indoor Air Handlers

These instructions are primarily intended to assist qualified individuals experienced in the properinstallation of heating and/or air conditioning appliances. Some local codes require licensedinstallation/service personnel for this type equipment. All installations must be in accordance withthese instructions and with all applicable national and local codes and standards.

Before beginning the installation, read these instructions thoroughly and follow all warnings andcautions in the instructions and on the unit. When performing brazing operations have a fireextinguisher readily available and use a quenching cloth and brazing shield.

Improper installation, service, adjustment, or maintenance can cause fire, electrical shock or otherconditions which may result in personal injury or property damage. Unless otherwise noted in theseinstructions, only factory authorized kits or accessories may be used when modifying this product.

Table of Contents

1. Air Handler Specifications ................................................................................................. 4-5Unit Dimensions .................................................................................................................... 4

2. Installation Requirements ..................................................................................................... 5Minimum Ampacity and Maximum Overcurrent Protection ................................................ 5

3. Air Ducts, Filters, Horizontal Applications ........................................................................ 6

4. Refrigerant Tubing Connections ......................................................................................... 9

5. Electrical Wiring .................................................................................................................... 11

6. Start-up and Adjustment .................................................................................................... 12

7. Optional Humidistat (Variable Speed Only) ....................................................................... 14

8. Optional Bonnet Control Switch (Variable Speed Only) ................................................. 15

9. Care and Maintenance ......................................................................................................... 15

3

t. AIR HANDLER SPECIFICATIONS

IndoorAir Handlers are designed and approvedfor attic, basement, alcove, closet and crawlspace installations.

Factory ready horizontal Air Handlers may beapplied in upflow or horizontal-left and -rightdischarge applications. These units may alsobe applied in downflow discharge when appliedwith the appropriate field kit (See TechnicalSpecifications).

Vertical only Air Handlers are factory ready forupflow applications. These units may be ap-plied in downflow or horizontal left and right

discharge applications when applied with theappropriate field kit (See Technical Specifica-tions).

Dimensional drawing for the unit is shown inFigure 1.

Field=installed electric heater kits are available.Available heater kits for these units are listed

in the Technical Specifications. Instructionsfor installing the electric heaters are includedwith the heaters.

"B" and "C" cabinet units equipped with stan-dard blowers may be upgraded to variablespeed with the addition of a variable speed

3/4 '_] /--_7/8" K,O.

3/4"q_ ]]- 3/4" 3/4"-

,¥ ,.

12 718"

, :,

-- <o:::7: ::7:.A ......... ,_

718" K,O.

_÷ _OI- --_17,;_::;2o:_i';_:L.II_

/_d I 1/8" K,O.

_F,_I 1/8,_ 1 1/8" K.O.

_ ] 2 718"

13/4,_ _ 2,,

31/4 ! -I 1-1l/z'

_Wu

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:::::::::::::::::::::: I

22"

............._g

Cabi net

Size H W A

A 41-5/16 14-3/16 12-3/4

B 43-5/16 19-11/16 18-1/4

C 43-5/16 22-7/16 21

Tall C 53-5/16 22-7/16 21

Figure 1. Unit Dimensions

conversion kit. See Technical Specificationsfor details.

Air handlers set up with 15 kw or more of electricheat will normally be configured for dual-circuitpower supply. They may, however, be con-nected to a single-circuit power supply with theaddition of the single circuit accessory kit (SeeTechnical Specifications). Select the wire sizeand over-current protection in accordance withthe minimum circuit ampacity and maximumover-current protection shown in Table 1.

2. INSTALLATION REQUIREMENTS

Check Equipment m All installations shall bemade as described in these installation instruc-tions and in accordance with all applicablenational and local codes including the require-ments of local utilities.

Requirements and Codes m Electrical powerwiring must be made in accordance with allapplicable local codes and ordinances, andwith the current revision of the National ElectricCode (ANSI/NFPA 70). Air ducts must beinstalled in accordance with the standards ofthe National Fire Protection Association "Stan-

dard for Installation of Air Conditioning and

Ventilation Systems" (NFPA 90A), "Standardfor Installation of Residence Type Warm AirHeating and Air Conditioning Systems" (NFPA90B), these instructions, and all applicablelocal codes.

National Fire Protection Association, Inc.Batterymarch ParkQuincy, Maine 02269www.nfpa.org(617) 770-3000

Location _ To insure proper condensatedrainage, the unit must be installed in a levelposition within 1/4 inch over the height, width,and depth of the unit. The best system perfor-mance will be obtained if the unit is located in

a centralized position with respect to the airdistribution system.

