Carrier 38XTZ 007-024 Installation, Operation And Maintenance Instructions

36- Fan high pressure switch (38XTZ 014).- Low pressurestat: This protects the 40ABZ/ALZ unitsagainst excessive low pressure in the evaporator or in therefrigerant lines.The low pressurestat has factory fixed non-adjustablesettings. To check, see section Initial checks.CAUTION: When any of these cuts out, the unit stops andwill not re-start until the contacts have been reclosed afterrectification of the fault.Table 13 - Pressure switch settings38XTZ 007, 008, 011, 016, 020 and 024Cut-out Cut-in ResetHigh pressurestat *2844 kPa *1863 kPa ManualLow pressurestat *265 kPa *363 kPa Automatic* Factory-calibrated38XTZ 014Cut-out Cut-in ResetHigh pressurestat *2844 kPa *1863 kPa- ManualLow pressurestat *265 kPa *363 kPa AutomaticHigh pressurestat, fan *2354 kPa *1863 kPa Automatic* Factory-calibratedWARNING: Alteration of factory settings other than thedesign set-point, without manufacturer's authorisation, mayvoid the warranty.Table 14 - Operating limitsZone Air temperature °CMin. Max.Cooling operation:IndoorMaximum +35 +21Minimum +19 +14OutdoorMaximum +40/44* -Minimum 19** -Indoor air flowMaximum +20% of nominal valueMinimum -20% of nominal valueHot water coil (accessory/option)Maximum water temperature 80°C* Sizes 007, 011, 014, 020 and 024: 40°CSizes 008 and 016: 44°C** With optional/accessory head pressure control, the unit will operate attemperatures below 19°C.ATTENTION: Operation of the units at temperatures, airflows, etc. outside the limits indicated in the table above cancause serious damage to the units and will void the Carrierwarranty.GENERAL MAINTENANCEATTENTION: Before starting any servicing or maintenanceoperation on the unit, make sure that the power supply hasbeen disconnected. A current discharge could cause personalinjury.In order to obtain maximum performance from the unit specialattention should be paid to the following points:- Electrical connections: The supply voltage should bewithin the limits permitted by the compressor and the unit.Ensure that no faulty contacts exist in the terminal blocks,contactor boards, etc. Make sure that all the electricalconnections are properly tightened, and that all theelectrical components (contactors, relays, etc) are firmlysecured to the corresponding rails.Pay special attention to the condition of the connectingcables between the control elements and the electrical box,and to that of the unit power supply cable. They should notbe twisted and there should be no slits or notches in theinsulation. Check the starting and running consumptionsare within the limits specified in the correspondingtechnical information.- Drainage: Frequently check that the drain is not obstructed,and that the condensate pan is clean and level. Ensure thatthe condensate drain pan of the 40ABZ/ALZ unit isperfectly clean and does not contain sludge or otherforeign substances, corrosion, etc. and is level.- Inlet filter: This should be cleaned periodically. Thefrequency depends on the purity of the entering air. Thefilter may be cleaned with a household vacuum cleaner, orby immersing it in water.- Refrigerant circuit: Ensure that there is no leakage ofrefrigerant or oil from the compressor. Check that the highand low side operating pressures are normal. Make surethat the coils are not dirty, if necessary clean with waterand air. Straighten bent aluminium fins with a suitable fincomb. Check for unusual compressor noise.- Controls: Check the operation of all electric controls, highand low pressurestats, etc.- Fans: The fan of the 38XTZ unit must rotate freely. Theremust not be any foreign elements in the fans of the40ABZ/ALZ indoor units. Please check:a) the condition of the pulleysb) the condition of the beltsc) the belt tension.Periodically check the condition of the belts and pulleys andensure that they are correctly aligned. Also ensure that thebelt tension is correct. At the first start-up, and after a longershut-down period, recheck the belt tension after a few hoursof operation.