Description
The Atlas Copco GA 11 VSD is the 11 kW member of the GA 7-75 VSD+ platform, the variable speed family that Atlas Copco built around an upright vertical layout and an oil-cooled interior permanent magnet motor. The inverter adjusts the motor speed continuously, so the delivered air follows the demand of the plant instead of the load/unload cycle of a fixed speed machine.
Four pressure settings from 5.5 to 12.5 bar(e) cover the common industrial networks with a maximum working pressure of 13 bar(e), and the flow window reaches from 7.3 to 32.9 l/s between idle and full speed. With a standard package of 196 kg and a sound level of 63 dB(A), the GA 11 VSD serves workshops that need more air than an entry machine delivers but have no room for a conventional horizontal compressor.
The economics of this machine rest on the hours between load phases. When the workshop pauses, the drive slows the GA 11 VSD to an idle of about 7.3 l/s instead of consuming full power unloaded, and the average energy saving of 50 percent against fixed speed operation comes directly from those hours. The lifecycle cost of the compressor falls by about 37 percent on the same account, because energy dominates the total cost of owning an air compressor.
Where the GA 11 VSD Fits in the Oil-Injected Range
Atlas Copco places the GA 11 VSD in the small GA 7-15 VSD+ group, one step above the GA 7 VSD and one below the GA 15 VSD. Plants that have outgrown a 7.5 kW unit, or that run two small compressors in a cascade, consolidate onto this single modulating machine with a flow window wide enough to cover both. The oil-injected design keeps the element lubricated and sealed by the oil film itself, which suits the general industrial duties of the 11 kW class, and the 5.5 bar(e) setting extends the reach to networks that run at moderate pressure.
What the VSD and FF Names Cover
The VSD part of the name refers to the variable speed drive: the frequency inverter in the VSD+ cubicle adjusts the motor speed so delivered air matches the demand curve of the plant at every moment. The FF suffix marks the Full Feature branch, which adds a refrigerant dryer and a second electronic no-loss drain inside the same upright frame. Both branches share the element, the motor and the control platform, so the treatment level can be raised later without changing the installation.
The Vertical WorkPlace Layout
The GA 11 VSD shares the patented vertical layout of its family, which turns the conventional horizontal compressor on its end. The footprint drops by up to 60 percent against a comparable horizontal unit, service points gather at the front of the machine, and the short oil and air paths inside the frame reduce pressure losses. A machine bay, a corner of the workshop or a niche beside the production line accepts the GA 11 VSD without any civil work.
Technical Specifications of the GA 11 VSD
The table below condenses the GA 11 VSD into its headline figures:
| Parameter | Value |
|---|---|
| Installed motor power | 11 kW / 15 hp |
| Working pressure settings | 5.5, 7, 9.5, 12.5 bar(e), maximum 13 bar(e) / 188 psig |
| Free air delivery | 7.3 to 32.9 l/s (15.5 to 69.7 cfm) |
| Noise level | 63 dB(A) |
| Weight, standard / Full Feature | 196 kg / 280 kg |
| Dimensions, Full Feature | 985 mm wide, 630 mm deep, 1420 mm high |
FAD Across the Four Pressure Settings
Each pressure version covers a wide flow window because the drive modulates between a low idle and full speed. The figures below apply to the GA 11 VSD in its four settings:
| Working pressure | FAD min-max (l/s) | FAD min-max (m³/h) | FAD min-max (cfm) |
|---|---|---|---|
| 5.5 bar(e) / 80 psig | 7.3 – 32.9 | 26.3 – 118.4 | 15.5 – 69.7 |
| 7 bar(e) / 102 psig | 7.3 – 32.5 | 26.3 – 117.0 | 15.5 – 68.8 |
| 9.5 bar(e) / 138 psig | 7.0 – 27.2 | 25.2 – 97.9 | 14.8 – 57.6 |
| 12.5 bar(e) / 181 psig | 7.6 – 23.5 | 27.4 – 84.6 | 16.1 – 49.8 |
The figures apply to the 50/60 Hz version of the machine. Unit performance is measured according to ISO 1217, annex E, edition 4:2009, and the FAD of the GA 7-15 VSD+ models is measured at the effective working pressures of 5.5, 7, 9.5 and 12.5 bar(e). The maximum working pressure of the platform is 13 bar(e) / 188 psig. The noise level of 63 dB(A) is the mean value measured at a distance of 1 m according to ISO 2151:2004 using the ISO 9614/2 sound intensity method, with a tolerance of 3 dB(A).
