Carrier 48/50HJ004-014 specifications Set the Outdoor Cooling and Heat- ing Thermostats

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Step 11 — Set the Outdoor Cooling and Heat- ing Thermostats

IMPORTANT: The energy recovery section unit is shipped with an outdoor thermostat set at 55 F which locks out mechanical cooling on the RTU (rooftop unit) and the energy recovery section compressor. If this feature is not desirable, the rooftop unit’s compressor can be allowed to run by relocating both gray wires to the same side of the Low Temperature Lockout Thermostat (LTLO) leaving the white wire on the opposite pole, locking out only the energy recovery section compressor. The LTLO is also accessible by removing the filter access panel and the door of the damper mounting bracket. Refer to Troubleshooting section.

COOLING — During the unoccupied period, the economizer mode of operation is used as the first stage of cooling. When the outside air temperature is below the cooling thermostat set point, the outside air will be used for first stage cooling.

HEATING — The heating thermostat should be adjusted to the second stage balance point (heat output of the energy re- covery section plus the heat output of the first stage on rooftop unit equals building load at this temperature). Above this set- ting, first stage heating will be the energy recovery section unit and second stage will be the first stage of the rooftop unit. Below this point first stage heating will be the energy recovery section unit plus first stage heating of the rooftop unit. The sec- ond stage will be the second stage of the rooftop unit.

HOOD TOP

DAMPER BLADE STOP

 

SHIPPED WITH UNIT

KNOB

IN 45° POSITION

SCREWS (2)

 

HOOD

 

SIDE

 

 

LTLO

 

MOUNTING

 

BRACKET

END CAP

HEATING POINT

THERMOSTAT

 

(RED LABEL)

 

COOLING SET POINT

 

 

THERMOSTAT (WHITE LABEL)

 

TEMPERATURE

 

 

 

 

COOLING

TEMPERATURE SWITCH

HOOD SIDE

LOCKOUT (LTLO)

 

 

 

SHIPPED WITH UNIT

SCREW INSTALLATION (2)

 

 

KNOB

 

ALUMINUM FILTER SCREEN

 

 

Fig. 11 — Energy Recovery Section Supply-Air Hood Assembly

HOOD TOP

HOOD SIDE

HINGE

HINGE PIN

BAROMETRIC

RELIEF DAMPER

60° LOCATION

45° LOCATION

HOOD SIDE

WIRE GUARD

30° LOCATION

DAMPER LIMITER

Fig. 12 — Energy Recovery Section Barometric Exhaust Air Hood Assembly

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Contents General ContentsSafety Considerations Side View END View InstallationDuct Opening Sizes Side View CRRFCURB002A00 Connector ALT GAS Power Control PKG. Accy Drain HoleRoof Curb Unit Size Accessory CRRFCURB001A00 CRBTMPWR002A00 Roof Curb Unit Size AccessoryCRBTMPWR003A00 CRBTMPWR004A00Part Number Unit Size Equipment SupportRear Right Left Side Front Right Side Page Page Page Make Electrical Connections MAX Weight48HJ008 w/62AQ200 Nominal IFM Conv Power Supply Disconnect Size UnitType Outlet FLA MCA Fuse or LRA Hacr BKR HacrSingle Disconnect Size HeaterPoint BOX Type30.8 025 Cont Type Outlet FLA MCA LRA Hacr BKR Power Supply Disconnect Size Unit Fuse orNominal IFM Conv 40.7 47.7 119 FLA LRA Hacr BKR Type Outlet FLA60.1 Crheater Fuse or Point BOX 68.0 420 68.0 82.8 519/519 017 21.7 25.0 Power Wiring Connections Low Voltage Connections Units with PremierLink Controls Set the Outdoor Cooling and Heat- ing Thermostats Height Width Depth Light Commercial Thermidistat AccessoryInstall Light Commercial Thermidistat Light Commercial Thermidistat Keypad To Test FAN Operational Information START-UP ServicePRE-START-UP Unit Operation Flow Diagram Heating CoolingTroubleshooting Typical Wiring Schematic Standard Controls Typical Wiring Schematic with PremierLink Controls Problem Cause Remedy Heating and Cooling TroubleshootingCopyright 2002 Carrier Corporation III. START-UP Rooftop Unit RTU and Energy Recovery AQ START-UP ChecklistPreliminary Information RTU III. START-UP IV. Light Commercial Thermidistat Accessory