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Page 13

HPXA16 SERIES

HPXA16 Cooling Cycle (Showing Gauge Manifold Connections)

Figure 17

NOTE 

− Use gauge ports on vapor line valve and liquid valve for evacuating refrigerant lines and indoor coil. Use vapor

gauge port to measure vapor pressure during charging.

OUTDOOR

COIL

EXPANSION/

CHECK VALVE

BIFLOW
FILTER /
DRIER

TO

HFC−410
A DRUM

LOW

PRESSURE

COMPRESSOR

REVERSING VALVE

VAPOR
LINE
VALVE

MUFFLER

NOTE − ARROWS INDICATE
DIRECTION OF REFRIGERANT FLOW

SERVICE

PORT

VAPOR

EXPANSION/CHECK VALVE

INDOOR UNIT

OUTDOOR UNIT

LIQUID

LINE

SERVICE

PORT

GAUGE MANIFOLD

DISTRIBUTOR

INDOOR

COIL

VAPOR
SERVICE
PORT

HUGH

PRESSURE

Table 3

Refrigerant Charge per Line Set Lengths

Liquid Line
Set Diameter

Ounces per 5 feet (grams per 1.52 meter)
adjust from 15 ft. (4.57m) line set*

3/8 in. (9.5mm)

3 ounces per 5 feet (85 grams per 1.52 meter)

*Add the amount shown if line length is greater than 15’ (4.57m), sub-
tract the amount shown if less than 15’.

IMPORTANT

Mineral oils are not compatible with HFC−410A. If
oil must be added, it must be a polyol ester oil.

The compressor is charged with sufficient polyol
ester oil for approved line set lengths.

Checking Charge

The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur
in the colder months. 

The method of charging is deter-

mined by the outdoor ambient temperature

.

Measure the liquid line temperature and the outdoor ambi-
ent temperature as outlined below:

1. Connect the manifold gauge set to the service valves:

low pressure gauge to 

vapor 

valve service port

high pressure gauge to 

liquid 

valve service port

Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HFC−410A. See
figure 17.

2. Set the room thermostat to call for heat. This will

create the necessary load for properly charging the
system in the cooling cycle.

3. Record outdoor ambient temperature using a digital

thermometer.

4. When the heating demand has been satisfied, switch

the thermostat to cooling mode with a set point of 68

F

(20

C). When pressures have stabilized, use a digital

thermometer to record the liquid line temperature.

5. The outdoor temperature will determine which charg-

ing method to use. Proceed with whichever of the fol-
lowing charging procedure deemed appropriate for the
situation.

Charge Using the Weigh-in Method –
Outdoor Temperature < 65

F (18

C)

If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, first, locate and repair any leaks and
then weigh in the refrigerant charge into the unit.

1. Recover the refrigerant from the unit.
2. Conduct leak check; evacuate as previously outlined.
3. Weigh in the unit nameplate charge. If weighing facili-

ties are not available or if charging the unit during
warm weather, use one of the following procedures.

Charge Using the Subcooling Method –
Outdoor Temperature < 65°F (18°C)

When the outdoor ambient temperature is below 65°F
(18°C), use the subcooling method to charge the unit. It
may be necessary to restrict the air flow through the out-
door coil to achieve pressures in the 325−375 psig
(2240−2585 kPa) range. These higher pressures are nec-
essary for checking the charge. Block equal sections of air
intake panels and move obstructions sideways until the liq-
uid pressure is in the 325−375 psig (2240−2585 kPa) range.
See figure 18.

Blocking Outdoor Coil

*Outdoor coil should be blocked one
side at a time with cardboard or plastic
sheet until proper testing pressures
are reached.

cardboard or plastic sheet

*Four−sided unit shown.

Figure 18

Summary of Contents for HPXA16 -060

Page 1: ...st be followed Fines and or in carceration may be levied for noncompliance INSTALLATION INSTRUCTIONS HPXA16 Series Units HEAT PUMP UNITS 504 954M 08 06 Supersedes 03 06 Table of Contents HPXA16 Outdoor Unit 1 Shipping Packing List 2 General Information 2 Unit Dimensions 2 Parts Arrangement 3 Setting the Unit 3 Electrical 4 Refrigerant Piping 6 Refrigerant Metering Device 8 Flushing Existing Line S...

Page 2: ...ass wool Disturbing the insulation during installation main tenance or repair will expose you to fiberglass wool dust Breathing this may cause lung cancer Fiber glass wool is known to the State of California to cause cancer Fiberglass wool may also cause respiratory skin and eye irritation To reduce exposure to this substance or for further information consult material safety data sheets available...