When an air handler is installed in or above a

living space, the installation of an auxiliary drainpan under the entire unit is required to reducethe possibility of property damage.

All servicing and cleaning of the air handler canbe done from the front. Adequate horizontalclearances should be provided to allow for

These wiring requirements are for units with optional heater kits. They can not beused with 115 volt units.

Single CircuitAux. Heat Min.*** I Wire I Maximum

Installed Circuit AWG I Over-current(Nom. KW) Amp. 75°C * Rating

Dual CircuitCircuit A Circuit B

Min,..lwirelwireMeximom ,n,"lWireWirel oximumCircuit AWG AWG Over-current Circuit AWG AWG Over-currentAmp. 60°C * 75°C * Rating Amp. 60°C * 75°C * Rating

none 5.0 14 15 5.0 14 14 15

005H 30.0 10 30 30.0 10 10 30

_ 008H 44.1 8 50 44.1 6 8 50

o _ 010H 55.0 6 60 55.0 6 6 60

_ 012H 65.4 4 70 65.4 8 8 40

_ 015H 80.0 4 90 55.0 6 6 60

020H 105.0 2 125 55.0 6 6 60

025H 119.6 1 125 59.2 4 6 60

30.2 8 8 40

25.0 10 12 30

50.0 4 8 50

60.0 4 6 60

none 5.0 14 15 5.0 14 14 15

005H 26.6 10 30 26.6 10 10 30

_ 008H 38.7 8 (6**) 40 38.7 8 8 (6**) 40

_ 010H 48.3 8 50 48.3 6 8 50

> _ 012H 57.9 6 60 31.4 8 8 40

_ 015H 69.9 4 70 48.3 6 8 50

020H 91.5 3 100 48.3 6 8 50

26.4 10 10 30

21.6 10 10 25

43.3 6 8 50

52.3 6 6 60025H 104.2 2 125 51.9

* All wire sizes for copper conductors only, based on NEC Table 310-16

**Required for C-cabinet variable speed.

***Circuit ampacity slightly higher for variable speed. See label on blower.

6O

Table 1. Minimum Ampacity and Maximum Overcurrent Protection5

service and care of the unit. A minimum 24 inchclearance at the front of the unit is recom-

mended. These units are suitable for attic,closet, crawl space or alcove installation atzero clearance from combustibles.

Location of the Room Thermostat m Theroom thermostat should be mounted 4 to 5 feet

above the floor, on an inside wall that has goodair circulation from all areas being controlled bythe thermostat. For optimum performance, it isessential that there be free circulation of air atthe thermostat location. Air movement shouldnot be obstructed by furniture, doors, draper-ies, etc. The thermostat should not be mountedwhere it will be affected by drafts, hot or coldwater pipes or air ducts in walls, radiant heatfrom a fireplace, lamps, the sun, a TV, etc.Consult the instruction sheet packed with thethermostat for mounting instructions.

Condensate Drain = The condensate panhas primary and secondary drain connections.The connections have 3/4 inch female pipethreads.

All condensate drains should be a minimum of

3/4 inch PVC pipe or equivalent. The drainshould maintain a minimum horizontal slope inthe direction of discharge of not less than 1 inchvertical for every 10 feet of horizontal.

If the air handler is located in or above a livingspace where damage may result from conden-sate overflow, an auxiliary drain pan shall beinstalled under the unit. A separate drain lineshould extend from the pan to a conspicuouspoint and serve as an alarm which indicatesthat the primary drain is restricted. As analternative to a separate drain line, an approvedwater level indicator or float switch deviceshould be used to shut down the unit in the event

water is detected in the auxiliary pan.

Install a 5 inch trap in the condensate drain lineas close to the coil as possible. Make sure thatthe top of the trap is below the bottom of thedrain pan to prevent the condensate from over-flowing the drain pan. Prime the trap with water.Insulate the drain if it is located in an uncondi-

tioned space, and test the condensate line forleaks. Consult local codes for additional re-

strictions or precautions.

NOTE: There must be only one trap in the drainline. Using more than one trap may preventdrainage.

IMPORTANT:The plastic drain pan must be level orslightly sloped toward the drain lines.

