5-Step Checklist for Verifying Your Atlas-Copco Compressor Setup Before It Goes Live

Who This Checklist Is For

If you're installing an Atlas-Copco compressor on-site—say a GA 37 VSD for a hospital or a 185 CFM portable for a construction fleet—this is for you. Same if you're an engineer specifying the system or the technician doing the final sign-off.

I review roughly 200+ compressed air setups annually for our company (we supply to medical, pharmaceutical, and industrial clients). Over the last few years, I've noticed the same five issues keep coming up—issues that aren't in the manual but should be. This checklist covers them.

Bottom line: these five checks will save you a call-back, and probably a redo.

Step 1: Confirm Cooling Fan Airflow Direction

This sounds basic, but you'd be surprised. In Q1 2024, we rejected a batch of three Atlas-Copco ZR 55 VSD units because the installation team had the cooling fan wired in reverse. The fan was pulling hot exhaust toward the intake of the adjacent unit—dropping efficiency by an estimated 12% before we caught it.

Here's what to check: the fan should push air away from the compressor core, typically through a duct or louver. If it's pulling air over the motor and then out, you've got a recirculation problem. Read the sticker on the fan shroud—most Atlas-Copco units have a visible arrow. If you don't see one, verify with a piece of paper: hold it near the grille and see which way it's pulled.

Put another way, this isn't a 'nice to have'—it's a compliance issue for any medical air installation (NFPA 99 requires positive ventilation in compressor rooms).

Step 2: Check Air Filter Orientation (Up or Down?)

This is the one that trips up most people. The question 'which way to put air filter in furnace up or down' gets asked a lot—and for good reason. On a typical Atlas-Copco screw compressor, the intake filter is mounted on the top or side. But here's the thing: if it's installed upside-down (i.e., the filter media facing downward), it can collect dirt and debris from the housing itself.

Let me give you a specific example. I once saw a fleet of Atlas-Copco XAS 185 units where the filter was oriented with the open face pointing down. Over three months, dust settled into the filter pleats, bypassing the pre-separator. The vendor claimed it was 'within industry standard.' We rejected all 12 units and specified a vertical orientation in the contract. Since then, zero contamination issues on those compressors.

So, rule of thumb: for a top-mounted filter, the open face should always point up or inward (toward the cleaner side of the housing). If you're unsure, look at the manual—or call Atlas-Copco tech support. They'll tell you.

Step 3: Validate the Cooling Fan Is Correctly Rated

This is related to Step 1, but different. Cooling fans on Atlas-Copco compressors must be matched to the expected ambient temperature range. For a standard indoor installation, a 60 Hz fan with a cfm rating of 10-20% above the compressor's heat rejection is typical. But here's where it gets tricky: some aftermarket 'universal' cooling fans claim to work but actually underperform.

I ran a blind test two years ago with our maintenance team: same fan size, same voltage, same price point—but one was OEM, one was aftermarket. The aftermarket moved 17% less air at full load. On a 100 hp compressor running 18 hours a day, that difference can push the compressor room ambient up by 8°F over time. Not catastrophic, but you'll see oil temp warnings during summer months.

If you're replacing a fan, invest the time to measure the actual cfm at the motor terminals, not just trust the label. Anemometers are cheap—a fan failure on a critical medical air system is not.

Step 4: Verify Medical Air Certifications (If Applicable)

If you're ordering an Atlas-Copco medical air compressor, there's a specific certification check that people miss. The unit must be NFPA 99 compliant (2023 edition) and ISO 7396-1:2023 rated for medical gas systems. But just having the sticker isn't enough—I've seen units with the label but the internal piping material didn't match the spec.

Here's the check: look at the copper tubing inside the compressor package (between the aftercooler and the outlet). It should be Type L or K medical-grade copper with a clean, no-flux solder joint. If it's standard plumbing copper with flux residue, it's not compliant. That flux can off-gas and contaminate the air supply. We had one vendor try to claim it was 'within tolerance.' We sent a sample to an independent lab, and the copper didn't meet CDA 122 spec. The unit was replaced at their cost.

Don't rely on the vendor's word—request the material test report (MTR) for any medical air unit over $18,000. It's a 30-minute check that can save a $22,000 redo.

Step 5: Record the Fault Codes and Service History

Finally, before you push the 'start' button, take five minutes to log the current fault codes from the controller. Every Atlas-Copco unit (from the Mk5 to the Elektronikon) has a diagnostic interface. I always request a screenshot of the live status screen and the last 50 fault codes. If there's a recurring code (like 'motor overtemperature' or 'low oil pressure'), you want to know before the unit goes into production.

Look, I'm not saying every code is a deal-breaker. But on a fleet of five Atlas-Copco GA 90 units we purchased in 2023, three of them had a 'pressure sensor fault' logged at startup. The vendor said it was 'factory calibration noise.' We insisted on a recalibration—and one of the sensors was actually defective. That single check saved us a potential failure two months later.

Trust me on this one: sixty seconds of checking codes now beats two hours of diagnosis later.

Common Mistakes to Avoid

• Skipping the fan direction check: It's the most common rework call we see. A reversed fan on a Atlas-Copco ZR compressor can reduce performance by 10-15% and invalidate the warranty.
• Ignoring the filter orientation debate: Even experienced technicians get this wrong. If you search 'which way to put air filter in furnace up or down,' you'll see the confusion. Apply the same logic to your compressor intake.
• Failing to document medical air certifications: If you need an atlas copco medical air compressor for a hospital, don't accept verbal assurances. Get the paperwork.
• Assuming the cooling fan is correct: Aftermarket fans might save $150 upfront but cost $1,500 in energy and maintenance over 12 months.

This checklist worked for us, but our situation was mid to large industrial installations with predictable maintenance schedules. If you're a small shop with a single portable unit, some steps (like checking medical certifications) won't apply. The fan and filter checks, though? Those are universal.