Lennox CBA38MV User Manual

INSTALLATION INSTRUCTIONS

THIS MANUAL MUST BE LEFT WITH THE

HOMEOWNER FOR FUTURE REFERENCE

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional HVAC installer or equivalent, service agency, or the gas supplier.

IMPORTANT

The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for noncompliance.

NOTICE

A thermostat is not included and must be ordered separately.

• A Lennox communicating thermostat must be used in communicating applications.

• In non-communicating applications, the Lennox ComfortSense® thermostat may be used, as well as other non-communicating thermostats.

In all cases, setup is critical to ensure proper system operation.

Field wiring for both communicating and noncommunicating applications is illustrated in diagrams, which begin on page 13.

IMPORTANT: Special procedures are required for cleaning the all-aluminum coil in this unit. See page 43 in this instruction for information.

Dave Lennox Signature® Collection CBA38MV Units

MULTI-POSITION AIR HANDLERS 507725-02 12/2019

Table of Contents

CBA38MV Upow and Downow Unit Dimensions ....... 2

CBA38MV Horiz. LH/RH Discharge Unit Dimensions ...3

General Information ....................................................... 4

Shipping and Packing List .............................................4

Installation Clearances ..................................................4

Requirements ................................................................5

Installing the Unit ........................................................... 5

Brazing Connections .....................................................9

Installing the Condensate Drain .................................. 11

Inspecting and Replacing Filters .................................12

Sealing the Unit ...........................................................12

Field Control Wiring ..................................................... 13

Air Handler Control Button, Display and Jumpers ....... 25

Target CFM Tables ......................................................30

Unit Operating Sequences ..........................................32

Unit Operating Sequences ..........................................34

Heat Pump Operation (Heating and Cooling) .............. 39

Cooling Operation ........................................................40

Error Code / Recall Mode ............................................ 41

Indoor Blower Test ....................................................... 42

Operation ..................................................................... 42

Repairing or Replacing Cabinet Insulation .................. 43

Homeowner Maintenance ............................................43

Professional Maintenance ...........................................43

IMPORTANT INFORMATION FOR INSTALLER

CHECK FOR AND REMOVE THE FOLLOWING ITEMS BEFORE OPERATING UNIT.

BLOWER HOUSING SUPPORT PAD.

Important Update: The CBA38MV Air Handler Control (AHC) has been enhanced to automatically configure (set-up) the electric heat when the ECBA38 electric heat harness is connected to CBA38MV air handler. Manual Configuration of the electric heat using the push button is no longer required. See page 32.

HORIZONTA L DRAIN PA N (SEE

UPFLOW APPLICATIONS ON PAGE 5 AND DOWNFLOW APPLICATIONS ON PAGE 8 )

CONFIGURE ELECTRIC HEAT

REFRIGERANT LINE PLUGS (SEE

BRAZING CONNECTION ON PAGE 9) .

ECB38

Page 1

CBA38MV Upow and Downow Unit Dimensions – Inches (mm)

3/4 (19)

11‐1/16 (281)

LINE VOLTAGE

INLETS (TOP

AND LEFT SIDE)

TOP VIEW

FLOW

RETURN AIR

FRONT VIEW

SUPPLY AIR

AIR

OPENING

LOW VOLTAGE

INLETS (TOP AND

RIGHT SIDE)

5/8 (16)

3/4 (19)

5/8 (16)

ELECTRIC HEAT

(FIELD-INSTALLED)

FILTER ACCESS

UP-FLOW POSITION

OPTIONAL

SUCTION

LINE

LIQUID

LINE

FILTER

2‐3/4 (70)

PIPING PLAT E DETAIL

1‐3/4 (44)

4‐3/8 (111)

3‐1/2 (89)

(FOR UP-FLOW AND DOWN-FLOW POSITIONS)

1‐1/8 (29)

(51)

5‐3/8

(137)

FILTER

SUCTION

BLOWER

COIL

RETURN AIR

)52( 1)61( 8/5

SIDE VIEW

5/8 (16)

LINE

LIQUID

LINE

OPTIONAL

ELECTRIC HEAT

(FIELD-INSTALLED)

LOW VOLTAGE

(RIGHT SIDE)

LINE VOLTAGE

(LEFT SIDE)

SUCTION LINE

CONDENSATE DRAINS (2) (HORIZONTAL)

LIQUID LINE

CONDENSATE DRAINS (2) (UP-FLOW AND DOWN-FLOW)

COIL

BLOWER

SUPPLY

11‐1/16 (281)

AIR

SIDE VIEW

5/8 (16)

DOWN-FLOW POSITION

5/8 (16)

Air Opening

1 (25)

TOP VIEW

AIR FLOW

SUPPLY AIR

FRONT VIEW

5/8 (16)

Return

FILTER ACCESS

5/8 (16)

CBA38MV Common Dimensions - Inches (mm)

Dim. -018/024 -030/-036 -042/-048 -060

49-1/4 (1251) 51 (1295) 58-1/2 (1486) 62‐1/2 (1588)

21-1/4 (540) 21-1/4 (540) 21‐1/4 (540) 21‐1/4 (540)

20-5/8 (524) 22‐5/8 (575) 24-5/8 (625) 24-5/8 (625)

19-3/4 (502) 19-3/4 (502) 19‐3/4 (502) 19‐3/4 (502)

19 (483) 21 (533) 23 (584) 23 (584)

20 (508) 20 (508) 20 (508) 20 (508)

