INSTALLATION INSTRUCTIONS · 2017. 4. 13. · 03/10 506374−01 Page 1 2010 Lennox Industries Inc. Dallas, Texas, USA RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE WARNING Improper

03/10 506374−01

�� Page 1

�2010 Lennox Industries Inc.Dallas, Texas, USA

RETAIN THESE INSTRUCTIONSFOR FUTURE REFERENCE

WARNINGImproper installation, adjustment, alteration, service ormaintenance can cause personal injury, loss of life, ordamage to property.

Installation and service must be performed by a licensedprofessional installer (or equivalent) or a service agency.

IMPORTANTThe Clean Air Act of 1990 bans the intentional venting ofrefrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992.Approved methods of recovery, recycling or reclaimingmust be followed. Fines and/or incarceration may belevied for noncompliance.

IMPORTANTThis unit must be matched with an indoor coil asspecified in Lennox Engineering Handbook. Coilspreviously charged with HCFC−22 must be flushed.

WARNINGElectric Shock Hazard. Can cause injuryor death. Unit must be grounded inaccordance with national and localcodes.

Line voltage is present at all componentswhen unit is not in operation on units withsingle-pole contactors. Disconnect allremote electric power supplies beforeopening access panel. Unit may havemultiple power supplies.

INSTALLATIONINSTRUCTIONS

Merit® Series 13ACX Units

AIR CONDITIONER506374−01 03/10Supersedes 11/09

TABLE OF CONTENTS

Shipping and Packing List 1. . . . . . . . . . . . . . . . . . . . . . . .

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical Unit Parts Arrangement 2. . . . . . . . . . . . . . . . . . .

Model Number Identification 3. . . . . . . . . . . . . . . . . . . . . .

General Information 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Gauge Set and Service Valves 3. . . . . . . . . . .

Recovering Refrigerant from Existing System 5. . . . . . .

New Outdoor Unit Placement 6. . . . . . . . . . . . . . . . . . . . .

New or Replacement Line Set 6. . . . . . . . . . . . . . . . . . . . .

Metering Devices and Flushing the System 10. . . . . . . .

Testing for Leaks 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Evacuating the System 13. . . . . . . . . . . . . . . . . . . . . . . . . . Electrical Connections 14. . . . . . . . . . . . . . . . . . . . . . . . . .

Servicing Unit Delivered Void of Charge 16. . . . . . . . . . .

Unit Start−Up 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

System Refrigerant 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removing and Installing Louvers 22. . . . . . . . . . . . . . . . .

System Operation 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Start−Up and Performance Checklist 24. . . . . . . . . . . . . .

Shipping and Packing List

Check the unit for shipping damage and listed times beloware intact. If damaged, or if parts are missing, immediatelycontact the last shipping carrier.

1 � Assembled outdoor unit

1 � Refrigerant flow control kit (Fixed Orifice)

1 � Liquid line filter drier

General

13ACX, which will also be referred to in this instruction asthe outdoor unit, uses HFC−410A refrigerant. This outdoorunit must be installed with a matching indoor unit and lineset as outlined in the Lennox 13ACX EngineeringHandbook.

This outdoor unit is designed for use in systems that useone of the following refrigerant metering devices:

� Thermal expansion valve (TXV)

� Fixed orifice

Litho U.S.A.

506374−01 03/10

Unit Dimensions − Inches (mm)

SIDE VIEW

SUCTION AND LIQUIDLINE CONNECTION

DISCHARGE AIR

SIDE VIEW

OUTDOORCOIL FAN

COMPRESSOR

A

B

A

OPTIONAL UNITSTANDOFF KIT (4)

(FIELD INSTALLED)

Model Numbers A B

−018 24−1/4 (616) 25−1/4 (641)

−024 24−1/4 (616) 25−1/4 (641)

−030 24−1/4 (616) 29−1/4 (743)

−036 24−1/4 (616) 29−1/4 (743)

−042 28−1/4 (724) 29−1/4 (743)

−048 28−1/4 (724) 37−1/4 (925)

−060 28−1/4 (724) 33−1/4 (845)

Typical Unit Parts Arrangement

COMPRESSORHARNESS

LIQUID LINE SERVICE VALVE SUCTION LINE SERVICE VALVE

OUTDOOR COIL

DISCHARGE LINE

HIGH PRESSURESWITCH (S4)

COMPRESS0R

GROUND LUG

CONTACTOR

CONTROL

CAPACITOR

CONTROL WIRELOOP

CUTOUT FOR HIGHVOLTAGE CONDUIT

NOTE � PLUMBING LAYOUT AND COMPRESSOR TYPE MAY VARY SLIGHTLY BETWEENMODEL SIZES.

13ACX SERIES

Model Number Identification

AC X13 024 −

Unit TypeAC = Air Conditioner

RefrigerantX = R−410A

Cooling Capacity − Tons

018 = 1.5024 = 2030 = 2.5036 = 3042 = 3.5048 = 4060 = 5

Minor Revision NumberNominal SEER

2

Voltage230 = 208/230V−1phase−60hz

230−−

WARNINGThis product and/or the indoor unit it is matched with maycontain fiberglass wool.

Disturbing the insulation during installation,maintenance, or repair will expose you to fiberglass wooldust. Breathing this may cause lung cancer. (Fiberglasswool is known to the State of California to cause cancer.)

Fiberglass wool may also cause respiratory, skin, andeye irritation.

To reduce exposure to this substance or for furtherinformation, consult material safety data sheetsavailable from address shown below, or contact yoursupervisor.

Lennox Industries Inc.P.O. Box 799900Dallas, TX 75379−9900

CAUTIONPhysical contact with metal edges and corners whileapplying excessive force or rapid motion can result inpersonal injury. Be aware of, and use caution whenworking near these areas during installation or whileservicing this equipment.

General Information

These instructions are intended as a general guide and donot supersede local codes in any way. Consult authoritieswho have jurisdiction before installation.

Operating Gauge Set and Service Valves

These instructions are intended as a general guide and donot supersede local codes in any way. Consult authoritieswho have jurisdiction before installation.

TORQUE REQUIREMENTS

When servicing or repairing heating, ventilating, and airconditioning components, ensure the fasteners areappropriately tightened. Table 1 lists torque values forfasteners.

IMPORTANTOnly use Allen wrenches of sufficient hardness (50Rc −Rockwell Harness Scale minimum). Fully insert thewrench into the valve stem recess.

Service valve stems are factory−torqued (from 9 ft−lbs forsmall valves, to 25 ft−lbs for large valves) to preventrefrigerant loss during shipping and handling. Using anAllen wrench rated at less than 50Rc risks rounding orbreaking off the wrench, or stripping the valve stemrecess.

See the Lennox Service and Application Notes #C−08−1for further details and information.

IMPORTANTTo prevent stripping of the various caps used, theappropriately sized wrench should be used and fittedsnugly over the cap before tightening.

When servicing or repairing HVAC components, ensurethe fasteners are appropriately tightened. Table 1 providestorque values for fasteners.

Table 1. Torque Requirements

Parts Recommended Torque

Service valve cap 8 ft.− lb. 11 NM

Sheet metal screws 16 in.− lb. 2 NM

Machine screws #10 28 in.− lb. 3 NM

Compressor bolts 90 in.− lb. 10 NM

Gauge port seal cap 8 ft.− lb. 11 NM

USING MANIFOLD GAUGE SET

When checking the system charge, only use a manifoldgauge set that features low loss anti−blow back fittings.

Manifold gauge set used with HFC−410A refrigerantsystems must be capable of handling the higher systemoperating pressures. The gauges should be rated for usewith pressures of 0 − 800 psig on the high side and a lowside of 30" vacuum to 250 psig with dampened speed to500 psi. Gauge hoses must be rated for use at up to 800psig of pressure with a 4000 psig burst rating.

506374−01 03/10

OPERATING SERVICE VALVES

The liquid and vapor line service valves are used forremoving refrigerant, flushing, leak testing, evacuating,checking charge and charging.

Each valve is equipped with a service port which has afactory−installed valve stem. Figure 1 provides informationon how to access and operating both angle and ball servicevalves.

(VALVE STEM SHOWNCLOSED) INSERT HEXWRENCH HERE

VALVE STEMFRONT-SEATED

TO OUTDOORUNIT

SERVICE PORTCORE

TO INDOORUNIT

SERVICE PORT

SERVICE PORT CAP

CLOSED TO BOTHINDOOR AND OUTDOOR

UNITS

STEM CAP

ANGLE−TYPESERVICE VALVE(FRONT−SEATED

CLOSED)

SERVICE PORTSERVICE PORT

CORE

TO OUTDOOR UNIT

STEM CAP

(VALVE STEMSHOWN OPEN)INSERT HEXWRENCH HERE

SERVICE PORT CAP

TO INDOORUNIT

OPEN TO BOTH INDOOR ANDOUTDOOR UNITS

ANGLE−TYPE SERVICE VALVE(BACK−SEATED OPENED)

BALL (SHOWN CLOSED)

SERVICE PORT CORE

TO INDOOR UNIT

TO OUTDOOR UNIT

TO OPEN ROTATE STEMCOUNTERCLOCKWISE 90°.