3. AIR DUCTS, FILTERS,HORIZONTALAPPLICATIONS

Air ducts should be installed in accordance withthe standards of the National Fire ProtectionAssociation "Standard for Installation of Air

Conditioning and Ventilation Systems" (NFPA90A), "Standard for Installation of ResidenceType Warm Air Heating and Air ConditioningSystems" (NFPA 90B), these instructions, andall applicable local codes.

Use transition fittings if the supply and/or returnair openings of the unit do not match the ductopenings. These transitions should be dimen-sioned in accordance with standard practice asspecified in the ASHRAE recommendations forduct transitions.

Flexible connectors should be used between

the unit and the ductwork to prevent transmis-sion of vibration from the unit to the structure. Ifelectric heater kits are installed, heat resistantmaterial must be used for the flexible connector

at the supply air end of the unit.

Air Filter Installation _ The filter may belocated in the return air duct system or installedinto the air handler filter track located in thebottom of the unit.

To install the filter, remove the filter door. Thefilter sizes for the air handler cabinets are:

Cabinet Filter

A 12x20x1

B 18x20x1

C 20 x 20 x 1

WARNING:Never operate the unit without a filteror with the doors removed. Dust and

lint in the return air can build up oninternal components, resulting in aloss of efficiency, equipmentdamage, and possible fire risk.

Upflow Applications m All air handlers arefactory shipped, ready for upflow configura-tion, all return air must enter from the bottom ofthe unit. A typical installation of the unit in aducted return air mode is shown in Figure 2.

Downflow Applications m The downflowaccessory kit (See Technical Specifications)is required for downflow applications. Instruc-tions for installing the downflow accessory kitare included with the kit. It is recommended that

the accessory be installed prior to installing theunit. All return air in downflow applications mustenter through the top of the unit. A typicalinstallation of the unit in a downflow applicationis shown in Figure 3.

NOTE: For 066 models, see addendum sheetwhen installing in horizontal, left or right.

Horizontal Left And Horizontal Right _ Airhandlers may or may not be shipped from thefactory with all the parts required for horizontalleft applications and horizontal right applica-tions (see Figure 5). If your unit does not haveparts for a horizontal application, a kit is avail-able (see Technical Specifications).

To Configure Unit for Horizontal LEFTInstallations:

1) Remove the coil access door.2) Remove the front drain pan support

bracket (if supplied).3) Slide the coil and drain pan assembly out

of the unit.

4) IMPORTANT: Remove the plug from oneof the threaded holes in the horizontal

drain pan. Completely remove the web=bing located in the threaded holes of thehorizontal drain pan. if webbing is notremoved, the drain will not function prop-erly and ceiling damage may occur.

5 insert a plug (from the horizontal drain pan)

Figure 2. Upflow Installation

into the open and unused drain hole in thedrain pan at the bottom of the unit to blockbypass air.

6) Remove the corresponding drain lineknockout from the coil access door toallow access to the horizontal drain.

7) Replace the door and attach the drain line.

To Configure Unit for Horizontal RIGHTInstallations:

1) Remove the coil access door. Unscrewthe line=set tube close-off plate from thefront left cabinet rail.

2) Remove the front drain pan supportbracket (if supplied).

3) Slide the coil and drain pan assembly outof the unit.

4) IMPORTANT: Remove the plug from oneof the threaded holes in the horizontal

drain pan. Completely remove the web-bing located in the threaded holes of thedrain pan. If webbing is not removed, thedrain will not function properly and ceilingdamage may occur.

5) Remove the sheet metal hairpin covers (ifsupplied) from the back of the coil anddiscard.

6) Place the horizontal drain pan on the oppo-site side of the coil. On units with 2 sets ofknockouts, remove the other set of knock-outs in the coil spacing plates and insertsupport rod.

7) Insert a plug (from the horizontal drain pan)into the open and unused drain hole in thedrain pan at the bottom of the unit to blockbypass air.

8 Slide the coil and the horizontal drain panassembly back into the unit. Reattachthe tube close off plate.

9 Remove the corresponding drain lineknockout from the coil access door toallow access to the horizontal drain.

10) Replace the door and attach the drain line.

Figure 3. Downflow Installation7

The unit may also be installed in a horizontalapplication with the unit suspended from theceiling. A typical installation of the unit in asuspended horizontal application is shown inFigure 5.

using appropriate fasteners for the type of ductused. Seal the joint between the duct and theunit to avoid air leakage and sweating. Thesupply air ductwork must be of noncombustiblematerial for the first 24 inches from the unit.

