There’s nothing like a classic hardware compressor. Visually it’s a masterpiece and sonically it’s unrivalled for its premium sound.
Meticulously modeled after the instantly legendary hardware original, this compressor effortlessly tames the loudest transients with flawless control and amazing tone. The discrete side features three custom transformer settings allowing you to subtly shift its tonal footprint: Nickel adds distinction and airiness, Iron fortifies mid and lower-mid ranges and Steel thickens and warms things up.
Motor
Motors convert electrical energy into mechanical work. They work on the principles of electromagnetism, which states that electric current applied to conductors creates a magnetic force that can turn or spin those conductors. Electric motors are used in many applications, including AC compressors.
There are two primary parts of the motor: an outer stator with coils energized by alternating current to produce a spinning magnetic field and an inner rotor with conductors that hold magnets or have AC or DC electrical windings. The rotor conductors are then turned by the magnetic field of the stator, creating a second spinning magnetic field that turns the shaft. The resulting mechanical energy produces torque and speed.
The motor also has a bearing assembly that supports the rotor. It is also often equipped with a fan that moves ambient air over the motor and the bearings to cool them, dissipating heat. This helps lower the rotor shaft’s friction, which is important for efficiency.
In an AC motor, a three-phase AC supply provides power to the stator. Each of the three phases of the AC power has a different frequency and produces a different magnitude of sinusoidal current in each of the stator’s windings, as shown in this figure. The result is a set of three sinusoidal currents forming the pattern shown at six instants in each cycle.
The rotor conductors, which are short-circuited together at each end, are driven by the current in the same way as brushes on a DC motor. The resulting currents induce voltage in the rotor windings that is proportional to their rotational speed and the width of the air gap between the rotor and the stator. The induced voltage is divided by the conductor resistance to give the rotor currents shown in this figure.
Coil
A coil is a series of turns, usually circular or cylindrical, of current-carrying wire designed to produce a magnetic field or to provide electrical resistance or inductance. When an electric current passes through a coil of wire, the magnetic field it creates around the core changes (or moves) and stores energy in the form of electromagnetic flux.
The coil’s shape and the number of turns of the winding are used to determine its inductance. A coil with a core made of ferromagnetic material has the greatest inductance, and a coil without a core is the least inductance. A coil can have more than one winding, but each winding must be insulated from the others to prevent induction between them. A coil with more than one insulated winding is often referred to as a multi-coil or variable coil.
Coils are often used in circuits to control current and power flow. For example, a variable capacitor uses a pair of iron-core coils to increase or decrease the magnetic saturation of the auxiliary winding, which in turn controls the capacitor’s effective value. An inductor consists of several coils of wire wrapped on or around a central metal core, and it can also be a single coil with a soft iron core.
It is important to keep the coil clean and free of obstructions in order to maximize airflow. Poorly maintained condenser coils are inefficient, requiring the system to work harder to achieve the same cooling effect. This can lead to higher energy bills and expensive AC service calls. It is recommended that you clean the coil with a shop vacuum crevice tool or spray a coil cleaning solution.
Expansion Valve
Your cooling system relies on a variety of components to cool air, including your compressor and expansion valve. Without these parts your system could not convert refrigerant into a cold gas that will absorb heat from the air in your home.
When refrigerant exits the compressor it is in a hot, high-pressure liquid state that requires low pressure to transform back into a cold gas. The expansion valve takes this heat-heated liquid, removing its pressure and cooling it down into a vapor that can be sprayed into the evaporator coils.
The expansion valve is also responsible for regulating the flow of refrigerant through your system. It does this through a metering orifice that can be opened or closed by an electronic controller based on signals received from the compressor’s pressure sensors and superheat sensor. This is done by transforming rotational movement from the controller into linear displacement through a small motor, which is used to control an electronic stepper screw inside the expansion valve assembly.
The expansion valve is very sensitive to residues and acids that linger in the air conditioning system, especially those that are created during compressor operation. The failure of the valve’s flow regulation can cause a sudden increase in refrigerant superheat, which can damage or destroy the compressor’s internals. This is why it is so important to keep your system free of excess debris.
Ensure the longevity and efficiency of your air conditioning system by scheduling regular air conditioner cleaning services. By removing debris and preventing the buildup of residues and acids, you can safeguard crucial components like the expansion valve, ensuring optimal functionality and preventing potential damage to your system.
Compressor Clutch
The compressor clutch is a plate-like disc that fits on top of the compressor shaft (not the pulley as many might think). When activated it connects the compressor to the shaft, locking up the pulley so that the engine power can be used directly to drive the AC compressor. The clutch is operated electrically, so that the compressor only needs to be driven when needed to function; this helps reduce engine load when idling.
The clutch also disconnects the compressor from the pulley when the system is turned off. This prevents the compressor from pulling high-pressure refrigerant back into the suction side of the air conditioning system. The clutch is operated by an electromagnetic coil (like the one shown in this picture).
Problems with the AC compressor clutch can result in the AC system not working at all, and can lead to the accumulation of large amounts of refrigerant. Occasionally the clutch can stick in the “on” position, keeping the compressor running constantly, and causing damage to the compressor.
The most common cause of this is a poor gap between the clutch plate and the compressor pulley. Using a feeler gauge, you can check the gap and adjust it according to the service manual specifications for your vehicle model. Insufficient refrigerant levels can also keep the clutch from engaging, so it is important to have refrigerant checked and recharged if necessary. Often it is possible to replace only the clutch, allowing you to save money if repairing or replacing the compressor isn’t the right option for your situation. In other cases, it is more cost-effective to simply replace the clutch and compressor together.
Orifice Tube
The orifice tube does a similar job to the expansion valve, and it’s just as important. This fixed hole allows a certain amount of refrigerant to flow from the compressor into the evaporator. There is a screen around it to help prevent trash from making its way into the evaporator. If the orifice tube gets clogged it can block the flow of refrigerant, causing your AC to fail to cool.
This tube is typically found between the accumulator and the evaporator on many vehicles. It’s sometimes tricky to pull and requires a special tool, so be prepared. The orifice tube is usually marked with a small arrow that points in the direction of flow. Substituting a different color orifice tube may not work, so be sure to get the correct one for your vehicle’s system.
Just like the accumulator, this is an extremely important AC component to keep in good condition. If it fails, liquid will make its way back into the compressor and starve it of oil, resulting in failure. The AC accumulator helps to prevent this by collecting the low-pressure liquid that would otherwise make its way to the drier.
The accumulator also keeps it from making its way to the high-pressure side of the system, where it could cause damage to the compressor. While the AC accumulator doesn’t have any moving parts, it can still be subject to wear and tear over time. This is especially true for off-road vehicles that operate in rocky terrain where the AC system will often run against high pressures. This will erode the plastic over time, causing it to crack and break. A failing AC accumulator can also result in a foul smell coming from the vents when the AC is running.