TO CLOSE ROTATE STEMCLOCKWISE 90°.

SERVICE PORT

SERVICE PORT CAP

STEM CAP

VALVE STEM

WHEN SERVICE VALVE IS CLOSED, THE SERVICE PORT IS OPEN TO THELINE SET AND INDOOR UNIT.

BALL−TYPE SERVICEVALVE

SERVICE VALVESVARIOUS TYPES

WHEN SERVICE VALVE IS OPEN, THE SERVICE PORT IS OPEN TO LINE SET,INDOOR AND OUTDOOR UNIT.

To Access Service Port:

A service port cap protects the service port core from contamination andserves as the primary leak seal.

1. Remove service port cap with an appropriately sized wrench.

2. Connect gauge set to service port.

3. When testing is completed, replace service port cap and tighten as fol-lows:

123

4567

8910

11 12

1/6 TURN

Operating Angle Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use a service wrench with a hex−head extension (3/16" for liquid line valve sizes and 5/16" for vapor line valvesizes) to back the stem out counterclockwise as far as it will go.

Operating Ball Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use an appropriately sized wrenched to open. To open valve, rotate stem counterclockwise 90°. To close rotate stem clockwise 90°.

Reinstall Stem Cap:

Stem cap protects the valve stem from damage and serves as the primary seal. Replace the stem cap andtighten as follows:

� With Torque Wrench: Finger tighten and then torque cap per Table 1.

� Without Torque Wrench: Finger tighten and use an appropriately sized wrench to turnan additional 1/12 turn clockwise.

NOTE � A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque.

123

4567

8910

11 12

1/6 TURN

� With Torque Wrench: Finger tighten and torque cap per Table 1.

� Without Torque Wrench: Finger tighten and use an appropriatelysized wrench to turn an additional 1/6 turn clockwise.

Figure 1. Angle and Ball Service Valves

13ACX SERIES

Recovering Refrigerant from Existing System

SERVICEDISCONNECT

SWITCH

MAIN FUSE BOX/BREAKER PANEL

Disconnect all power to the existing outdoor unit at the servicedisconnect switch or main fuse box/breaker panel.

DISCONNECT POWER CONNECT MANIFOLD GAUGE SET

MANIFOLD GAUGES

RECOVERY MACHINE

CLEAN RECOVERYCYLINDER

OUTDOOR UNIT

HIGHLOW

Connect a gauge set, clean recovery cylinder and a recoverymachine to the service ports of the existing unit. Use theinstructions provided with the recovery machine to make theconnections.

METHOD 1:Us this method if the existing outdoor unit is not equipped with shut−off valves, or if the unit is not operational and you plan to use the existingHCFC−22 to flush the system.

Remove all HCFC−22 refrigerant from the existing system. Check gauges after shutdown to confirm that the entire system is completely void ofrefrigerant.

METHOD 2:Use this method if the existing outdoor unit is equipped with manual shut−off valves, and you plan to use new HCFC−22 refrigerant to flush thesystem.

The following devices could prevent full system charge recovery into the outdoor unit:

� Outdoor unit’s high or low−pressure switches (if applicable) when tripped can cycle the compressor OFF.

� Compressor can stop pumping due to tripped internal pressure relief valve.

� Compressor has internal vacuum protection that is designed to unload the scrolls (compressor stops pumping) when the pressure ratio meetsa certain value or when the suction pressure is as high as 20 psig. (Compressor suction pressures should never be allowed to go into a vacuum.Prolonged operation at low suction pressures will result in overheating of the scrolls and permanent damage to the scroll tips, drive bearings andinternal seals.)

Once the compressor can not pump down to a lower pressure due to one of the above system conditions, shut off the vapor valve. Turn OFF the

main power to unit and use a recovery machine to recover any refrigerant left in the indoor coil and line set.

Perform the following task:

A. Start the existing HCFC−22 system in the cooling mode and close the liquid line valve.

B. Use the compressor to pump as much of the existing HCFC−22 refrigerant into the outdoor unit until the outdoor system is full. Turn the outdoor unitmain power OFF and use a recovery machine to remove the remaining refrigerant from the system.

NOTE � It may be necessary to bypass the low pressure switches (if equipped) to ensure complete refrigerant evacuation.

C. When the low side system pressures reach 0 psig, close the vapor line valve.

D. Check gauges after shutdown to confirm that the valves are not allowing refrigerant to flow back into the low side of the system.

RECOVERINGREFRIGERANT FROM SYSTEM

Remove existing HCFC−22 refrigerant using one of the following procedures:

RECOVERING REFRIGERANT

IMPORTANT � Some system configurations may contain higher than normal refrigerant charge due to either large internal coil volumes,and/or long line sets.

1 2

3

506374−01 03/10

New Outdoor Unit Placement

See Unit Dimensions on Page 2 for sizing mounting slab,platforms or supports. Refer to Figure 2 for mandatoryinstallation clearance requirements.

*

* *

*

NOTES:

� Service panel access clearance of 30 in. (762 mm) must bemaintained.

� Clearance to one of the other three sides must be 36 in. (914mm).

� Clearance on one of the remaining two sides may be 12 in. (305mm) and the final side may be 6 in. (152 mm).

� Clearance required on top of unit is 48 in. (1219 mm).

� A clearance of 24 in. (610 mm) must be maintained between twounits.

Figure 2. Installation Clearances

POSITIONING CONSIDERATIONS

CAUTIONIn order to avoid injury, take proper precaution when lift-ing heavy objects.

Consider the following when positioning the unit:

� Some localities are adopting sound ordinances basedon the unit’s sound level registered from the adjacentproperty, not from the installation property. Install the

unit as far as possible from the property line.

� When possible, do not install the unit directly outsidea window. Glass has a very high level of soundtransmission. For proper placement of unit in relation

to a window see the provided illustration in Figure 3.

INSTALL UNIT AWAYFROM WINDOWS

TWO 90� ELBOWS INSTALLED IN LINE SETWILL REDUCE LINE SET VIBRATION

Figure 3. Outside Unit Placement

PLACING OUTDOOR UNIT ON SLAB

When installing a unit at grade level, the top of the slabshould be high enough above the grade so that water fromhigher ground would not collect around the unit asillustrated in Figure 4.

GROUND LEVEL

MOUNTINGSLAB

BUILDINGSTRUCTURE

DISCHARGE AIR

Figure 4. Typical Slab Mounting at Ground Level

Slab may be level or have a slope tolerance away from thebuilding of not more than two degrees, or 2 inches per 5feet (51 mm per 1524 mm) as illustrated in Figure 4.

INSTALLING OUTDOOR UNIT ON ROOF

Install the unit at a minimum of 4 inches (102 mm) abovethe surface of the roof. Ensure the weight of the unit isproperly distributed over roof joists and rafters. Redwoodor steel supports are recommended.

New or Replacement Line Set

This section provides information on installation orreplacement of existing line set. If line set is not beinginstalled or replace then proceed to Brazing Connectionson Page 9.

13ACX SERIES

If refrigerant lines are routed through a wall, seal andisolate the opening so vibration is not transmitted to thebuilding. Pay close attention to line set isolation duringinstallation of any HVAC system. When properly isolatedfrom building structures (walls, ceilings. floors), therefrigerant lines will not create unnecessary vibration andsubsequent sounds.

Also, consider the following when placing and installing ahigh−efficiency air conditioner:

REFRIGERANT LINE SET

Field refrigerant line set consists of liquid and suction linesfrom the outdoor unit to the indoor unit coil. Use LennoxL15 (braze, non−flare) series line set, or field−fabricatedrefrigerant lines that meet the specifications listed below.

Table 2. Refrigerant Line Set

Model

Valve FieldConnections

Recommended Line Set

LiquidLine

SuctionLine

LiquidLine

SuctionLine

L15 LineSet

−018−024−030

3/8 in.(10 mm)

3/4 in.(19 mm)

3/8 in (10 mm)

3/4 in.(19 mm)

L15−4115 ft. − 50 ft.

(4.6 m − 15 m)

−036−042−048

3/8 in.(10 mm)

7/8 in.(22 mm)

3/8 in.(10 mm)

7/8in. (22 mm)

L15−6515 ft. − 50 ft.

(4.6 m − 15 m)

−0603/8 in.

(10 mm)1−1/8 in.(29 mm)

3/8 in.(10 mm)

1−1/8 in.(29 mm)

FieldFabricated

NOTE � Some applications may required a field provided 7/8" to1−1/8" adapter

NOTE − When installing refrigerant lines longer than 50feet, contact Lennox Technical Support ProductApplications for assistance or Lennox piping manual. Toobtain the correct information from Lennox, be sure tocommunicate the following points:

� Model (13ACX) and size of unit (e.g. −060).

