ABAC AS-20503TMD 20 HP Rotary Screw Air Compressor - 131 Gallon Tank Mount with Dryer, 150 PSI, 54 CFM, 71 dBA

The ABAC AS-20503TMD is a complete 20 HP compressed air station on one base: a rotary screw compressor, a 131 gallon air receiver and an integrated refrigerated dryer, mounted, piped and wired together at the factory. It delivers 54 CFM at 150 PSI and runs at 71 dBA. Because the three pieces arrive matched as one unit, installation comes down to setting it in place, bringing 208-230-460V three-phase power to it and connecting the air line. There is no separate dryer to size, site, pipe and find floor space for.

Key specifications

• Model: AS-20503TMD (part number 4152043934)
• Motor: 20 HP, energy efficient
• Air delivery: 54 CFM
• Working pressure: 150 PSI
• Noise level: 71 dBA
• Tank: 131 gallon receiver, tank mount
• Integrated refrigerated air dryer
• Power supply: 208-230-460/3/60
• Fully integrated aluminum block air end
• Vertical oil separation technology
• Digital controller with programmed maintenance menus
• Dimensions: 76 x 27 x 62 in
• Weight: 908 lbs

Why the 150 PSI build

Pressure and airflow trade against each other on the same 20 HP motor. Built identically, the 125 PSI AS-20253TMD carries 60.6 CFM and the 175 PSI AS-20753TMD carries 48.5 CFM. The 150 PSI machine is the middle choice, and it is the right one when tooling, press equipment or a long run of distribution piping needs headroom above a 125 PSI compressor without needing a full 175 PSI. Regulating down from a higher setting costs energy, so buy the pressure the plant actually works at rather than the largest number on the page.

How it compares

Within the 20 HP 150 PSI range the question is how much of the air system arrives as one piece. The AS-20503BM base mount is the compressor alone at 516 lbs in a 37 x 28 x 40 in footprint, for a shop that already owns a receiver and a dryer. The AS-20503TM adds the receiver at 813 lbs. This TMD package adds the dryer on top of that at 908 lbs on the same 76 x 27 x 62 in base, so the extra 95 lbs buys dry air without a second machine on the floor. On airflow, the 15 HP AS-15503TMD sits below it at 46.4 CFM and 69 dBA, and the 25 HP AS-25503TMD above it at 92.2 CFM.

Typical applications

Production and fabrication floors, machine shops running several CNC cells, automotive and fleet service bays, tire and truck shops, plasma cutting, pneumatic controls and air logic, and spray finishing or powder coating work where water in the air line turns into runs, fisheyes and sticking valves. Drying the air at the compressor keeps condensate out of the distribution piping instead of leaving it for traps and filters downstream to catch, which matters most on long overhead runs where the air cools on its way to the tool.

Installation and service notes

Size the disconnect and the conductors to the motor nameplate for a 20 HP three-phase load, and confirm which of the 208, 230 or 460 volt taps the machine is wired for before energizing it. Leave clearance on the cooling air side and keep the room ventilated, because the refrigerated dryer rejects heat into the same space the compressor does. Oil, oil filter and the separator element are the recurring service items on a screw, so keep a set on the shelf rather than ordering them when the controller asks for them. A rotary screw is built for continuous duty, so this machine is meant to run through a full shift and hold line pressure rather than cycle on and off the way a piston compressor does.

Part of the ABAC AS-B screw range from the Atlas Copco group, built around a fully integrated aluminum block air end, vertical oil separation technology and an energy efficient motor. Air delivery on the 20 HP models is quoted as free air delivery and measured to ISO 1217 Annex C, and the noise figure is measured to ISO 2151:2004 using ISO 9614/2. Compare the rest of the rotary screw air compressors, or browse refrigerated air dryers if you are adding drying capacity to a compressor you already own.