The field-supplied hanger straps must be con-nected to the unit within 2 inches of the inlet endof the unit and within 4 inches of the outlet end

of the unit as shown in Figure 5. If the strapspass in front of the unit, leave adequate roomfor removal of the doors and filter.

CAUTION'.Make certain that the fasteners used

to connect the hanger straps to theunit do not contact internal wiring orrefrigerant tubes,

NOTE: In all horizontal applications in whichthe unit is installed above a finished ceilingand/or living space, a secondary drain panmust be installed under the entire unit to

avoid damage to the ceiling in the event ofcondensate overflow.

Supply Air Ducts m Bend up the flanges onthe top of the unit and connect the supply airduct over them. Secure the duct to the flange,

Some installations with a short, straight runfrom the unit to the first branch takeoff mayrequire acoustical lining inside the supply airductwork. Acoustical insulation must be inaccordance with the current revision of the

Sheet Metal and Air Conditioning ContractorsNational Association (SMACNA) applicationstandard for duct liners.

Duct lining material must be UL classified battsor blankets with a fire hazard classification of

FHC-25/50 or less. Fiber ductwork may beused in place of internal duct liners if the fiberductwork is in accordance with the currentrevision of the SMACNA construction standard

on fibrous glass ducts.

Fibrous ductwork and internal acoustical liningmust be NFPA Class I air ducts when tested perUL Standard 181 for Class 1 ducts.

Through-the-Floor Installations m When-ever the supply or return air ducts passthrough the floor, a 1/4" thick noncombus-tible resilient gasket must be used betweenthe duct, unit and floor.

% \ \

Horizontal=left InstallationFigure 4.

E;

Figure 5. Horizontal=right Installation, Suspended from Ceiling8

Ductwork in Unconditioned Spaces m Allductwork located in unconditioned space mustbe adequately insulated to prevent excess ductloss and condensation. All externally insulatedductwork must have an adequate vapor seal.Consult your Distributor for the recommendedtype and thickness of insulation for your area.

4. REFRIGERANT TUBINGCONNECTIONS

Note: Do not remove seals from the coil until

tubing connections are ready to be made. Seethe instructions packaged with the condensingunit for the correct procedure for connection ofthe refrigerant lines.

Note: The air handler coil does not contain a

refrigerant charge. Reference installation in-structions included with outdoor unit for infor-

mation regarding the refrigerant charge in-cluded in the outdoor unit.

Note: The following instructions are for airhandler models employing an orifice for therefrigerant metering device.

The orifice employed in the air handlers hasbeen sized for use with the most popularlymatched outdoor unit. The orifice size in the

coil as shipped from the factory is listed on theair handler rating plate. Check that the orificesize provided with the air handler is correct forthe outdoor unit being applied. If the orifice sizeis incorrect it should be replaced as follows:

1. Loosen the distributor body halves byapplying two wrenches and squeezingthem together as shown in Figure 6, to turnthe assembly nut counterclockwise.

2. Continue to unscrew the assembly nut toseparate it from the distributor body.

3. Insert a light=gauge wire hook between thedistributor body and the orifice to lift theorifice out of the body (See Figure 7).

Carefully remove the orifice being carefulnot to scratch either part.

4. Check the actual size of the new orifice

(the size is stamped on the side of theorifice).

5. Insert the new orifice in the distributor bodyas shown in Figure 8.

6. After installing the orifice in the distributorbody, re-attach the assembly nut to thedistributor body and tighten it to 10-12 ft/Ibsof torque. If no torque wrench is available,mark a line along both the nut and bodyafter hand tightening and then tighten anadditional 1/4turn. The misalignmentofthetwo lines will show how much the nut is

tightened.7. Check the assembly for leaks after refrig-

erant pressure is applied.

Note: When brazing the line set to the coil inunits with TXV valves, wrap a wet rag aroundthe TXV sensing bulb to protect it from over-heating.

Note: On horizontal or downflow applicationsof models with the TXVs, to ensure properperformance, the sensing bulb must be re-positioned so it is in the 4 o'clock to 8 o'clockposition on the suction tube after final orienta-tion of the air handler.