� Line set diameters for the unit being installed as listedin Table 2 and total length of installation.

� Number of elbows and if there is a rise or drop of thepiping.

MATCHING WITH NEW OR EXISTING INDOOR COILAND LINE SET

The RFC1−metering line consisted of a small bore copperline that ran from condenser to evaporator coil. Refrigerantwas metered into the evaporator by utilizingtemperature/pressure evaporation effects on refrigerant inthe small RFC line. The length and bore of the RFC linecorresponded to the size of cooling unit.

If the 13ACX is being used with either a new or existingindoor coil which is equipped with a liquid line which servedas a metering device (RFCI), the liquid line must bereplaced prior to the installation of the 13ACX unit.Typically a liquid line used to meter flow is 1/4" in diameterand copper.

LIQUID LINE FILTER DRIER INSTALLATION

The filter drier (one is shipped with each 13ACX unit) mustbe field installed in the liquid line between the outdoor unit’sliquid line service valve and the indoor coil’s meteringdevice (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 willvoid the warranty. A replacement filter drier is availablefrom Lennox. See Brazing Connections on Page 9 forspecial procedures on brazing filter drier connections tothe liquid line.

OUTDOORUNIT

LIQUID LINESERVICE VALVE

LIQUID LINEFILTER DRIER

LINELIQUIDLINE

BRAZE CONNECTIONPOINTS

Figure 5. Typical Liquid Line Filter Drier Installation

CAUTIONBrazing alloys and flux contain materials which arehazardous to your health.

Avoid breathing vapors or fumes from brazingoperations. Perform operations only in well ventilatedareas.

Wear gloves and protective goggles or face shield toprotect against burns.

Wash hands with soap and water after handling brazingalloys and flux.

IMPORTANTThe Environmental Protection Agency (EPA) prohibitsthe intentional venting of HFC refrigerants duringmaintenance, service, repair and disposal of appliance.Approved methods of recovery, recycling or reclaimingmust be followed.

IMPORTANTIf this unit is being matched with an approved line setor indoor unit coil which was previously charged withmineral oil, or if it is being matched with a coil whichwas manufactured before January of 1999, the coiland line set must be flushed prior to installation. Takecare to empty all existing traps. Polyol ester (POE) oilsare used in Lennox units charged with HFC−410Arefrigerant. Residual mineral oil can act as aninsulator, preventing proper heat transfer. It can alsoclog the expansion device, and reduce the systemperformance and capacity.Failure to properly flush the system per theinstructions below will void the warranty.

506374−01 03/10

ANCHORED HEAVY NYLONWIRE TIE OR AUTOMOTIVE

MUFFLER-TYPE HANGER

STRAP LIQUID LINE TOVAPOR LINE

WALLSTUD

LIQUID LINE

NON−CORROSIVEMETAL SLEEVE

VAPOR LINE − WRAPPEDIN ARMAFLEX

AUTOMOTIVEMUFFLER-TYPE HANGER

REFRIGERANT LINE SET � TRANSITIONFROM VERTICAL TO HORIZONTAL

Line Set Isolation � The following illustrations areexamples of proper refrigerant line set isolation:

STRAPPINGMATERIAL (AROUND

VAPOR LINE ONLY)

TAPE ORWIRE TIE

WIRE TIE (AROUNDVAPOR LINE ONLY)

FLOOR JOIST ORROOF RAFTER

TAPE ORWIRE TIE

To hang line set from joist or rafter, use either metal strapping materialor anchored heavy nylon wire ties.

8 FEET (2.43 METERS)

STRAP THE VAPOR LINE TO THE JOISTOR RAFTER AT 8 FEET (2.43 METERS)INTERVALS THEN STRAP THE LIQUIDLINE TO THE VAPOR LINE.

FLOOR JOIST OR

ROOF RAFTER

REFRIGERANT LINE SET � INSTALLING HORIZONTAL RUNS

NOTE � Similar installation practices should be used if line set isto be installed on exterior of outside wall.

PVCPIPE

FIBERGLASSINSULATION

CAULK

OUTSIDEWALL

VAPOR LINE WRAPPEDWITH ARMAFLEX

LIQUIDLINE

OUTSIDE WALL LIQUID LINEVAPOR LINE

WOOD BLOCKBETWEEN STUDS

STRAP

WOOD BLOCK

STRAP

SLEEVE

WIRE TIE

WIRE TIE

WIRE TIE

INSIDE WALL

REFRIGERANT LINE SET � INSTALLINGVERTICAL RUNS (NEW CONSTRUCTION SHOWN)

INSTALLATION

LINE SET

NOTE � Insulate liquid line when it is routed through areas where thesurrounding ambient temperature could become higher than thetemperature of the liquid line or when pressure drop is equal to or greaterthan 20 psig.


IMPORTANT � Refrigerant lines must not contact structure.


8 FEET (2.43 METERS)

IMPORTANT � Refrigerant lines must not contact wall

WARNING � Polyol ester (POE) oils used with HFC−410Arefrigerant absorb moisture very quickly. It is very important that therefrigerant system be kept closed as much as possible. DO NOTremove line set caps or service valve stub caps until you are readyto make connections.

Figure 6. Line Set Installation

13ACX SERIES

CUT AND DEBUR

CAP AND CORE REMOVAL

Cut ends of the refrigerant lines square(free from nicks or dents) and debur theends. The pipe must remain round and donot pinch end of the line.

Remove service cap and corefrom both the vapor and liquid lineservice ports.

ATTACHED GAUGES

OUTDOORUNIT

LIQUID LINE

VAPOR LINE

LIQUID LINE SERVICEVALVE

VAPOR LINESERVICE

VALVE

ATTACHGAUGES

INDOORUNIT

SERVICE PORT MUST BE OPEN TO ALLOW EXITPOINT FOR NITROGEN

A. Connect gauge set low pressure side to liquid line servicevalve.

B. Connect gauge set center port to bottle of nitrogen withregulator.

NITROGEN

HIGHLOW

USE REGULATOR TO FLOWNITROGEN AT 1 TO 2 PSIG.

WRAP SERVICE VALVE FLOW NITROGEN

To protect components duringbrazing, wrap a wet cloth aroundthe liquid line service valve bodyand copper tube stub and useanother wet cloth underneath thevalve body to protect the basepaint.

Flow regulated nitrogen (at 1 to 2 psig) through the refrigerationgauge set into the valve stem port connection on the liquid line servicevalve and out of the valve stem port connection on the vapor servicevalve.

NOTE � The fixed orifice or checkexpansion valve metering device at theindoor unit will allow low pressurenitrogen to flow through the system.

NIT

RO

GE

N

HIGHLOW

USE REGULATOR TOFLOW NITROGEN AT 1

TO 2 PSIG.

BRAZE LINE SET

INSTALL SERVICE PORT CAPS ONLY

Braze the liquid line to the liquid lineservice valve. Turn off nitrogen flow.

After all connections have been brazed, disconnect manifold gaugeset from service ports, cool down piping with wet rag and remove allwrappings. Do not reinstall cores until after evacuation procedure.Reinstall service port caps if desired to close off refrigerant ports.

IMPORTANT � Connect gauge set low pressure side to vaporline service valve and repeat procedure starting at paragraph 4for brazing the liquid line to service port valve.

SERVICE PORT CORE

SERVICE PORT CAPSERVICE PORT

WARNING � Allow braze joint to coolbefore removing the wet rag from theservice valve. (TEMPERATURES ABOVE250ºF CAN DAMAGE VALVE SEALS

CONNECTIONS

BRAZING

12

3

4 5

6

7

B

A

POINT FLAME AWAY FROMSERVICE VALVE

NOTE − Use silver alloy brazing rods with five or six percent minimum silveralloy for copper−to−copper brazing, 45 percent alloy for copper−to−brass andcopper−to−steel brazing.

Figure 7. Brazing Connections

506374−01 03/10

Metering Devices and Flushing the System

SENSINGLINE

TEFLON RING

FIXED ORIFICE

(Uncased Coil Shown)

BRASS NUT

LIQUID LINE ASSEMBLY(INCLUDES STRAINER)

LIQUID LINE ORIFICE HOUSING

DISTRIBUTOR TUBES

DISTRIBUTORASSEMBLY

REMOVE AND DISCARDWHITE TEFLON SEAL (IF

PRESENT)

A. On fully cased coils, remove the coil access and plumbing panels.

B. Remove any shipping clamps holding the liquid line and distributorassembly.

C. Using two wrenches, disconnect liquid line from liquid line orificehousing. Take care not to twist or damage distributor tubes duringthis process.

