Carrier AQUAZONE 50RHC Installation And Service Instructions Manual

Also see for AQUAZONE 50RHC: Operating and troubleshooting

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Carrier AQUAZONE 50RHC Installation And Service Instructions Manual Manual pdf 33 page image

33Operating LimitsENVIRONMENT — This equipment is designed for indoorinstallation ONLY. Extreme variations in temperature, hu-midity and corrosive water or air will adversely affect theunit performance, reliability and service life.POWER SUPPLY — A voltage variation of ± 10% ofnameplate utilization voltage is acceptable.UNIT STARTING CONDITIONS — Depending on themodel, units start and operate in an ambient temperature of45 F with entering-air temperature at 40 F or 50 F, entering-water temperature at 20 F or 50 F and with both air and water atthe flow rates used.NOTE: These operating limits are not normal or continuousoperating conditions. Assume that such a start-up is for thepurpose of bringing the building space up to occupancytemperature. See Tables 18 and 19 for operating limits.1. Restore power to system.2. Turn thermostat fan position to ON. Blower shouldstart.3. Balance airflow at registers.4. Adjust all valves to the full open position and turn onthe line power to all heat pump units.5. Operate unit in the cooling cycle. Refer to Tables 18and 19 for unit operating limits.NOTE: Three factors determine the operating limits of aunit: (1) entering-air temperature, (2) water temperature and(3) ambient temperature. Whenever any of these factors areat a minimum or maximum level, the other two factors mustbe at a normal level to ensure proper unit operation. SeeTables 18 and 19.Scroll Compressor Rotation — It is important tobe certain compressor is rotating in the proper direction. Todetermine whether or not compressor is rotating in the prop-er direction:1. Connect service gages to suction and discharge pressurefittings.2. Energize the compressor.3. The suction pressure should drop and the dischargepressure should rise, as is normal on any start-up.If the suction pressure does not drop and the dischargepressure does not rise to normal levels:1. Turn off power to the unit. Install disconnect tag.2. Reverse any two of the unit power leads.3. Reapply power to the unit and verify pressures are correct.The suction and discharge pressure levels should now moveto their normal start-up levels.When the compressor is rotating in the wrong direction, theunit makes more noise and does not provide cooling.After a few minutes of reverse operation, the scroll com-pressor internal overload protection will open, thus activatingthe unit lockout. This requires a manual reset. To reset, turn thethermostat on and then off.NOTE: There is a 5-minute time delay before the compressorwill start.Unit Start-Up Cooling Mode1. Adjust the unit thermostat to the warmest position.Slowly reduce the thermostat position until the compres-sor activates.2. Check for cool air delivery at unit grille a few minutesafter the unit has begun to operate.3. Verify that the compressor is on and that the water flowrate is correct by measuring pressure drop through theheat exchanger using P/T plugs. See Table 20. Check theelevation and cleanliness of the condensate lines; anydripping could be a sign of a blocked line. Be sure thecondensate trap includes a water seal.4. Check the temperature of both supply and discharge wa-ter. Compare to Table 21. If temperature is within range,proceed. If temperature is outside the range, check thecooling refrigerant pressures in Table 21.5. Check air temperature drop across the coil when com-pressor is operating. Air temperature drop should bebetween 15 and 25 F.Table 18 — Operating Limits — 50RHC,RVC UnitsLEGENDTable 19 — Operating Limits —50RHR,RHS,RVR,RVS,RDS UnitsLEGENDNOTE: Value in heating column is dry bulb only. Any wet bulb read-ing is acceptable.Table 20 — Water Temperature ChangeThrough Heat ExchangerWhen the disconnect switch is closed, high voltage ispresent in some areas of the electrical panel. Exercisecaution when working with the energized equipment.Failure to heed this warning could lead to personalinjury. AIR LIMITS 50RHC,RVCCooling HeatingMin. Ambient Air – db 45 F 45 FRated Ambient Air – db 80.6 F 68 FMax. Ambient Air – db 110 F 85 FMin. Entering Air – db/wb 70/61 F 50 FRated Entering Air – db/wb 80.6/66.2 F 68 FMax. Entering Air – db/wb 95/76 F 80 FWATER LIMITSMin. Entering Water 50 F 50 FNormal Entering Water 60-90 F 60-70 FMax. Entering Water 110 F 90 FNormal Water Flow 2.5-3.0 gpm per tondb — Dry Bulbwb — Wet BulbAIR LIMITS COOLING (F) HEATING (F)Min. Ambient Air 45 45Rated Ambient Air 80 70Max. Ambient Air 100 85Min. Entering Air 50 40Rated Entering Air db/wb 80/67 70Max. Entering Air db/wb 110/83 80WATER LIMITSMin. Entering Water 30 20Normal Entering Water 50-90 30-60db — Dry Bulbwb — Wet BulbWATER FLOW RATE (GPM)COOLINGRISE (F) HEATINGDROP (F)Min Max Min MaxFor Closed Loop: Ground Source orCooling/Boiler Systems at 3 gpm/ton 9 12 4 8For Open Loop: Ground Water Systems at1.5 gpm/ton 20 26 10 17