In this article, we will discuss the essential parameters that every refrigeration and air conditioning technician must know about compressors. Let’s dive in!
1. RLA (Rated Load Amperage)
The RLA indicates the nominal current that the compressor should use under normal working conditions. This value is provided by the manufacturer and is used, among other things, to determine the appropriate wire gauge for installation.
2. FLA (Full Load Amperage)
The FLA represents the maximum current a compressor can consume at full load. This means the compressor can operate above the RLA value. Furthermore, the thermal protector (circuit breaker) will disconnect the compressor if the current exceeds the FLA.
3. LRA (Locked Rotor Amperage)
The LRA is the current the compressor consumes during startup. It represents the high current peak generated at the moment the compressor begins operation.
Thermodynamic Parameters
4. LBP (Low Back Pressure)
A compressor labeled as LBP is designed for low temperatures, with typical applications ranging between -35°C and -10°C.
5. MBP (Medium Back Pressure)
MBP compressors are ideal for medium-temperature applications, with a range between -10°C and 0°C.
6. HBP (High Back Pressure)
HBP compressors are suitable for high-temperature applications, typically between 0°C and 15°C.
Note: It is common to find compressors labeled as LBP/MBP or MBP/HBP, which indicates they can operate within more than one temperature range.
Mechanical Parameters
7. LST (Low Starting Torque)
LST identifies compressors with low starting torque. These compressors do not require a start capacitor and are used in systems with capillary expansion devices.
8. HST (High Starting Torque)
HST compressors have high starting torque and mandatorily require a start capacitor. Some models may also include run capacitors depending on the application.
Cooling Capacity
Although not an acronym-based parameter, cooling capacity is crucial when selecting a compressor. It represents the amount of thermal energy the evaporator can absorb, expressed in watts, kilocalories/hour, or BTU/hour.
It’s important to remember that selecting a compressor should not be based solely on the electrical power in HP, as different types of compressors (piston, scroll, rotary) can have varying efficiencies and cooling capacities.
Cooling capacity depends on the evaporation temperature, so it’s vital to choose a compressor that matches the system’s specific requirements.
