Refrigerant control devices.
Many types of refrigerant control components are used in mobile air conditioning systems today. These refrigerant control devices vary in complexity and design according to the type of system, make, model and year of the car they are installed in. What they have in common is their purpose. These devices keep an eye on refrigerant level, temperature and pressure inside the hvac system therefore maintaining the air conditioning parameters in your car within a safe and as efficient as possible threshold providing maximum cold air output with the less fuel consumption. It is critical for modern a/c systems to cool down your car fast but at the same time putting minimum load over the engine and with the least stress for ac components.
The life of the a/c automotive main components: a/c lines, hoses, hvac compressor, condenser, evaporator, evaporator pressure regulators, etc. will be determined by the correct operation of these refrigerant control devices. Replacing damaged main a/c components without finding the cause or the failing control device that was unable to monitor, activate/deactivate and report to the ECM or PCM an out of range parameter in the system will only lead to more expensive repairs in the future.
These are some of the refrigerant control devices that will help the ECM, PCM or BCM to make correct decisions that will ensure long-lasting ac components in your vehicle’s system:
Automotive a/c Dual Pressure Switch
The dual pressure switch is usually fitted between the thermal expansion valve and the receiver drier. It detects pressure on the high side of the system and switches on the cooling fan to high speeds and turns off the magnetic hvac compressor clutch shutting down the compressor when the pressure is abnormal, thus preventing a/c system component damage.
Automotive A/C High Pressure Relief Valves
The high pressure relief valve is a blow off valve, designed to release refrigerant into the atmosphere if pressures get to a point where it could irreversibly damage any a/c component. The dual contact pressure switches have replaced most HPRV to prevent refrigerant venting to the atmosphere adding more contamination.
Automotive A/C Fusible plugs.
Japanese manufacturers often used a fusible plug, or melting bolt, in their systems. These plugs were designed to melt if high side temperatures became too high. This would allow the system to release the refrigerant, and protect the system from damage. A problem with the fusible plugs is they are onetime use devices and won’t reset once the high pressure has been released. With fusible plugs you end up losing the whole system charge and adding more contamination to the atmosphere.
Automotive A/C Low Pressure Cutoff Switch.
The low pressure cutoff switch shuts the compressor down when refrigerant levels drop too low, preventing the compressor from running when refrigerant levels are too low to provide enough lubrication back to the compressor.
Automotive A/C High Pressure Cutoff Switch.
Some vehicles have a high pressure cutoff switch designed to shut the system off if pressures get too high.
Automotive A/C Low Side Refrigerant Temperature Sensor.
Some A/C systems use a low side refrigerant temperature sensor, which is a thermistor that changes resistance in relation to temperature.
Automotive A/C High Side Refrigerant Temperature Sensor.
It is used to help the engine control module (ECM) or Power train control module (PCM) to determine when to turn the compressor on and off and when to run the cooling fans.
automotive A/C Superheat Switch and Thermal Limiter Fuse.
The superheat switch and thermal limiter fuse protect the compressor against loss of refrigerant and oil. They monitor the temperature of the vapor coming out from the evaporator core and sends a signal to the thermal limiter if the temperature of the vapor gets too high activating a circuit that will shut down the hvac compressor.
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