MINI SPLIT Parts Explained! Understand What They Do!

Understanding the Cooper and Hunter Inverter Mini Split Heat Pump Unit

Overview of Internal Components

• KRA M Gacho introduces the Cooper and Hunter inverter mini split heat pump unit, focusing on its internal parts and their functions.

• The sound deadening covers around the compressor and accumulator are removed; tar tape is used to reduce vibration between copper tubes.

• Unlike standard air discharge units, mini splits do not accumulate water in this area due to their side air discharge design.

Compressor Functionality

• The system uses a rotary compressor that typically pumps R41 or R32 refrigerant, with R41 being common in the US.

• The compressor operates on constant voltage but varying frequency, allowing for adjustable pumping speed which affects capacity.

• Inverter systems can adjust the speeds of the compressor, electronic expansion valve (EEV), outdoor fan, and indoor fan for efficiency.

Accumulator Tank Insights

• The accumulator tank serves multiple functions including oil return to the compressor; it has a strainer screen to prevent debris from entering.

• Liquid refrigerant levels vary based on system capacity; overcharging can lead to liquid refrigerant damaging the compressor.

• A larger accumulator may be used in multi-zone systems; it ensures only vapor enters the compressor while managing oil return.

Discharge Line Mechanics

• The discharge line carries high-pressure vapor from the compressor; it's crucial for monitoring temperature via a thermistor placed along this line.

• A muffler is installed on the discharge line to minimize pulsations caused by changing frequencies at the inverter compressor.

Understanding Refrigerant Flow and System Components

Muffler and Refrigerant Accumulation

• The frequency of refrigerant flow changes can cause vibrations, leading to noise; mufflers are used to deaden this sound by providing space for refrigerant accumulation.

• Inside the muffler, there is no desiccant; it serves as a gathering place for refrigerant before it moves into the reversing valve.

Reversing Valve Mechanism

• The reversing valve has a U-shaped slide mechanism that connects different pipes, allowing for directional flow control of the refrigerant based on pressure differences.

• High pressure on one side of the valve causes it to slide in that direction, changing the flow of refrigerant throughout the system.

Electric Expansion Valve (EEV)

• The EEV acts as a pressure reduction device, separating high and low-pressure sides of the system; its operation involves adjusting hole size via a rotating pin controlled by electrical signals.

• The EEV is powered by 12 volts from an outdoor PCB and features multiple coils that manage its function through varying voltage signals.

Importance of Proper Installation

• When removing or reinstalling an EEV head, it's crucial to return it to its original position to ensure proper functionality within the system.

Temperature Sensors in Refrigeration Systems

• Temperature sensors like thermistors measure resistance changes based on temperature; they monitor both air and refrigerant temperatures critical for system performance.

• Thermistors are mounted directly onto tubing to continuously measure refrigerant temperature while K-type sensors monitor outdoor air temperature before heat exchange occurs.

Understanding Mini Split Systems and Their Components

Fan Motor Operation

• The fan motor operates at a fixed voltage with a variable frequency, affecting airflow across the outdoor coil. Lower electrical frequencies result in slower fan speeds, while higher frequencies increase speed.

Base Pan Heater Functionality

• A base pan heater is installed to prevent freezing during heating mode, ensuring condensate does not freeze on the coil. This is crucial for maintaining system efficiency in colder conditions.

Crank Case Heater Importance

• The crank case heater, mounted at the rotary compressor's base, uses low wattage to heat both refrigerant and oil for optimal low-temperature operation. This preparation is essential for efficient system performance.

Control Boards Overview

• The system typically includes two main boards: the Intelligent Power Module (IPM) and the Printed Circuit Board (PCB). These boards manage various functions including communication between indoor and outdoor units.

Electrical Connections and Communication

• The PCB communicates with an indoor unit PCB through temperature sensors that monitor conditions at both ends, allowing efficient control of components like fans and compressors based on real-time data.

Wiring Specifications

• Main power wires are housed in flexible sleeves or conduits to protect against environmental factors; these wires carry 240 volts as opposed to standard communication wires used in single-speed systems. Proper insulation is critical for safety and functionality.

Surge Protection Necessity

• Two primary causes of mini split failures include refrigerant leaks from poor flares and electrical surges due to voltage fluctuations; thus, surge protection devices should be installed at disconnect points or breakers to safeguard equipment.

Service Valves Role

• Service valves retain refrigerant until installation completion; they must only be opened after pressure testing and vacuuming lines are confirmed secure to prevent leaks during operation. Proper flare connections are vital for system integrity.

This structured overview provides insights into key components of mini split systems, emphasizing their operational significance and maintenance requirements for effective performance.

Cooper and Hunter Mini Split Installation Insights

Importance of Quality Flare Nuts

• The flare nuts from the unit are often cut off due to their inferior quality compared to manufacturer-supplied ones, which meet specific torque specifications.

• In this case, since the line set is also from Cooper and Hunter, the existing flare nuts will remain attached for connection purposes.

• Utilizing the existing flares on the line set ensures compatibility with service valves during installation.

Additional Resources

• Viewers are encouraged to check links in the description for more information on Cooper and Hunter HVAC systems.

• AcerTech.com offers several articles and videos dedicated to mini splits for further learning opportunities.