Allied Air Enterprises 4HP16LT manual Preservice Check

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adjustment; turning the unit off and back on before pressures equalize puts stress on unit compressor.

Fan Switch

In AUTO or INT (intermittent) mode, the blower operates only when the thermostat calls for heating or cooling. This mode is generally preferred when humidity control is a priority. The ON or CONT mode provides continuous indoor blower operation, regardless of whether the compressor or auxiliary heat are operating. This mode is required when constant air circulation or filtering is desired.

System Switch

Set the system switch for heating, cooling, or auto opera- tion. The auto mode allows the heat pump to automatically switch from heating mode to cooling mode to maintain predetermined comfort settings. Many heat pump thermo- stats are also equipped with an emergency heat mode which locks out heat pump operation and provides temporary heat supplied by the auxiliary heat.

Indicating Light

Most heat pump thermostats have an amber light which indicates when the heat pump is operating in the emer- gency heat mode.

Temperature Indicator

The temperature indicator displays the actual room temperature.

Programmable Thermostats

Your system may be controlled by a programmable thermo- stat. These thermostats provide the added feature of programmable time-of-day setpoints for both heating and cooling. Refer to the user’s information manual provided with your particular thermostat for operation details.

Preservice Check

If your system fails to operate, check the following before calling for service:

Check to see that all electrical disconnect switches are ON.

Make sure the thermostat temperature selector is properly set.

Make sure the thermostat system switch is properly set.

Replace any blown fuses, or reset circuit breakers.

Make sure unit access panels are in place.

Make sure air filter is clean.

Locate unit model number and have it handy before calling.

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Contents 4HP16LT Series Fastener Torque Installation ClearancesTorque Table GeneralRoof Mounting Electrical WiringSlab Mounting Slab MountingThermostat Designations Without Auxiliary HeatWith Auxiliary Heat Outside Unit Placement Installation Installing Refrigerant LineBrazing Connection Procedure Refrigerant Line Sets Transition from Vertical to Horizontal Refrigerant Line Sets Installing Horizontal RunsR22 refrigerant will be used to flush the system Flushing Existing Line Set and Indoor CoilFlushing Connections Liquid and Suction Line Service Valves Refrigerant Metering DeviceManifold Gauge Set To Close Liquid or Suction Line Service Valve Service ValveBall Type Service Valve Valve Open To Open Liquid or Suction Line Service ValveEvacuation Refrigerant Charge Adjustment Ambient temperatureRefrigerant Charging Cooling Cycle Charge Using Weigh-In MethodBlocking Outdoor Coil R410A Temperature/Pressure ChartNormal Operating Pressures Approach Values for TXV Systems Check Charge Using Normal Operating PressuresFilter Drier OperationSensor Temp. / Resistance Range Defrost Board Pressure Switch ConnectionsDelay Mode Issue Defrost Control Board Diagnostic LEDs LED Description System Diagnostic ModuleInterpreting the Diagnostic LEDs Flash CodesShort Cycling 24VAC Power Wiring Miswired Module Troubleshooting Thermostat Demand Wiring Miswired Module Codes Maintenance Case of extended power outage Heat Pump OperationThermostat Operation Preservice Check Sequence of Operation Start-Up and Performance ChecklistCooling HeatingSingle Stage Wire Diagram Two Stage Wire Diagram