Figure 7. Removal of Orifice

Figure 6. Wrenches onDistributor Body and Assembly Nut

Figure 8. OrificeInsertion in Distributor Body

9

NOTE: Jumper 11 I 1/

WlandW2 /I Thermostattogether when / _G R W Ystaged heater © © O ()

kits areused ' I I I

without Ill

NOTE: Jumper I I I I

Wl and W2 I / Thermostat / I

k_tsareused _l iXi i..L --_NOTE,°=pe,oWitth;oUctr /I rbe_uWe:nWh2e:nnd°E(__

thermostats. _ I I T-Star, d.....

I '1 Ac I

Air Handier A/C OD Section

Typical Air Conditioner w/StandardAir Handler

NOTE: Jumper 11 1 1W1 and W2 /I Thermostat I /together when / _G R Wstaged heater (_ (? () Y

kits are used

without Ill

c Y

\NOTE: in AC applications,the O and Y connectionmust be connected as shown.

Air Handier A/C OD Section

Typical Air Conditioner withVariable Speed Air Handler

Air Handier Heat Pump ODSection

Typical Heat Pump w/Standard Air Handler

NOTE: JumperW1 and W2

together when

staged heaterkits are used

without

outdoor

thermostats•

Thermostat JI _ RW2C EO Y I

R

Air Handier Heat Pump ODSection

Typical Heat Pump with Optional OutdoorThermostat and Variable Speed Air Handler

Figure 9. Typical Air Conditioning and Heat Pump System Connections

10

NOTE: Jumper

Wl and W2 Thermostat

together when G R W Y2 Y1staged heater © © © c_ okits are used

without

outdoor

thermostats.

--)WI _' --

o ÷.)

G (__I

R@.

c 0

,iq_.

c Y1

Yeltow__

Black

Y21 __NOTE: in AC applications, the O and Y

connection must be connected as shown.

Air Handler A/C OD Section

Typical 2-Stage Air Conditionerwith Variable Speed Air Handier

NOTE: Jumper

W1 and W2

together when

staged heaterkits are used

withoutoutdoor

thermostats.

\w2_

wl @_

00

c GYellow/ _1_Y2Black

Air Handler

TypicalOptional

ThermostatG RW2C E OY1Y2 W1W3

R

C 0 Y1 Y2

Heat Pump OD Section

2-Stage Cooling Heat Pump withOutdoor Thermostat and Variable

Speed Air Handier

Figure 10. Typical 2=Stage Air Conditioning and2=Stage Heat Pump System Connections

WARNING:To avoid the risk of electric shock,

personal injury or death, disconnect allelectrical power to the unit before per-

forming any maintenance or service,

The unit may have more than one elec-

trical power supply,

5. ELECTRICAL WIRING

General m Electrical power wiring must bemade in accordance with all applicable localcodes and ordinances, and with the currentrevision of the National Electric Code (ANSI/NFPA 70). If any of the original wire as suppliedwith the unit must be replaced, it must bereplaced with wire material having the samegauge and temperature rating.

Line Voltage m Before proceeding with theelectrical connections, make certain that thevoltage, frequency, and phase of the supplysource are the same as those specified on therating plate. Also, verify that the service pro-vided by the utility is sufficient to handle theadditional load imposed by this equipment.

See the unit wiring label for proper high and lowvoltage wiring. Make all electrical connectionsin accordance with the National Electric Code

and any applicable local codes or ordinances.

Use a separate branch electrical circuit for thisunit. A disconnecting means must be locatedwithin sight of, and readily accessible to, the unit.When electric heat packages with circuit break=ers are field=installed, the circuit breaker may beused as a disconnecting means in most appli-cations. Reference the NEC and Local Codes

for Disconnect requirements.

208/240 volt units are shipped from the fac-tory wired for 240 volt transformer operation.For 208 volt operation, remove the lead fromthe transformer terminal marked 240v andconnect it to the terminal marked 208v. For

maximum ampacity and overcurrent protec-tion, see Table 1.

Provide power supply (or supplies) for the unit inaccordance with Table 1, the unit wiring diagramand the unit rating plate. Connect the line-voltageleads to the corresponding pigtails (or markedterminals on the circuit breaker when the fieldinstalled circuit breaker kits are used) inside thecontrol compartment. Replace the power plugwith the heater kit plug when installing a heater

11

kit.Usecopperwire onlyfor the linevoltagepowersupplytothisunit.Aluminumsupplywiremaybeusedifa heaterkit is installed.UseULlistedconduitanda conduitconnectorforcon-nectingthe supplywiresto the unit andforobtainingpropergrounding.Groundingmayalsobeaccomplishedbyusingthegroundinglugprovidedin thecontrolbox.

