Automan AC31 1-stage professional piston compressor - 3Hp, 200lt receiver mounted

Fitting out a small workshop, a busy home garage or a trade unit usually starts with the same question: where does the compressed air come from without a big spend or a three-phase supply? The Atlas Copco Automan AC31 (4116028588), a belt-driven single-stage piston (reciprocating) air compressor, is built to answer exactly that. It delivers compressed air for tyre work, blowing, stapling, general shop jobs and the everyday running of air tools, at up to 10 bar (145 psi).

Most of that work is stop-start rather than continuous, which is where the 200 litre horizontal receiver proves its value. A tank that size holds a solid reserve for short bursts of heavier use and reduces how often the motor restarts, instead of cycling constantly. Day to day you set the delivery on the adjustable pressure regulator, read tank and outlet pressure off the two gauges, and connect through the quick coupling; the pressure switch carries Off and Automatic buttons for hands-off running. This portable, wheeled design moves easily around the shop on its braked front wheel and full rubber-grip handle, and at 75 dB(A) the low pump speed keeps the noise down while you work nearby.

Under the belt guard the AC31 keeps things deliberately simple, using an oil-lubricated piston pump with cast iron cylinders and a slow-running compressor block, a large flywheel for cooling and an aftercooler that strips out some of the moisture as air leaves the pump. Fewer moving parts mean less to go wrong and low-cost, uncomplicated servicing, which suits an entry-level machine. Power is equally undemanding, running from a standard 230 V single-phase 50 Hz supply with a direct-on-line start, so there is no three-phase installation to arrange, unlike a rotary screw compressor. Do check that your circuit can handle the motor's start-up current, as it draws a brief inrush at start-up.

Because the pump is oil-lubricated, the delivered air carries a small amount of oil and is not clean, dry or food-grade. Breathing air, food, medical or pharmaceutical work all call for a dedicated oil-free compressor from the Atlas Copco range rather than this pump, and any drying or filtration you need is specified and supplied separately. And like every piston compressor, the AC31 is designed for intermittent duty; if your tools demand constant air hour after hour, an Atlas Copco rotary screw is the better fit. For a 2.2 kW (3 hp) piston on a 200 litre tank, kept to a regular service schedule, it stays a dependable and cost-effective source of shop air. If you would like us to confirm the AC31 suits your application, contact us with a note on your setup.