Carrier 48PG20---28 Specifications

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.PC 1

10Step 6 — Install Flue Hood and Inlet Hood —Flue hood (smaller hood), inlet hood (larger hood), and screensare shipped inside the unit in the fan sec

11Size gas-supply piping for 0.5-in. wg maximum pressuredrop. Do not use supply pipe smaller than unit gas connection.Step 9 — Make Electrical Connect

12Set heat anticipator settings as follows:Settings may be changed slightly to provide a greater degreeof comfort for a particular installation.Step 1

13Table 4A — Electrical Data (Units Without Optional Powered Convenience Outlet)See Legend and Notes on page 15.UNITSIZE48HGNOMINALVOLTAGE(3 Ph, 60 Hz

14Table 4B — Electrical Data (Units With Optional Powered Convenience Outlet)UNITSIZE48HGNOMINALVOLTAGE(3 Ph, 60 Hz)VOLTAGERANGECOMPRESSOROFM IFMPOWER

15LEGEND AND NOTES FOR TABLES 4A AND 4BLEGEND*Fuse or HACR circuit breaker.NOTES:1. In compliance with NEC requirements for multimotor and com-binatio

16Step 11 — Position Optional Power Exhaust orBarometric Relief Damper Hood —The optionalpower exhaust or barometric relief dampers are shippedassembl

17Fig. 21 — Power Exhaust or Barometric Relief Damper Mounting DetailsFig. 22 — Bracket and Hood Positioning

18PRE-START-UPProceed as follows to inspect and prepare the unit for initialstart-up:1. Remove all access panels.2. Read and follow instructions on al

19Condenser Fans and Motors — Condenser fans andmotors are factory set. Refer to Condenser-Fan Adjustmentsection (page 49) as required.Return-Air Filt

2INSTALLATIONStep 1 — Provide Unit SupportROOF CURB — Assemble or install accessory roof curb inaccordance with instructions shipped with this accesso

20Table 6 — Fan Performance — 48PGE20 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

21Table 7 — Fan Performance — 48PGF20 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

22Table 8 — Fan Performance — 48PGD24 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

23Table 9 — Fan Performance — 48PGE24 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

24Table 10 — Fan Performance — 48PGF24 Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive r

25Table 11 — Fan Performance — 48PGD28 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

26Table 12 — Fan Performance — 48PGE28 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

27Table 13 — Fan Performance — 48PGF28 — Vertical Supply/Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor drive

28Table 14 — Fan Performance — 48PGD20 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

29Table 15 — Fan Performance — 48PGE20 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

3Fig. 1 — Roof Curb Details

30Table 16 — Fan Performance — 48PGF20 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

31Table 17 — Fan Performance — 48PGD24 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

32Table 18 — Fan Performance — 48PGE24 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

33Table 19 — Fan Performance — 48PGF24 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

34Table 20 — Fan Performance — 48PGD28 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

35Table 21 — Fan Performance — 48PGE28 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

36Table 22 — Fan Performance — 48PGF28 — Horizontal Supply and Return UnitsLEGENDBoldface indicates field-supplied motor/drive required.NOTES:1. Motor

37Table 23 — Power Exhaust Fan Performance — 48PG20-28LEGENDESP — External Static PressureTable 24 — Operation Air Quantity Limits*7000 cfm minimum re

38Table 25 — Evaporator Fan Motor Specifications (cont)NOTES:1. Extensive motor and electrical testing ensures that the motors can be uti-lized with c

39Table 26 — Accessory/FIOP Static Pressure (in. wg)* — 48PG20-28LEGEND*The static pressure must be added to the external static pressure. The sum and

4NOTES:1. Add 150 lb (68 kg) for domestic crating.2. See label for unit location on roof curb.DOES NOT INCLUDE ERV ( ENERGY RECOVERY VENTILATOR) OPTIO

40Table 28 — EconoMi$er IV Sensor Usage*CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on many different base units. As such, these kits may c

41Differential Dry Bulb Control— For differential dry bulbcontrol the standard outdoor dry bulb sensor is used in conjunc-tion with an additional acce