WARNING:The unit cabinet must have an uninter-

rupted and unbroken electrical groundto minimize the risk of personal injuryif an electrical fault should occur. This

ground may consist of electrical wireor approved conduitwhen installed inaccordance with existing national orlocal codes.

Low Voltage m Install the grommet, which ispacked with the unit, in the hole for low=voltagewires. When the low voltage wires are posi-tioned in this grommet, the grommet will preventchafing and/or shorting of the low voltage leads.Connect the low=voltage wiring to the thermo-stat and the outdoor unit and the appropriatescrew terminal located on the control board.

NOTE: Where local codes require that thethermostat wiring must be routed through aconduit or raceway, splices can be made insidethe unit; however, all wiring mustbe NEC Class 1 and must be separated fromincoming power leads.

IMPORTANT! On variable speed modelswhen the unit is used in an air conditioningsystem, connect the "O" terminal to the"Y" terminal. See Figure 9 & 10.

CAUTION'.Isolation must be maintained from the

external Class 2 output of any trans-former in a cooling circuit. Use a ther-mostat with isolating contacts to pre-vent inter=connection of Class 2 out-

puts.

Check all factory wiring per the unit wiringdiagram and inspect the factory wiring connec-tions to be sure none were loosened in transitor installation.

CAUTION'.Make sure all doors are installed be-

fore restoring power to the unit.

6.START=UPANDADJUSTMENT

General m Prior to start-up, verify that:1. The line voltage power leads are securely

connected and that the unit is properlygrounded.

2. The low voltage wires are securely con=nected to the correct leads from the unit.

3. The upper and lower doors are in place andsecurely connected to the unit.

NOTE: The control board is programmed witha 40 second off delay in the cooling mode for

optimum system performance and efficiency.

Selecting Proper Blower Speed for Multi=Speed Units = The blower speed is presetat the factory for operation at the same speedfor heating and cooling, by using the blowermotor jumpering terminal on the blower motorand connecting it to the desired speed with boththe red and black wires connected to thejumpering terminal. For optimum systemperformance and comfort, it may be necessaryto change the factory set speed. To change theblower speed, disconnect all electrical power tothe unit and remove the upper door. Removethe black and red wires from the blower motor

jumpering terminal. Discard the blower motorjumpering terminal.

Connect the heating speed wire (red) and thecooling speed wire (black) to the desired blowerspeed marked on the terminal block of theblower motor. Terminal 4 = Hi speed, terminal5 = Med speed and terminal 6 = Low speed.

Replace the upper door and secure it to the unit.Restore power to the unit.

Selecting continuous low speed fan op=eration (Standard Blower) = The air handleris equipped with the option of continuous low

12

speedfan operation.To selectthis option,breakthetablocatedontopofthecontrolboardmarked"BREAKFORLOWSPEEDCONTFAN".Whenthetabis brokenandG isener-gizedwithoutY, the air handlerwill operateusingthe heatingspeed.WiththetabbrokenandG&YorY isenergized,theairhandlerwilloperateintheselectedcoolingspeed(includ-ing40secblower-offdelay).

NOTE:To achievecontinuouslowspeedfanoperationY must be connectedat the airhandler.

SelectingProper Airflow for Variable SpeedUnits m Variable speed air handlers areequipped with a microprocessor-controlledvariable speed motor that is pre-programmedto deliver optimum airflow in a variety ofconditions and system configurations. Beforeoperation, the air handler must be configured tomatch the unit with the system, system options,and climatic conditions. Once configured, theair handler responds directly to the thermostatinputs, aswell asthe optional humidistat (Section7) and bonnet switch (Section 8) (if installed).During normal operation, the motor will graduallychange speeds during start-up, shut down,when thermostat inputs change, and when theduct static pressure changes (vents closed oropened, filter clogging, etc.). The air handler isconfigured by setting the selector switches andremoving jumper connectors as directed below.IMPORTANT! This air handler has been

designed to give the installer maximumflexibility to optimize system performance,efficiency, and comfort, Because there areso many different ways to set up the airhandler it is important to read and followthese directions carefully.

Determining Nominal System Capacity==In order to select the appropriate airflows for theair handler the nominal system capacity mustbe known. The nominal system capacity isalways the nominal capacity of the outdoor unit.In some cases the nominal system capacity isnot the same as the nominal capacity of the airhandler. Always refer to the nominal capacityof the outdoor unit to determine the nominal

system capacity.

