ABAC AS-20S253BM 20 HP Rotary Screw Air Compressor - Base Mount, 125 PSI, 81.9 CFM, 67 dBA

The ABAC AS-20S253BM is a 20 HP rotary screw air compressor for shops that need a lot of air, quietly, across a full shift. It delivers 81.9 CFM at 125 PSI and runs at 67 dBA. This is the base mount version, so it ships without a tank and plumbs into an air receiver you already own or one sized to your demand. Power is 208-230-460V three-phase.

Key specifications

• Model: AS-20S253BM (part number 4152028455)
• Motor: 20 HP, energy efficient
• Air delivery: 81.9 CFM, free air delivery per ISO 1217 Annex C
• Working pressure: 125 PSI
• Noise level: 67 dBA, measured per ISO 2151:2004
• Mounting: base mount, no tank
• Power supply: 208-230-460/3/60
• Weight: 690 lbs
• Dimensions: 44 x 31 x 49 in
• Fully integrated aluminum block air end
• Eco friendly vertical oil separation

Typical applications

Production and fabrication floors, automotive and fleet service bays, tire and truck shops, cabinet and woodworking shops, and any operation where a reciprocating compressor is working too hard to hold line pressure. A rotary screw is designed for continuous duty, so it maintains a steady line pressure through a full shift instead of recovering between jobs.

Installation notes

Because this is a base mount machine, settle the receiver before it arrives. The tank has to suit the duty cycle and the size of the largest single air draw on the system, and an undersized one will make a 20 HP screw cycle more than it should. At 44 x 31 x 49 inches and 690 lbs this is a set in place unit, so check the door width and the floor route in advance. Run it on a dedicated three-phase circuit sized to the motor nameplate, and leave clear space on the cooling air side so the package is not recirculating its own hot air. Oil, oil filter, air filter and separator element are the scheduled service items on a screw package, and keeping a spare set on the shelf stops a routine service from turning into downtime.

How it compares

The S in AS-20S is the difference worth understanding: against the standard AS-20253BM at the same 20 HP and the same 125 PSI, this machine delivers 81.9 CFM instead of 60.6 CFM and runs at 67 dBA instead of 71 dBA. That is roughly 21 CFM more air from the same motor rating, which is what shops reach for when sandblasting, plasma cutting, or several bays running at once are pulling a standard 20 HP unit down. If your tools need a higher line pressure instead of maximum volume, the AS-20S503BM holds 150 PSI at 78 CFM from the same 690 lb, 44 x 31 x 49 in package.

Sizing the rest of the system

Base mount is the starting point for a modular compressed air system: pair it with a receiver sized to your demand, then add a dryer downstream if your air tools or finishing work need moisture control. If you would rather buy the moisture control already matched, mounted and wired, the AS-20S253BMD adds an integrated refrigerated dryer on the same base, and the AS-20S253TMD arrives as a complete station on a 132 gallon receiver. Buying the dryer separately instead? Size it above 81.9 CFM from our refrigerated air dryers.

Part of the ABAC AS-B screw range from the Atlas Copco group, built around a fully integrated aluminum block, eco friendly vertical oil separation and an energy efficient motor. Browse the rest of our rotary screw air compressors.