G5 VSD P 5,5kW variable speed drive Oil-Injected screw compressor with integrated dryer - 8bar, receiver mounted

Growing past a piston compressor is a common turning point for a small business, and the Atlas Copco G5 VSD FF-8 (8152104026) screw air compressor is built for exactly that stage. Once a workshop or short production line is running air tools and equipment for most of the day, a machine that cannot keep pace becomes the bottleneck. The unit is an oil-injected rotary screw compressor driven by a variable speed drive, supplied as FF, short for Full Feature (the dryer is built in), and tank-mounted on its own air receiver, so it is ready to work as delivered. Where a piston unit has run out of headroom, or a smaller screw compressor no longer supplies enough air, it fills the gap.

Output is 14.9 l/s of free air (about 31.6 cfm) at pressures up to 8 bar (116 psi). Matching that to your workshop is a matter of totalling the air demand of the tools and machines that run together at peak, then keeping that total comfortably below the figure above. Hand tools, a blast cabinet or a spray gun each sit well within it. Feed several operators on air at the same time, or a larger machine tool, and you are working the compressor at the load it was designed for.

Within our smallest VSD screw range, the G5 VSD sits towards the top, so it supplies more air than the smaller models in the same family. Businesses that need a steady volume of air through the day are the natural fit; where demand is only light and occasional, a smaller model in the range may cover it.

The variable speed behaviour is what sets this apart from a fixed-speed alternative. A fixed-speed unit runs at full output and then unloads or stops the moment demand falls away, losing energy on every cycle. Here the Variable Speed Drive keeps the motor tracking your actual air demand, easing back when the workshop falls quiet rather than switching on and off. The practical result is more stable pressure at the tool, reduced component wear from constant stopping and starting, and less energy wasted over a shift. It suits any operation where air use rises and falls rather than holding a constant level.

Behind that is a 5.5 kW (7.5 hp) IE3 premium efficiency motor rated for 100% duty cycle, so continuous running is well within its design rather than something it needs to recover from.

Air quality follows the strengths of a rotary screw, which handles long hours cleanly, the continuous duty a rotary screw is built for, where a piston is designed for shorter, intermittent runs. Being oil-injected, a small amount of oil is carried through into the compressed air (typically around 5 mg/m³ on this unit). Moisture is taken out by the integrated dryer, protecting pipework and tools from water and rust, while the built-in oil separator and filter hold carryover low. What you get is clean, dry, general-purpose workshop air.

That air is not oil-free, and the distinction matters. Breathing air, food or beverage contact, and pharmaceutical or medical applications call for a genuinely oil-free compressor from the Atlas Copco range; no amount of filtering on an oil-injected unit will make it suitable for those. For everyday tools, painting, blasting and general production, however, it is very much at home.

This is a 400 V, three-phase, 50 Hz machine, a standard industrial supply rather than a domestic wall socket. If your site has only single-phase power, a three-phase supply must be installed first, so confirm three-phase availability before ordering.

Control is handled by the Elektronikon Nano controller. You can manage and monitor the compressor at the panel, and connect through the SMARTLINK app on a phone to follow status and servicing remotely, which makes it straightforward to catch a developing problem early.

Installation is undemanding. Cooling air discharges from the top and the cabinet is compact, so the unit can go against a wall or into a corner without much fuss. It draws in air up to 46 °C, needs an ambient of at least 1 °C, and holds full output up to 1000 m altitude before it begins to derate. At around 70 dB(A) it is quiet enough for many workshops to house it near the point of use rather than in a separate plant room.

To close on sizing, work to the tools you run together rather than the single largest, and keep to the service schedule so reliability and warranty cover both hold. For a busy shop whose air use swings through the day, the G5 VSD's variable speed keeps pace with changing demand; if you need still more air, a larger model such as the G7 VSD steps up.