How to Adjust Air Pressure on Air Compressor
According to one study, air compressors consume 10% of the energy used in the industrial sector. Atlas Copco air compressors are available in a variety of configurations, such as:
- Piston compressors (ideal for hobbyists and small-scale applications)
- Oil-lubricated air compressors (for large-scale applications)
- Oil-free air compressors (for applications that require a Class 0 standard of air purity)
Furthermore, they are backed by proven technology, making them reliable, energy-efficient, and cost-effective.
Critical parameter
The critical parameter of an air compressor is the pressure, which is adjusted using a pressure switch in a typical air compressor. Larger configurations of air compressors may be fitted with a central compressor controller.
The pneumatic devices connected to the air compressor will require optimum pressure to produce the desired results efficiently. Therefore, the pressure set-point of the air compressor will be dictated by the pressure requirement of the pneumatic devices, even if it is lower than the recommended pressure setting of the air compressor. Setting the pressure higher or lower than what the pneumatic devices require can be counterproductive, as it can result in greater running costs.
For instance, the AH 10-6 Atlas Copco air compressor has a maximum specified pressure of 8 bar (116 psi). If the pneumatic device connected to it has a specified pressure of 4 bar (58 psi), then the pressure set-point of the air compressor should also be 4 bar (58 psi). This generalisation can be applied to both small and large air compressors., higher maintenance costs, and even the failure of your pneumatic devices.
Pressure switch
The pressure of an air compressor is adjusted using the pressure switch. It contains two pressure set-points: cut-out (upper limit) and cut-in (lower limit). When the air compressor pressure exceeds these limitations, the pressure switch sends an electrical signal to the compressor pump to stop or start.
A typical pressure switch will contain one or two large adjustable springs, whose tension can be varied to set the pressure set-points. Some pressure switches may contain an additional smaller spring to vary differential pressure (hysteresis), which is the difference between cut-out and cut-in pressure set points. Generally, 0.8 bar - 1 bar (12 psi - 14 psi) is set as the differential pressure, unless bespoke applications require a higher setting.
Pressure switches that vary differential pressure will have only one large adjustable spring for cut-in pressure and a smaller spring for the former. If the pneumatic devices require a minimum pressure of 4 bar, then the cut-in pressure is set at 4 bar. If set at 1 bar, the differential pressure will set the cut-out pressure point at 5 bar (4 bar + 1 bar).
Regardless of the pressure switch model, the basic adjustment principle stays the same. However, it is highly recommended to read the air compressor manual to identify the specific procedure to adjust the pressure set-points.
Adjusting methodology
Step 1: Ensure that the compressor is unplugged from the power supply. Empty the tank using the drain valve to drain the pressure from the system.
Step 2: Open the cover of the pressure switch. Identify the adjustable springs by referring to the label, datasheet, or operating manual. The large spring (or springs) sets the cut-in (and cut-out) pressure, while the smaller spring (if present) sets the differential pressure. The springs will be attached to screws for adjustment.
Step 3: Set the cut-in pressure by adjusting the screw. Turning the screw clockwise increases pressure, whereas turning it counter-clockwise decreases pressure.
Step 4: Plug the compressor in and turn it on. The compressor will run until the cut-out pressure is attained.
Step 5: Using the drain valve, release the compressed air at a slow rate and check the new cut-in value. The compressor should turn on when the pressure drops to the cut-in point. Adjust the spring if necessary. Repeat Step 1 before adjusting the cut-in value.
Step 6: Cut-out pressure or differential pressure can now be set, depending on the model of the pressure switch. Clockwise rotation of the screw increases the pressure, while a counter-clockwise rotation decreases the pressure. Ensure the compressor is unplugged and the tank is empty before adjusting.
Step 7: Turn on the compressor and verify if the compressor motor stops when the pressure reaches the cut-out point. Adjust if necessary.
After completing the adjustment, run the compressor to verify whether the motor stops at the desired cut-out point. Similarly, the cut-in point can be tested using the drain valve. After verification, adjusting the air pressure of the air compressor is said to be completed. Ensure adherence to proper safety protocols before attempting this procedure.
Are Atlas Copco air compressors suitable for your business, then get in touch with our compressed air specialist now and book a free consultation.