Atlas Copco GA5-18VSDS Variable Speed Rotary Screw Air Compressor Series

The Atlas Copco GA VSDS is the variable speed version of the GA rotary screw line in the 7.5 to 25 HP range: GA5, GA7, GA11, GA15 and GA18. The drive matches motor speed to air demand, so a GA5 will turn down from 40.5 CFM to about 14 CFM and a GA18 from 138 CFM to 29 CFM without unloading, blowing down or cycling a receiver. Pressure stays flat at the setpoint and the compressor draws only the power the plant is using at that moment.

Who it is for. Any shop whose air demand swings through the day: body shops, machine shops, cabinet and sign shops, small plants with a second shift that runs lighter than the first. If a fixed speed 10 to 25 HP screw spends half its hours idling and unloading, a VSDS of the same frame usually pays for the price difference in power savings. It also replaces pairs of large piston compressors that were installed to cover peak demand and spend the rest of the day cycling.

Configurations. Each frame is sold as a P model (compressor only) or an FF model (Full Feature, with an integrated refrigerated dryer). The GA5, GA7 and GA11 can be ordered base mounted or on a 53 gallon tank; the GA15 and GA18 are base mount only. Pressure options are 175 PSI on all frames and 150 PSI on the GA11 and GA15. Every unit is three phase, in 200 to 230 V or 460 V.

Install and power notes. Give the cabinet clear space on the inlet and exhaust sides for cooling air, and plan on ducting the hot exhaust out of a small room. Size the feeder and disconnect for the frame horsepower and the voltage you order. A P model needs a receiver and a separate dryer downstream; an FF model still benefits from a dry receiver after the dryer so the drive is not chasing every tool pull. Base mounted units ship on a pallet by truck freight.

What to pair it with. A receiver sized at roughly 2 to 3 gallons per CFM, a refrigerated air dryer if you choose a P model, an aluminum compressed air pipe run sized for the full flow, and the Atlas Copco service kit on the hour interval in the manual. Compare other sizes on the 7.5 HP, 10 HP, 15 HP, 20 HP and 25 HP pages, or see the full Atlas Copco line. Not sure which frame covers your tools? Send us the tool list and duty cycle and we will size it.

Available Variants & SKUs

All variants and part numbers for this product are listed below for easy reference and ordering.