24-5/8 (625) 26‐3/8 (670) 27‐7/8 (708) 27‐7/8 (708)

24-5/8 (625) 24-5/8 (625) 30-5/8 (778) 34‐5/8 (879)

Page 2

CBA38MV Horizontal Left- and Right-Hand Discharge Unit Dimensions – Inches (mm)

5‐3/8 (137)

CONDENSATE

DRAINS (2)

(UP-FLOW

AND

DOWN-FLOW)

CONDENSATE

DRAINS (2)

(HORIZONTAL)

PIPING PLAT E

DETAIL

5/8 (16)

5‐3/4

(46)

RETURN AIR

OPENING

END VIEW

Horizontal Position

(Left‐Hand Air

Discharge)

1‐3/4

(44)

(51)

1‐1/2

(38)

1 (25)

FILTER ACCESS

LIQUID

LINE

SUCTION

LINE

1‐1/8

(29)

4‐3/8 (111)

FILTER

Horizontal Position

(Right‐Hand Air

Discharge)

Coil

LIQUID

SUCTION

LINE

TOP VIEW

AIR

FLOW

FRONT VIEW

BLOWER

OPTIONAL ELECTRIC

HEAT (FIELD-INSTA LLED)

Coil

5/8 (16)

INLETS (BOTTOM

LINE VOLTAGE

INLETS (TOP

AND RIGHT

SIDE)

LOW VOLTAGE

AND RIGHT

SIDE)

FOR DIMENSIONS “A” THROUGH

“H”, SEE CHART ON PAGE 2.

11‐1/16

3/4 (19)

(281)

Supply

4‐3/8 (111)

1‐1/8

(29)

Air

Opening

END VIEW

3/4 (19)

LOW VOLTAGE

3/4 (19)

11‐1/16

(281)

Supply

Air Opening

LINE VOLTAGE INLETS

(BOTTOM AND LEFT SIDE)

END VIEW

INLETS (TOP AND

LEFT SIDE)

OPTIONAL ELECTRIC

HEAT (FIELD INSTALLED)

5/8 (16)

CONDENSATE DRAINS (2)

Air Flow

(HORIZONTA L)

FRONT VIEW

FILTER

TOP VIEW

SUCTION

LINE

1‐3/4

(44)

LIQUID

LINE

5‐3/4 (146)

SUCTION LINE

PIPING PLAT E

DETAIL

FILTER ACCESS

1‐1/2 (38)

LIQUID

LINE

1 (25)

Return

Air Opening

END VIEW

(51)

5‐3/8 (137)

5/8 (16)

Page 3

Model Number Identication

230CB 38 036-01

060 = 5 tons (17.6 kW)

--6

Unit Type

CB = Air Handler

Coil Type

A = Aluminum Coil

Series

Configuration

MV = Multi-Position, Variable

speed blower motor

Nominal Cooling Capacity

018/024 = 1.5 to 2 tons (5.3 to 7 kW) 030 = 2.5 tons (8.8 kW) 036 = 3 tons (10.6 kW) 042 = 3.5 tons (12.3 kW)

048 = 4 tons (14.1 kW)

CAUTION

As with any mechanical equipment, contact with sharp sheet metal edges can result in personal injury. Take care while handling this equipment and wear gloves and protective clothing.

General Information

This indoor unit with all-aluminum coil is designed for

installation with optional eld-installed electric heat and a

matched outdoor unit that is charged with HFC-410A refrigerant. These units, designed for indoor installation in

multiple positions, are completely assembled for upow

and horizontal right-hand discharge before being shipped from the factory.

All CBA38MV air handlers are equipped with a factory-installed, internally mounted check / expansion valve, which is suitable for use in HFC-410A applications.

This air handler is compatible with the ComfortSense® non-communicating thermostat and non-communicating outdoor units. In addition, this unit has the enhanced capability of communicating with the communicating thermostats and communicating outdoor units using the Lennox RSBus protocols.

NOTE - For downow or horizontal left-hand air discharge, certain eld modications are required.

These instructions are intended as a general guide and do not supersede local or national codes in any way. Consult authorities having jurisdiction before installation.

Minor Revision Number

Refrigerant Metering Device

2 = Fixed Orifice 3 = TXV - Bleed port (indoor unit)

4 = TXV - Non-bleed port (indoor unit) 5 = TXV - Non-bleed port (outdoor unit) 6 = TXV - R410A Non-bleed port (indoor unit)

Voltage

230 = 208/230V-60hz-1ph

Check the air handler for shipping damage; if found, immediately contact the last carrier.

Installation Clearances

Cabinet 0 inch (0 mm)

To Plenum 0 inch (0 mm)

To Outlet Duct within 3 feet (914 mm) 0 inch (0 mm)

Floor See Note #1

Service / Maintenance See Note #2

Units installed on combustible oors in the downow position with

electric heat require optional downow additive base.

Front service access – 24 inches (610 mm) minimum.

NOTE - If cabinet depth is more than 24 inches (610 mm), allow a minimum of the cabinet depth plus 2 inches (51 mm).

IMPORTANT

This unit must be matched with an indoor coil as

specied in the Lennox Product Specications (EHB). Coils previously charged with HCFC-22 must be ushed.

WARNING

During blower operation, the ECM motor emits energy that may interfere with pacemaker operation. Interference is reduced by both the sheet metal cabinet and distance.

