Carrier 50YA Installation And Start-up Instructions Manual
Also see for 50YA: Product data
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5. Check Balanced Water Flow Rate to Heat Pump: Make surethat the inlet and outlet water temperatures are recorded.This check will eliminate nuisance unit trip-outs resultingfrom water velocities that are either too low or too high; it canalso prevent the occurrence of erosive water flow rates.6. Check System Water Loop : Verify that all air is removedfrom the system. (Air in the system will impair unit operationand cause corrosion in the system piping).7. Check Unit Filters: Check to ensure that unit filter is clean;this will contribute to the proper operation of the unit byensuring adequate airflow across the coil.Before checking fans, open unit disconnect switch to preventinjury or death due to electrical shock or contact with movingparts.8. Check Unit Fans: Manually rotate fans to make sure that theyrotate freely, and that they are secured properly to the fanshaft. Do not oil fan motors on start-up; they were lubricatedat the factory.START-UPHigh voltage is present in some areas of the electrical panelswith the disconnect switch(es) closed. Be sure to exercisecaution when working with energized equipment.1. Adjust all valves to the full open position, and turn on the linepower to all heat pump units.2. Operate the unit first in the cooling cycle. Room temperatureshould be in the normal range (approximately 75°F to 85°F,dry bulb). Loop water temperature entering the heat pumpshould normally be at least 60°F, but not in excess of 95°F.NOTE: Three factors determine the operating limits of a unit: (l)return air temperature, (2) water temperature, and (3) ambienttemperature. Whenever any one of these factors is at a minimumor maximum level, the other 2 factors must be at normal levels toensure proper unit operation.a. For heat pumps equipped with an optional, accessorymanual changeover thermostat, adjust the thermostat tem-perature indicator to the lowest setting, and turn the selectorswitch to COOL. At this time, both the fan and compressorshould run.b. For heat pumps equipped with an optional, accessoryautomatic changeover thermostat, set the thermostat tem-perature indicators to the far left position, and turn theselector switch to AUTO. At this time both the fan and thecompressor should run.c. Check the elevation and flow of the condensate line.3. Operate each heat pump in the heating cycle immediately afterchecking cooling cycle operation.NOTE: Horizontal and vertical heat pumps are designed to startheating at a minimum return air temperature of 50°F with a normalwater flow rate and ambient temperature.a. If the unit is equipped with an accessory thermostat, adjustthe thermostat temperature indicator to the highest settingand set the selector switch to HEAT; both the fan andcompressor should run.b. If the unit is equipped with an accessory thermostat, set thethermostat temperature indicator levers to the far rightposition with the selector switch still set on AUTO; boththe fan and compressor should run.4. If the unit fails to operate, conduct the following checks:Table 1—Potential Problem AreasPOTENTIAL PROBLEMS USE COPPER COIL USE CUPRONICKEL COILSCALINGCalcium and Magnesium Salts(hardness)Iron OxideLess than 350 ppm (25 grain/gal-lons)LowMore than 350 ppm (up to seawater)HighCORROSION*pHHydrogen SulfideCarbon DioxideDissolved OxygenChlorideTotal Dissolved Solids7-9Less than 10 ppmLess than 50 ppmOnly with pressurized water tankLess than 300 ppmLess than 1000 ppm5 to 7 and 9 to 1010 to 50 ppm50 to 75 ppmAll systems300 to 600 ppm1000 to 1500 ppmBIOLOGICAL GROWTHIron Bacteria Low HighSUSPENDED SOLIDS Low High*IMPORTANT: If the concentration of these corrosives exceeds the maximum tabulated in the Cupronickel column, then the potential for serious corrosion problemsexists.Table 2—Antifreeze SolutionsTYPEMINIMUM TEMPERATURE FORFREEZE PROTECTION10°F 15°F 20°F 25°FMethanol 25% 21% 16% 10%PropyleneGlycol 26% 23% 19% 9%GS4 22% 17% 13% 9%Notes: 1. All percentages are by volume (gal/gal), not weight.2. Do not use calcium chloride as antifreeze.3. Consult local codes before selection.6 |
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