Carrier OMNIZONE 50XCA06-24 - Manual (Page 7)

7
Selection procedure (50XCA08 unit example)
I Determine design conditions.
Given:
Cooling Requirements
Total Cooling Capacity (TC) . . . . . . . . .82,000 Btuh
Sensible Cooling Capacity (SHC) . . . . .65,000 Btuh
Evaporator Air Quantity. . . . . . . . . . . . . 3,000 Cfm
Condenser Air Quantity . . . . . . . . . . . . . 3,500 Cfm
Summer Entering-Air Conditions:
Entering dry bulb (edb) . . . . . . . . . . . . . . . . .80 F
Entering wet bulb (ewb) . . . . . . . . . . . . . . . .67 F
Entering Condenser Air Temp (EAT) . . . . . . .95 F
Unit Voltage . . . . . . . . . . . . . . . . . . . . . . . . 460 V
Fan Requirements
External Static Pressure Required
ESP (in. wg) . . . . . . . . . . . . . . . . . . . . . . . . . .0.75
II Select unit based on cooling requirements.
Enter Gross Cooling Capacities table for 50XCA08
unit at 3000 cfm and required wet bulb of 67 F and
read down to the section displaying capacities with
95 F entering-air temperature. The 50XCA08 pro-
vides a total capacity closest to design requirements.
For example:
Unit selection — 50XCA08
Selected at 3000 cfm of 80 F edb, 67 F ewb enter-
ing air.
TC = 83,800 Btuh
SHC = 66,500 Btuh
(See correction factor table, below the cooling
capacity tables.)
Compressor — Power Input = 5.85 kW
Leaving Air db
= 59.9 F
Leaving Air wb at 67 F wb
= 58.3 F
III Fan requirements.
External static pressure (ESP) required 0.75 in. wg
Enter Evaporator Fan Performance table for cfm, and
static pressure required to obtain the following data:
For 3000 cfm and 0.75 ESP, by interpolation the
fan operates at 877 rpm and requires 0.98 brake
horsepower.
Since standard motor horsepower is 1.0, it will pro-
duce the necessary cfm and ESP for this job.
36
24 (TYP)
SERVICE CLEARANCE
NOTE: Dimensions are in inches.
a50-8502