York sunline 2000 Installation Manual

Also see for Sunline 2000: Installation instruction Installation instructions Installation instructions Technical guide Technical guide

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York sunline 2000 Installation Manual Manual pdf 38 page image

362242-YIM-B-010938 Johnson Controls Unitary ProductsStart 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 Fig-ure 11.2. 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 13).After readings have been obtained, remove the tubesand reinstall the two 5/16” dot plugs that were removedin Step 1.NOTE: De-energize the compressors before taking anytest measurements to assure a dry indoor coil.OPERATIONSEQUENCE OF OPERATIONS OVERVIEWFor these units, the thermostat makes a circuitbetween “R” and “Y1” for the cooling cycle.The call is passed to the unit control board (UCB),which then determines whether the requested operationis available and, if so, which components to energize.For heating, the thermostat makes a circuit between“R” and “W1”. The UCB energizes the compressor andcondenser fan allowing the unit to run in heating mode.A demand defrost control operates the defrost cycle on3 thru 5 units, and a time/temperature control operatesthe defrost cycle on 6 ton units.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.Failure to properly adjust the total system airquantity and static pressure can result inextensive system damage.FIGURE 13 - PRESSURE DROP ACROSS COIL00.10.20.30.40.50.60.70.80.90 500 1000 1500 2000 2500 3000 3500NOMINAL CFMPRESSURE DROP (IWG)036048060072