Atlas Copco GA 250 VSD (FF) Oil-injected Air Compressor

The Atlas Copco GA 250 VSD is the largest variable speed drive model in the Atlas Copco GA 160+-315 (VSD) series of oil-injected rotary screw compressors. It covers a working pressure range from 5 to 10 bar(e) and delivers between 211 and 900 l/s of free air delivery, with 250 kW of installed motor power at 50 Hz. Where air demand stays around the clock, the fixed-speed Atlas Copco GA 250 Oil-injected Air Compressor remains the simpler reference.

Every unit arrives as an all-in-one package. The VSD compressor element, gear-driven transmission, coolers, motor, and Elektronikon controller are mounted on a structural skid inside a silenced canopy. An oil-containing frame comes as standard, so the machine does not need a separate foundation, and ducting connections can be arranged with flexibility on site.

GA 250 VSD Technical Specifications

At 50 Hz the installed motor power is 250 kW for both versions. Unit performance is measured according to ISO 1217, Annex C and E, Edition 4 (2009), at an absolute inlet pressure of 1 bar and an intake air temperature of 20°C.

At 60 Hz the installed motor power is 335 hp across both versions. Weight depends on the version: the GA 250 VSD weighs between 5255 and 6301 kg over its Standard and Full Feature configurations.

Dimensions and Weight

Integrated VSD Technology

The GA 250 VSD follows air demand by automatically adjusting motor speed. Tests show average energy savings of up to 35% compared with fixed-speed operation, and the total life cycle spending on a compressor drops by an average of 22%. Even installations with a stable demand profile save energy with VSD.

The integrated design keeps the net pressure band within 0.10 bar (1.5 psi), so downstream processes see a steady supply. Flexible pressure selection from 4 to 13 bar through electronic gearing trims electricity consumption, and the specific converter and motor design holds efficiency across the whole speed range. All Atlas Copco GA VSD compressors are EMC tested and certified, so compressor operation does not influence external equipment and vice versa.

The frequency converter sits in a cool overpressure cubicle with a cooling booster, which keeps electrical components stable in ambient temperatures up to 50°C (122°F). The whole package is engineered and tested to run without vibration or noise gaps across the entire frequency range, an issue that external VSD solutions often cannot avoid.

Core Design Features

High-efficiency motor

The TEFC IP55 motor uses Class F insulation with temperature rise B, protecting it against dust and chemicals. It supports continuous operation in ambient temperatures up to 55°C (131°F), with 46°C (115°F) as the standard rating.

Screw element and transmission

Inside the element, an asymmetric rotor profile works with carefully selected bearings to keep wear low. The gear-driven transmission is maintenance-free, totally enclosed, and protected against dirt and dust, holding the element in its optimal working range. A Bowex coupling absorbs the thrust load and adds reliability.

Air intake filter

The superior air intake filter removes 99.9% of dirt particles larger than 3 μm. This cuts the dust load reaching the fine filter, doubling the filter element lifetime without reducing filter efficiency.

Service access

All service parts sit behind large opening doors, and a unique sliding system gives access to the oil coolers. Long-lifetime consumables stretch service intervals, and Roto-Xtend Duty fluid with an 8000-hour change interval is available as an option.

Air Quality and the GA 250 VSD FF

The GA FF (Full Feature) version adds an integrated refrigerant dryer that guarantees a pressure dewpoint of +3°C (37°F). All wires and pipes come assembled from the factory, and the dryer performs at ambient conditions up to 46°C (115°F). A patented Saver Cycle Control stops the dryer when the compressor stops or unloads, then restarts it when the dewpoint begins to rise.

An integrated water separator with electronic drain comes as standard and removes 100% of condensate. Air quality over the range:

Control and Monitoring

The Elektronikon unit controller manages both the compressor and the integrated converter. Its high resolution color display shows running conditions in plain readings, and clear icons give fast access to all important settings. Warning indications, maintenance scheduling, and online visualization of the machine status are built in, with support for 31 different languages. Remote functions work over Ethernet as standard, and SMARTLINK is available for central data monitoring.

For multi-machine rooms, the ES system controller watches over the whole compressed air network from a single point. The Elektronikon can also hold two different system pressure bands, and the Delayed Second Stop function runs the drive motor only when needed, keeping energy use low during periods of reduced demand.

Energy Recovery

Compression heat normally escapes through the coolers, but the integrated energy recovery system on the GA 250 VSD can return up to 94% of the compressor shaft power as useful heat. The recovered energy leaves the package as hot water at 85°C to 90°C (185°F to 194°F), ready for space heating, showers, steam boilers, or process use. The main heat exchanger module is built into the compressor, so linking it to an existing water circuit takes modest investment. Warm air heat recovery through ducting offers a simpler route for workshops and warehouses, with motorized louver flaps available to control airflow across seasons.

Where the GA 250 VSD Works

Mining operations run the GA 250 VSD around the clock and value its high reliability in harsh conditions. Energy industry sites use it to protect downstream equipment, since the integrated water separator and stable pressure extend component lifetime. Metal industry plants gain from quick installation, flexible ducting, and economical servicing through accessible components and long service intervals. In general industry, the machine covers machinery operation, plant maintenance, cleaning, pneumatic tools and controls, and sand- and shot-blasting.

GA 250 VSD FAQ

What pressure versions does the GA 250 VSD come in?
At 50 Hz there are two versions: 8.5 bar and 10 bar. At 60 Hz the same two versions are rated 8.6 bar (125 psi) and 10.4 bar (150 psi).

How much air does it deliver?
Capacity FAD spans from 211 l/s at minimum speed to 900 l/s at full speed on the 8.5 bar version, so one machine can follow a wide demand profile.

What is the difference between Standard and FF?
The FF (Full Feature) configuration adds an integrated refrigerant dryer with a +3°C pressure dewpoint and an electronic condensate drain. FF units on the 50 Hz 8.5 bar setting deliver slightly less air at maximum speed.

Can it replace a fixed-speed compressor on stable loads?
Yes. The manufacturer states that even the roughly 8% of installations with stable demand still save energy with VSD, so the machine suits both fluctuating and steady profiles.

Does it need a special electrical room for the converter?
No. The frequency converter is pre-mounted in a cooled overpressure cubicle on the machine itself, rated for ambient temperatures up to 50°C.

Which industries suit this machine best?
Mining, energy, metal, and general industry are the segments named for the series, from around-the-clock mining duty to plant maintenance and shot-blasting.