Shipping and Packing List

Package 1 of 1 contains: 1 – Assembled air handler unit

1 – Pipe nipple (Sch80, 3/4" I.D. x 5")

1 – Downow shields and foam tapes (required for down-

ow conguration only)

1 – Horizontal drip shield (CBA38MV-060 only)

1 – Warranty card

Page 4

WARNING

Improper installation of the air handler can result in personal injury or death.

Do not allow external combustion products or other contaminants to enter the return air system or to be mixed with air that will be supplied to the living space. Use sheet metal screws and joint tape or duct mastic to

seal return air system to air handler. In platform installations, the air handler should be sealed airtight to the return air plenum. A door must never be used as a portion of the return air duct system. The base must provide a stable support and an airtight seal to the air handler. Allow absolutely no sagging, cracks, gaps. etc.

For no reason should return and supply air duct systems ever be connected to or from other heating devices

such as a replace or stove. etc. Fire, explosion, carbon

monoxide poisoning, personal injury and/or property damage could result.

Requirements

In addition to conforming to manufacturer’s installation instructions and local municipal building codes, installation of Lennox air handler units (with or without optional electric heat), shall conform with the following National Fire Protection Association (NFPA) standards:

• NFPA No. 90A - Standard for Installation of Air Conditioning and Ventilation Systems

• NFPA No. 90B - Standard for Installation of Residence Type Warm Air Heating and Air Conditioning Systems

This unit is approved for installation clearance to combustible material as stated on the unit rating plate. Accessibility and service clearances must take precedence over combustible material clearances.

4 - Replace access panel.

UPFLOW APPLICATION

Use the following procedures to congure the unit for upow operations:

1 - Remove access panels.

2 - Remove and discard the horizontal drip shield (-060

model, used only on horizontal applications) and the corrugated padding between the blower and coil assembly.

3 - The horizontal drain pan must be removed when

the coil blower is installed in the upow position.

Removing the horizontal drain pain will allow proper

air ow and increased e󰀩ciency.

4 - After removing the horizontal drain pan, place the

unit in the desired location. Set unit so that it is level. Connect return and supply air plenums as required

using sheet metal screws as illustrated in gure 1.

5 - Install units that have no return air plenum on a

stand that is at least 14" from the oor to allow for proper air return. Lennox o󰀨ers an optional upow

unit stand as listed in table 1.

HORIZONTAL DRAIN PAN (MUST BE REMOVED)

UP-FLOW / DOWN-FLOW DRAIN PAN

Installing the Unit

These units are factory-congured for upow and horizontal right-hand discharge installation. For downow or horizontal left-hand discharge, certain eld modications

are required.

DISASSEMBLE/REASSEMBLE AIR HANDLER UNITS

The air handler units consists of two factory-assembled sections. It may be necessary to disassemble the sections when positioning the unit for installation.

To disassemble:

1 - Remove access panels.

2 - Remove both blower and coil assemblies. This will

lighten the cabinet for lifting.

3 - Remove one screw from the left and right posts

inside the unit. Remove one screw from each side on the back of the unit. Unit sections will now separate.

To reassemble:

1 - Align cabinet sections together.

2 - Reinstall screws.

3 - Replace blower and coil assemblies.

FIGURE 1. Upow Conguration

TABLE 1. Optional Side-Return Unit Stand

(Upow Only)

Model Kit Number

All unit sizes

45K32

HORIZONTAL RIGHT-HAND DISCHARGE APPLICATION

Use the following procedures to congure the unit for horizontal right-hand discharge operations:

NOTE – For horizontal applications, a secondary drain pan is recommended. Refer to local codes.

NOTE – When air handler is located above a nished space, the secondary drain pan must have a larger footprint than the air handler. In addition, a 3/4" (19.1mm) overow drain line must be:

• Connected to secondary drain pan

• Connected to the overow drain outlet of the air handler drain pan.

Page 5

NOTE - (-060 Model Only) Before operating the unit, re-

UP-FLOW / DOWN-FLOW DRAIN

HORIZONT PA

FRONT VIEW END VIEW

move access panels and the horizontal drip shield and the corrugated padding between the blower and coil assembly. Discard the corrugated padding and the downow drip shields.

NOTE - (-060 Model Only) Install the horizontal shield on the front edge of the horizontal drain pan as illustrated in gure 2.

1 - No further adjustment is necessary. Set unit so that it

is sloped 1/4" towards the drain pan end of the unit.

2 - If the unit is suspended, the entire length of the

cabinet must be supported. If you use a chain or strap, use a piece of angle iron or sheet metal attached to the unit (either above or below) to support the length of the cabinet. Use securing screws no longer than 1/2" to avoid damaging the

coil or lter as illustrated in gure 3. Use sheet

metal screws to connect the return and supply air plenums as required.

HORIZONTAL DRIP SHIELD (-060 MODELS)

PAN

2 - Remove the downow rail then replace screws.

3 - Seal around the exiting drain pipe, liquid line, and

suction line to prevent humid air from inltrating into

the unit.

1/2" SCREWS MAXIMUM

ANGLE IRON OR

SHEET METAL

ELECTRICAL INLET CLEARANCE 4" (102 mm)

FIGURE 3. Suspending Horizontal Unit

IMPORTANT

When removing the coil, there is possible danger of equipment damage and personal injury. Be careful when removing the coil assembly from a unit installed in rightor left-hand applications. The coil may tip into the drain pan once it is clear of the cabinet. Support the coil when removing it.