D. Remove and discard fixed orifice, valve stem assembly if presentand Teflon washer as illustrated above.

E. Use a field−provided fitting to temporary reconnect the liquid line tothe indoor unit’s liquid line orifice housing.

F. Reverse above order to install.

TYPICAL CHECK EXPANSION VALVEREMOVAL PROCEDURE

TWO PIECE PATCH PLATE(UNCASED COIL ONLY)

VAPORLINE

DISTRIBUTORASSEMBLY

DISTRIBUTORTUBES

LIQUIDLINE

MALE EQUALIZERLINE FITTING

EQUALIZERLINE

CHECKEXPANSION

VALVE

TEFLONRING

(Uncased Coil Shown)STUB END

TEFLONRING

SENSING BULB

LIQUID LINEORIFICE

HOUSING

LIQUID LINEASSEMBLY WITH

BRASS NUT

A. On fully cased coils, remove the coil access and plumbing panels.

B. Remove any shipping clamps holding the liquid line and distributor as-sembly.

C. Disconnect the equalizer line from the check expansion valve equaliz-er line fitting on the vapor line.

D. Remove the vapor line sensing bulb.

E. Disconnect the liquid line from the check expansion valve at the liquidline assembly.

F. Disconnect the check expansion valve from the liquid line orifice hous-ing. Take care not to twist or damage distributor tubes during this pro-cess.

G. Remove and discard check expansion valve and the two Teflon rings.

H. Use a field−provided fitting to temporary reconnect the liquid line to theindoor unit’s liquid line orifice housing.

LOW HIGH

EXISTINGINDOOR

UNIT

GAUGEMANIFOLD

INVERTED HCFC−22CYLINDER CONTAINSCLEAN HCFC−22 TO BEUSED FOR FLUSHING.

LIQUID LINE SERVICEVALVE

INLET

DISCHARGE

TANKRETURN

CLOSEDOPENED

RECOVERYCYLINDER

RECOVERY MACHINE

NEWOUTDOOR

UNIT

VAPOR LINESERVICE VALVE

VA

PO

R

LIQ

UID

1

A. Inverted HCFC−22 cylinder with clean refrigerant to the vapor servicevalve.

B. HCFC−22 gauge set (low side) to the liquid line valve.

C. HCFC−22 gauge set center port to inlet on the recovery machine withan empty recovery tank to the gauge set.

D. Connect recovery tank to recovery machines per machineinstructions.

CONNECT GAUGES AND EQUIPMENT FORFLUSHING PROCEDURE

A

B

CD

B

OR

FLUSHING LINE SET

A. Set the recovery machine for liquid recovery and start the recov-ery machine. Open the gauge set valves to allow the recoverymachine to pull a vacuum on the existing system line set and in-door unit coil.

B. Invert the cylinder of clean HCFC−22 and open its valve to allowliquid refrigerant to flow into the system through the vapor linevalve. Allow the refrigerant to pass from the cylinder and throughthe line set and the indoor unit coil before it enters the recoverymachine.

C. After all of the liquid refrigerant has been recovered, switch therecovery machine to vapor recovery so that all of the HCFC−22vapor is recovered. Allow the recovery machine to pull down to 0the system.

D. Close the valve on the inverted HCFC−22 drum and the gaugeset valves. Pump the remaining refrigerant out of the recoverymachine and turn the machine off.

The line set and indoor unit coil must be flushed with at least thesame amount of clean refrigerant that previously charged the sys-tem. Check the charge in the flushing cylinder before proceeding.

LINE SET AND INDOOR COIL (1 OF 2)

FLUSHING

1

2

3

CAUTION �This procedure should not be performed on sys-tems which contain contaminants (Example compressor burnout.

TYPICAL FIXED ORIFICE REMOVAL ANDREPLACEMENT PROCEDURE

13ACX SERIES

A. Attach the vapor line sensing bulb in the proper orientationas illustrated to the right using the clamp and screws pro-vided.

NOTE � Confirm proper thermal contact between vapor lineand check expansion bulb before insulating the sensing bulbonce installed.

B. Connect the equalizer line from thecheck expansion valve to theequalizer vapor port on the vaporline. Finger tighten the flare nutplus 1/8 turn (7 ft−lbs) as illus-trated below.

The check expansion valve unit can be installed internal orexternal to the indoor coil. In applications where an uncased coilis being installed in a field−provided plenum, install the checkexpansion valve in a manner that will provide access for fieldservicing of the check expansion valve. Refer to belowillustration for reference during installation of check expansionvalve unit.

TYPICAL CHECK EXPANSION VALVE INSTALLATION PROCEDURE

TWO PIECEPATCH PLATE

(UNCASEDCOIL ONLY)

VAPORLINE

LIQUID LINEORIFICE

HOUSINGDISTRIBUTOR

TUBES

LIQUID LINE

MALE EQUALIZER LINEFITTING (SEE

EQUALIZER LINEINSTALLATION FORFURTHER DETAILS)

SENSINGLINE

EQUALIZERLINE

CHECKEXPANSION

VALVE

TEFLONRING

(Uncased Coil Shown)

SENSING BULB INSULATION IS REQUIREDIF MOUNTED EXTERNAL TO THE COILCASING. SENSING BULB INSTALLATIONFOR BULB POSITIONING.

STUBEND

TEFLONRING

LIQUID LINEASSEMBLY WITH

BRASS NUT

DISTRIBUTORASSEMBLY

This outdoor unit is designed for use in systems that use check expansion valve metering device. See the Lennox 13ACX Engineering Handbookfor approved check expansion valve kit match−ups and application information.

A. Remove the field−provided fitting that temporary reconnected the liquidline to the indoor unit’s distributor assembly.

B. Install one of the provided Teflon rings around the stubbed end of thecheck expansion valve and lightly lubricate the connector threads andexpose surface of the Teflon ring with refrigerant oil.

C. Attach the stubbed end of the check expansion valve to the liquid lineorifice housing. Finger tighten and use an appropriately sized wrench toturn an additional 1/2 turn clockwise as illustrated in the figure above, or20 ft−lb.

D. Place the remaining Teflon washer around the other end of the checkexpansion valve. Lightly lubricate connector threads and expose sur-face of the Teflon ring with refrigerant oil.

E. Attach the liquid line assembly to the check expansion valve. Fingertighten and use an appropriately sized wrench to turn an additional 1/2turn clockwise as illustrated in the figure above or 20 ft−lb.

ON 7/8" AND LARGER LINES,MOUNT SENSING BULB ATEITHER THE 4 OR 8 O’CLOCKPOSITION. NEVER MOUNT ONBOTTOM OF LINE.

12

ON LINES SMALLER THAN 7/8",MOUNT SENSING BULB ATEITHER THE 3 OR 9 O’CLOCKPOSITION.

12

BULB

VAPOR LINE

VAPOR LINE

NOTE � NEVER MOUNT ON BOTTOM OF LINE.

BULB

BULBBULB

VAPOR LINE

FLARE NUT

COPPER FLARESEAL BONNET

MALE BRASS EQUALIZERLINE FITTING

FLARE SEAL CAP

OR

123

4567

8910

11 121/2 TURN

SENSING BULB INSTALLATION

EQUALIZER LINE INSTALLATION

123

45

678

910

11 12

1/8 TURN

FLUSHING LINE SET AND INDOOR COIL (2 OF 2)

4

A. Remove and discard either the flare seal cap or flare nutwith copper flare seal bonnet from the equalizer line porton the vapor line as illustrated in the figure to the right.

B. Remove and discard either the flare seal cap or flare nutwith copper flare seal bonnet from the equalizer line port onthe vapor line as illustrated in the figure to the right.

506374−01 03/10

Leak Testing the System

TO VAPORSERVICE VALVE

HFC−410A

MANIFOLD GAUGE SET

OUTDOOR UNIT

HIGHLOW

NITROGEN

NOTE � Normally, the high pressure hose is connected to the liquid line port. How-ever, connecting it to the vapor port better protects the manifold gauge set from highpressure damage.

A. With both manifold valves closed, connect the cylinder of HFC−410A refrigerant to the center port of the manifold gauge set. Openthe valve on the HFC−410A cylinder (vapor only).

B. Open the high pressure side of the manifold to allow HFC−410A into the line set and indoor unit. Weigh in a trace amount ofHFC−410A. [A trace amount is a maximum of two ounces (57 g) refrigerant or three pounds (31 kPa) pressure]. Close the valve onthe HFC−410A cylinder and the valve on the high pressure side of the manifold gauge set. Disconnect the HFC−410A cylinder.

C. Connect a cylinder of dry nitrogen with a pressure regulating valve to the center port of the manifold gauge set.

D. Adjust dry nitrogen pressure to 150 psig (1034 kPa). Open the valve on the high side of the manifold gauge set in order to pressurize theline set and the indoor unit.

E. After a few minutes, open one of the service valve ports and verify that the refrigerant added to the system earlier is measurablewith a leak detector.

F. After leak testing disconnect gauges from service ports.


LINE SET AND INDOOR COIL

After the line set has been connected to the indoor unit and air conditioner, check the line set connections andindoor unit for leaks. Use the following procedure to test for leaks:

LEAK TEST

A. Connect an HFC−410A manifold gauge set highpressure hose to the vapor valve service port.

B. With both manifold valves closed, connect thecylinder of HFC−410A refrigerant to the center portof the manifold gauge set.

