How To Adjust Pressure Switch on An Air Compressor

Is your air compressor not cutting off at the right pressure? This could be a sign that your pressure switch needs adjusting. Properly setting your pressure switch is crucial for ensuring safety and efficiency. In this post, you'll learn the key steps to safely adjust the cut-in and cut-out pressure settings of your air compressor.

Safety Precautions When Adjusting the Pressure Switch on an Air Compressor

Turn Off the Compressor and Disconnect Power

Before adjusting the pressure switch, turn off the compressor completely. Unplug it or flip off the breaker to prevent accidental startups. This is crucial because compressors can unexpectedly cut in, causing injury or electrical hazards. Ensure there is no power running to the system before proceeding.

Bleed the Tank to Release Air Pressure

Once powered down, it’s essential to release the air pressure from the tank. Open the drain valve carefully to bleed the excess air, minimizing the risk of an unexpected burst of pressure. Ensure that the tank is fully emptied before continuing.

Personal Protective Equipment (PPE)

When working on the pressure switch, always wear safety goggles and gloves. This protects your eyes and hands from debris or electrical shocks. Non-conductive tools are highly recommended for additional safety, especially when dealing with electrical connections.

Tools You Need for Adjusting the Pressure Switch

Essential Tools

To adjust the pressure switch on your air compressor, you’ll need a few essential tools:

• Screwdriver or wrench: Depending on your compressor model, these are necessary for accessing and adjusting the switch settings. Always check your manual to see which tool fits your specific switch.

• Dielectric grease or electrical solvent: These ensure smooth movement of the set screws and prevent future corrosion on electrical contacts. If the switch hasn’t been adjusted in a while, it can help loosen the screws.

  
  

Optional Tools

While the essential tools are often enough, a few optional items can make the process smoother and help maintain your system:

• Sandpaper: If the contacts are corroded, a light sanding with sandpaper can clean them up and improve the performance of the switch.

• Teflon tape: For reassembly, using Teflon tape on threaded connections ensures a tight, leak-proof seal, preventing air leaks during operation.

  
  

Quick Reference Chart

Step-by-Step Guide on How to Adjust the Pressure Switch on an Air Compressor

Step 1 – Locate the Pressure Switch

To begin, you need to identify the pressure switch on your air compressor. It’s usually found near the motor or tank, housed in a rectangular or cylindrical box with wires leading to it.

• Fixed range switches only allow for basic pressure adjustments.

• Adjustable range switches offer more control, with multiple adjustment screws for cut-in and cut-out pressure.

Knowing your switch type is important for accurate adjustments.

Step 2 – Adjust the Cut-in Pressure

Once the switch is located, you can adjust the cut-in pressure. This controls when the compressor starts to refill air.

• Clockwise turns on the adjustment nut increase pressure.

• Counterclockwise turns reduce it.

Cut-in pressure should be set according to the requirements of your tools. Most pneumatic tools operate best around 70-90 PSI, but always refer to your specific tool's manual for guidance.

Step 3 – Adjust the Cut-out Pressure

Next, adjust the cut-out pressure—this determines when the compressor stops after reaching maximum pressure. Proper cut-out settings protect your compressor from overworking.

• As with the cut-in adjustment, turn clockwise to increase cut-out pressure and counterclockwise to lower it.

• Maintain a 20-40 PSI differential between cut-in and cut-out to ensure your compressor operates efficiently without frequent cycling.

  
  

Step 4 – Test the Pressure Switch Settings

After making the necessary adjustments, it’s crucial to test the pressure settings. Power on the compressor and monitor its operation:

• Note when the compressor starts (cut-in) and stops (cut-out).

• If the settings aren’t quite right, make small adjustments and test again.

Watch for any inconsistent pressure, and ensure all air tools are functioning as expected.

Proper testing ensures the system runs smoothly and efficiently, meeting your specific needs.

Common Problems When Adjusting an Air Compressor Pressure Switch

Pressure Switch Doesn’t Engage/Disengage Correctly

If your pressure switch fails to engage or disengage as expected, there may be an electrical or mechanical issue. Start by ensuring all connections are secure and the switch is correctly installed.

Here are some steps to troubleshoot:

• Check electrical contacts: If the switch isn’t engaging, inspect the electrical connections for any signs of corrosion or loose wires. Clean or tighten the contacts as needed.

• Examine the diaphragm: A worn or damaged diaphragm may cause the switch to malfunction. If you suspect the diaphragm is faulty, it may need to be replaced.

• Test the compressor motor: If the compressor motor doesn’t start after adjusting the switch, check the motor for issues like overheating or power loss. Use a multimeter to verify voltage flow between the switch and motor.

If these troubleshooting steps don’t resolve the problem, consider replacing the pressure switch entirely.

Air Leaks Around the Switch

Air leaks are a common issue, especially in older compressors, and they often occur near the pressure switch or its components. Here’s how to identify and fix air leaks:

• Listen for hissing sounds: A constant hissing noise around the pressure switch is a clear indicator of an air leak.

• Inspect the diaphragm: If air is leaking from the pressure switch, the diaphragm could be cracked or worn out. Replacing the diaphragm can resolve this.

• Check connection points: Leaks can also occur around threaded connections. Use Teflon tape to seal these areas securely and prevent further leakage.

Regularly inspecting these components can help you catch leaks early, preventing pressure loss and maintaining efficiency in your compressor system.

Maintaining Your Air Compressor After Pressure Switch.

Regular Inspections

Regularly inspecting your air compressor ensures that the pressure switch operates correctly and identifies early signs of wear. Inspections should be performed monthly or after every 20-40 hours of use to prevent malfunction or failure.

Key points to check during inspections:

• Visual inspection: Look for visible wear, loose connections, or frayed wiring around the pressure switch.

• Pressure consistency: Ensure that the compressor maintains a stable cut-in and cut-out range. If the pressure fluctuates, recheck the settings.

• Signs of corrosion: Corrosion on contacts or components can disrupt electrical performance. Clean contacts regularly to avoid issues.

Cleaning and Lubrication

Keeping your pressure switch clean and lubricated ensures smooth operation and extends its lifespan. Here are the steps to maintain it:

1. Power down the compressor: Unplug the compressor and release any residual pressure from the tank before cleaning.

2. Clean electrical contacts: Use a non-flammable electrical solvent or dielectric grease to clean dirty or corroded contacts. Avoid using flammable liquids near electrical components.

3. Lubricate moving parts: Apply a light coat of dielectric grease to the adjustment screws and moving parts of the pressure switch to prevent rust and ensure smooth adjustments.

4. Inspect for debris: Look for dust or dirt buildup around the switch and clean it using a small brush or compressed air.

   
   

Adjusting your air compressor's pressure switch is of vital importance for safety and efficiency. Aivyter is involved in the development, manufacturing, marketing, and servicing of many types of air compressors. If you have any questions about air compressors, just contact us!