When the compressor stops, the plant stops with it. That is the moment nobody wants to be working out what to do next.
Some of what takes a compressor down is genuinely a service call. Some of it is a tripped breaker, a closed valve or a fault code that tells you exactly what happened. The difference between those two situations is about ten minutes of looking. Learn the six checks worth doing before you pick up the phone, the details to have written down when you do, and the situations where you should stop checking and call straight away. Fluid-Aire Dynamics offers a four hour emergency response across all five of our service centers.
Before You Touch Anything: Two Rules
Industrial air compressors run at high pressure, high voltage and high temperature. Every check in this article is something you can do from outside the machine.
Two rules apply to all of them.
Do not open electrical panels. Stop there and call.
Do not work on energized equipment. A compressor can automatically restart without warning. If you are going near the machine, follow your plant lockout and tagout procedure first.
Nothing below requires removing a guard, opening a panel, or bypassing a safety device. If a situation seems to call for any of those, that is the point where the check ends and the service call begins.
1. Is the Compressor Actually Getting Power?
This sounds too simple to be worth checking. It is also one of the most common reasons a technician arrives to find nothing wrong with the compressor.
Work outward from the machine:
- Is the control panel lit at all? A completely dark panel usually points at supply, not at the compressor
- Has the breaker at the disconnect tripped? Note whether it tripped, because a breaker that trips again immediately is a real fault and not a nuisance trip
- Did anything else in the plant go down at the same time? That points at the supply rather than the machine
- Has anyone worked on the electrical supply recently, including overnight or on a weekend shift?
If the breaker has tripped, do not keep resetting it. A breaker that trips repeatedly is doing its job and something is drawing current it should not. That is a call.
2. What Is the Controller Telling You?
Modern rotary screw compressors do not usually fail silently. The controller records what happened, and that record is the single most useful thing you can give a technician.
Look at the display and write down exactly what it says, including the code. Do not paraphrase it. A fault code is specific, and the exact characters matter.
Common categories you might see:
- High discharge temperature
- Motor overload
- High pressure
- Low sump pressure
- Sensor or transducer fault
- Service interval reached
That last one matters more than people expect. That is not a breakdown, it’s simply a timed maintenance reminder.
Do not clear the fault before you have written it down. Once it is cleared, the technician is working blind. Our guide to troubleshooting an industrial air compressor covers what the common faults usually mean.
3. Check the Pressure at the Machine, Not the Gauge You Trust
When production reports no air, the compressor is the obvious suspect. It is often not the cause.
Compare two readings:
- The discharge pressure at the compressor
- The pressure at the point in the plant where the problem was reported
If the compressor is making pressure and the far end of the plant is not seeing it, the compressor is working and the problem is between the two. Look at:
- A closed or partly closed isolation valve, especially after recent work
- A blocked or collapsed filter element
- A dryer that has iced up or gone into a fault
- A large leak or a burst hose somewhere on the distribution system
This check alone resolves a meaningful number of calls, and it is the one most often skipped.
4. How Hot Is the Compressor Room?
High discharge temperature is one of the most common shutdown causes, and the reason is frequently outside the machine.
Check:
- Is the room noticeably hotter than usual?
- Are the ventilation fans running?
- Is the intake or the cooler face blocked with dust, cardboard or packaging?
- Has anything been stacked against the machine or in front of a vent since the last time you looked?
- Is it the hottest part of the day, and did the shutdown happen at the same time yesterday?
A compressor that trips on high temperature in the afternoon and runs fine in the morning is telling you that the environment may be at fault. Our guide on the key factors that affect where you place your air compressor covers ventilation and layout in more detail.
5. Look for Water and Oil Where They Should Not Be
A visual walk around takes two minutes and often explains the fault code.
- Oil on the floor under the machine, or a visibly dropping oil level
- Water pooling under the receiver tank or at the dryer
- A filter bowl full of liquid
- Discoloured or scorched wiring insulation visible from outside the machine, which is a stop and call situation
- An unusual noise before the shutdown, and whether anyone can describe it
Note what you find rather than cleaning it up. A technician wants to see where the oil came from.
6. Collect These Six Details Before You Call
The single fastest thing you can do to shorten a repair is to have the right information ready. A technician who knows the model and the fault code before leaving can often bring the part with them, which is the difference between one visit and two.
Have these ready:
- Make and model of the compressor
- Serial number
- Total running hours from the controller
- The exact fault code or message on the display
- When it happened, and whether it has happened before
- What changed recently, including maintenance, electrical work, production changes or weather
When to Stop Checking and Call Immediately
Some situations are not diagnostic exercises. Stop and call if you see any of these:
- A breaker that trips again as soon as it is reset
- Any smell of burning, visible smoke or scorched insulation
- A safety relief valve that has lifted
- Audible air escaping from the machine itself rather than from a drain
- Oil loss that is significant or ongoing
- Any situation that seems to require opening a panel or removing a guard
- Any doubt at all about whether it is safe
Downtime is expensive, but a damaged machine or an injured operator costs more than a service call.
What Happens When You Call Us
Fluid-Aire Dynamics offers a four hour emergency response guarantee from five service centers throughout the US, covering a ninety mile radius around each one. Our technicians are factory trained, and we carry parts for the brands we service.
Tell us what you found in the checks above and we will tell you what we think it is before we arrive. If it is something you can resolve yourself, we will say so.
Contact Fluid-Aire Dynamics for emergency air compressor repair, or talk to us about a preventive maintenance agreement that catches these faults before they take the plant down.