1CONNECT GAUGE SET

2TEST FOR LEAKS

AB

NOTE � Later in the procedure, the HFC−410Acontainer will be replaced by the nitrogen container.

WARNINGWhen using a high pressure gas such asdry nitrogen to pressurize a refrigerationor air conditioning system, use aregulator that can control the pressuredown to 1 or 2 psig (6.9 to 13.8 kPa).

WARNINGRefrigerant can be harmful if it is inhaled. Refrigerantmust be used and recovered responsibly.

Failure to follow this warning may result in personal injuryor death.

WARNINGFire, Explosion and Personal SafetyHazard.

Failure to follow this warning couldresult in damage, personal injury ordeath.

Never use oxygen to pressurize orpurge refrigeration lines. Oxygen,when exposed to a spark or openflame, can cause damage by fireand/or an explosion, that could resultin personal injury or death.

IMPORTANTLeak detector must be capable of sensing HFCrefrigerant.

13ACX SERIES

Evacuating the System

A. Open both manifold valves and start the vacuum pump.

B. Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).

NOTE � During the early stages of evacuation, it is desirable to close the manifold gauge valve at least once. A rapid rise in pressureindicates a relatively large leak. If this occurs, repeat the leak testing procedure.

NOTE � The term absolute pressure means the total actual pressure within a given volume or system, above the absolute zero ofpressure. Absolute pressure in a vacuum is equal to atmospheric pressure minus vacuum pressure.

C. When the absolute pressure reaches 23,000 microns (29.01 inches of mercury), close the manifold gauge valves, turn off the vacuumpump and disconnect the manifold gauge center port hose from vacuum pump. Attach the manifold center port hose to a dry nitrogencylinder with pressure regulator set to 150 psig (1034 kPa) and purge the hose. Open the manifold gauge valves to break the vacuum inthe line set and indoor unit. Close the manifold gauge valves.

D. Shut off the dry nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release thedry nitrogen from the line set and indoor unit.

E. Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until theabsolute pressure does not rise above 500 microns (29.9 inches of mercury) within a 20−minute period after shutting off the vacuum pumpand 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 toan upright cylinder of HFC−410A refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set andindoor unit.

G. Perform the following:

OUTDOOR

UNIT

TO VAPORSERVICE VALVE

TO LIQUID LINESERVICE VALVE

MICRONGAUGE

VACUUM PUMP

A34000 1/4 SAE TEE WITHSWIVEL COUPLER

500

MANIFOLDGAUGE SET

HFC−410A

RECOMMENDMINIMUM 3/8" HOSE

A. Connect low side of manifold gaugeset with 1/4 SAE in−line tee to vapor lineservice valve

B. Connect high side of manifold gaugeset to liquid line service valve

C. Connect micron gauge availableconnector on the 1/4 SAE in−line tee.

D. Connect the vacuum pump (withvacuum gauge) to the center port of themanifold gauge set. The center port linewill be used later for both the HFC−410Aand nitrogen containers.

HIGHLOW

123

45

678

910

11 12

1/6 TURN

NITROGEN


EVACUATING

1CONNECT GAUGE SET

A

B

C

D

2EVACUATE THE SYSTEM

� Close manifold gauge valves.

� Shut off HFC−410A cylinder.

� Reinstall service valve cores by removing manifold hose from service valve. Quickly install cores withcore tool while maintaining a positive system pressure.

� Replace the stem caps and secure finger tight, then tighten an additional one−sixth (1/6) of a turn asillustrated.

LINE SET AND INDOOR COIL

NOTE � Remove cores from service valves (if not al-ready done).

506374−01 03/10

IMPORTANTUse a thermocouple or thermistor electronic vacuumgauge that is calibrated in microns. Use an instrumentcapable of accurately measuring down to 50 microns.

WARNINGDanger of Equipment Damage. Avoid deep vacuumoperation. Do not use compressors to evacuate asystem. Extremely low vacuums can cause internalarcing and compressor failure. Damage caused bydeep vacuum operation will void warranty.

Evacuating the system of non−condensables is critical forproper operation of the unit. Non−condensables are

defined as any gas that will not condense undertemperatures and pressures present during operation ofan air conditioning system. Non−condensables and watersuction combine with refrigerant to produce substancesthat corrode copper piping and compressor parts.

Electrical

In the U.S.A., wiring must conform with current local codesand the current National Electric Code (NEC). In Canada,wiring must conform with current local codes and the currentCanadian Electrical Code (CEC).

Refer to the furnace or air handler installation instructionsfor additional wiring application diagrams and refer to unitnameplate for minimum circuit ampacity and maximumovercurrent protection size.

24VAC TRANSFORMER

Use the transformer provided with the furnace or airhandler for low-voltage control power (24VAC − 40 VAminimum)

Refer to the unit nameplate for minimum circuit ampacity, and maximumfuse or circuit breaker (HACR per NEC). Install power wiring and properlysized disconnect switch.

NOTE � Units are approved for use only with copper conductors.Ground unit at disconnect switch or to an earth ground.

SIZE CIRCUIT AND INSTALL SERVICEDISCONNECT SWITCH

NOTE � 24VAC, Class II circuit connections are made in the controlpanel.

Install room thermostat (ordered separately) on an inside wallapproximately in the center of the conditioned area and 5 feet (1.5m) fromthe floor. It should not be installed on an outside wall or where it can beaffected by sunlight or drafts.

THERMOSTAT

5 FEET(1.5M)

INSTALL THERMOSTAT

SERVICEDISCONNECT

SWITCH

MAIN FUSE BOX/BREAKER PANEL

WARNINGElectric Shock Hazard. Can cause injury or death. Unit must be grounded in accordance with national andlocal codes.

Line voltage is present at all components when unit is not in operation on units with single-pole contactors.Disconnect all remote electric power supplies before opening access panel. Unit may have multiple powersupplies.

13ACX SERIES

Any excess high voltage field wiring should be trimmed andsecured away from any low voltage field wiring. To facilitate aconduit, a cutout is located in the bottom of the control panel.Connect conduit to the control panel using a proper conduit fitting.

ROUTING HIGH VOLTAGE/ GROUND AND CONTROL WIRING

HIGH VOLTAGEFIELD WIRING

LOW VOLTAGEFIELD WIRING

FACTORYWIRING

WIRE RUN LENGTH AWG# INSULATION TYPE

LESS THAN 100’ (30 METERS) 18 TEMPERATURE RATING

MORE THAN 100’ (30 METERS) 16 35ºC MINIMUM.

Install low voltage wiring from outdoor to indoor unit and from thermostatto indoor unit as illustrated.

HIGH VOLTAGE / GROUND WIRES

CONTROL WIRING

A. Run 24VAC control wires through hole with grommet and secure withprovided wire tie.

B. Make 24VAC thermostat wire connections. Locate the two wires from thecontactor and make connection using field provided wire nuts:

� Yellow to Y1

� Black to C (common)

NOTE � For proper voltages, select thermostat wire (control wires)gauge per Table above.

NOTE � Wire tie provides low voltage control wire strain relief and tomaintain separation of field installed low and high voltage circuits.

W1

Y

G

C

R

Y

G

C

THERMOSTAT INDOOR UNIT

POWER

HEAT

COOLING

INDOORBLOWER

COMMON

OUTDOORUNIT

Y1

C

W

R

SINGLE PHASE

NOTE � Do not bundle any excess 24VAC control wires insidecontrol panel.

CONTROLWIRING

HIGH VOLTAGECONNECTIONS(CONTACTOR)

GROUND

GROMMETAND WIRE TIE

HIGH VOLTAGEFLEXIBLE CONDUIT A

B

Figure 8. Typical 13ACX Unit Wiring Diagram

506374−01 03/10

TO LIQUIDLINE SERVICE

VALVE

TEMPERATURESENSOR

DIGITAL SCALE

REFRIGERANT TANK

TEMPERATURE SENSOR(LIQUID LINE)

MANIFOLD GAUGE SET

A. Close manifold gauge set valves and connect the center hose to a cylinder of HFC−410A. Set for liquid phase charging.

B. Connect the manifold gauge set’s low pressure side to the suction line service port.

C. Connect the manifold gauge set’s high pressure side to the liquid line service port.

D. Position temperature sensor on liquid line near liquid line service port.

OUTDOOR UNIT

CHARGE INLIQUID PHASE

CONNECTIONS FOR TESTING AND CHARGING

GAUGE SET

A

C

D

LOW HIGH

B SUCTION LINESERVICE PORTCONNECTION

Figure 9. Gauge Set Setup and Connections

Servicing Units Delivered Void of Charge

If the outdoor unit is void of refrigerant, clean the systemusing the procedure described below.

