Quck answer
To wire an outside AC condenser, follow these steps:
1. Turn off the power: Before starting any electrical work, make sure to turn off the power to the condenser unit at the main electrical panel.
2. Gather the materials: You will need electrical wires, wire connectors, a wire stripper, and a screwdriver.
3. Connect the wires: Remove the access panel from the condenser unit and locate the terminal block. Connect the wires according to the manufacturer’s instructions, usually matching the colors.
4. Secure the connections: Use wire connectors to secure the connections and prevent any loose wires.
5. Test the connection: Turn the power back on and test the unit to ensure it is working properly.
Remember, if you are unsure about any step or lack experience with electrical work, it is best to hire a professional electrician to wire the outside AC condenser.
Handling the electrical wiring on a condenser is not a task that a DIYer should normally undertake, given that it involves high-voltage components and wiring connections that are difficult to access. Typically, these connections are made during the installation or replacement of an entire system, which is the responsibility of a professional HVAC contractor or licensed electrician.
Replacing a condenser also requires cutting the lines that carry refrigerant, which can result in the release of liquid refrigerant, an environmental issue that your community may not approve of. Connecting a new condenser involves soldering work to rejoin the refrigerant piping, and may also require adding more liquid refrigerant to a system, which local codes may not permit you to do, even if you wanted to.
For various reasons, then, this is not a DIY project for most people. However, if you’re interested in learning more, keep reading.
About the Components
The condenser is one of three essential components of a home air conditioning system. It is responsible for releasing the heat accumulated by the evaporator inside the house. The condenser, along with the compressor and fan, is housed in the metal cabinet outside the home. The third vital component, the evaporator, is located inside the house near the furnace blower mechanism.
How Air Conditioning Functions
Despite their complexity, air conditioners rely on simple physics, taking advantage of the fact that liquids absorb heat as they convert to gas, while gases release heat when they change back to liquids. It is the refrigerant inside the sealed piping of the air conditioning system that performs this function.
Simply put, the cycle of any central air conditioner is for the evaporator to absorb heat from inside the house as the liquid refrigerant evaporates and turns into a gas inside the sealed piping. The gaseous refrigerant then moves outside to the outdoor unit, where the compressor compresses the gas back into liquid form. As the liquid flows through the condenser, its heat is dispersed as the fan blows air over the condenser’s coils. The liquid refrigerant is then pumped back to the evaporator, where the cycle continues — gas to liquid, liquid to gas, transferring heat from one space to the other.
While there are other components to an air conditioning system, this basic overview explains why the condenser is so vital — it is this component that actually releases heat to the outdoors, and without it, your home would not cool at all.
Wiring an Air Conditioning Condenser
When a service professional installs a new condenser and finishes the refrigerant piping connections, connecting the electrical wiring will typically involve the following:
The installer or electrician must install two sets of wires when connecting the condenser. Both are connected to the same contactor relay, located inside the condensing unit. One set of wires provides high-voltage 240-volt current that powers the fan and compressor unit, while the other set of wires are low-voltage wires that run from the thermostat and inside furnace unit to turn the outside condenser ON and OFF when needed.
Turning Off the Power and Taking Off the Cover
Before beginning installation, the service person must ensure that the power is turned off. This typically involves shutting off two circuit breakers: one labeled FURNACE or AIR HANDLER, and the other labeled AC or AIR CONDITIONER.
Next, the service person will remove the control panel cover on the outside unit of the air conditioner, if it hasn’t already been removed. The control panel is located above the copper refrigerant lines that enter the unit. To remove the cover, pull it straight down from the condensing unit. Inside the control panel, you’ll see a black block with screw terminals and a can-shaped capacitor.
Connecting the Ground and High-Voltage Wires
The service person will push the high-voltage wires from the air conditioner disconnect box up through the wire clamp in the bottom of the box. These wires consist of two insulated power wires and one bare copper ground wire. The insulated wires may be black and red or black and white, and both carry 120 volts of hot current.
Credit: Bryan Trandem
The bare copper ground wire is connected to the ground terminal block first, using a flathead screwdriver. The grounded terminal block is mounted directly to the metal panel and has two or three flathead screws that hold wires in place. The copper wire is inserted into the ground terminal block and tightened with a screw.
The service person will strip about 1/2 inch of insulation from the ends of both insulated high-voltage wires using wire strippers. The stripped ends of these wires are then inserted into the high-voltage wire terminals. In a 240-volt circuit, both wires are hot, so either screw terminal will work. They are inserted into slots at the bottom of the contactor and tightened with screw terminals to secure the wires.
Credit: Bryan Trandem
The contactor, a black box-shaped component with spring-loaded bus bars and a low-voltage operating coil, acts as a high-voltage switch. The wires from the disconnect box connect to one end of the contactor, typically from the bottom. The fan and compressor wires connect to the other end of the contactor, typically at the top, and are already attached by the manufacturer. The two hot wires from the disconnect box must be inserted fully into the contacts and the screws fully tightened.
Connecting the Low-Voltage Wires
The installer will then insert the low-voltage wire set into the control box through the access opening. The low-voltage wire set consists of two individual wire strands inside an outer plastic sheathing.
Using a razor knife, the installer removes 2 to 3 inches of the outer plastic sheathing from the low-voltage cable, then strips about 1/2 inch of insulation from each inner conductor using wire strippers. The low-voltage wires usually use white and red insulation, but the colors do not matter.
To complete the installation process, the installer connects the low-voltage thermostat wires to the contactor by twisting together one wire from the contactor with one low-voltage wire and securing them with a wire nut. The remaining two wires are twisted together and secured with another wire nut, regardless of their colors. The low-voltage wires are then attached to push fittings on the side of the contactor block. The wire clamp is tightened with a flathead screwdriver, and the access cover of the condensing unit is replaced and screwed securely. The AC system’s power is turned on, and the unit is tested to ensure its proper operation.
FAQ
1. What is an outside AC condenser and what is its function?
An outside AC condenser is an essential component of an air conditioning system. It is typically located outside a building and is responsible for releasing heat from the refrigerant that has been absorbed indoors. The condenser consists of a compressor, a condenser coil, and a fan. When the refrigerant reaches the condenser, it is compressed by the compressor, causing it to become hot. The condenser coil then helps dissipate the heat, allowing the refrigerant to cool down and return to a liquid state. The fan helps to expel the hot air from the condenser to the surrounding environment, ensuring proper heat transfer.
2. What are the basic steps to wire an outside AC condenser?
Wiring an outside AC condenser involves several important steps to ensure a safe and efficient connection. Firstly, it is crucial to turn off the power supply to the condenser unit. Then, the electrical wires need to be properly stripped and prepared for connection. The wiring should be done according to the manufacturer’s instructions and local electrical codes. Typically, there will be three wires to connect: the power supply wire, the control wire, and the ground wire. These wires should be securely connected to the corresponding terminals in the condenser unit. Finally, the power supply can be turned back on to test the connection and ensure proper operation.
3. Are there any safety precautions to consider when wiring an outside AC condenser?
Yes, there are several safety precautions to consider when wiring an outside AC condenser. Firstly, always make sure to turn off the power supply before starting any wiring work. This will prevent the risk of electrical shock. Additionally, it is important to follow the manufacturer’s instructions and local electrical codes to ensure a safe and compliant installation. Properly grounding the condenser unit is also essential to protect against electrical faults. It is recommended to use insulated tools and wear appropriate personal protective equipment, such as gloves and safety glasses, when working with electrical components. If unsure about any aspect of the wiring process, it is best to consult a qualified electrician.