FIGURE 2. Right-Hand Discharge Conguration

HORIZONTAL RIGHT-HAND DISCHARGE APPLICATION IN HIGH-HUMIDITY AREAS

For horizontal applications in high humidity areas, remove

the downow rail closest to the drain pan.

To remove rail:

1 - Remove the screws from the rail at the back of unit

and at the cabinet support rail.

AL DRAIN

NO ADJUSTMENT IS NECESSARY

DOWN-FLOW RAIL

HORIZONTAL LEFT-HAND DISCHARGE APPLICATION

NOTE – For horizontal applications, a secondary drain pan is recommended. Refer to local codes.

NOTE - (-060 Model Only) Before operating the unit, re- move access panels and the horizontal drip shield and the corrugated padding between the blower and coil assembly. Discard the corrugated padding and the downow drip shields. (The shields are used for downow applications only.)

Page 6

HORIZONTAL DRIP SHIELD (-060 MODEL)

DRAIN PAN

CABINET

SUPPORT

DRAIN PAN

REINSTALLED

HERE

TOP CAP ROTATED TO

CORRECT POSITION

90º

BEND

TOP CAP SCREWS

3/16” PLASTIC PLUG (REAR COIL END SEAL)

HORIZONTA L DRIP SHIELD SCREW (FRONT COIL END SEAL)

DRAIN PAN SHIPPING LOCATION

INSTALL DRAIN PAN

BETWEEN TA B AND

EXTERIOR INNER WALL.

DETAIL C

REINSTALLED HERE REMOVED FROM HERE

———— DRAIN PLUGS ————

FRONT VIEW

COIL SHOWN IN UPFLOW POSITION FOR EASY

CONVERSION (LEFT-HAND AIR DISCHARGE )

DETAIL A

FIGURE 4. Field Modication for Left-Hand Discharge

Use the following procedures to congure the unit for horizontal left-hand discharge operations:

1 - Pull the coil assembly from unit. Pull o󰀨 the horizontal

drain pan.

2 - Remove the drain plugs from back drain holes on

horizontal drain pan and reinstall them on front holes.

IMPORTANT

After removal of drain pan plug(s), check drain hole(s) to verify that drain opening is fully open and free of any debris. Also check to make sure that no debris has fallen into the drain pan during installation that may plug up the drain opening.

3 - Rotate drain pan 180º front-to-back and install it on

the opposite side of the coil.

4 - Remove screws from top cap. Remove horizontal

drip shield screw located in the center of the back

coil end seal as illustrated in gure 4 on page 5.

5 - Rotate horizontal drip shield 180º front-to-back.

6 - Remove plastic plug from left hole on coil front

end seal and reinstall plug in back hole. Reinstall horizontal drip shield screw in front coil end seal. Drip shield should drain downward into horizontal drain pan inside coil.

NOTE – Be very careful when reinstalling the screws into the coil end plate engaging holes. Misaligned screws may damage the coil.

7 - From the upow position, ip cabinet 90º to the

left and set into place. Replace blower assembly. Secure coil in place by bending down the tab on the

cabinet support rail as illustrated in gures 4 and 5.

TOP CAP

DETAIL B

BEND

90º

DOWN-FLOW RAIL FRONT EDGE OF HORIZONTAL

ALIGN HOLES WITH HOLES IN COIL END PLATE. STARTING WITH THE ROUND HOLES ON THIS END.

BACK COIL END SEAL

FIGURE 5. Left-Hand Discharge Conguration

8 - Install the horizontal shield (-060 model) on the

front edge of the horizontal drain pan as illustrated

in gure 5.

NOTE – For horizontal applications in high humidity ar- eas, remove the downow rail closest to the drain pan. To remove rail, remove screw from rail at back of unit and at cabinet support rail. Remove downow rail then replace screws. Also, seal around the exiting drain pipe, liquid and suction lines to prevent inltration of humid air.

9 - Knock out drain seal plate from access door. Secure

plate to cabinet front ange with screw provided.

10 - Flip access door and replace it on the unit.

11 - Set unit so that it is sloped 1/4ʺ toward the drain

pan end of the unit. Connect return and supply air plenums as required using sheet metal screws.

Page 7

DOWNFLO

1” WIDE FOAM TAPE (LONGER PIECE)

12 - If suspending the unit, it must be supported along the

entire length of the cabinet. If using chain or strap, use a piece of angle iron or sheet metal attached to the unit (either above or below) so that the full length of the cabinet is supported. Use securing

screws no longer than 1/2ʺ to avoid damage to coil or lter, as illustrated in gure 3 on page 6. Connect

return and supply air plenums as required using sheet metal screws.

DOWNFLOW APPLICATION

Use the following procedures to congure the unit for downow operations:

IMPORTANT

If electric heat section with circuit breakers (ECB29/

ECB31) is installed in a CBA38MV unit in a downow

application, the circuit breakers must be rotated 180° to the UP position. See ECB29/ECB31 installation instructions for more details.

HORIZONTA L DRAIN P

(REMOVE FROM UNIT)

UP-LOAD /

DRAIN PAN

FIGURE 6. Downow Discharge Position

Table 2 outlines the sizes of the various drip shields.

NOTE - (-060 Model Only) Remove access panels and horizontal drip shield from the corrugated padding between the blower and coil assembly.

1 - Remove the coil assembly from the unit.

2 - For best e󰀩ciency and air ow, remove the

horizontal drain pan from the units in downow positions as illustrated in gure 6.