1. Leak check system using procedure outlined on Page12.

2. Evacuate the system using procedure outlined onPage 13.

3. Use nitrogen to break the vacuum and install a newfilter drier in the system.

4. Evacuate the system again using procedure outlinedon Page 13.

5. Weigh in refrigerant using procedure outlined underStart−Up and Charging Procedures.

6. Monitor the system to determine the amount ofmoisture remaining in the oil. It may be necessary toreplace the filter drier several times to achieve therequired dryness level. If system dryness is notverified, the compressor will fail in the future.

Unit Start−Up

IMPORTANTIf unit is equipped with a crankcase heater, it should beenergized 24 hours before unit start−up to preventcompressor damage as a result of slugging.

1. Rotate fan to check for binding.

2. Inspect all factory− and field−installed wiring for looseconnections.

3. After evacuation is complete, open the liquid line andsuction line service valves to release the refrigerantcharge (contained in air conditioner) into the system.

4. Replace the stem caps and tighten to the value listedin Table 1.

5. Check voltage supply at the disconnect switch. Thevoltage must be within the range listed on the unit’snameplate. If not, do not start the equipment until youhave consulted with the power company and thevoltage condition has been corrected.

6. Set the thermostat for a cooling demand. Turn onpower to the indoor handler and close the airconditioner disconnect switch to start the unit.

7. Recheck voltage while the unit is running. Power mustbe within range shown on the nameplate.

8. Check system for sufficient refrigerate using theprocedures that follow.

System Refrigerant

This section outlines procedures for:

1. Connecting gauge set for testing and charging;

2. Checking and adjusting indoor airflow;

3. Adding or removing refrigerant.

13ACX SERIES

ADDING OR REMOVING REFRIGERANT

This system uses HFC−410A refrigerant which operates at much higher pressures than HCFC−22. The pre−installed liquidline filter drier is approved for use with HFC−410A only. Do not replace it with components designed for use with HCFC−22.This unit is NOT approved for use with coils which use capillary tubes or fixed orifices as a refrigerant metering device.

Check airflow using the Delta−T (DT) process using the illustration in Figure 10.

Cº TDrop – DT = ºF ACTION

53º 19 – 15 = 4 Increase the airflow58º 14 – 15 = −1 (within +3º range) no change62º 10 – 15 = −5 Decrease the airflow

DT80 24 24 24 23 23 22 22 22 20 19 18 17 16 15

78 23 23 23 22 22 21 21 20 19 18 17 16 15 14

76 22 22 22 21 21 20 19 19 18 17 16 15 14 13

74 21 21 21 20 19 19 18 17 16 16 15 14 13 12

72 20 20 19 18 17 17 16 15 15 14 13 12 11 10

70 19 19 18 18 17 17 16 15 15 14 13 12 11 10

57 58 59 60 61 62 63 64 65 66 67 68 69 70

Temperature of airentering indoorcoil ºF

INDOOR COIL

DRY BULB

DRYBULB

WET BULB

B

TDrop

19º

A

Dry

−bu

lb

Wet−bulb ºF

A

72º

B

64º

C

53º

air flowair flow

All temperatures are expressed in ºF

1. Determine the desired DT � Measure entering air temperature using dry bulb (A) and wet bulb (B). DTis the intersecting value of A and B in the Table (see triangle).

2. Find temperature drop across coil � Measure the coil’s dry bulb entering and leaving air temperatures(A and C). Temperature Drop Formula: (TDrop) = A minus C.

3. Determine if fan needs adjustment � If the difference between the measured TDrop and the desiredDT (TDrop–DT) is within +3º, no adjustment is needed. See example below:

4. Adjust the fan speed � See indoor unit instructions to increase/decrease fan speed.

Assume DT = 15 and A temp. = 72º, these C temperatures would necessitate stated actions:

AIRFLOW

Use the following procedure to adjust for optimal air flow across the indoor coil:

INDOOR COIL

Changing air flow affects all temperatures; rechecktemperatures to confirm that the temperature dropand DT are within +3º.

Figure 10. Checking Indoor Airflow over Evaporator Coil using Delta−T (DT) Chart

506374−01 03/10

WHEN TO CHARGE?

� Warm weather best� Can charge in colder weatherCHARGE METHOD? Determine by:

� Metering device type� Outdoor ambient temperatureREQUIREMENTS:

� Sufficient heat load in structure

� Indoor temperature between 70-80ºF(21−26ºC)

� Manifold gauge set connected to unit� Thermometers:

− to measure outdoor ambienttemperature− to measure liquid line temperature− to measure suction linetemperature

TXV RFC

APPROACH ORSUBCOOLING

WEIGH-INSUPERHEAT

65ºF

(18.3ºC) and

Above

START: Determine how refrigerant is metered

39ºF

(3.8ºC) and

Below

Whichmeteringdevice?

WEIGH-IN

64ºF

(17.7ºC) and

Below

40ºF

(4.4ºC) and

Above

Figure 11. Determining Charge Method

WEIGH IN TXV

START: Measure outdoor ambient temperature 1. Check Liquid and suction line pressures2. Compare unit pressures with Table 3,

Normal Operating Pressures.

3. Conduct leak check; evacuate aspreviously outlined.

4. Weigh in the unit nameplate charge plusany charge required for line set differencesover feet.

Liquid Line

Set Diameter

Ounces per 5 feet (g per 1.5 m)adjust from 15 feet (4.6 m) line set*

3/8" (9.5 mm) 3 ounce per 5’ (85 g per 1.5 m)

NOTE − *If line length is greater than 15 ft. (4.6 m), add thisamount. If line length is less than 15 ft. (4.6 m), subtract thisamount.

Refrigerant Charge per Line Set Length

USE EITHER APPROACHOR SUBCOOLING

METHOD

This nameplate is for illustration

purposes only. Go to actual

nameplate on outdoor unit for

charge information.

ABOVE orBELOW65ºF

(18.3ºC) and

Above

64ºF

(17.7ºC) and

Below

Figure 12. HFC−410A Weigh In TXV Method

13ACX SERIES

DO NOT CHARGE UNIT

(Results of charging at lowtemperatures not reliable)

START: Measure outdoor ambient temperature

USE WEIGH-IN METHOD

Weigh-in or remove refriger-ant based upon line length

APPº (Approach) Values(F:+/−1.0° [C: +/−0.6°])

1. Confirm proper airflow across coil using Figure10.

2. Compare unit pressures with Table 3, NormalOperating Pressures.

3. Set thermostat to call for heat (must have acooling load between 70-80ºF (21−26ºC).

4. Connect gauge set.

5. When heat demand is satisfied, set thermostatto call for cooling.

6. Allow temperatures and pressures to stabilize.

7. Record outdoor ambient temperature:

AMBº =_________

8. Record liquid line temperature:

LIQº = __________

9. Subtract to determine approach (APPº):

LIQº_____ − AMBº _____ = APPº_____

10. Compare results with table below.

Figure 13. HFC−410A Approach TXV Charge

ABOVE orBELOW

If value is greater than shown (high approach),

add refrigerant; if less than shown (liquid

temperature too close to ambient temperature,

low approach), remove refrigerant.

If refrigerant is added

or removed, retest to

confirm that unit is

properly charged.

ºF (ºC)* −018 −024 −030 −036 −042 −048 −060

Any 4 (2.2) 8 (4.4) 8 (4.4) 11 (6.1) 9 (5.0) 8 (4.4) 9 (5.0)

*Temperature of air entering outdoor coil

64ºF

(17.7ºC) and

Below

65ºF

(18.3ºC) and

Above

DO NOT CHARGE UNIT

(Results of charging at lowtemperatures not reliable)


USE WEIGH-IN METHOD

Weigh-in or remove refrigerantbased upon line length

SCº (Subcooling) Values (F:+/−1.0° [C: +/−0.6°])

BLOCK OUTDOOR COIL: [sometimes necessarywith lower temperatures] Use cardboard or plasticsheet to restrict the airflow through the outdoor coilto achieve pressures from 325−375 psig(2240−2585 kPa). Higher pressures are needed tocheck charge. Block equal sections of air intakepanels and move coverings sideways until theliquid pressure is in the above noted ranges.

If value is MORE

than shown, remove

refrigerant.



3. Set thermostat to call for heat (must have acooling load between 70-80ºF (21−26ºC)

4. Connect gauge set

5. Measure outdoor ambient temperature

6. When heat demand is satisfied, set thermostat tocall for cooling


NOTE − If necessary, block outdoor coil tomaintain 325 − 375 psig.

8. Record liquid line temperature:

LIQº = ______

9. Measure liquid line pressure and use the value todetermine saturation temperature (see Table 4):

SATº = ______

10. Subtract to determine subcooling (SCº):

SATº_____ − LIQº _____ = SCº _____

11. Compare results with table below.

Figure 14. HFC−410A Subcooling TXV Charge

MORE orLESS

If value is LESS

than shown, add

refrigerant.

If refrigerant is added

or removed, verify

charge using the

Approach Method.

