Want to know how to set the PSI on your air compressor? Start Here.
Air compressor buying guides always tell you to check tools performance ratings before paying for it. PSI is the measure of maximum pressure that an air compressor can safely operate at.
It should not be confused with Horse power which refers to the motor’s power output or with SCFM, the measure of the amount of air that a compressor tool can deliver. Basically the higher the SCFM usually translates to more power and speed but it is also influenced by a unit’s Pounds per Square Inch or PSI.
PSI often affects performance by dictating the kind of tools that you can attach to your air compressor. It is for this reason that experts on the subject recommend purchase of units that can power all your tools. It is useless to know your PSI without the CFM because when you reduce one, the other automatically increases.
In light of this principle, air compressor users are advised to ensure that their tools produce the correct CFM at the right PSI for optimum performance.
Setting the PSI like a pro
You need to set an air compressor’s PSI every time you need to use it. This allows you to regulate ideal force for the tools attached to your unit. If you make any mistakes at this point, your air compressor might damage your valuable tools or lead to poor performance. All air compressor models come with a pressure switch that makes this process easier.
Basic compressors usually have cut-in and cut-out pressure points which simply describe the pressure at which it starts and stops. They automatically stop when they get to the cut-out point and restart when it falls to the cut-in pressure point.
The difference between cut-in and cut-out pressure is called pressure differential or pressure band. If this is too small, your air compressor tool will keep starting and stopping, a situation which could damage the switch beyond repair not to mention the negative impact on other components.
The wrong setting can also lead to serious personal injury not to mention causing extensive damage to property.
How to set the PSI using the pressure switch
This depends on the make of the switch but you only need to adjust the pressure setting without having to adjust the differential. The fixed differential stands at 0.8-1 bar and it is easy to find that information on the user manual. Pressure switches for air compressors with already set differential usually have only one set screw that allows you to adjust the pressure.
For compressor models whose differential must be manually adjusted, there is the switch with two set screws. Setting psi for such compressors can be quite confusing but with a little keenness, it is rather easy.
The big screw on most models is for setting the cut in pressure while the smaller one allows you to set the cut-out pressure relative to cut-in pressure. It is worth noting then, that as you change the big screw’s position, you also affect the small screw.
To verify an air compressor’s cut-in pressure, start it when the tank is empty and allow it to run until it stops. Then open the drain to let some air escape and wait for the pressure in the tank to reduce.
Pay attention to the moment when it restarts and write down the cut-in pressure. For cut-out pressure, you need to let the air compressor run until it stops after restarting and record the pressure at this point.
Setting PSI on an air compressor can be very complicated especially because the rules vary according to the model. Unless it is a fixed differential model, it is important to read the user manual beforehand to prevent accidents due to excess pressure.
Some manufacturers set their air compressors at 6 bar cut-in pressure and 1 bar cut out for a pressure bar of 7 but it is better to verify this before using any tool. This is because some unscrupulous dealers misleading information that can lead to damage or compromise your tools’ performance.
If you are still confused about how to set the PSI on your air compressor, do not be afraid to ask as it is certainly better to be safe than sorry. You can also ask for a demonstration at the store where you bought the tool for specific instructions on how to safely set PSI.