Lenox Elite Series XP14 Units HEAT PUMPS Optimizing System Refrigerant Charge, Amps x Volts x

Models: 50677201 Elite Series XP14 Units HEAT PUMPS

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OUTDOOR UNIT

DISTRIBUTOR

 

 

NOTE − ARROWS INDICATE DIRECTION

 

 

 

 

OF REFRIGERANT FLOW

 

REVERSING VALVE

CHECK / EXPANSION

 

 

VALVE

 

 

 

OUTDOOR

 

 

COIL

 

BI−FLOW FILTER / DRIER

 

INDOOR UNIT

 

 

 

MUFFLER

 

 

TRUE SUCTION

VAPOR

 

PORT

 

SERVICE

 

 

 

 

PORT

LIQUID LINE

COMPRESSOR

 

SERVICE PORT

 

 

 

 

 

CHECK / EXPANSION VALVE

INDOOR

NOTE − Use gauge ports on vapor line valve and liquid valve for evacuating refrigerant lines andCOIL indoor coil. Use true suction port to measure vapor pressure during charging.

Figure 21. Heat Pump Cooling Cycle

Optimizing System Refrigerant Charge

This section provides instructions on optimizing the system charge. This section includes:

SOptimizing procedure

SAdjusting indoor airflow

SUsing subcooling method

SApproved matched components, targeted subcooling (SC) values and add charge values

efficiency. Make any air flow adjustments before continuing with the optimizing procedure.

5.Use subcooling method to optimize the system charge (see figure 23). Adjust charge as necessary.

ADJUSTING INDOOR AIRFLOW

Heating Mode Indoor Airflow Check

(Only use when indoor unit has electric heat)

SNormal operating pressures

STemperature pressures

OPTIMIZING PROCEDURE

1.Move the low−side manifold gauge hose from the vapor line service valve to the true suction port (see figure 19).

2.Set the thermostat for either cooling or heating demand. Turn on power to the indoor unit and close the outdoor unit disconnect switch to start the unit.

3.Allow unit to run for five minutes to allow pressures to stabilize.

4.Check the airflow as instructed under Adjusting Indoor Airflow to verify or adjust indoor airflow for maximum

Indoor blower airflow (CFM) may be calculated by energizing electric heat and measuring:

STemperature rise between the return air and supply air temperatures at the indoor coil blower unit,

SMeasuring voltage supplied to the unit,

SMeasuring amperage being drawn by the heat unit(s).

Then, apply the measurements taken in the following formula to determine CFM:

Amps x Volts x 3.41

CFM =

1.08 x Temperature rise (F)

Cooling Mode Indoor Airflow Check

Check airflow using the Delta−T (DT) process using figure 22.

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XP14 SERIES

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Lenox Elite Series XP14 Units HEAT PUMPS Optimizing System Refrigerant Charge, Adjusting Indoor Airflow, Amps x Volts x