Description
The Atlas Copco GA 37 VSD opens the GA 37-110 VSD+ platform and brings variable speed drive to the 37 kW class of the oil-injected screw range. An oil-cooled interior permanent magnet motor rated at 37 kW drives the compression element, and the drive adjusts its speed continuously so the delivered air follows the demand of the plant. The working pressure band runs from 4 to 12.5 bar with a maximum working pressure of 13 bar(e), and free air delivery spans 26 to 133 l/s between idle and full speed. With a standard package of 860 kg and a sound level of 67 dB(A), the GA 37 VSD fits into machine rooms where every decibel and every square meter count.
For many plants this is the first inverter-driven compressor in the room. The change is easiest to see on the electricity meter: when production pauses, the drive slows to an idle of 26 l/s instead of running unloaded at full speed, and the energy savings of up to 50 percent come from the hours that used to be wasted between load phases.
Where the GA 37 VSD Fits in the Oil-Injected Range
Atlas Copco positions the GA 37 VSD at the base of the GA 37-110 VSD+ family, below the GA 45 VSD and the GA 55 VSD. Plants that run one or two small fixed speed compressors today, or that are replacing an aging piston unit, find here a machine with the same footprint discipline but a fundamentally different energy logic. The oil-injected design keeps the element lubricated and sealed by the oil film itself, which suits the general industrial duties of the 37 kW class, and the 4 bar low-pressure setting extends the reach to dedicated low-pressure networks.
What the VSD and FF Names Cover
The VSD part of the name refers to the variable speed drive: the in-house designed Neos inverter 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, filtration and an electronic no-loss drain inside the same enclosure. Both branches share the element, the motor and the control platform, so the treatment level can be raised later without changing the installation.
Technical Specifications of the GA 37 VSD
The table below condenses the GA 37 VSD into its headline figures:
| Parameter | Value |
|---|---|
| Installed motor power | 37 kW / 50 hp |
| Working pressure range | 4 to 12.5 bar(e), maximum 13 bar(e) / 188 psig |
| Free air delivery | 26 to 133 l/s (55 to 282 cfm) |
| Noise level | 67 dB(A) |
| Weight, standard / Full Feature | 860 kg / 1060 kg |
| Dimensions, Full Feature | 1656 mm wide, 1100 mm deep, 1968 mm high |
VSD+ Flow Range Across the Pressure Band
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 37L VSD⁺ in its four settings:
| Working pressure | FAD min-max (l/s) | FAD min-max (m³/h) | FAD min-max (cfm) |
|---|---|---|---|
| 4 bar(e) / 58 psig | 26 – 133 | 94 – 479 | 55 – 282 |
| 7 bar(e) / 102 psig | 26 – 132 | 93 – 475 | 55 – 279 |
| 9.5 bar(e) / 138 psig | 25 – 116 | 89 – 418 | 53 – 246 |
| 12.5 bar(e) / 181 psig | 38 – 99 | 138 – 355 | 81 – 209 |
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 is measured at the effective working pressures of 4, 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 67 dB(A) is the mean value measured at a distance of 1 m at maximum working pressure according to ISO 2151:2004 using the ISO 9614/2 sound intensity method, with a tolerance of 3 dB(A).
The turndown behavior is what separates this machine from a small fixed speed unit. At 4, 7 and 9.5 bar the GA 37 VSD idles down to 25 or 26 l/s, close to one fifth of its full-speed delivery at those settings. During breaks, shift changes and weekend ramps the machine keeps the network pressurized at that low idle instead of blowing surplus air, and the pressure band stays within the limits the controller defines.
Dimensions and Weight
The standard package of the GA 37 VSD measures 1100 mm deep, 1153 mm wide and 1968 mm high, and the Full Feature branch widens to 1656 mm to house the integrated dryer while depth and height stay unchanged. The package weighs 860 kg and the Full Feature branch 1060 kg, figures it shares with the GA 45 VSD on the same frame. The upright layout stands tall rather than long, so a machine bay sized for the previous compressor usually accepts the GA 37 VSD without civil work.
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 37 VSD instead adjusts the motor speed so the machine tracks the demand curve of the plant. The pressure band stays where the setpoint is, the machine idles down when consumption allows it, and the electricity bill reflects the air actually produced. Variable speed drive technology generates energy savings of up to 50 percent, and the lowered system pressure that VSD+ allows adds further savings because every bar of unnecessary pressure costs energy.
Starting Under System Pressure
The GA 37 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. In a mixed machine room the same behavior lets the GA 37 VSD act as a trim unit beside fixed speed base load machines without interaction problems on the header.
The iPM Motor and Neos Inverter
Oil-Cooling and IP66 Protection
The interior permanent magnet motor of the GA 37 VSD exceeds IE5 standards, and it runs oil-cooled: the same oil circuit that lubricates and seals the element also removes the heat from the motor windings. This design keeps the motor compact and protects it against dust and moisture with IP66 pressure-tight sealing, so no cooling air has to be blown through the motor compartment and no cooling filter has to be serviced there.
