Carrier 50YDV Installation, Operation And Maintenance Instructions

Carrier 50YDV Installation, Operation And Maintenance Instructions Manual pdf 42 page image

R e s i d e n t i a l P a c k a g e d U n i t s - 6 0 H z P u r o n ®R e v. : 4 J a n . , 2 0 1 242Preventive MaintenanceWater Coil Maintenance(Direct ground water applications only) - If the system isinstalled in an area with a known high mineral content(125 P.P.M. or greater) in the water, it is best to establish aperiodic maintenance schedule with the owner so the coilcan be checked regularly. Consult the well water applicationssection of this manual for a more detailed water coil materialselection. Should periodic coil cleaning be necessary, usestandard coil cleaning procedures, which are compatiblewith the heat exchanger material and copper water lines.Generally, the more water flowing through the unit, the lesschance for scaling. Therefore, 1.5 gpm per ton [2.0 l/m perkW] is recommended as a minimum flow. Minimum flowrate for entering water temperatures below 50°F [10°C] is 2.0gpm per ton [2.6 l/m per kW].Water Coil Maintenance(All other water loop applications)Generally water coil maintenance is not needed for closedloop systems. However, if the piping is known to havehigh dirt or debris content, it is best to establish a periodicmaintenance schedule with the owner so the water coil canbe checked regularly. Dirty installations are typically the resultof deterioration of iron or galvanized piping or componentsin the system. Open cooling towers requiring heavy chemicaltreatment and mineral buildup through water use can alsocontribute to higher maintenance. Should periodic coilcleaning be necessary, use standard coil cleaning procedures,which are compatible with both the heat exchanger materialand copper water lines. Generally, the more water fl owingthrough the unit, the less chance for scaling. However, flowrates over 3 gpm per ton (3.9 l/m per kW) can produce water(or debris) velocities that can erode the heat exchanger walland ultimately produce leaks.Hot Water Generator CoilsSee water coil maintenance for ground water units. If thepotable water is hard or not chemically softened, the hightemperatures of the desuperheater will tend to scale evenquicker than the water coil and may need more frequentinspections. In areas with extremely hard water, a HWG isnot recommended.FiltersFilters must be clean to obtain maximum performance.Filters should be inspected every month under normaloperating conditions and be replaced when necessary. Unitsshould never be operated without a filter.Washable, high effi ciency, electrostatic filters, when dirty,can exhibit a very high pressure drop for the fan motor andreduce air fl ow, resulting in poor performance. It is especiallyimportant to provide consistent washing of these filters (inthe opposite direction of the normal air flow) once per monthusing a high pressure wash similar to those found at self-serve car washes.Condensate DrainIn areas where airborne bacteria may produce a “slimy”substance in the drain pan, it may be necessary to treat thedrain pan chemically with an algaecide approximately everythree months to minimize the problem. The condensate panmay also need to be cleaned periodically to insure indoorair quality. The condensate drain can pick up lint and dirt,especially with dirty filters. Inspect the drain twice a year toavoid the possibility of plugging and eventual overflow.CompressorConduct annual amperage checks to insure that amp drawis no more than 10% greater than indicated on the serialplate data.Fan MotorsAll units have lubricated fan motors. Fan motors shouldnever be lubricated unless obvious, dry operationis suspected. Periodic maintenance oiling is notrecommended, as it will result in dirt accumulating in theexcess oil and cause eventual motor failure. Conduct annualdry operation check and amperage check to insure ampdraw is no more than 10% greater than indicated on serialplate data.Air CoilThe air coil must be cleaned to obtain maximumperformance. Check once a year under normal operatingconditions and, if dirty, brush or vacuum clean. Care mustbe taken not to damage the aluminum fins while cleaning.CAUTION: Fin edges are sharp.CabinetDo not allow water to stay in contact with the cabinet forlong periods of time to prevent corrosion of the cabinet sheetmetal. Generally, vertical cabinets are set up from the floora few inches [7 - 8 cm] to prevent water from entering thecabinet. The cabinet can be cleaned using a mild detergent.Refrigerant SystemTo maintain sealed circuit integrity, do not install servicegauges unless unit operation appears abnormal. Referencethe operating charts for pressures and temperatures. Verifythat air and water flow rates are at proper levels beforeservicing the refrigerant circuit.