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Page 3

14ACX SERIES

IMPORTANT !

If this unit is being matched with an approved line
set or indoor unit coil that was previously charged
with mineral oil, or if it is being matched with a coil
which was manufactured before January of 1999,
the coil and line set must be flushed prior to installa­
tion. Take care to empty all existing traps. Polyol es­
ter (POE) oils are used in Lennox units charged with
HFC-410A refrigerant. Residual mineral oil can act
as an insulator, preventing proper heat transfer. It
can also clog the expansion device and reduce sys­
tem performance and capacity.
Failure to properly flush the system per this instruc­
tion and the detailed Installation and Service Proce­
dures manual will void the warranty.

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 ex­
posed to a spark or open flame, can
cause fire and/or an explosion, that could
result in property damage, personal inju­
ry or death.

WARNING

When using a high pressure gas such as
nitrogen to pressurize a refrigeration or air
conditioning system, use a regulator that
can control the pressure down to 1 or 2 psig
(6.9 to 13.8 kPa).

WARNING

Polyol ester (POE) oils used with HFC-410A refrigerant
absorb moisture very quickly. It is very important that
the refrigerant system be kept closed as much as
possible. DO NOT remove line set caps or service valve
stub caps until you are ready to make connections.

IMPORTANT !

Some scroll compressors have an internal vacuum
protector that will unload scrolls when suction pres­
sure goes below 20 psig. A hissing sound will be
heard when the compressor is running unloaded.
The protector will reset when low pressure rises
above 40 psig. DO NOT REPLACE COMPRESSOR.

LIQUID LINE FILTER DRIER INSTALLATION

The provided filter drier must be field installed in the liquid
line between the outdoor unit's liquid line service valve and
the indoor coil's metering device (fixed orifice or TXV) as
illustrated in figure 5. This filter drier must be installed to
ensure a clean, moisture-free system. Failure to install the
filter drier will void the warranty. A replacement filter drier is
available from Lennox. See 

Brazing Connections

 page 6

for special procedures on brazing filter drier connections to
the liquid line.

OUTDOOR

UNIT

LIQUID LINE

SERVICE VALVE

LIQUID LINE

FILTER DRIER

LINE

LIQUID

LINE

BRAZE CONNECTION POINTS

FIGURE 5

Typical Liquid Line Filter Drier Installation

WARNING

Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.
Failure to follow this warning may result in personal injury
or death.

NOTE

 - When installing refrigerant lines longer than 50

feet, refer to the Refrigerant Piping Design and Fabrication
Guidelines manual available on LennoxPros.com (Corp.
9351-L9), or contact the Technical Support Department
Product Application group for assistance.

TABLE 2. REFRIGERANT LINE SET — INCHES (MM)

Model Number (-xx*)

Valve Size Connections

Recommended Line Sets

Liquid Line

Suction  Line

L15 Line Set Model

Line Set Length

Catalog Number

14ACX-018-230AXX
14ACX-024-230AXX
14ACX-030-230AXX

3/8” (10 mm)

3/4” (19 mm)

L15-41-20

20 feet (6.1 m)

89J56

L15-41-30

30 feet (9.1 m)

89J57

L15-41-40

40 feet (12.2 m)

89J58

L15-41-50

50 feet (15.2 m)

89J59

14ACX-036-230AXX

14ACX-041-230-XX

14ACX-042-230AXX

14ACX-047-230-XX
14ACX-048-230-XX

3/8” (10 mm)

7/8” (22 mm)

L15-65-30

30 feet (9.1 m)

89J60

L15-65-40

40 feet (12.2 m)

89J61

L15-65-50

50 feet (15.2 m)

89J62

14ACX-059-230-XX
14ACX-060-230-XX

3/8” (10 mm)

1-1/8” (29 mm) **

Field-fabricated

N/A

N/A

*  Applicable to all minor revision numbers unless otherwise specified.

** Some applications may require a field-provided 1-1/8” to 7/8” adapter.

Summary of Contents for Merit 14ACX-018-230

Page 1: ...tdoor air conditioner is designed for use with HFC 410A refrigerant only This unit must be installed with an approved indoor air handler or coil See the Lennox 14ACX Product Specifications bulletin EH...

Page 2: ...ing or stowing the panels consider any weather conditions especially wind that may cause panels to be blown around and damaged NOTICE Roof Damage This system contains both refrigerantand oil Some rubb...

Page 3: ...e rises above 40 psig DO NOT REPLACE COMPRESSOR LIQUID LINE FILTER DRIER INSTALLATION The provided filter drier must be field installed in the liquid line between the outdoor unit s liquid line servic...

Page 4: ...THE LIQUID LINE TO THE SUCTION LINE FLOOR JOIST OR ROOF RAFTER REFRIGERANT LINE SET INSTALLING HORIZONTAL RUNS NOTE Similar installation practices should be used if line set is to be installed on ext...

Page 5: ...ndoor unit s liquid line orifice housing LOW HIGH EXISTING INDOOR UNIT GAUGE MANIFOLD CYLINDER CONTAINING CLEAN HCFC 22 TO BE USED FOR FLUSHING Positioned to deliver liquid refrigerant LIQUID LINE SER...

Page 6: ...d debur the ends The pipe must remain round Do not crimp end of the line Remove service cap and core from both the suction and liquid line service ports 1 2 ANGLE TYPE SERVICE VALVE SERVICE PORT CORE...

Page 7: ...WHEN BRAZING LINE SET TO SERVICE VALVES POINT FLAME AWAY FROM SERVICE VALVE PREPARATION FOR NEXT STEP 7 WRAP SERVICE VALVES To help protect service valve seals during brazing wrap water saturated clo...

Page 8: ...TION EQUALIZER LINE INSTALLATION A Remove and discard either the flare seal cap or flare nut with copper flare seal bonnet from the equalizer line port on the suc tion line as illustrated in the figur...

Page 9: ...door unit E After a few minutes open one of the service valve ports and verify that the refrigerant added to the system earlier is measurable with a leak detector F After leak testing disconnect gauge...

Page 10: ...utting off the vacuum pump and closing the manifold gauge valves F When the absolute pressure requirement above has been met disconnect the manifold hose from the vacuum pump and connect it to a cylin...

Page 11: ...re only with this product CAUTION Failure to use properly sized wiring and circuit breaker may result in property damage Size wiring and circuit breaker s per Product Specifications bulletin EHB and u...

Page 12: ...t and secure with provided wire tie B Make 24VAC thermostat wire connections Locate the two wires from the contactor and make connection using field provided wire nuts Yellow to Y1 Black to C common R...

Page 13: ...ped with a service port which has a factory installed valve stem Figures 15 and 16 provide information on how to access and operate both angle and ball type service valves Torque Requirements When ser...

Page 14: ...he tables provided on the charging procedure sticker located on the unit access panel Detailed information is provided in the 14ACX Installation and Service Procedures manual Corp0638 L10 which is ava...

Page 15: ...as necessary 6 Inspect contactor contacts for pitting or burn marks Replace as necessary 7 Check outdoor fan motor for worn bearings bushings Replace as necessary 8 Inspect and clean outdoor coils if...

Page 16: ...re Supply Air Temperature Ambient Temperature Return Air Temperature System Refrigerant Charge Refer to manufacturer s information on unit or installation instructions for required subcooling and appr...

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