Carrier GT-PX Split Series Installation, Operation & Maintenance Instructions Manual

23R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 AR e v. : 5 J u n e , 2 0 0 8C a r r i e r : Tu r n t o t h e E x p e r t sHot Water GeneratorFigure 15: Typical HWG Installation(Indoor Compressor Section)Figure 16: HWG Double Tank In stal la tion(Indoor Compressor Section)Shut-off Valve #2Cold InletHot Outletto homeInsulated water lines -5/8” OD, 50 ft maximumPoweredWaterHeaterUpperelement to120 - 130°F[49 - 54°C]Lowerelement to100 - 110°F[38 - 43°C]DomesticCold SupplyTee and drainShut-off Valve #3[16mm OD, 15 metersmaximum]Shut-off ValveShut-offValve #4Shut Off Valve #2Insulated water lines - 5/8” OD, 50 ft maximum[16mm OD, 15 meters maximum]Upper element to 130°F [54°C](or owner preference)Cold InletHot Outlet tohousePoweredWater HeaterCold Inlet fromDomestic supplyHot OutletUnpoweredWater HeaterField Supplied 3/4” brass nipple and “T”Lower element to 120°F [49°C]Shut-offValve #1Shut-offValve #4Shut-offValve #3The HWG (Hot Water Generator) or desuperheateroption provides considerable operating cost savings byutilizing excess heat energy from the heat pump to helpsatisfy domestic hot water requirements. The HWGis active throughout the year, providing virtually freehot water when the heat pump operates in the coolingmode or hot water at the COP of the heat pump duringoperation in the heating mode. Actual HWG waterheating capacities are provided in the appropriate heatpump performance data.Heat pumps equipped with the HWG option includea built-in water to refrigerant heat exchanger thateliminates the need to tie into the heat pumprefrigerant circuit in the fi eld. The control circuit andpump are also built in for residential equipment. Figure15 shows a typical example of HWG water pipingconnections on a unit with built-in pump. This pipinglayout minimizes scaling potential.Electric water heaters are recommended. If a gas,propane, or oil water heater is used, a second preheattank must be installed (Figure 16). If the electric waterheater has only a single center element, the dual tanksystem is recommended to insure a usable enteringwater temperature for the HWG.Typically a single tank of at least 52 gallons (235 liters)is used to limit installation costs and space. However,a dual tank, as shown in Figure 16, is the most efficientsystem, providing the maximum storage and temperatesource water to the HWG. Using a concentric or coaxialhot water tank connection fitting eliminates the need totie into the hot water tank cold water piping, but is moresusceptible to scaling. The optional concentric fitting(part # S69619804) is available from your equipmentsupplier and should be installed as shown in Figure17 for applications with low scaling potential or wherea water softener is used. Consult Table 3 for scalingpotential tests.It is always advisable to use water softeningequipment on domestic water systems to reducethe scaling potential and lengthen equipment life.In extreme water conditions, it may be necessary toavoid the use of the HWG option since the potentialcost of frequent maintenance may offset or exceedany savings.R-410 systems inherently have a lower hot gastemperature than R-22 systems because theequipment is more efficient (i.e. less waste heatis available). It is possible that energy could betransferred from the water heater to the hot gas lineinstead of from the hot gas line to the water heaterduring certain times of the year. To prevent this fromoccuring, a temperature switch will deactivate thepump at those conditions that typically occur in thecooling mode with entering water temperatures of lessthan 50°F [10°C].