Carrier 50YDV Installation, Operation And Maintenance Instructions

Carrier 50YDV Installation, Operation And Maintenance Instructions Manual pdf 34 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 234Unit Start-Up and Operating ConditionsUnit and System CheckoutBEFORE POWERING SYSTEM, please check the following:UNIT CHECKOUTφ Balancing/shutoff valves: Insure that all isolation valvesare open and water control valves are wired.φ Line voltage and wiring: Verify that voltage is withinan acceptable range for the unit and wiring and fuses/breakers are properly sized. Verify that low voltage wiringis complete.φ Unit control transformer: Insure that transformer has theproperly selected voltage tap. Residential 208-230V unitsare factory wired for 230V operation unless specifiedotherwise.φ Loop/water piping is complete and purged of air. Water/piping is clean.φ Antifreeze has been added if necessary.φ Entering water and air: Insure that entering water and airtemperatures are within operating limits of Table 8.φ Low water temperature cutout: Verify that low watertemperature cut-out on the CXM/DXM control is properlyset.φ Unit fan: Manually rotate fan to verify free rotation andinsure that blower wheel is secured to the motor shaft.Be sure to remove any shipping supports if needed.DO NOT oil motors upon start-up. Fan motors are pre-oiled at the factory. Check unit fan speed selection andcompare to design requirements.φ Condensate line: Verify that condensate line is open andproperly pitched toward drain.φ HWG pump is disconnected unless piping is completedand air has been purged from the system.φ Water fl ow balancing: Record inlet and outlet watertemperatures for each heat pump upon startup. Thischeck can eliminate nuisance trip outs and high velocitywater flow that could erode heat exchangers.φ Unit air coil and filters: Insure that filter is clean andaccessible. Clean air coil of all manufacturing oils.φ Unit controls: Verify that CXM field selection options areproperly set. Low voltage wiring is complete.φ Blower speed is set.φ Service/access panels are in place.SYSTEM CHECKOUTφ System water temperature: Check water temperaturefor proper range and also verify heating and cooling setpoints for proper operation.φ System pH: Check and adjust water pH if necessary tomaintain a level between 6 and 8.5. Proper pH promoteslongevity of hoses and fittings (see Table 3).φ System fl ushing: Verify that all air is purged from thesystem. Air in the system can cause poor operation orsystem corrosion. Water used in the system must bepotable quality initially and clean of dirt, piping slag,and strong chemical cleaning agents. Some antifreezesolutions may require distilled water.φ Flow Controller pump(s): Verify that the pump(s) is wired,purged of air, and in operating condition.φ System controls: Verify that system controls function andoperate in the proper sequence.φ Low water temperature cutout: Verify that low watertemperature cut-out controls are set properly(FP1 - JW3).φ Miscellaneous: Note any questionable aspects ofthe installation.Unit Start-up Procedure1. Turn the thermostat fan position to “ON.” Blowershould start.2. Balance air flow at registers.3. Adjust all valves to their full open position. Turn on theline power to all heat pump units.4. Room temperature should be within the minimum-maximum ranges of Table 8b. During start-up checks,loop water temperature entering the heat pump shouldbe between 30°F [-1°C] and 95°F [35°C].5. Two factors determine the operating limits of watersource heat pumps, (a) return air temperature, and (b)water temperature. When any one of these factors is at aminimum or maximum level, the other factor must be atnormal level to insure proper unit operation.a. Adjust the unit thermostat to the warmest setting.Place the thermostat mode switch in the “COOL”position. Slowly reduce thermostat setting until thecompressor activates.b. Check for cool air delivery at the unit grille within afew minutes after the unit has begun to operate.Note: Units have a five minute time delay in thecontrol circuit that can be bypassed on the CXM/DXM control board as shown below in Figure 27. Seecontrols description for details.c. Verify that the compressor is on and that the waterflow rate is correct by measuring pressure dropthrough the heat exchanger using the P/T plugs andcomparing to Tables 9a through 9b.d. Check the elevation and cleanliness of thecondensate lines. Dripping may be a sign of aѥ CAUTION! ѥѥ CAUTION! ѥCAUTION! Verify that ALL water control valves are openand allow water flow prior to engaging the compressor.Freezing of the coax or water lines can permanentlydamage the heat pump.CAUTION! To avoid equipment damage, DO NOTleave system filled in a building without heat during thewinter unless antifreeze is added to the water loop. Heatexchangers never fully drain by themselves and willfreeze unless winterized with antifreeze.