Carrier 50ZH Product Data

Also see for 50ZH024: Installation, Start-Up and Service Instructions Installation instructions

Contents

Selection procedureI Determine cooling and heating requirements atdesign conditions.Given:Required Cooling Capacity (TC) . . . . . 28,000 BtuhSensible Heat Capacity (SHC) . . . . . . 20,500 BtuhRequired Heating Capacity . . . . . . . . . 28,550 BtuhOutdoor Entering-Air Temperature . . . . . . . . . 95 FOutdoor-Air Winter Design Temperature . . . . . 20 FIndoor-Air Winter Design Temperature . . . . . . 70 FIndoor Entering-Air Temperature . . . . . . . 80 F edb,67 F ewbIndoor-Air Quantity . . . . . . . . . . . . . . . . 1125 cfmExternal Static Pressure . . . . . . . . . . . . 0.20 in. wgElectrical Characteristics (V-Ph-Hz) . . . . . . 230-1-60edb — entering dry bulbewb — entering wet bulbII Select unit based on required cooling capacity.Enter Cooling Capacities table at condenser enteringtemperature of 95 F, indoor air entering at 1125 cfmand 67 F ewb (entering wet bulb). The 50ZH030 unitwill provide a total cooling capacity of 28,800 Btuhand a sensible heat capacity of 21,700 Btuh.For indoor-air temperature other than 80 F edb(entering dry bulb), calculate sensible heat capacity cor-rection, as required, using the formula found inNote 3 following the cooling capacities tables.NOTE: Unit ratings are net capacities.III Select electric heat.Enter the unit 50ZH030 Heating Capacities table at1125 cfm. At 70 F return indoor air and 20 F air en-tering outdoor coil, the integrated heating capacity is15,500 Btuh. (Select integrated heating capacity valuesince deductions for outdoor-coil frost and defrostinghave already been made. No correction is required.)The required heating capacity is 28,550 Btuh. There-fore, 13,050 Btuh (28,550 – 15,500) additional elec-tric heat is required.Determine additional electric heat capacity in kW.13,050 Btuh = 3.8 kW of heat required3414 Btuh/kWEnter the Electrical data table on page 17 for 208/230 v, single-phase, 50ZH030 unit. The 5-kW heaterat 240 v most closely satisfies the heating required. Tocalculate kW at 230 v, multiply the heater kW by mul-tiplication factor 0.92 found in the MultiplicationFactors table on page 15.5 kW x 0.92 = 4.6 kW4.6 x 3414 = 15,704 BtuhTo calculate kW at 208 v, see Multiplication Factorstable on page 15.Total unit heating capacity is 31,204 Btuh (15,500+ 15,704).IV Determine fan speed and power requirementsat design conditions.Before entering the air delivery tables, calculate thetotal static pressure required. From the given, the Ac-cessory Electric Heat Pressure Drop table, Wet CoilPressure Drop table, and the Filter Pressure Drop table,find:External static pressure 0.20 in. wgFilter 0.09 in. wgElectric heat 0.11 in. wgWet coil 0.07 in. wgTotal static pressure 0.47 in. wgEnter the table for Dry Coil Air Delivery — Hori-zontal Discharge at 1125 cfm and 230-v high speed.By interpolation, the standard motor will deliver0.48 in. wg static pressure. This will adequately handlejob requirements.8