Carrier 48VT(N) Maintenance, Air Filter, Indoor Blower and Motor, 48VT--A, Unit Operation Hazard

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MAINTENANCE

MAINTENANCE

To ensure continuing high performance and to minimize the possibility of premature equipment failure, periodic maintenance must be performed on this equipment. This combination heating/cooling unit should be inspected at least once each year by a qualified service person. To troubleshoot cooling or heating of units, refer to Tables 10, 11 and 12.

NOTE: Consult your local dealer about the availability of a maintenance contract.

!WARNING

PERSONAL INJURY AND UNIT DAMAGE HAZARD

Failure to follow this warning could result in personal injury or death and unit component damage.

The ability to properly perform maintenance on this equipment requires certain expertise, mechanical skills, tools and equipment. If you do not possess these, do not attempt to perform any maintenance on this equipment, other than those procedures recommended in the Owner’s Manual.

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow these warnings could result in personal injury or death:

1.Turn off electrical power to the unit and install a lockout tag before performing any maintenance or service on this unit.

2.Use extreme caution when removing panels and parts.

3.Never place anything combustible either on or in contact with the unit.

4.Should overheating occur or the gas supply fail to shut off, turn off external main manual gas valve to the unit. Then shut off electrical supply.

!CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in improper operation.

Errors made when reconnecting wires may cause improper and dangerous operation. Label all wires prior to disconnecting when servicing.

The minimum maintenance requirements for this equipment are as follows:

1.Inspect air filter(s) each month. Clean or replace when necessary. Certain geographical locations may require more frequent inspections.

2.Inspect indoor coil, outdoor coil, drain pan, and condensate drain each cooling season for cleanliness. Clean when necessary.

3.Inspect blower motor and wheel for cleanliness at the beginning of each heating and cooling season. Clean when necessary. For first heating and cooling season, inspect blower wheel bi-monthly to determine proper cleaning frequency.

4.Check electrical connections for tightness and controls for proper operation each heating and cooling season. Service when necessary. Ensure electrical wiring is not in contact with refrigerant tubing or sharp metal edges.

5.Check and inspect heating section before each heating season. Clean and adjust when necessary.

6.Check flue hood and remove any obstructions, if necessary.

Air Filter

IMPORTANT: Never operate the unit without a suitable air filter in the return-air duct system. Always replace the filter with the same dimensional size and type as originally installed. (See Table 1 for recommended filter sizes.)

Inspect air filter(s) at least once each month and replace (throwaway-type) or clean (cleanable-type) at least twice during each heating and cooling season or whenever the filter(s) becomes clogged with dust and/or lint.

Indoor Blower and Motor

NOTE: All motors are prelubricated. Do not attempt to lubricate these motors.

For longer life, operating economy, and continuing efficiency, clean accumulated dirt and grease from the blower wheel and motor annually.

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or death.

Disconnect and tag electrical power to the unit before cleaning the blower motor and wheel.

Cleaning the Blower Motor and Wheel

1.Remove and disassemble blower assembly as follows:

a.Remove blower access panel (see Fig. 19).

b.Disconnect 5 pin plug and 4 pin plug from indoor blower motor. Remove capacitor if required.

c.On all units, remove blower assembly from unit. Remove screws securing blower to blower partition and slide assembly out. Be careful not to tear insulation in blower compartment.

d.Ensure proper reassembly by marking blower wheel and motor in relation to blower housing before disassembly.

e.Loosen setscrew(s) that secures wheel to motor shaft. Remove screws that secure motor mount brackets to housing, and slide motor and motor mount out of housing.

2.Remove and clean blower wheel as follows:

a.Ensure proper reassembly by marking wheel orientation.

b.Lift wheel from housing. When handling and/or cleaning blower wheel, be sure not to disturb balance weights (clips) on blower wheel vanes.

c.Remove caked-on dirt from wheel and housing with a brush. Remove lint and/or dirt accumulations from wheel and housing with vacuum cleaner, using soft brush attachment. Remove grease and oil with mild solvent.

d.Reassemble wheel into housing.

e.Reassemble motor into housing. Be sure setscrews are tightened on motor shaft flats and not on round part of shaft. Reinstall blower into unit. Reinstall capacitor.

f.Connect 5 pin plug and 4 pin plug to indoor blower motor.

g.Reinstall blower access panel (see Fig. 19).

