York SUNLINE MAGNUM DJ180 Installation Manual

Also see for SUNLINE MAGNUM DJ 180: Technical guide Technical guide Installation manual

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York SUNLINE MAGNUM DJ180 Installation Manual Manual pdf 42 page image

175231-YIM-A-070642 Unitary Products GroupAIR BALANCEStart the supply air blower motor. Adjust the resis-tances in both the supply and the return air duct sys-tems to balance the air distribution throughout theconditioned space. The job specifications may requirethat this balancing be done by someone other than theequipment installer.To check the supply air CFM after the initial balancinghas been completed:1. Remove the two 5/16" dot plugs from the blowermotor and the filter access panels shown in theDimensions and Clearances Figure 13.2. Insert at least 8" of 1/4 inch tubing into each ofthese holes for sufficient penetration into the airflow on both sides of the indoor coil.NOTE: The tubes must be inserted and held in a posi-tion perpendicular to the air flow so that veloc-ity pressure will not affect the static pressurereadings.3. Using an inclined manometer, determine the pres-sure drop across a dry evaporator coil. Since themoisture on an evaporator coil may vary greatly,measuring the pressure drop across a wet coilunder field conditions would be inaccurate. Toassure a dry coil, the compressors should be deac-tivated while the test is being run.4. Knowing the pressure drop across a dry coil, theactual CFM through the unit can be determinedfrom the curve in Pressure Drop vs. Supply AirCFM Figure 22.After readings have been obtained, remove the tubesand reinstall the two 5/16" dot plugs that were removedin Step 1.NOTE: DE-ENERGIZE THE COMPRESSORSBEFORE TAKING ANY TEST MEASURE-MENTS TO ASSURE A DRY INDOOR COIL.OPERATIONSEQUENCE OF OPERATIONS OVERVIEWFor these units, the thermostat makes a circuitbetween "R" and "Y1" for the first stage of cooling.The call is passed to the unit control board (UCB),which then determines whether the requested opera-tion is available and, if so, which components to ener-gize.For gas heating, the UCB monitors the "W1" call butdoes not handle the operation of the gas furnace. Anignition control board controls the gas heater operation.For electric heat units, the UCB passes the call to theelectric heater.In both cases, when the "W1" call is sensed, the indoorair blower is energized following a specified heatingdelay.If at any time a call for both heating and cooling arepresent, the heating operation will be performed. Ifoperating, the cooling system is halted as with a com-pletion of a call for cooling. Heating always takes prior-ity.FIGURE 22 - PRESSURE DROP ACROSS A DRYINDOOR COIL VS SUPPLY AIR CFMFOR ALL UNIT TONNAGESPRESSURE DROP ACROSS A DRY INDOOR COIL VS SUPPLY AIR CFM00.050.10.150.20.250.30.350.40.454000 5000 6000 7000 8000 9000 10000 11000 12000NOMINAL AIR FLOW (CFM)PRESSURE DROP (IWG)Failure to properly adjust the total system airquantity can result in extensive blower dam-age.