ABOVE orBELOW

ºF (ºC)* −018 −024 −030 −036 −042 −048 −060

Any 10 (5.6) 10 (5.6) 9 (5.0) 12 (6.7) 9 (5.0) 9 (5.0) 7 (3.9)

*Temperature of air entering outdoor coil

64ºF

(17.7ºC) and

Below

65ºF

(18.3ºC) and

Above

CARDBOARD ORPLASTIC SHEET

506374−01 03/10

WEIGH IN RFC

START: Measure outdoor ambient temperature1. Check Liquid and suction line pressures

2. Compare unit pressures with Table 3,Normal Operating Pressures.

3. Conduct leak check; evacuate aspreviously outlined.

4. Weigh in the unit nameplate charge plusany charge required for line set differencesover feet.

Liquid Line

Set Diameter

Ounces per 5 feet (g per 1.5 m)

adjust from 15 feet (4.6 m) line set*

3/8" (9.5 mm) 3 ounce per 5’ (85 g per 1.5 m)

NOTE − *If line length is greater than 15 ft. (4.6 m), add this

amount. If line length is less than 15 ft. (4.6 m), subtract this

amount.

Refrigerant Charge per Line Set Length

USE SUPERHEAT

This nameplate is for illustration purposes

only. Go to actual nameplate on outdoor unit

for charge information.

ABOVE orBELOW

39ºF

(3.8ºC) and

Below

40ºF

(4.4ºC) and

Above

Figure 15. HFC−410A Weigh In RFC Method


NOTE − Do not attempt to charge system where adash appears, system could be overcharged.Superheat is taken at suction line service port.Suction line superheat must never be less than 5ºFat the suction line service port.

USE WEIGH-IN METHOD

Weigh-in or remove refrigerantbased upon line length

SHº (Superheat) Values (+/−5ºF)

Wet Bulb (air entering indoor coil)

ºF* 50 52 54 56 58 60 62 64 66 68 70 72 74 76

40 15 18 20 23 26 29 32 34 38 41 43 46 48 51

45 13 16 18 21 24 27 30 33 36 39 41 44 46 49

50 11 14 16 19 22 25 28 31 34 37 39 42 44 47

55 9 12 14 17 20 23 27 30 33 36 38 40 42 44

60 7 10 12 15 18 21 24 27 30 33 35 38 40 43

65 - 6 10 13 16 19 21 24 27 30 33 36 38 41

70 - - 7 10 13 16 19 21 24 27 30 33 36 39

75 - - - 6 9 12 15 18 21 24 28 31 34 37

80 - - - - 5 8 12 15 18 21 25 28 31 35

85 - - - - - - 8 11 15 19 22 26 30 33

90 - - - - - - 5 9 13 16 20 24 27 31

95 - - - - - - - 6 10 14 18 22 25 29

100 - - - - - - - - 8 12 16 21 24 28

105 - - - - - - - - 5 9 13 17 22 26

110 - - - - - - - - - 6 11 15 20 25

115 - - - - - - - - - - 8 14 18 24

* Dry−bulb temperature (ºF) of entering outdoor ambient air.



3. Use SUPERHEAT to correctly charge unit or toverify the charge is correct.4. Set thermostat to call for heat (must have a coolingload between 70-80ºF (21−26ºC)

5. Connect gauge set.

6. When heat demand is satisfied, set thermostat tocall for cooling.


8. Measure the suction line pressure and use the usevalue to determine saturation temperature (Table4):

SATº =_________

9. Record suction line temperature:

VAPº =_________

10. Subtract to determine superheat (SHº):

VAPº − _____ SATº ______ = SHº______

11. Record the wet bulb temperature (air enteringindoor coil):

WB =_______

12. Record outdoor ambient temperature.

13. Compare results with table to the left.

If value is MORE

than shown, then

ADD refrigerant.

If value is LESS than

shown, then REMOVE

refrigerant.

If refrigerant is

REMOVED, retest to


properly charged.

MORE orLESS

If refrigerant is

ADDED, retest to


properly charged.

ABOVE orBELOW39ºF

(3.8ºC) and

Below

40ºF

(4.4ºC) and

Above

Figure 16. HFC−410A Superheat RFC Method

13ACX SERIES

Table 3. HFC−410A Normal Operating Pressures (Liquid +10 and Suction +5 psig)

IMPORTANTUse this table to perform maintenance checks; it is not a procedure for charging thesystem. Minor variations in these pressures may be due to differences in installations.Significant deviations could mean that the system is not properly charged or that aproblem exists with some component in the system.

13ACX −018 −024 −030 −036 −042 −048 −060

�F (�C)* Liquid / Suction Liquid / Suction Liquid / Suction Liquid / Suction Liquid / Suction Liquid / Suction Liquid / Suction

Expansion Valve (TXV)

65 (18) 233 / 132 244 / 137 248 / 127 263 / 135 238 /132 235 / 132 241 / 130

70 (21) 251 / 133 263 / 138 263 / 131 281 / 138 262 / 133 254 / 132 260 / 130

75 (24) 265 / 133 285 / 139 284 / 132 302 / 140 280 / 134 276 / 134 280 / 132

80 (27) 292 / 135 307 / 140 307 / 134 325 / 142 301 / 136 298 / 134 299 / 134

85 (29) 314 / 136 329 / 141 330 / 135 349 / 142 327 / 137 323 / 135 321 / 135

90 (32) 338 / 137 354 / 142 355 / 136 375 / 143 353 / 138 350 / 137 344 / 134

95 (35) 362 / 138 379 / 143 380 / 137 404 / 144 377 / 140 377 / 138 371 / 135

100 (38) 388 / 140 404 / 144 407 / 138 433 / 145 404 / 141 406 / 140 400 / 137

105 (41) 415 / 141 438 / 145 434 / 139 462 / 147 435 / 142 430 / 141 428 / 139

110 (43) 444 / 142 464 / 147 465 / 141 494 / 149 465 / 143 464 / 142 458 / 141

115 (45) 475 / 143 495 / 148 497 / 142 527 / 150 499 / 144 495 / 143 484 / 142

Fixed Orifice (RFC)

65 (18) 233 / 121 246 / 126 245 / 123 261 / 134 246 / 126 247 / 125 248 / 124

70 (21) 250 / 124 265 / 129 265 / 126 281 / 136 263 / 128 266 / 128 266 / 126

75 (24) 270 / 128 286 / 132 286 / 129 301 / 138 284 / 131 286 / 131 288 / 130

80 (27) 291 / 131 307 /135 308 / 132 324 / 140 305 / 133 307 / 133 309 / 133

85 (29) 313 / 134 330 / 137 331 / 135 346 / 142 327 / 135 329 / 135 330 / 135

90 (32) 335 / 136 353 / 140 355 / 138 371 / 144 350 / 138 353 / 138 354 / 138

95 (35) 359 / 138 378 / 142 380 / 140 396 / 146 374 / 140 377 / 140 377 / 140

100 (38) 383 / 140 402 / 143 405 / 142 422 / 148 399 / 142 403 / 142 406 / 142

105 (41) 409 / 142 428 / 145 431 / 144 448 / 150 424 / 144 428 / 144 431 / 144

110 (43) 436 / 145 456 / 147 458 / 146 477 / 151 452 / 146 455 / 146 457 / 146

115 (46) 464 / 147 486 / 149 487 / 148 506 / 153 481 / 148 483 / 147 484 / 148

*Values shown are typical pressures; indoor unit match up, indoor air quality equipment, and indoor load will cause the pressures to vary.**Temperature of the air entering the outside coil.

Table 4. HFC−410A Temperature � Pressure (Psig)

°F °C Psig °F °C Psig

−40 −40.0 11.6 60 15.6 170

−35 −37.2 14.9 65 18.3 185

−30 −34.4 18.5 70 21.1 201

−25 −31.7 22.5 75 23.9 217

−20 −28.9 26.9 80 26.7 235

−15 −26.1 31.7 85 29.4 254

−10 −23.3 36.8 90 32.2 274

−5 −20.6 42.5 95 35.0 295

0 −17.8 48.6 100 37.8 317

5 −15.0 55.2 105 40.6 340

10 −12.2 62.3 110 43.3 365

15 −9.4 70.0 115 46.1 391

20 −6.7 78.3 120 48.9 418

25 −3.9 87.3 125 51.7 446

30 −1.1 96.8 130 54.4 476

35 1.7 107 135 57.2 507

40 4.4 118 140 60.0 539

45 7.2 130 145 62.8 573

50 10.0 142 150 65.6 608

55 12.8 155

506374−01 03/10

Removing and Installing Louvers

WARNING

To prevent personal injury, or damage to panels, unit or structure, be sure to observe the following:

While installing or servicing this unit, carefully stow all removed panels out of the way, so that the panels will not cause injury to personnel,nor cause damage to objects or structures nearby, nor will the panels be subjected to damage (e.g., being bent or scratched).