3 - Rotate cabinet 180º from the upright position. See

gure 6. You may need to rst remove the blower

assembly to lighten the cabinet for lifting.

4 - Foam tape that is provided creates a seal between

the drip shield and the coil so that water does not leak into the air stream. The foam tape pieces are precut. Apply the tape to the drip shields as

illustrated in gure 7 and specied as follows:

• Apply two pieces of foam tape provided down both ends of each shield. The tape should measure

4-3/4ʺ X 2ʺ (120 X 25 mm). Ensure that the tape

covers both sides of the shield equally.

• Apply the longer piece of 1 inch wide foam tape between the end pieces of tape.

5 - From the underside of the coil, install the downow

drip shield rmly in place as illustrated in gure 8.

TABLE 2. Downow Drip Shields (Tape Required)

Units Length Width

-018/024 Not Required Not Required

-030 15-7/8ʺ 4-11/16ʺ

-036, -042 17-7/8ʺ 4-11/16ʺ

-048, -060 19-7/8ʺ 4-11/16ʺ

DRIP SHIELD

SIDE

VIEW

2” WIDE FOAM TAPE

FIGURE 7. Applying Foam Tape to Drip Shield

COIL

DRIP SHIELD

DRIP PAN

FIGURE 8. Downow Drip Shields

6 - Replace the coil assembly and blower if you have

removed it. Replace the coil access panel.

7 - Set the unit so that it is level. Using sheet metal

screws, connect the return and supply air plenums as required.

NOTE - For downow application, metal or Class I supply and return air plenums must be used.

Page 8

AIR

HANDER

UNIT

COMBUSTIBLE FLOOR

PROPERLY SIZED

FLOOR OPENING

ADDITIVE BASE

FIGURE 9. Downow Combustible Flooring Base

8 - For downow installation on combustible ooring,

an additive base must be used as illustrated in gure 9 on page 9. See CBA38MV Product Specications (EHB) for downow combustible ooring base kits

available for this air handler.

9 - Cut an opening appropriately sized for combustible

base. Base dimensions are illustrated in gure 10.

After opening has been cut, set the additive base into opening. Connect outlet air plenum to the additive base. Set the unit on the additive base so

anges of the unit drop into the base opening and

seal against the insulation strips. The unit is now locked in place. Install return air plenum and secure with sheet metal screws.

Brazing Connections

WARNING

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

WARNING

Danger of re. Bleeding the refrigerant

charge from only the high side may result in pressurization of the low side shell and suction tubing. Application of a brazing torch to a pressurized system may result in ignition of the refrigerant and oil mixture. Check the high and low pressures before applying heat.

WARNING

Danger of explosion! Can cause equipment damage, injury, or

death. When using a high pressure gas such as

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

1‐5/8 (41)

20 (508)

1‐5/8 (41)

5/8 (16)

TOP VIEW

11‐3/8

(289)

SUPPLY AIR OPENING

22‐5/8 (575) -018/024

24‐5/8 (625) -030, 036

26‐5/8 (676) -042, 048, 060

13‐1/2 (343)

OPENING

SIDE VIEW

23-1/4 (591)

INCHES (MM)

3 (76)

FIGURE 10. Downow Combustible Base Dimensions

CAUTION

Brazing alloys and ux contain materials which are

hazardous to your health. Avoid breathing vapors or fumes from brazing operations.

Perform operations only in well ventilated areas. Wear gloves and protective goggles or face shield to

protect against burns. Wash hands with soap and water after handling brazing

alloys and ux.

IMPORTANT

To prevent the build-up of high levels of nitrogen when purging, it must be done in a well-ventilated area. Purge low-pressure nitrogen (1 to 2 psig) through the refrigerant piping during brazing. This will help to prevent oxidation and the introduction of moisture into the system.

Page 9

LINE.

PLEASE READ IMPORTANT ISSUES CONCERNING BRAZING

NOTE — REFER TO OUTDOOR UNIT INSTALLATION INSTRUCTIONS FOR REFRIGERANT PIPING SIZE REQUIREMENTS .

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

REMOVE ACCESS PANEL

REMOVE RUBBER PLUG FROM BOTH LIQUID

AND SUCTION LINES

NOTE — CBA38MV SERIES UNITS USE NITROGEN OR DRY AIR AS A HOLDING CHARGE. IF THERE IS NO PRESSURE WHEN THE RUBBER PLUGS ARE REMOVED, CHECK THE COIL FOR LEAKS BEFORE INSTALLING.

EITHER REMOVE OR PUSH PIPE WRAPPING BACK

THROUGH HOLE IN PIPING PLATE BEFORE LINE SET CONNECTION AND BRAZING.

OPERATIONS ON PAGE 10 BEFORE PROCEEDING.

USE A WET RAG TO PROTECT CTXV

SENSING BULB WHEN BRAZING SUCTION LINE CONNECTIONS.

LOW

HIGH

PIPING PLATE

CONNECT PIPES

NOTE — REFRIGERANT LINE SETS SHOULD BE ROUTED TO ALLOW FILTER ACCESSIBILITY.

REPEAT PREVIOUS PROCEDURE FOR LIQUID

FLOW REGULATED NITROGEN (AT 1 TO 2 PSIG)

THROUGH THE REFRIGERATION GAUGE SET INTO THE VALV E STEM PORT CONNECTION ON THE OUTDOOR UNIT LIQUID LINE SER VICE VALVE AND OUT OF THE VALV E STEM PORT CONNECTION ON THE SUCTION SERVICE VALVE.