IES2 Power Drive Efficiency
The Neos inverter was designed in-house and controls the iPM motor as a matched pair. Together the inverter and motor exceed the IES2 requirements of EN 50598 for power drive efficiency, which keeps the losses between the mains supply and the compressor shaft low across the whole speed range. The inverter carries IP5x protection inside a robust aluminum enclosure, and its heat dissipates in a separate compartment so the electronic components remain cool and their lifetime improves.
Full Feature: The Integrated Refrigerant Dryer
The Full Feature branch integrates a refrigerant dryer into the package, sized for the GA 37 VSD so no excess energy is consumed at part load. The dryer holds the pressure dew point between 2 and 3 degrees Celsius at the reference conditions, and the whole treatment chain sits inside the same upright frame. Plants gain dry air at the outlet without piping a second unit, and the floor space stays reserved for production instead of air treatment.
Condensate Management
Condensate from the dryer and the separator leaves through an electronic no-loss drain, which removes the water without wasting compressed air. The drain is controlled and monitored by the controller, so a blocked or failing drain is reported on the panel instead of silently flooding the downstream network.
Monitoring, Control and Connectivity
The Elektronikon Touch controller governs the GA 37 VSD and logs the operational parameters. SMARTLINK remote monitoring is standard and reports the running data of the GA 37 VSD to a computer or smartphone, so the service planning is based on real data instead of fixed calendars. OPC UA connectivity integrates the compressor into the production monitoring system as well, which turns the machine into a data point on the factory floor rather than a closed box in the corner.
Energy Recovery as an Option
A specifically developed energy recovery system can be built into the GA 37 VSD, recovering up to 75 percent of the power input as hot air or hot water. Ducted hot air covers auxiliary or main heating of workshops and warehouses, while the hot water variant feeds radiators, industrial cleaning lines and sanitary facilities. For a small plant the recovered energy offsets a noticeable share of the heating bill, and the payback of the compressed air investment shortens accordingly.
Applications of the GA 37 VSD
The GA 37 VSD serves plants whose demand fluctuates: workshops with intermittent machine tools, bakeries and food producers with batch cycles, laboratories and packaging lines that pause between orders. The 4 bar low-pressure setting fits textile air, glass molding and pneumatic conveying networks that run dedicated low-pressure headers. Plants replacing a pair of small fixed speed compressors consolidate onto the GA 37 VSD because its wide flow window replaces cascade control with a single modulating machine, and plants that grow beyond it step into the GA 45 VSD on the same platform.
Service and Support Around the GA 37 VSD
The drive train of the GA 37 VSD runs without a gearbox or coupling between motor and element, which removes slippage losses and the maintenance items that come with them. Service points are arranged for access from the front of the machine, and the electronic components sit in their own compartment away from the hot compressor section. Atlas Copco fluids and lubricants are tailored to the platform with anti-oxidation additives that hold their protective qualities across the service interval. For the drive motor overhaul scope on the GA VSD+ platform, see the GA VSD+ Motor Overhaul Kit. Seadweer supports the GA 37 VSD with original spare parts, service kits and technical documentation for every configuration.
FAQ
What does VSD⁺ mean on the GA 37 VSD?
VSD⁺ is the Atlas Copco designation for variable speed drive generation with an interior permanent magnet motor and the in-house Neos inverter. The motor speed follows the air demand, which removes unloaded running and saves up to 50 percent energy compared with fixed speed operation.
How much air does the GA 37 VSD deliver?
The flow window reaches from 26 l/s at idle to 133 l/s at full speed on the 4 bar setting. At 7 bar the machine covers 26 to 132 l/s, and at 12.5 bar it covers 38 to 99 l/s depending on the actual demand.
Is the GA 37 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 37 VSD is the entry machine of the oil-injected GA 37-110 VSD+ platform.
What does FF add to the GA 37 VSD?
The Full Feature branch integrates a refrigerant dryer with a pressure dew point of 2 to 3 degrees Celsius, filtration and an electronic no-loss drain inside the same enclosure. The branch measures 1656 mm wide instead of 1153 mm, while depth and height stay unchanged.
How loud is the GA 37 VSD?
The mean sound pressure level is 67 dB(A), measured at 1 m distance at maximum working pressure according to ISO 2151:2004 with a tolerance of 3 dB(A). The machine can share a room with workshops or sit behind a partition wall without nuisance.
Can the GA 37 VSD replace two small compressors?
In many rooms it can. The flow window from 26 to 133 l/s covers the demand of two cascaded small units, and the electronic control replaces their alternating operation with one modulating machine that holds a narrow pressure band.
George Papadopoulos –
We held back from variable speed for years because our demand looked too small to justify it. The GA 37 VSD changed that calculation: the machine idles through our afternoon dip instead of unloading, and the power bill dropped from the first full month. It stands where our old piston unit used to stand and it is far quieter, so the compressor room door stays open in summer. Seadweer matched the pressure setting to our network before the machine shipped.