
no need for special tools,
optimal lubricating fluid

Lowest maintenance costs,
easy serviceability
long service intervals

Packaged, silencing enclosure,
with all inter-connecting piping
and wiring

Easy and quick installation, commissioning and start up,
Minimal installation costs.

Low noise level

Rigid base frame with
integrated forklift slots

Saving transports costs;
facilitating movement by the use of a forklift truck.

Intelligent control system
communicating in your personal language

The user-friendly, intuitive navigation system will contribute to a low training costs
of your operating people

Tighter pressure control minimises energy consumption

Variety of optional features

Ability to customize a compressor for particular application requirements