PLACE A WET RAG AGAINST PIPING

PLATE AND AROUND THE SUCTION LINE CONNECTION. A

BRAZE CONNECTION. ALLOW PIPE TO

COOL BEFORE REMOVING WET RAG FROM CTXV SENSING BULB AND PIPING PANEL AREA.

FIGURE 11. Brazing Connections

CONNECT GAUGES AND

START NITROGEN FLOW

REFER TO INSTRUCTIONS PROVIDED WITH OUTDOOR UNIT FOR LEAK TESTING, EVACUATING AND CHARGING PROCEDURES

NITROGEN

Page 10

TABLE 3. CBA38MV Refrigerant Connections and

LEFT-HAND AIR

UP-FLOW OR

RIGHT-HAND AIR

Line Set Requirements

Model

-018/ 024

-030

-036

-042

-048

-060

NOTE - Some applications may require a eld-provided 7/8ʺ to 1-1/8ʺ adapter.

Liquid

Line

3/8ʺ

(10mm)

3/8ʺ

(10mm)

3/8ʺ

(10mm)

3/8ʺ

(10mm)

Vapor

Line

3/4ʺ

(19mm)

3/4ʺ

(19mm)

7/8"

(22mm)

7/8"

(22mm)

L15 Line Sets

L15 line set sizes are dependant on unit match-up. See Product

Specications (EHB) for

outdoor unit to determine correct line set sizes

Field fabricated

NOTE - When installing refrigerant lines longer than 50 feet, see the Lennox Refrigerant Piping Design and Fabrication Guidelines, CORP. 9351-L9, or contact Lennox Technical Support Product Applications for assistance.

Installing the Condensate Drain

IMPORTANT

MAIN DRAIN

Connect the main drain and route downward to drain line or sump. Do not connect drain to a closed waste system.

See Figure 13 for typical drain trap conguration.

OVERFLOW DRAIN

It is recommended that the overow drain is connected to an overow drain line for all units. If overow drain is not

connected, it must be plugged with provided cap.

For downow orientation, the overow drain MUST be connected and routed to a overow drain line. See Figure 12 for main and overow drain locations based on coil

orientation.

DISCHARGE

OVERFLOW

DRAIN ON LEFT

DOWN-FLOW

DISCHARGE

MAIN DRAIN ON

RIGHT

FIGURE 12. Main and Overow Drain Locations

Based on Coil Orientation

BEST PRACTICES

The following best practices are recommended for the condensate removal process:

• Main and overow drain lines should NOT be smaller than both drain connections at drain pan.

• Overow drain line should run to an area where home- owner will notice drainage.

• It is recommended that the overow drain line be vented and a trap installed. Refer to local codes.

• Condensate drain lines must be congured or provided with a cleanout to permit the clearing of blockages and for maintenance without requiring the drain line to be cut.

Page 11

ABOVE

PIPE NIPPLE PROVIDED IN BAG ASSEMBLY - SCH 80, 3/4” I. D. X 5” - 34K7401 (1): CUT THE PIPE IN HALF AND USE IT TO ROUTE THE MA IN DRAIN.

FINISHED

SPACE?

OVERFLOW DRAIN LINE

ALWAYS RUN AN OVERFLOW DRAIN LINE. IF NOT POSSIBLE TO ROUTE OVERFLOW DRAIN LINE, INSTA LL LOW VOLTAGE OVERFLOW SWITCH KIT. WIRE KIT TO SHUT DOWN COMPRESSOR PER INSTRUCTIONS.

LENNOX #

X3169

COMPACT OVERFLOW SWITCH WITH 3/4” FEMALE SLIP INLET

AND MALE ADAPTER, TWO PA RT DESIGN FOR USE WHERE OBSTRUCTIONS PREVENT DIRECT THREADING

CLEAN OUT

PRESS IN

(DO NOT GLUE)

VENT MUST EXTEND

ABOVE HEIGHT OF

COIL DRAIN PAN BY

TWO INCHES (51MM)

VENT

MAIN

DRAIN

PIPE NIPPLE

AIR HANDLER DRAIN PA N

OVERFLOW

DRAIN

YES

NOTE — WHEN A AIR HANDLER IS LOCATED

ABOVE A FINISHED SPACE THE SECONDARY DRAIN PA N MUST HAVE A LARGER FOOTPRINT THAN THE AIR HANDLER.

DRAIN

SECONDARY

DRAIN PAN

WHEN A COIL IS LOCATED ABOVE A FINISHED SPACE, A 3/4” (19.1MM) SECONDARY DRAIN LINE MUST BE:

CONNECTED TO SECONDARY DRAIN PAN

CONNECTED TO THE OVERFLOW DRAIN OUTLET OF THE AIR HANDLER DRAIN PAN.

TRAPS MUST BE DEEP ENOUGH TO OFFSET MAXIMUM STATIC DIFFERENCES — GENERALLY, TWO INCHES (51MM).

LENNOX P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90.

FIGURE 13. Typical Main and Overow Drain Installations

CUT TO

REQUIRED

LENGTH

PROVIDED

SIDE VIEW

1” X 3/4” X 3/4”

REDUCING

TEE WITH

PLUG

P-TRAP

LENNOX

49P66, J-TRAP #

91P90 OR ANY

PVC SCH 40 P- OR

J-TRAP 3/4”

FOR NEGATIVE PRESSURE COILS (BLOWER AFTER COIL) TRAPS ARE REQUIRED ON ALL DRAIN LINES CONNECTED TO COIL.