Page 3: ... high enough above ground or roof to allow adequate drainage of defrost water and prevent ice build up 3 In heavy snow areas do not locate unit where drifting will occur The unit base should be elevated above the depth of average snows NOTE Elevation of the unit may be accomplished by constructing a frame using suitable materials If a sup port frame is constructed it must not block drain holes in ...

Page 4: ...te for minimum circuit ampacity and maximum overcurrent protection size WARNING Electric Shock Hazard Can cause in jury or death Unit must be grounded in accordance with national and local codes Line voltage is present at all compo nents when unit is not in operation on units with single pole contactors Dis connect all remote electric power sup plies before opening access panel Unit may have multi...

Page 5: ...O HPXA16 Outdoor Unit and CB31MV CB32MV Thermostat Designations CB31MV CBX32MV TB1 D R H W1 O SignatureStat A2 Thermostat Figure 7 W2 Y1 O Y1 G C W2 W1 RT 14 L Some connections may not apply Refer to specific thermostat and indoor unit Y2 Y2 Y2 Y2 OUT Outdoor Unit Defrost Board HPXA16 Wiring Diagram Figure 8 Shipped as shown above with terminal crimped to blue wire use terminal or cut off terminal...

Page 6: ...ttention to line set isolation during installation of any heat pump or a c system When properly isolated from building structures walls ceilings floors the refrigerant lines will not create unnecessary vibration and subsequent noises Also consider the following when placing and installing a high efficiency outdoor unit 1 Placement Be aware some localities are adopting sound ordinances based on how...

Page 7: ...rant lines must not contact wall WOOD BLOCK BETWEEN STUDS STRAP SLEEVE WOOD BLOCK STRAP SLEEVE WIRE TIE WIRE TIE WIRE TIE Figure 11 INSIDE WALL Refrigerant Line Sets Installing Horizontal Runs METAL SLEEVE STRAPPING MATERIAL Around vapor line only TAPE OR WIRE TIE WIRE TIE Around vapor line only FLOOR JOIST OR ROOF RAFTER TAPE OR WIRE TIE To hang line set from joist or rafter use either metal stra...

Page 8: ...roperly with an HCFC 22 valve Check Expansion Valve Systems Check expansion valves equipped with either Chatleff or flare type fittings are available from Lennox Refer to the EngineeringHandbookforapplicableexpansionvalvesfor use with specific match ups If you install a check expansion valve with an indoor coil that includes a fixed orifice remove the orifice before the check expansion valve is in...

Page 9: ...CFC 22 refrigerant back into the outdoor unit It may be necessary to by pass the low pressure switches to ensure com plete refrigerant evacuation When the low side system pressures reach 0 psig close the vapor line valve Disconnect all power to the existing outdoor unit Check gauges after shutdown to confirm that the valves are not allowing refrigerant to flow back into the low side of the system ...

Page 10: ...gen to break the vacuum on the refriger ant lines and indoor coil before removing the recovery machine gauges and HCFC 22 refrigerant drum Re install pressure tap valve cores into HPXA16 service valves 11 Install the provided check expansion valve approved for use with HFC 410A refrigerant in the liquid line at the indoor coil Manifold Gauge Set Manifold gauge sets used with systems charged with H...

Page 11: ...be used and recovered responsibly Failure to follow this warning may result in personal injury or death WARNING Fire Explosion and Personal Safety Hazard Failure to follow this warning could result in damage personal injury or death Never use oxygen to pressurize or purge refrigeration lines Oxygen when exposed to a spark or open flame can cause damage by fire and or an explosion that could result...

Page 12: ...ose from the cylinder Open the manifold gauge valves to release the dry nitrogen from the line set and indoor unit 8 Reconnect the manifold gauge to the vacuum pump turn the pump on and continue to evacuate the line set and indoor unit until the absolute pressure does not rise above 500 microns 29 9 inches of mercury within a 20 minute period after shutting off the vacuum pump and closing the mani...

Page 13: ...hose to an upright cylinder of HFC 410A See figure 17 2 Set the room thermostat to call for heat This will create the necessary load for properly charging the system in the cooling cycle 3 Record outdoor ambient temperature using a digital thermometer 4 When the heating demand has been satisfied switch the thermostat to cooling mode with a set point of 68 F 20 C When pressures have stabilized use ...

