Lenox P506640-01, Elite Series XP16 Units Heat Pumps System Operation, Unit Components

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System Operation

IMPORTANT

Some scroll compressor have internal vacuum protector that will unload scrolls when suction pressure goes below 20 psig. A hissing sound will be heard when the compressor is running unloaded. Protector will reset when low pressure in system is raised above 40 psig. DO NOT REPLACE COMPRESSOR.

This section addresses:

SUnit components (sensors, temperature switch, pressure switches and demand defrost control)

SSecond−stage operation

UNIT COMPONENTS

Demand Defrost Control (A108)

The demand defrost control measures differential temperatures to detect when the system is performing poorly because of ice build−up on the outdoor coil. The controller self−calibrates when the defrost system starts and after each system defrost cycle. The demand defrost control’s: components are shown in figure 25.

SDemand defrost control connections, jumpers and LED locations are shown in figure 25.

SDemand defrost control connections, jumpers and LED descriptions are listed on table 9.

SDemand defrost control status, fault and lockout LEDs are listed in table 10.

TEST PINS (P1)

DEFROST TERMINATION PIN SETTINGS (P1)

SENSOR PLUG IN (COIL AND AMBIENT SENSORS) (P4)

DELAY PINS (P5)

REVERSING VALVE (O OUT)

PRESSURE SWITCH CIRCUIT CONNECTIONS

LOW AMBIENT

THERMOSTAT PINS

(P3)

DIAGNOSTIC LEDS

(DS1 AND DS2)

24V TERMINAL STRIP

CONNECTIONS (P2)

Note − Component locations vary by board manufacturer.

Figure 25. Demand Defrost Control (A108)

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Contents Table of Contents Shipping and Packing ListGeneral Side View Unit Dimensions − inches mmModel Number Identification XP16−024 Base Section XP16 Base with LegsTypical Unit Parts Arrangement Caps and Fasteners Torque RequirementsDetail a Using Manifold Gauge SET Operating Gauge Set and Service ValvesOperating Service Valves To Access Service Port Operating Ball−Type Service Valve3RECOVERING Refrigerant Recovering Refrigerant from Existing System1DISCONNECT Power Method Method 2 LimitationsNew Outdoor Unit Placement Detail a Outside Unit Placement Placement, Slab Mounting and Stabilizing UnitRemoving and Installing Panels Louvered Panel InstallationLouvered Panel Removal Line Set Requirements NEW or Replacement Line SET InstallationUsing Existing Line SET Adding Polyol Ester OIL RequirementsRefrigerant Line SET From Vertical to Horizontal Refrigerant Line SET Alling Horizontal RunsBrazing Connections Brazing Procedures 1CUT and Debur6BRAZE Line SET Wrap Service ValvesFlow Nitrogen 7PREPARATION for Next Step2CONNECT Gauges and Equipment for Flushing Procedure Sensing Bulb Installation Installing New Indoor Metering DeviceIndoor Expansion Valve Installation Equalizer Line InstallationTest for Leaks Evacuating Line Set and Indoor Coil S S SElectrical Connections Size Circuit and Install Disconnect2INSTALL Thermostat 24VAC Transformer4HIGH Voltage Power Supply Connections LOW Voltage ConnectionsTypical Field Wiring Typical Unit Wiring Diagram −024, −036 and −048 Only Typical Unit Wiring Diagram −060 Only Unit Start−Up Unit START−UPLeak CHECK, Repair and Evacuate Connect Manifold Gauge SET and Weigh in ChargeCalculating System Charge for Outdoor Unit Void of Charge Connections for Optimizing System Charge Indoor UnitOptimizing Procedure Adjusting Indoor AirflowOptimizing System Refrigerant Charge SATº LIQºSCº = XP16−036−230 XP16−048−230XP16−060−230 Temperature Pressures Normal Operating PressuresSystem Operation Unit ComponentsTest DelayDS2 Green LED FAN TWO Connectors 24VACSlow Demand Defrost Control A108 Diagnostic LedsDS2 DS1 OFFSECOND−STAGE Operation Emergency Heat Amber Light Defrost Control CONNECTIONS, Jumpers Settings and FeaturesDefrost System Defrost System OverviewCompressor Delay Mode P5 Operational Mode OverviewDefrost Cycle Actuation Defrost Demand Mode Thirty 30 Minute TimeTemperature Mode TIME/TEMPERATURE Mode HOW did Defrost TERMINATE?Degrees Resistance Fahrenheit 136.3 2680 High Discharge Sensor RT28 Temperature / Resistance Range Test Pin P1 Functions S STwo−Stage Modulation Compressors Checks MaintenanceProcedure Tools RequiredHomeowner Outdoor Unit FAN Motor TemperatureCompressor PressuresCooling Mode XP16 Start−Up and PerformanceStart UP Checks