How to Wire an Air Compressor Switch: A Comprehensive Guide

An air compressor is an essential tool for various applications, from automotive repair to industrial manufacturing. However, before you can make use of your air compressor, you need to ensure that it is wired properly. One important aspect of this process is the air compressor switch wiring diagram. In this article, we will provide a comprehensive guide on how to wire an air compressor switch in a step-by-step approach to help you accomplish your wiring needs.

What is an Air Compressor Switch?

An air compressor switch is a device used to control the operation of an air compressor. Usually, it is mounted on the air compressor and serves as a bridge between the power source and the motor. It is designed to turn the air compressor on and off automatically based on the tank pressure. When the pressure drops below a predetermined level, the switch closes the circuit and turns the compressor on. Conversely, when the pressure reaches the maximum level, the switch opens the circuit and shuts the compressor off.

Parts of an Air Compressor Switch

An air compressor switch consists of two main parts: the pressure switch and the power switch. The pressure switch is responsible for monitoring the tank pressure and signaling the power switch to turn the motor on or off. It has two pressure settings: the cut-in pressure and the cut-out pressure. The cut-in pressure is the minimum pressure at which the switch turns the compressor on, while the cut-out pressure is the maximum pressure at which the switch turns the compressor off. The power switch, on the other hand, is responsible for turning the motor on or off when signaled by the pressure switch. It is usually a rocker switch with two positions: on and off.

Types of Air Compressor Switches

There are two main types of air compressor switches: the single-pole, single-throw (SPST) switch and the double-pole, double-throw (DPDT) switch. The SPST switch has one set of contacts that either open or close the circuit when the switch is turned on or off. It is usually used for small air compressors with low horsepower motors. The DPDT switch, on the other hand, has two sets of contacts that can be connected in different ways depending on the application. It is usually used for larger air compressors with high horsepower motors.

Tools and Materials Needed

Before we proceed with the wiring process, let us first identify the tools and materials needed:

Tools Materials
Screwdriver Air compressor switch
Wire stripper/cutter Wire connectors
Electrical tape Wire

Step-by-Step Guide on How to Wire an Air Compressor Switch

Step 1: Turn off the Power

The first step before wiring an air compressor switch is to turn off the power supply to the compressor. This is to ensure your safety and prevent any electrical accidents from happening. Locate the power source of the air compressor and flip the switch or unplug the unit from the wall socket.

Step 2: Remove the Cover of the Pressure Switch

Next, locate the pressure switch of the air compressor and remove the cover. This will give you access to the terminals where the wires will be connected. The pressure switch usually has four terminals: two for the power switch and two for the motor.

Step 3: Connect the Power Wires

Using a screwdriver, connect the power wires to the two terminals of the power switch. The wires are usually color-coded, so it is easy to identify which one goes where. The black wire is the hot wire and should be connected to the brass terminal, while the white wire is the neutral wire and should be connected to the silver terminal. Tighten the screws to secure the wires in place.

Step 4: Connect the Motor Wires

Using a wire stripper/cutter, strip the insulation off the motor wires and connect them to the two terminals of the pressure switch. The motor wires are usually color-coded as well. The black wire is the hot wire and should be connected to the NO (normally open) terminal, while the white wire is the neutral wire and should be connected to the common terminal. Tighten the screws to secure the wires in place.

Step 5: Test the Wiring

Before you replace the cover of the pressure switch, test the wiring to ensure that it is working properly. Turn the power back on and observe the operation of the compressor. The switch should turn the motor on when the tank pressure drops below the cut-in pressure and turn it off when it reaches the cut-out pressure.

FAQ

Q: Can I use any type of air compressor switch?

A: No, you should select an air compressor switch that is compatible with the motor of your air compressor. Check the specifications of the switch to ensure that it can handle the amperage of your motor.

Q: How do I know the cut-in and cut-out pressure of my compressor?

A: The cut-in and cut-out pressure of your compressor can be found in the manual or on the label of the compressor. Make sure to set the pressure switch to the values indicated.

Q: What size wire should I use for the motor?

A: The size of the wire depends on the amperage of the motor. Consult an electrician or refer to the manual of the air compressor for the recommended wire size.

Q: Can I wire the air compressor switch myself?

A: Yes, you can wire the air compressor switch yourself as long as you follow the proper procedures and safety precautions. If you are not confident with your electrical skills, it is best to seek the help of a licensed electrician.

Q: How often do I need to replace the air compressor switch?

A: The air compressor switch can last for several years with proper maintenance. However, if you notice any signs of wear or malfunction, such as failure to turn on or off, it is best to replace the switch immediately.

Conclusion

Wiring an air compressor switch may seem daunting, but with the proper tools and guidance, it can be accomplished with ease. Make sure to follow the steps provided in this guide and observe safety precautions to ensure a successful and safe wiring process. If you have any questions or concerns, do not hesitate to seek the help of a licensed electrician.