ContentsSAFETY CONSIDERATIONS
TABLE OF CONTENTSFig. 1 - Unit 48VT-A
Installation InstructionsINTRODUCTION
RECEIVING AND INSTALLATIONStep 1 - Check Equipment
Step 2 - Provide Unit Support48VT--A
Fig. 2 - 48VT-A24-30Unit DimensionsA0914648VT--A
Fig. 3 - 48VT-A36-60Unit DimensionsA0914748VT
Fig. 4 - Roof Curb DimensionsSMALL CURB
ROOF CURB DETAILStep 5 - Rig and Place Unit
ACCESS PANELS MUST BE IN PLACE WHEN RIGGINGInspection
Rigging/Lifting of Unit See FigStep 8 - Install Gas Piping
Step 7 - Install Flue HoodStep 6 - Connect Condensate Drain
Fig. 6 - Condensate TrapConfiguring Units for Downflow Vertical Discharge
Step 9 - Install Duct ConnectionsFig. 7 - Sediment Trap
FIRE OR EXPLOSION HAZARDFig. 8 - Supply and Return Duct Opening
Table 1 - Physical Data - Unit 48VT-A48VT--A
Horizontal Duct CoversTable 2 - Maximum Gas Flow Capacity
Table 1 - Physical Data - Unit 48VT-ACont’dTable 3 - Heating Inputs
48VT--ASpecial Procedures for 208-VOperation
Step 10 - Install Electrical ConnectionsHigh-VoltageConnections
Control Voltage ConnectionsPRE-START-UP
Balance Point Setting-Thermidistator HybridTransformer Protection
ThermostatSTART-UP
Step 3 - Start-upHeating and Make Adjust- mentsStep 1 - Check for Refrigerant Leaks
Step 2 - Unit Sequence of OperationFig. 11 - Burner Assembly
Adjust Gas InputCheck Heating Control
Check Gas InputCheck Burner Flame
Limit SwitchesNormal Operation
Airflow and Temperature RiseRollout Switch
Step 4 - Start-upCooling and Make Adjust- mentsChecking and Adjusting Refrigerant Charge
Indoor Airflow and Airflow AdjustmentsContinuous Fan Operation
Gas Heating Fan Speed Set-upTable 6 - Color Coding for Indoor Fan Motor Leads
48VT--ATable 8 - 48VT-AWet Coil Pressure Drop
Fig. 14 - Interface Fan Board IFB48VT--A
Table 7 - Filter Pressure Drop Table IN. W.CUNIT
48VT--AHeating
48VT--A1295
48VT--A1445
48VT--A1448
48VT--A48VT A
Fig. 15 - 208/230-1-60Wiring Diagram, Unit 48VT-A48VT--A
Fig. 16 - 208/230-3-60Wiring Diagram, Unit 48VT-AA0920948VT--A
Fig. 17 - Cooling Charging Table-Subcooling50VT500173 REV
A09099Cleaning the Blower Motor and Wheel
MAINTENANCEAir Filter
Indoor Blower and MotorInduced Draft combustion air Blower Assembly
Limit SwitchFig. 18 - Blower Housing and Flue Collector Box
Fig. 19 - Unit Access PanelsOutdoor Fan
Electrical Controls and WiringRefrigerant Circuit
Fig. 20 - Removal of Motor and Blower WheelLoss of Charge Switch
Pressure SwitchesHigh-PressureSwitch
Gas InputPageLCS - Loss of Charge Switch
HPS - High Pressure SwitchFig. 24 - Refrigerant Circuit
AccuraterMetering De viceSTART-UPCHECKLIST
TROUBLESHOOTINGUNIT OPERATION AND SAFETY HAZARD
Synthetic Roof Precautionary Procedure48VT--A
PURONR R-410AQUICK REFERENCE GUIDE48VT--A
SYMPTOMTable 13 - Troubleshooting Guide-LEDStatus Codes
Table 12 - Troubleshooting Guide-Heating48VT--AI. PRELIMINARY INFORMATION MODEL NO
Remove and Store in Job FilesTEMPERATURES
PRESSURESCatalog No 48VT---05SI
48VT--AEdition Date 04/09
Replaces 48VT---04SI