2”

(51MM)

TRAP DEPTH

TO APPROVED

DRAIN

DRAIN LINE SHOULD SLOPE A MINIMUM OF ONE INCH PER 10 FEET (25MM PER 3 METERS)

Inspecting and Replacing Filters

IMPORTANT

Filter access door must be in place during unit operation. Excessive warm air entering the unit from unconditioned

space may result in water blow-o󰀨 problems.

Filters may be duct-mounted or installed in the cabinet. A

lter is installed at the factory. Note that lter access door ts over access panel. Air will leak if the access panel is placed over the lter door.

Filters should be inspected monthly and must be cleaned or replaced when dirty to assure proper furnace operation.

To replace lter:

1 - Loosen the thumbscrews holding the lter panel in

place.

2 - Slide the lter out of the guides on either side of

cabinet.

3 - Insert new lter.

4 - Replace panel.

See table 4 for replacement lter sizes.

TABLE 4. Filter Dimensions

CBA38MV Filter Size – In. (mm)

-018/024, -030, -036 20 x 20 x 1 (508 x 508 x 25)

-042, -048, -060 20 x 24 x 1 (508 x 610 x 25)

Sealing the Unit

WARNING

There must be an airtight seal between the bottom of

the air handler and the return air plenum. Use berglass

sealing strips, caulking, or equivalent sealing method between the plenum and the air handler cabinet to ensure a tight seal. Return air must not be drawn from a room where this air handler or any gas-fueled appliance (i.e., water heater), or carbon monoxide-producing

device (i.e., wood replace) is installed.

Seal the unit so that warm air is not allowed into the cabinet. Warm air introduces moisture, which results in water

blow-o󰀨 problems. This is especially important when the

unit is installed in an unconditioned area.

Page 12

Make sure the liquid line and suction line entry points are

sealed with either the provided exible elastomeric thermal insulation, or eld provided material (e.g. Armaex,

Permagum or equivalent). Any of the previously mentioned materials may be used to seal around the main and auxiliary drains, and around open areas of electrical inlets.

Field Control Wiring

WARNING

Electric Shock Hazard. Can cause injury or death. Foil-faced insulation has conductive characteristics

similar to metal. Be sure there are no electrical

connections within a ½ʺ of the insulation. If the foil-faced

insulation comes in contact with electrical voltage, the foil could provide a path for current to pass through to the outer metal cabinet. While the current produced may not be enough to trip existing electrical safety devices (e.g. fuses or circuit breakers), the current can be enough to cause an electric shock hazard that could cause personal injury or death.

Wiring must conform to the current National Electric Code ANSI/NFPA No. 70, or Canadian Electric Code Part I, CSA Standard C22.1, and local building codes. Refer to following wiring diagrams. See unit nameplate for minimum circuit ampacity and maximum over-current protection size.

WARNING

Run 24V Class II wiring only through specied low

voltage opening. Run line voltage wiring only through

specied high voltage opening. Do not combine voltage

in one opening

Select the proper supply circuit conductors in accordance with tables 310-16 and 310-17 in the National Electric Code, ANSI/NFPA No. 70 or tables 1 through 4 in the Canadian Electric Code, Part I, CSA Standard C22.1.

Separate openings have been provided for 24V low voltage and line voltage. Refer to the dimension illustration of

specic location.

CAUTION

USE COPPER CONDUCTORS ONLY.

WIRING CONNECTIONS

1 - Install line voltage power supply to unit from a

properly installed circuit breaker.

2 - Ground unit at unit disconnect switch or to an earth

ground.

NOTE – Connect conduit to the unit using a proper conduit tting. Units are approved for use only with copper conductors. A complete unit wiring diagram is located on the back side of the unit’s access panel.

3 - Install low voltage wiring from outdoor to indoor unit

and from thermostat to indoor unit.

NOTE – For proper voltages, select thermostat wire gauge per the following chart:

ELECTROSTATIC

DISCHARGE

(ESD)

Precautions and

Procedures

CAUTION

Electrostatic discharge can a󰀨ect

electronic components. Take care during unit installation and service to protect the unit’s electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the unit, the control and the technician at the same electrostatic potential. Touch hand and all tools on an unpainted unit surface before performing any service procedure to neutralize electrostatic charge.

Page 13

Cut Size: 7" wide x 10" tall

FIGURE 14. CBA38MV Air Handler Unit Typical Wiring Diagram

Page 14

DETAIL A

NOTE - Due to varying duct designs and air flow conditions, relocation of the discharge sensor may be required to insure accurate sensing.

ELECTRIC HEAT RELAY

PART NO. 49W91

19 IN.

(483 MM)

SENSOR

(CENTER SIDE-T0 -SIDE)

5-1/2 IN.

(140 MM)

THE AIR HANDLER CONTROL (AHC) HAS TWO SCREW TERMINALS MARKED DISCHARGE AIR SENSOR. THE SENSOR IS REQUIRED FOR EVENHEAT OPERATION, IS FIELD-MOUNTED AND MUST BE ORDERED SEPARATELY (CATALOG # 88K38).