Selecting the Basic Cooling/Heat PumpAirflow-== The basic cooling/heat-pump airflowis selected by setting switches 1 through 4 onthe thermostat input board located on the

blower. All airflows for other modes of operation(except electric heat) are determined by thisbasic setting.

Table 2 shows the basic airflow values versus

the airflow selector switch settings. Table 2also shows the range of basic air flow settingsrecommended for each nominal systemcapacity.

Note: The 15+ SEER variable speed air han-dlers that are matched with a 2-stage coolingoutdoor unit, are programmed to operate at75% of the selected airflow while the system isin the Io-cool mode and 100% of the selectedairflow while in hi-cool mode.

NOTE: The CFM values listed in the tables are

not dependent on duct static pressure. Themotor automatically compensates for changesin duct static pressure (within the limits of themotor).

For maximum capacity and energy efficiency,select an airflow at or near the top of the rangefor that nominal capacity. For maximumdehumidification, select an airflow near themiddle or bottom of the range for that nominalcapacity. Additional information on humiditycontrol can be found in the sections labeled

"Humidistat" and "Delay Setting".

NOTE: If coil icing is observed, the basiccooling/heat-pump airflow selected may be toolow. Double-check to be sure the settingselected is within the range shown in Table 2.Also check to be sure the system is properlycharged (see outdoor unit InstallationInstructions). If icing continues to occur, raisethe selected airflow one or two steps.

When operating in the heat pump mode, ahigher basic airflow setting will increase theenergy efficiency and capacity but will alsodecrease the supply air temperature. Theoptional Bonnet Control Switch may be addedto increase the supply air temperature in theheat-pump mode when the supply airtemperature is below a comfortable level. Formore details see the section labeled "BonnetControl Switch".

Selecting the Minimum Electric HeatAirflow-= The minimum electric heat airflow isselected by setting switches 5 and 6. Selectingthe minimum electric heat airflow sets the

minimum air flowthatwill be produced whenever

13

CFM7208008608859601060112511851250131513751450

Basic Air-Flow SettingB-Cabinet C-Cabinet

Switch Switch NominalNumber NominalCa Number

1123010 0010 0110 0010 1110 0110 1011 0111 0011 0111 0011 1111 1

Table 2.

4 CFM 1 2 3 41 1075 0 0 0 10 1140 1 0 0 11 1225 0 0 0 00 1300 1 0 0 00 1380 0 0 1 00 1465 1 0 1 01 1555 0 1 0 11 1665 1 1 0 10 1775 0 1 0 00 1900 1 1 0 00 20000 2150

Note: I=ON_ 0=OFF

0,,011,,_-1 1 1 0

Air Flow Selection for Variable Speed Models

electric heater kits are used. When the electric

heater kits are energized along with a heatpump, the airflow may be higher depending onthe basic cooling/heat-pump airflow setting.

Reference Table 3 for recommended minimumelectric heat airflow settings. The minimumelectric heat airflow setting may be set higher,but must never be set lower than the settingshown in Table 3.

Selecting the Delay Profile--- The delay profileis selected by setting switches 7 and 8 (seeTable 4). Delay profile selection controls thestart=up and shut-down characteristics of theair handler. By varying the start-up and shut=down characteristics of the air handler the

system can be optimized for energy efficiency,humidity control, and comfort.

Select "Delay A" or "Delay B" for highest energyefficiency. "Delay A" has a two=step "on" delay.The blower will begin operation at 31% airflow

for 30 seconds. The second step operation is75% airflow for 30 seconds. After the two-step"on" delay has been completed, the bloweroperation will be 100% until the thermostat hasbeen satisfied. "Delay A" also provides a 60second "off" delay at 50% airflow.

"Delay B" has a single step 30 second "on"delay at 50% airflow. "Delay B" also providesa 90 second "off" delay at 50% airflow. Selectthe delay profile which is most suited to theapplication.

The "De-Hum." delay profile may be used whenhumidity control is desired without the use of theoptional humidistat. If the "De=Hum." delayprofile is selected, the air handler will run at 75%airflow for the first 10 minutes of each coolingcycle. If the "De=Hum." delay profile is selected,the basic cooling/heat-pump speed should beselected at or near the top of the range for thatnominal capacity (see Table 2).

Switch Number

Nominal KW CFM 1 2 3 4 5 6 7 8

0.5 o :,.lo 500 o.

