how does an air compressor pressure switch work?

An air compressor is a vital piece of equipment commonly used in various automotive, industrial, and home applications. One crucial component of an air compressor is the pressure switch, which is responsible for turning the compressor on and off based on the desired pressure level. But how does an air compressor pressure switch work exactly? 

Here, I will explore the inner workings of an air compressor pressure switch, including its components, function, and operation. And by the end of this article, you will better understand how this helps regulate the air pressure in your compressor and keeps it functioning appropriately.

What Is An Air Compressor Switch?

what is an air compressor switch?

The air compressor is a critical piece of equipment designed to automatically make the driver off or on while operating to secure the air pressure output. It is an electrical switch that is activated by the pressure levels of the airflow. And this triggers the driver to turn it on and off accordingly. 

In addition, the switch program turns on when the output pressure drops below a specific level and turns off when the pressure reaches a predetermined value. While the switch’s actions control the driver and, subsequently, the pressure pump. 

Therefore, the purpose of incorporating this adaptive switch is to guarantee that the compressor operates within safe limits. Moreover, the output pressure remains suitable for the intended application.

Components Of Air Compressor Pressure Switch

components of air compressor pressure switch

Here I will discuss the equipment of the air compressor pressure switch and their works. Check them out–

ON/OFF Switch

The on and off switches work to operate and discharge the pressure on the motor. The main reason to have a pressure switch is so that the machine can control and maintain the required pressure level.

Terminals and Connections 

The power supply for the air compressor is controlled by the pressure switch, which determines when it should start or stop. And it is connected to the outgoing and incoming wires via terminals. The metal switch contacts can be separated or joined to control the current flow.

Spring for Adjustment

Springs are needed for regulating the machine’s cutout and cut-in levels. When you compress the spring, the flap will employ tremendous pressure just before the spring separates the connectors. If the spring is relaxed, less force will be needed for the connectors to slide apart.

Moreover, using springs can control the levels at which an air compressor cuts in and out. By compressing the spring, the flap will apply tremendous pressure just before the spring separates the connectors. Conversely, if the spring is relaxed, less force will be needed to slide it.


The diaphragm in the compressor functions as a rubber seal that responds to pressure force, causing it to move up and down. As a result of this movement, the contacts may connect or disconnect.

Pressure Unloading Valve

The relief valve on the pressure switch aims to decrease the pressure between the compressor and the valve. Positioned at the pressure switch’s base and linked to the pressure regulator by metal or nylon tubing. 

When the contacts are separated, the valve is unlocked. This safety valve intends to prevent an excessive pressure build-up that could result in injury.

Working of Air Compressor Pressure Switch

working of air compressor pressure switch

Applying force to the switch triggers a sensor commonly activated by a diaphragm. This diaphragm undergoes deformation or compression due to the compressed air, making it the most widespread component in these pressure switches. These switches are designed to generate a particular range of pressure distribution in the output.

As long as the device utilizes compressed air, the pressure switch attached to the air compressor will remain operational. However, the cycle will halt when there is a problem or an absence of an external power supply. The pressure switch and adjacent casing’s leakage can cause significant issues and interrupt the entire operation.

Cut-in Pressure Setting

You can modify the cut-in pressure using any switch as long as it is within the device’s allowable limits. Nevertheless, certain regulators may have a variable range while others have a fixed differential, usually from 0.8 to 1 bar.

Cutout Pressure Setting

The pressure that builds up in the compression chamber, the cutout pressure or reverse pressure, will eventually impact the curve of the diaphragm. This will cause the compressor pressure switch to move because the diaphragm will bend.

What Are The Different Types Of Air Compressor Pressure Switches?

what are the different types or air compressor pressure switches?

The pressure switch can be of two different types. Such as–

Float Switches

The float switch is a standard pressure switch for air compressors. It works by using a small float inside that moves with the pressure and activates a contactor to turn the compressor on or off. Also, it triggers a safety valve to prevent over-pressurization of the tank.

for more information about air compressor pressure switches click here

Timer Switches

Timer switches are for air compressors with a built-in timer to turn the compressor on and off at regular intervals. They help conserve energy by restarting the compressor after briefly pausing when the pressure drops. 

However, float switches are becoming more popular among manufacturers as they are simpler and safer to operate.

Final Words

This article has explained the functioning of an air compressor pressure switch. Hopefully, the information provided above was helpful to you. It is highly advised to seek professional help if you are not knowledgeable about repairing pressure switches. 

In addition, it is crucial to perform regular maintenance on your air compressor pressure switch to ensure its efficient performance. And feel free to contact us if you have further queries.


How do I know if the pressure switch is bad on a compressor?

The pressure switch on an air compressor can go bad over time, leading to various issues, such as failure to turn on or off, inconsistent pressure readings, or leaking air. To determine if the pressure switch is damaged, you should perform basic troubleshooting, such as testing the button with a multimeter, checking for visible damage, or consulting the user manual.

How does the air compressor pressure switch unloader work?

Once the air pressure in the compressor tank reaches the cutout pressure set by the pressure switch, which is the point where the air supply stops, the button will automatically turn off and stop the motor’s power supply. As a result, the unloader valve will open and release the accumulated air.

What pressure switch is used on an air compressor?

The mechanical pressure switch is more appropriate for managing high levels of voltage and amperage in comparison to an electronic pressure switch. It can be utilized to modify pressure levels using a contact alteration.

How to adjust a pressure switch on a compressor?

To adjust a pressure switch on a compressor, locate the switch and turn off the compressor. Then, change the pressure settings according to the owner’s instructions. Once the settings are adjusted, turn the compressor back on and test the pressure levels to ensure they are within the desired range.

How does a 30-50 pressure switch work?

A 30-50 pressure switch is a device that controls the operation of a water pump. It monitors the water pressure in the system and turns the pump on when the pressure drops below 30 PSI. When the pressure reaches 50 PSI, the switch turns the pump off. This cycle repeats as needed to maintain water pressure in the system.

Watch a video: How Does An Air Compressor Pressure Switch Work?

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