Dimensions and Weight
The standard package of the GA 11 VSD measures 610 mm wide, 630 mm deep and 1420 mm high, and the Full Feature branch widens to 985 mm to house the integrated dryer while depth and height stay unchanged. The package weighs 196 kg and the Full Feature branch 280 kg, figures it shares with the GA 7 VSD and the GA 15 VSD on the same small frame. The upright layout stands tall rather than long, so the GA 11 VSD passes through standard doors and occupies about half a square meter of floor.
How the Drive Matches Air Demand
Pressure Stability Without Unloaded Running
A fixed speed machine reacts to falling demand by loading and unloading, and every unloaded minute consumes power while producing no air. The GA 11 VSD instead adjusts the motor speed so the machine tracks the demand curve of the workshop. The flow range spans 20 to 100 percent, the pressure band stays inside the narrow window the controller defines, and the electricity bill reflects the air actually produced. On average the VSD+ technology saves 50 percent of the energy a fixed speed unit consumes under the same fluctuating profile, and the specific energy requirement drops a further 15 percent against the previous GA VSD generation.
Starting Under System Pressure
The GA 11 VSD starts and stops under full system pressure. No network venting is needed before a restart after a weekend shutdown, and no unloading sequence delays the first cubic meter of air on Monday morning. The inverter also removes the peak current penalty of a direct-online start, which matters in workshops where the electrical supply is shared with production equipment. In a mixed machine room the same behavior lets the GA 11 VSD act as a trim unit beside a larger base load machine.
The iPM Motor and the VSD+ Cubicle
Oil-Cooling and IP66 Protection
The interior permanent magnet motor of the GA 11 VSD reaches IE4 efficiency, outperforming IE3 class machines, and it runs oil-cooled: the same oil circuit that lubricates and seals the element also removes the heat from the motor. This design keeps the motor compact and protects it with IP66 pressure-tight sealing, so no cooling air has to be blown through the motor and no cooling filter has to be serviced. The oil-lubricated motor bearing needs no regreasing, which removes one of the routine maintenance items of conventional drives.
Sentinel Valve and Direct Drive
Between motor and element there are no gears, no belts and no shaft seal, so no transmission losses occur and the alignment never drifts. The Sentinel valve replaces the conventional inlet throttle: it optimizes the inlet flow to the air end, eliminates blow-off losses and is maintenance free. The drive train of the GA 11 VSD therefore carries fewer wearing parts than any geared or belted machine of the same class.
Full Feature: The Integrated Refrigerant Dryer
The Full Feature branch integrates a refrigerant dryer into the upright package, sized for the GA 11 VSD so no excess energy is consumed at part load. The dryer holds the pressure dew point at 3 degrees Celsius at the reference conditions, and the whole treatment chain sits inside the same frame on a 985 mm width. Plants gain dry air at the outlet without piping a second unit, and the dryer uses a refrigerant whose global warming potential has been reduced by about 50 percent through a lower refrigerant charge, with zero ozone depletion.
Condensate Management
Condensate from the dryer and the separator leaves through an electronic no-loss drain, which removes the water without wasting compressed air. A manual bypass integrated in the drain keeps the condensate moving during a power failure, so the network never floods. The GA 11 VSD carries this drain as standard on every version, standard and Full Feature alike.