Page 14: ...turation temperature Liquid line tem perature Subcooling 5 Compare the subcooling value with those in table 5 If subcooling is greater than shown recover some refrig erant If subcooling is less than shown add some re frigerant Be aware of the HFC 410A refrigerant cylin der It will be light maroon colored Refrigerant should be added through the vapor line valve in the liquid state NOTE Some HFC 410...

Page 15: ...le 8 add refrigerant to lower the approach temperature or recover refrigerant from the system to increase the approach temperature Table 8 Approach Values for Charging Model Number Second Stage High Capacity Ap proach Temperature Liquid Line Temp Outdoor Ambient F C HPXA16 024 4 0 1 2 2 5 HPXA16 036 7 0 1 3 9 5 HPXA16 048 8 0 1 4 4 5 HPXA16 060 10 0 1 5 6 5 System Operation The outdoor unit and in...

Page 16: ...e off the compressor and the strike counter in the board will count one strike The low pressure switch is ignored under the following conditions during the defrost cycle and 90 seconds after the ter mination of defrost when the average ambient sensor temperature is be low 15 F 9 C for 90 seconds following the start up of the compressor during test mode High Pressure Switch HI PS When the high pres...

Page 17: ...harge if applicable 24 4 to 350 176 41 000 to 103 1 2 Yellow Note Sensor resistance decreases as sensed temperature increases see figure 20 Figure 20 Ambient and Coil Sensor Discharge Sensor RESISTANCE OHMS RESISTANCE OHMS TEMPERATURE ºF TEMPERATURE ºF 5750 7450 9275 11775 15425 19975 26200 34375 46275 62700 200 325 250 425 600 825 1175 1700 2500 3750 5825 100 90 80 70 60 50 40 30 20 10 0 300 280 ...

Page 18: ...olenoid output will be energized NOTE Figure 8 on page 5 shows the correct Y2 field wir ing If first stage compressor output is active in heating mode and the outdoor ambient temperature is below the selected compressor lock in temperature the second stage com pressor solenoid output will be energized without the Y2 input If the jumper is not connected to one of the tempera ture selection pins on ...

Page 19: ...e board after power up The TEST pins are ignored and the test function is locked out if the shunt is applied on the TEST pins before power up Board timings are reduced the low pressure switch is ig nored and the board will clear any active lockout condition Each test pin shorting will result in one test event For each TEST the shunt jumper must be removed for at least 1 second and reapplied Refer ...

Page 20: ... draws 2 Ch k t h i h b OFF ON Low Pressure LOCKOUT p p g g system 3 Improper metering device installed or incorrect operation p p 2 Check system charge using approach sub cooling temperatures 3 Check system operating pressures and SLOW Flash OFF High Pressure Fault installed or incorrect operation of metering device 4 Incorrect or improper sensor location or connection to sys t 3 Check system ope...

Page 21: ...ating Check the amperage draw at the outdoor fan motor compressor and indoor blower motor Values should be compared with those given on unit nameplate Check clean or replace indoor unit filters Check the refrigerant charge and gauge the system pressures Check the condensate drain line for free and unob structed flow clean if necessary Adjust blower speed for cooling Measure the pressure drop over ...

Page 22: ...pply Voltage Unit Off Indoor Blower RPM S P Drop Over Indoor Dry Outdoor Coil Entering Air Temp COOLING 2ND STAGE Liquid Line Pressure Vapor Pressure Refrigerant Charge Checked HEATING 2ND STAGE Liquid Line Pressure Vapor Pressure Refrigerant Charge Checked Vapor Pressure 1st Stage 2nd Stage Refrigerant Lines Leak Checked Properly Insulated Outdoor Fan Checked Service Valves Fully Opened Caps Tigh...

Page 23: ...f installed IMPORTANT Sprinklers and soaker hoses should not be installed where they could cause prolonged exposure to the outdoor unit by treated water Prolonged exposure of the unit to treated water i e sprinkler systems soakers waste water etc will corrode the surface of steel and aluminum parts and diminish performance and longevity of the unit Heat Pump Operation Your new Lennox heat pump has...

Page 24: ...ch from heating mode to cooling mode to maintain pre determined comfort settings Many heat pump thermo stats are also equipped with an emergency heat mode which locks out heat pump operation and provides tempo rary heat supplied by the auxiliary heat Indicating Light Most heat pump thermostats have an amber light which in dicates when the heat pump is operating in the emergency heat mode Temperatu...

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