950:,:,:,:o ::6-20 . oo _

Note: 0=Off, 1=On

Table 3. Minimum Electric Heat Airflow(all models)

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Switch Number

Delay Description 1 2 3 4 5 6 7 8

De,ayA o oDelayB 0NoDelay 0

Note: 0=Off, 1=On

Table 4. Delay Settings (all models)

7. OPTIONAL HUMIDISTAT(Variable Speed Only)

The optional humidistat may be installed in thereturn air duct to provide excellent humiditycontrol when needed and maximum systemcapacity and energy efficiency when humiditylevels are normal. The humidistat senses when

humidity in the return air stream is above apreset level (field adjustable) and sends a signalto the motor to reduce the airflow so that more

moisture may be removed until the humiditylevel drops. The air handler is pre=programmedfor humidistat operation. Remove jumperconnector installed between the two terminalsmarked "HUM" on the circuit board.

Note: The 15+ SEER air handlers that arematched with a 2=stage cooling outdoor unitand the humidistat is installed will not dropbelow 75% of the selected blower speed whenthe system is operating in Io-cool mode and thehumidistat opens.

Installation= Install the humidistat in the returnair duct as directed in the installation instructionsincluded with the kit. Wire the humidistat throughthe low=voltage wire entrance in the air handler(Figure 1) to the quick=connect terminals marked"HUM". Wire the humidistat to open on rise inhumidity.

8. OPTIONAL BONNETCONTROL SWITCH(Variable Speed Only)

The optional bonnet control switch is recom=mended in variable speed heat=pump systemswhere supply air temperatures may drop belowa comfortable level during normal operation.The bonnet control switch senses when the

supply air temperature is below a preset comfortlevel (set by installer) and sends a signal to themotor to reduce the airflow. The supply airtemperature increases when the airflow is re=duced. Airflow will resume to normal levels if

electric strip heat is energized. The air handleris pre=programmed to accept bonnet switchinputs. Remove jumper connector installedbetween "BI" and "B2" on the circuit board. The

bonnet switch will not affect the cooling cycle.

Installation-- Install the bonnet control switchin the supply air duct as directed in the installationinstructions included with kit. Locate the bulb

close to the unit, but not within the sight of theheating elements. Wire the bonnet control switchto the circuit board and through the low-voltagewire entrance in the air handler, and remove

jumper connector between "BI" and "B2" wireswitch to close on temperature rise typically R& W. Set the thermostat as desired near 105°F.

9. CAREAND MAINTENANCE

General m For continued high performance,and to minimize the risk of equipment failure, itis essential that periodic maintenance be per-formed on this equipment. The ability to properlyperform maintenance on this equipment requirescertain mechanical skills and tools. If you do notpossess these skills, contact your dealer formaintenance. Consult your local dealer as to theavailability of a maintenance contract.

Do not store any of the following on, or in contactwith, the unit: Rags, brooms, vacuum cleaners,or other cleaning tools, spray or aerosol cans,soap powders, bleaches, waxes, cleaning com=pounds, plastics or plastic containers, paperbags or other paper products, gasoline, kero=sene, cigarette lighter fluid, dry cleaning fluids,paint thinners, or other volatile fluids.

Proper maintenance is most important to achievethe best performance from an air handler. At aminimum, this maintenance should include thefollowing items.

1. Inspect and clean or replace the air filter atthe beginning of each heating and coolingseason, or more frequently as required.

2. Inspect the cooling coil, drain pan, andcondensate drain at the beginning of eachcooling season for cleanliness. Clean thesecomponents as necessary using a milddetergent and water. Flush the coil, drainpan, and condensate drain after cleaning toremove all detergent. Use caution whencleaning these components so that theinsulation does not become wet.

3. Inspect the blower motor and wheel forcleanliness at the beginning of each heatingand cooling season. Clean the motor asnecessary.

4. Inspect electrical connections for tightnessatthe beginning of each heating and coolingseason. Service as necessary.

WARNING:

Use caution when removing parts fromthis unit. Personal injury can result fromsharp metal edges present in all equip-ment of sheet metal construction.

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iNSTALLER: PLEASE LEAVE THESEiNSTALLATiON iNSTRUCTiONS

WiTH THE HOMEOWNER

IIIllllllllllllllllllllllIll708274B (Replaces 708274A)

Specifications and illustrations subject to changewithout notice and without incurring obligations.

Printed in U.S.A. (08/04)