Monitoring and Control
The Elektronikon graphic controller governs the GA 11 VSD and displays the key parameters of the day, the week and the month, with 32 language settings on board. The dual pressure set point function creates two different system pressure bands, manually or automatically, to squeeze the energy waste out of low-use periods, and the week timer supports any working scheme from single shifts to seven-day operation.
Integrated Saver Cycles switch the fan off in light load conditions and start and stop the dryer according to the required dew point suppression. SMARTLINK data monitoring reports the running data of the GA 11 VSD to a computer or smartphone, so the service planning is based on real data instead of fixed calendars.
Applications of the GA 11 VSD
The GA 11 VSD serves plants whose demand fluctuates: workshops with intermittent machine tools, food producers with batch cycles, laboratories, tire shops and packaging lines that pause between orders. The 9.5 and 12.5 bar(e) settings fit laser cutting assist air and small injection duties, while the 5.5 bar(e) version suits blowing and conveying networks that run at moderate pressure. Plants consolidating a two-compressor cascade replace the alternating control logic with the single modulating GA 11 VSD, and plants that grow further step into the GA 15 VSD on the same platform. Workshops that prefer the newest drive technology can also consider the GA 11 VSDS, the third generation variable speed line that Atlas Copco presents separately.
Service and Support Around the GA 11 VSD
The drive train of the GA 11 VSD runs without a gearbox or coupling between motor and element, which removes slippage losses and the maintenance items that come with them. Fewer components mean fewer service positions, and the oil filter and separator are integrated with a bypass valve for quick replacement. Atlas Copco fluids and lubricants are tailored to the platform with anti-oxidation additives that hold their protective qualities across the service interval. Seadweer supports the GA 11 VSD with original spare parts, service kits and technical documentation for every configuration.
FAQ
What does VSD+ mean on the GA 11 VSD?
VSD+ is the Atlas Copco designation for the variable speed drive generation with an interior permanent magnet motor and the dedicated inverter in the VSD+ cubicle. The motor speed follows the air demand, which removes unloaded running and saves 50 percent energy on average compared with fixed speed operation.
How much air does the GA 11 VSD deliver?
The flow window reaches from about 7.3 l/s at idle to 32.9 l/s at full speed on the 5.5 bar(e) setting. At 7 bar(e) the machine covers 7.3 to 32.5 l/s, and at 12.5 bar(e) it covers 7.6 to 23.5 l/s depending on the actual demand.
Is the GA 11 VSD an oil-injected machine?
Yes. The element is lubricated and sealed by injected oil in the usual rotary screw manner, and the oil is separated from the delivered air inside the package. The GA 11 VSD belongs to the oil-injected GA 7-75 VSD+ platform.
What does FF add to the GA 11 VSD?
The Full Feature branch integrates a refrigerant dryer with a pressure dew point of 3 degrees Celsius and a second electronic no-loss drain inside the same upright frame. The branch measures 985 mm wide instead of 610 mm, while depth and height stay unchanged, and the package weight rises from 196 to 280 kg.
How loud is the GA 11 VSD?
The mean sound pressure level is 63 dB(A), measured at 1 m distance according to ISO 2151:2004 with a tolerance of 3 dB(A). A conversation next to the machine stays undisturbed, so the GA 11 VSD can stand directly in the workshop instead of a separate compressor room.
Can the GA 11 VSD replace two small compressors?
In many rooms it can. The flow window from 7.3 to 32.9 l/s covers the combined output of two cascaded small units, and the electronic control replaces their alternating operation with one modulating machine that holds a narrow pressure band at every demand level.
Lars Jensen –
We used to alternate an old 7.5 kW piston unit with a rented diesel backup whenever demand spiked, and the pressure band wandered all day. The GA 11 VSD now covers the whole range by itself: it crawls through the morning ramp-up, takes the afternoon peak without dropping below 6 bar, and the electricity bill fell even though we produce more air than before. The vertical frame stands where the old vessel used to stand and it is barely audible. Seadweer configured the 7 bar version and had it running the same week.