Hayward HP21404T Heat Pump Installation Manual - Page 17

FIGURE 15: Location of Components (Heating Operation Flow Shown) Heat From Air C TXV Reversing A Valve E Hot Water Out D Cold Water In B Air Coil (Evaporator) Compressor Water Heat Exchanger (Condenser) The heat pump takes heat from the environment and uses it to heat the pool water. During heat pump operation, high temperature, high-pressure sub cooled liquid Refrigerant (A) is throttled by Metering Device (TXV) and turned into low temperature, low-pressure saturated liquid (B). The two-phase Refrigerant flows through the Air Coil (Evaporator), where the liquid refrigerant evaporates into vapor by absorbing heat from the surrounding air. At the outlet of the Air Coil (Evaporator) it becomes a low temperature, low pressure superheated vapor (C). The Compressor receives this flow at the suction line (D), and compresses it into a high temperature, high pressure superheated vapor, which is discharged from the Compressor (E) and flows into the Water Heat Exchanger (Condenser). The heat carried by the flow is then released to the pool water. At the same time, the high temperature, high-pressure superheated vapor is then condensed back to high-pressure sub cooled liquid (A), which completes the cycle. The water, which is being forced through the Water Heat Exchanger (Condenser) by the pool pump, is thus heated as it passes through. Heat Pump Protection Features These heat pumps are equipped with safeguards that will stop heater operation to protect the unit in case of the following events: • Excessively high refrigerant pressure • Excessively high water temperature • Loss of refrigerant • Fan Motor Failure • Evaporator Freeze-up • Low Ambient Temperature Control Setup Heat Only Models This pool heater is equipped with a digital thermostat which allows the user to select the desired water temperature. The heater will then function automatically to maintain the desired temperature. The heater has 3 modes of operation: 1. SPA - in this mode, the heater will automatically function to maintain the water temperature setting for SPA mode. 2. POOL - in this mode, the heater will automatically function to maintain the water temperature setting for POOL mode. 3. REMOTE OPERATION - In this mode the heater will respond to a remote call for heat or to control unit operation mode. Use the set button in Figure 16a to select POOL/SPA modes. The arrows will indicate which mode is currently active. Control Setup Heat/Cool Models This pool heater is equipped with a digital thermostat which allows the user to select the desired water temperature. The heater will then function automatically to maintain the desired temperature. The heater has 4 modes of operation: 1. HEAT - in this mode, the heater will automatically function to maintain the water temperature setting for HEAT mode. 2. COOL - in this mode, the heater will automatically function to maintain the water temperature setting for COOL mode 3. AUTO - in this mode, the heater will automatically function to maintain the water temperature setting for AUTO. It will operate in HEAT or COOL mode as required. 4. REMOTE OPERATION - In this mode the heater will respond to a remote call for HEAT or COOL mode. Use the set button in Figure 16b to select HEAT/ COOL/AUTO modes. The arrows will indicate which mode is currently active. 16 USE ONLY HAYWARD GENUINE REPLACEMENT PARTS