Carrier 50JZ Product Data

Also see for 50JZ 024-060: Installation and operating instructions Guide to operating and maintaining Guide to operating and maintaining Product data Installation, Start-Up and Service Instructions

Contents

10I Determine cooling and heating requirements at designconditions:Given:Required Cooling Capacity (TC) . . . . . . . . . 33,500 BtuhSensible Heat Capacity (SHC) . . . . . . . . . . . 24,500 BtuhRequired Heating Capacity . . . . . . . . . . . . . . 25,000 BtuhCondenser Entering Air Temperature . . . . . . . . . . . . 95°FIndoor-Air Temperature . . . . . . . . . . 80°F edb, 67°F ewbEvaporator Air Quantity . . . . . . . . . . . . . . . . . . .1200 cfmExternal Static Pressure. . . . . . . . . . . . . . . . . . . 0.2 in. wgElectrical Characteristics. . . . . . . . . . . . . . . . . . . 208-1-60II Select unit based on required cooling capacity.Enter Net Cooling Capacities table at condenser enteringtemperature of 95°F. The 50JZ036 unit at 1200 cfm and67°F ewb (entering wet bulb) will provide a total capacityof 36,600 Btuh and a SHC of 28,200 Btuh. Calculate SHCcorrection, if required, using Note 4 under CoolingCapacities tables.III Select electric heat.Enter the 50JZ036 unit Heating Extended Performancetable at 1200 cfm. At 70°F return indoor air and 20°F airentering outdoor coil, the integrated heating capacity is17,400 Btuh. (Select integrated heating capacity valuesince deductions for outdoor-coil frost and defrosting havealready been made. No correction is required.)The required heating capacity is 25,000 Btuh. Therefore,7,600 Btuh (25,000 – 17,400) additional electric heat isrequiredDetermine additional electric heat capacity in kw.7,600 Btuh3414 Btuh/kWEnter the Electric Heater table on page 5 for 208/230 v,single-phase, unit. The 5-kw heater at 240v most closelysatisfies the heating required. To calculate kw at 230v,multiply the heater kw by multiplication factor 0.92 foundin the Multiplication Factors table on page 17.5 kw x 0.92 = 4.6 kw4.6 kw x 3414 Btuh/kw = 15,704 BtuhTotal unit heating capacity is 33,104 Btuh (17,400 +15,704).IV Determine fan speed and power requirements at designconditions.Before entering the air delivery tables, calculate the totalstatic pressure required. From the given, Filter PressureDrop Table, Electrical Heat Pressure Drop table, and theWet Coil Pressure Drop table, find:External static pressure 0.200 in. wgFilter 0.130 in. wgElectric Heaters 0.000 in. wgTotal static pressure 0.330 in. wgEnter the table for Wet Coil Air Delivery — HorizontalDischarge, 230 and 460v. At 0.33 in. wg external staticpressure and medium speed, the motor delivers 1171 cfm,and 467 watts. Adjusting for 208v, the motor delivers 1054cfm (deduct 10%) and 420 watts.V Select unit that corresponds to power source available.The Electrical Data table shows that the unit is designed tooperate at 208-1-60.= 2.2 kw of heat requiredSelection Procedure