42CONTROLCURVEABCDCONTROL POINTAPPROX. °F (°C)AT 50% RH73 (23)70 (21)67 (19)63 (17)12 14 16 18 20 22 24 26 28

43Minimum Position Control— There is a minimum damperposition potentiometer on the EconoMi$er IV controller. SeeFig. 28. The minimum damper position m

443. Use the Up/Down button to select the preset number. SeeTable 29.4. Press Enter to lock in the selection.5. Press Mode to exit and resume normal o

45When ignition occurs the IGC board will continue to moni-tor the condition of the rollout and limit switches, the hall effectsensor, as well as the

46SERVICECleaning —Inspect unit interior at beginning of each heat-ing and cooling season and as operating conditions require. Re-move unit top panel

475. Thoroughly apply Totaline® environmentally sound coilcleaner solution to all coil surfaces including finned area,tube sheets and coil headers.6.

48FAN SHAFT BEARINGS — Lubricate bearings at least ev-ery 6 months with suitable bearing grease. Typical lubricantsare given below:*Preferred lubrican

49Table 30 — Belt Tension AdjustmentCondenser-Fan Adjustment (Fig. 35)1. Shut off unit power supply.2. Remove condenser-fan assembly (grille, motor, m

5Fig. 4 — Base Unit Dimensions

50Refrigerant Charge — Amount of refrigerant charge islisted on unit nameplate. Refer to Carrier GTAC II; Module 5;Charging, Recovery, Recycling, and

514. Set main gas valve to ON position.5. Set thermostat at setting to call for heat.6. Remove screw cap covering regulator adjustment screw(see Fig.

52Table 32 — Altitude Compensation*NATURAL GAS*As the height above sea level increases, there is less oxygen per cubic foot of air. Therefore, heat in

53Fig. 42 — Typical Low Voltage Control Schematic

54Fig. 43 — Typical Power Schematic

55Fig. 44 — Typical Component Arrangement — 48PG20,24

56Fig. 45 — Typical Component Arrangement — 48PG28THERMOSTAT/IGC MARKINGSBM — Blower MotorC—CommonCM — Inducer MotorCS — Centrifugal SwitchG—FanIFO —

57TROUBLESHOOTINGUnit Troubleshooting —Refer to Tables 33-35 andFig. 46.Table 33 — Cooling Service AnalysisLEGENDTXV — Thermostatic Expansion ValvePRO

58Table34—GasHeatingServiceAnalysisPROBLEM CAUSE REMEDYBurners Will Not Ignite. Misaligned spark electrodes. Check flame ignition and sensor electrode

59Fig. 46 — IGC Control (Heating and Cooling)LEGENDNOTE: Thermostat Fan Switch in the“AUTO” position.IDM — Induced-Draft MotorIGC — Integrated Gas Uni

6Table 1 — Physical DataLEGEND*Aluminum evaporator coil/aluminum condenser coil.UNIT 48PG 20 24 28VOLTAGE 208/230 and 460 575 208/230 and 460 575 208/

60Table 35 — IGC Board LED Alarm CodesLEGEND NOTES:1. There is a 3-second pause between alarm code displays.2. If more than one alarm code exists, all

61DCV (Demand Controlled Ventilation) AND POWEREXHAUST — To check DCV and Power Exhaust:1. Make sure EconoMi$er IV preparation procedure hasbeen perfo

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.PC 1

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.PC 1

7Table 2 — Fan Motor and Drive Data — Vertical Supply/Return48PG20 24 28208/230 and 460 575 208/230 and 460 575 208/230 and 460 575LOW RANGEMotor Hp 3

8Table 3 — Fan Motor and Drive Data — Horizontal Supply/Return48PG20 24 28208/230 and 460 575 208/230 and 460 575 208/230 and 460 575LOW RANGEMotor Hp

9Step 4 — Field Fabricate Ductwork — On verticalunits, secure all ducts to roof curb and building structure. Donot connect ductwork to unit. For horiz