When it comes to air conditioning systems, a 3 wire fan delay Klixon is a common component that plays a critical role in regulating the temperature. Understanding how it works and how it is wired can help HVAC professionals troubleshoot problems and ensure that the system runs smoothly. In this article, we will dive into the details of the 3 wire fan delay Klixon wiring diagram, including its purpose, components, and important considerations.
What is a 3 Wire Fan Delay Klixon and What is its Purpose?
A 3 wire fan delay Klixon is a temperature-sensitive switch that controls the fan operation in an air conditioning system. Specifically, it is designed to turn on the fan motor after the compressor has completed its cycle, which helps to prevent the system from overheating and also increases energy efficiency. The delay in fan operation is necessary because the fan blowing air across the evaporator coil can cause the coil to freeze up if it is started too soon.
The 3 wire fan delay Klixon is typically located in the air handler unit of the AC system, and it has three wires that connect to the fan motor, the thermostat, and the compressor. When the thermostat calls for cooling, the compressor initiates, and the Klixon switch senses the temperature of the refrigerant in the suction line. If the temperature is below a certain threshold, the switch remains open, and the fan motor does not start. Once the threshold temperature is reached, the switch closes, and the fan motor is energized after a set delay time.
Components of the 3 Wire Fan Delay Klixon
The 3 wire fan delay Klixon is a small, disc-shaped component with a bimetallic disc and a heater coil inside. The disc expands and contracts with temperature changes, which triggers the switch to open or close. The heater coil is connected to the fan motor and provides the necessary time delay before the fan starts. The switch also has a small metal tab that can be manually pushed in to reset the switch if it becomes tripped.
Important Considerations When Wiring the 3 Wire Fan Delay Klixon
Wiring mistakes can result in poor system performance or even damage to the fan motor or compressor. Here are some important considerations to keep in mind when wiring the 3 wire fan delay Klixon:
- Wire the Klixon switch in series with the fan motor so that it is energized only when the fan is running.
- Wire the switch in parallel with the compressor contactor so that it closes when the compressor starts.
- Use wire connectors or terminals that are rated for the current and voltage of the system.
- Make sure all wiring connections are tight and secure.
- Follow the wiring diagram provided by the manufacturer or consult a professional.
Wiring Diagram for the 3 Wire Fan Delay Klixon
Below is a wiring diagram for the 3 wire fan delay Klixon:
| Wire Color | Function |
| Black | Fan Motor |
| Brown | Compressor Contactor |
| Violet | Thermostat |
The black wire connects to one side of the fan motor, and the other side of the motor is connected to the other two wires. The brown wire connects to one side of the compressor contactor, and the violet wire connects to the thermostat. The other side of the compressor contactor and the other side of the thermostat connect to the power source.
FAQ About the 3 Wire Fan Delay Klixon Wiring Diagram
What happens if the 3 wire fan delay Klixon switch fails?
If the Klixon switch fails, it can potentially cause the fan motor to run continuously, which can lead to overheating and damage to the compressor. It is important to replace a failed switch as soon as possible to prevent further damage to the system.
What is the purpose of the heater coil in the 3 wire fan delay Klixon?
The heater coil provides a time delay before the fan motor starts. This delay allows the refrigerant in the system to reach the proper temperature before the fan blows air over the evaporator coil, which helps to prevent freezing and improve energy efficiency.
Can the 3 wire fan delay Klixon be bypassed?
No, the Klixon switch should not be bypassed. Doing so can result in poor system performance and potential damage to the system components.
Can I install a 3 wire fan delay Klixon myself?
It is recommended to have a professional HVAC technician install the Klixon switch. Improper installation can result in wiring mistakes, which can lead to poor system performance or damage to the system components.
What is the lifespan of a 3 wire fan delay Klixon?
The lifespan of a Klixon switch can vary depending on the usage and environment of the AC system. On average, a Klixon switch can last between 5-10 years before needing replacement.
How do I troubleshoot a problem with the 3 wire fan delay Klixon?
If the fan motor is not starting or the system is not cooling properly, the Klixon switch may be at fault. Check the wiring connections to ensure they are tight and secure. Use a multimeter to check the resistance of the switch to see if it is functioning properly. If the switch is faulty, it will need to be replaced.
What are some signs that the 3 wire fan delay Klixon switch is failing?
Some signs of a failing Klixon switch include the fan motor running continuously, the system not cooling properly, or the fan motor not starting at all. If you notice any of these issues, it is important to have the system inspected by a professional HVAC technician.