3.Restore electrical power to unit. Start unit and check for proper blower rotation and motor speeds during heating and cooling cycles.

48VT-- A

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Contents Installation Instructions TABLE OF CONTENTSSAFETY CONSIDERATIONS Fig. 1 - Unit 48VT-AStep 2 - Provide Unit Support RECEIVING AND INSTALLATIONINTRODUCTION Step 1 - Check EquipmentFig. 2 - 48VT-A24-30Unit Dimensions 48VT--AA09146 Fig. 3 - 48VT-A36-60Unit Dimensions 48VT--AA09147 ROOF CURB DETAIL Fig. 4 - Roof Curb Dimensions48VT SMALL CURBRigging/Lifting of Unit See Fig ACCESS PANELS MUST BE IN PLACE WHEN RIGGINGStep 5 - Rig and Place Unit InspectionFig. 6 - Condensate Trap Step 7 - Install Flue HoodStep 8 - Install Gas Piping Step 6 - Connect Condensate DrainFIRE OR EXPLOSION HAZARD Step 9 - Install Duct ConnectionsConfiguring Units for Downflow Vertical Discharge Fig. 7 - Sediment TrapHorizontal Duct Covers Table 1 - Physical Data - Unit 48VT-AFig. 8 - Supply and Return Duct Opening 48VT--A48VT--A Table 1 - Physical Data - Unit 48VT-ACont’dTable 2 - Maximum Gas Flow Capacity Table 3 - Heating InputsControl Voltage Connections Step 10 - Install Electrical ConnectionsSpecial Procedures for 208-VOperation High-VoltageConnectionsThermostat Balance Point Setting-Thermidistator HybridPRE-START-UP Transformer ProtectionStep 2 - Unit Sequence of Operation Step 3 - Start-upHeating and Make Adjust- mentsSTART-UP Step 1 - Check for Refrigerant LeaksCheck Gas Input Adjust Gas InputFig. 11 - Burner Assembly Check Heating ControlAirflow and Temperature Rise Limit SwitchesCheck Burner Flame Normal OperationIndoor Airflow and Airflow Adjustments Step 4 - Start-upCooling and Make Adjust- mentsRollout Switch Checking and Adjusting Refrigerant Charge48VT--A Gas Heating Fan Speed Set-upContinuous Fan Operation Table 6 - Color Coding for Indoor Fan Motor LeadsTable 7 - Filter Pressure Drop Table IN. W.C Fig. 14 - Interface Fan Board IFBTable 8 - 48VT-AWet Coil Pressure Drop 48VT--AUNIT 48VT--AHeating 48VT--A1295 48VT--A1445 48VT--A1448 48VT--A48VT A Fig. 15 - 208/230-1-60Wiring Diagram, Unit 48VT-AFig. 16 - 208/230-3-60Wiring Diagram, Unit 48VT-A 48VT--AA09209 A09099 Fig. 17 - Cooling Charging Table-Subcooling48VT--A 50VT500173 REVIndoor Blower and Motor MAINTENANCECleaning the Blower Motor and Wheel Air FilterFig. 19 - Unit Access Panels Limit SwitchInduced Draft combustion air Blower Assembly Fig. 18 - Blower Housing and Flue Collector BoxFig. 20 - Removal of Motor and Blower Wheel Electrical Controls and WiringOutdoor Fan Refrigerant CircuitGas Input Pressure SwitchesLoss of Charge Switch High-PressureSwitchPage AccuraterMetering De vice HPS - High Pressure SwitchLCS - Loss of Charge Switch Fig. 24 - Refrigerant CircuitSynthetic Roof Precautionary Procedure TROUBLESHOOTINGSTART-UPCHECKLIST UNIT OPERATION AND SAFETY HAZARD48VT--A PURONR R-410AQUICK REFERENCE GUIDE48VT--A SYMPTOMTable 12 - Troubleshooting Guide-Heating Table 13 - Troubleshooting Guide-LEDStatus Codes48VT--A PRESSURES Remove and Store in Job FilesI. PRELIMINARY INFORMATION MODEL NO TEMPERATURESReplaces 48VT---04SI 48VT--ACatalog No 48VT---05SI Edition Date 04/09
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