While handling or stowing the panels, consider any weather conditions, especially windy conditions, that may cause panels to be blownaround and battered.

WARNING

PANEL A

PANEL B PANEL C

PANEL D

When removing the unit panels. Remove panel A

first, then B, C and finally D. When reinstalling pan-

els, reverse that order starting with panel D, C, B

and finally A.

ORDER OF REMOVAL AND REINSTALLATION

REMOVAL

REPEAT STEPS 1, 2 AND

3 TO REMOVE PANELS B,

C AND FINALLY D.

STEP 1

STARTING WITH PANEL D,

INSERT PANEL UNDER UNIT

TOP CAP LIP AND LIFT

SLIGHTLY TO CLEAR SIDE LIP

OF PANEL FROM BASE.

PANEL A

PANEL A

STEP 2

INSTALLATION

REPEAT STEPS 1 AND 2 TO INSTALL PANELS C,

B AND FINALLY A.

TO REMOVE PANEL,REMOVE MOUNTINGSCREWS SECURINGPANEL TO THE UNIT.

SLIGHTLY LIFT PANEL A INORDER TO CLEAR SIDELIPS OF PANEL FROMBASE OF UNIT.

STEP 3TILT PANEL OUT SLIGHTLYAND PULL DOWNWARDTO REMOVE.

STEP 1

STEP 2MOVE PANEL IN TOWARDS UNIT.ALIGN LEFT/RIGHT SIDE LIPS OFPANEL WITH GROOVE INSERTSALONG LEFT/RIGHT SIDE OF UNIT.

PANEL D

TOP CAP

BASE

SIDE

GROOVE

STEP 3

SECURE PANEL, WITHMOUNTING SCREWS.

13ACX SERIES

System Operation

The outdoor unit and indoor blower will cycle on and off asdictated by demands from the room thermostat. When thethermostat’s blower switch is in the ON position, the indoorblower will operate continuously.

HIGH PRESSURE SWITCH

13ACX units are equipped with a high-pressure switch thatis located in the liquid line of the compressor as illustratedin figure on Page 2.

The switch is a Single Pole, Single Throw (SPST),manual−reset switch which is normally closed andremoves power from the compressor when discharge

pressure rises above factory setting at 590 + 10 psi. Themanual−reset switch can be identified by a red cap that ispress to preform the reset function.

Maintenance

DEALER

WARNINGElectric shock hazard. Can cause injuryor death. Before attempting to performany service or maintenance, turn theelectrical power to unit OFF at disconnectswitch(es). Unit may have multiple powersupplies.

WARNINGImproper installation, adjustment, alteration, service ormaintenance can cause personal injury, loss of life, ordamage to property.

Installation and service must be performed by a licensedprofessional installer (or equivalent) or a service agency.

Maintenance and service must be performed by a qualifiedinstaller or service agency. At the beginning of eachcooling season, the system should be checked as follows:

Outdoor Unit1. Outdoor unit fan motor is pre−lubricated and sealed.

No further lubrication is needed.

2. Visually inspect all connecting lines, joints and coils forevidence of oil leaks.

3. Check all wiring for loose connections.

4. Check for correct voltage at unit (unit operating).

5. Check amp draw on outdoor fan motor.

Motor Nameplate:_________ Actual:__________.

6. Inspect drain holes in coil compartment base andclean if necessary.

NOTE - If insufficient cooling occurs, the unit should begauged and refrigerant charge should be checked.

Outdoor Coil

Clean and inspect outdoor coil (may be flushed with awater hose). Ensure power is off before cleaning.

NOTE � It may be necessary to flush the outdoor coilmore frequently if it is exposed to substances which arecorrosive or which block airflow across the coil (e.g., peturine, cottonwood seeds, fertilizers, fluids that may containhigh levels of corrosive chemicals such as salts)

Sea Coast � Moist air in ocean locations can carry salt,which is corrosive to most metal. Units that are locatednear the ocean require frequent inspections andmaintenance. These inspections will determine thenecessary need to wash the unit including the outdoor coil.Consult your installing contractor for properintervals/procedures for your geographic area or servicecontract.

Indoor Unit1. Clean or change filters.

2. Lennox blower motors are prelubricated andpermanently sealed. No more lubrication is needed.

3. Adjust blower speed for cooling. Measure the pressuredrop over the coil to determine the correct blower CFM.Refer to the unit information service manual for pressuredrop tables and procedure.

4. Belt Drive Blowers − Check belt for wear and propertension.

5. Check all wiring for loose connections.

6. Check for correct voltage at unit. (blower operating)

7. Check amp draw on blower motor.

Motor Nameplate:_________ Actual:__________.

Indoor Coil1. Clean coil if necessary.

2. Check connecting lines, joints and coil for evidence ofoil leaks.

3. Check condensate line and clean if necessary.

HOMEOWNERCleaning of the outdoor unit’s coil should be performed bya trained service technician. Contact your dealer and setup a schedule (preferably twice a year, but at least once ayear) to inspect and service your outdoor unit. Thefollowing maintenance may be performed by thehomeowner.

CAUTIONPhysical contact with metal edges and corners while applying excessiveforce or rapid motion can result in personal injury. Be aware of, and usecaution when working near these areas during installation or whileservicing this equipment.

IMPORTANTSprinklers and soaker hoses should not be installedwhere they could cause prolonged exposure to theoutdoor unit by treated water. Prolonged exposure of theunit to treated water (i.e., sprinkler systems, soakers,waste water, etc.) will corrode the surface of steel andaluminum parts and diminish performance and longevityof the unit.

Outdoor CoilThe outdoor unit must be properly maintained to ensure itsproper operation.

506374−01 03/10

� Please contact your dealer to schedule properinspection and maintenance for your equipment.

� Make sure no obstructions restrict airflow to theoutdoor unit.

� Grass clippings, leaves, or shrubs crowding the unitcan cause the unit to work harder and use more

energy.

� Keep shrubbery trimmed away from the unit andperiodically check for debris which collects around theunit.

Routine Maintenance

In order to ensure peak performance, your system must beproperly maintained. Clogged filters and blocked airflowprevent your unit from operating at its most efficient level.

1. Air Filter � Ask your Lennox dealer to show youwhere your indoor unit’s filter is located. It will be eitherat the indoor unit (installed internal or external to thecabinet) or behind a return air grille in the wall orceiling. Check the filter monthly and clean or replaceit as needed.

2. Disposable Filter � Disposable filters should bereplaced with a filter of the same type and size.

NOTE � If you are unsure about the filter required for yoursystem, call your Lennox dealer for assistance.

3. Reusable Filter � Many indoor units are equippedwith reusable foam filters. Clean foam filters with amild soap and water solution; rinse thoroughly; allowfilter to dry completely before returning it to the unit orgrille.

NOTE � The filter and all access panels must be in placeany time the unit is in operation.

4. Electronic Air Cleaner � Some systems areequipped with an electronic air cleaner, designed toremove airborne particles from the air passing throughthe cleaner. If your system is so equipped, ask yourdealer for maintenance instructions.

5. Indoor Unit � The indoor unit’s evaporator coil isequipped with a drain pan to collect condensateformed as your system removes humidity from theinside air. Have your dealer show you the location ofthe drain line and how to check for obstructions. (Thiswould also apply to an auxiliary drain, if installed.)

Thermostat OperationSee the ComfortSense® 7000 thermostat homeownermanual for instructions on how to operate your thermostat.

Preservice CheckIf your system fails to operate, check the following beforecalling for service:

� Verify room thermostat settings are correct.

� Verify that all electrical disconnect switches are ON.

� Check for any blown fuses or tripped circuit breakers.

� Verify unit access panels are in place.

� Verify air filter is clean.

� If service is needed, locate and write down the unitmodel number and have it handy before calling.

Accessories

For update−to−date information, see any of the followingpublications:

� Lennox 13ACX Engineering Handbook

� Lennox Product Catalog

� Lennox Price Book

Start−Up and Performance Checklist

Job Name Job no. Date

Job Location City State

Installer City State

Unit Model No. Serial No. Service Technician

Nameplate Voltage

Rated Load Ampacity Compressor Outdoor Fan

Maximum Fuse or Circuit Breaker

Electrical Connections Tight? � Indoor Filter clean? � Supply Voltage (Unit Off)

Indoor Blower RPM S.P. Drop Over Indoor (Dry) Outdoor Coil Entering Air Temp.

Discharge Pressure Suction Pressure Refrigerant Charge Checked? �

Refrigerant Lines: Leak Checked? � Properly Insulated? � Outdoor Fan Checked? �

Service Valves: Fully Opened? � Caps Tight? � Thermostat

Voltage With Compressor Operating Calibrated? � Properly Set? � Level? �

Documents

INSTALLATION INSTRUCTIONS · 2017. 4. 13. · 03/10 506374−01 Page 1 2010 Lennox Industries Inc. Dallas, Texas, USA RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE WARNING Improper