DISCHARGE SENSOR

(DAT)

TEMPERATURE RESISTANCE

CHART

TEMPRESISTANCE ºF (OHMS) 30 34,566 40 26,106 50 19,904 60 15,313 70 11,884 80 9,298 90 7,332 100 5,826

22V DIRECT CURRENT COIL

30 AMP CONTACT RATING

DETAIL B

9-PIN CONNECTOR

9-PIN

CONNECTOR

AIR HANDLER CONTROL

SECURING SCREWS

AIR HANDLER CONTROL L-BRACKET MOUNTING PLATE

CBA38MV AIR HANDLER CONTROL

PART NO. 16X40

FASTEN THE PROBE

BRACKET TO THE

PLENUM WITH TWO

SELF-TAPPING SHEET

METAL SCREWS.

PLENUM

NOTE — EVENHEAT MODE CANNOT BE ENABLED WITH HARMONY III DISCHARGE AIR SENSOR.

DUE TO EACH CONTROL REQUIRING ITS OWN

FIGURE 15. Component Connections

Page 15

CONNECT WIRES TO DISCHARGE AIR SENSOR

TERMINAL ON AIR HANDLER CONTROL.

AIR CONDITIONER UNIT (TWO-STAGE)

OPTIONAL N.C. CONDENSATE FLOAT SWITCH

RED

YELLOW

BLUE

BLACK

CBA38MV

COMFORTSENSE

7500

AIR HANDLER CONTROL COMES FROM FACTORY WITH A METAL JUMPER BETWEEN W1 TO W2 AND W2 TO W3. SEE

FIGURE 21 FOR HEAT SECTION CONFIGURATION.

WHEN A CONVENTIONAL 24V NON-COMMUNICATING THERMOSTAT IS USED WITH THE CBA38 AIR HANDLER, THE FLOAT SWITCH MUST

BE WIRED TO BREAK "Y1 COMPRESSOR DEMAND" WIRE TO THE OUTDOOR UNIT. A FLOAT SWITCH CONNECTED TO "FLOAT SW" TERMINALS WILL NOT SHUT OFF THE COOLING WHEN A 24V NON-COMMUNICATING THERMOSTAT IS USED

DO NOT CONNECT A CONDENSATE FLOAT SWITCH TO THE "FLOAT SW"

TERMINAL WHEN A NON-COMMUNICATING THERMOSTAT IS USED

IMPORTANT – WHEN A CONVENTIONAL 24V NON-COMMUNICATING THERMOSTAT IS USED WITH THE CBA38 AIR HANDLER, THE FLOAT SWITCH MUST BE WIRED TO BREAK "Y1 COMPRESSOR DEMAND" WIRE TO THE OUTDOOR UNIT. A FLOAT SWITCH CONNECTED TO "FLOAT SW" TERMINALS WILL NOT SHUT OFF THE COOLING WHEN A 24V NON-COMMUNICATING THERMOSTAT IS USED.

IMPORTANT – USE CARE WHEN CUTTING OPTION JUMPERS. SEE JUMPER AND LINK GUIDE FOR FURTHER DETAILS.

CUT ON-BOARD JUMPER R-DS WHEN DEHUMIDIFICATION TERMINAL IS USED.

CUT ON-BOARD JUMPER Y1-Y2 FOR TWO-STAGE AC

DO NOT CUT ON-BOARD JUMPER R -O.

AIR HANDLER

CONTROL

Y1-Y2

2-STAGE

COMPR

R-O HEAT PUMP

R-DS

DEHUM

HARMONY

CUT FOR OPTION

HEAT PUMP

UNIT

(TWO-STAGE)

OUT

FIGURE 16. Control (Field Wiring) – Cooling Application (Non-Communicating)

OPTIONAL N.C. CONDENSATE FLOAT SWITCH

FLOAT SW

CBA38MV

W1 W1

COMFORTSENSE

FLOAT SW

7500

Y2Y2

X2658 OUTDOOR SENSOR IS REQUIRED FOR OUTDOOR TEMPERATURE DISPLAY, DEW POINT CONTROL, HEAT

PUMP AND DUAL FUEL BALANCE POINTS.

WHEN A CONVENTIONAL 24V NON-COMMUNICATING

THERMOSTAT IS USED WITH THE CBA38 AIR HANDLER, THE FLOAT SWITCH MUST BE WIRED TO BREAK "Y1 COMPRESSOR DEMAND" WIRE TO THE OUTDOOR UNIT. A FLOAT SWITCH CONNECTED TO "FLOAT SW" TERMINALS WILL NOT SHUT OFF THE COOLING WHEN A 24V NON-COMMUNICATING THERMOSTAT IS USED.

DO NOT CONNECT A CONDENSATE FLOAT SWITCH TO THE

O. D.

SENSOR

(X2658)

"FLOAT SW" TERMINAL WHEN A NON-COMMUNICATING THERMOSTAT IS USED.

FIELD PROVIDED JUMPER BETWEEN Y2 OUT BL ON

HEAT PUMP TO Y2 ON CBA38MV.

IMPORTANT – USE CARE WHEN CUTTING OPTION JUMPERS. SEE JUMPER AND LINK GUIDE FOR FURTHER DETAILS.

CUT ON-BOARD JUMPER R-DS WHEN DEHUMIDIFICATION TERMINAL IS USED.

CUT ON-BOARD JUMPER Y1-Y2 FOR TWO-STAGE HP

CUT ON-BOARD JUMPER R -O.

Y1-Y2

2-STAGE

COMPR

R-O

HEAT

PUMP

R-DS

DEHUM

HARMONY

CUT FOR OPTION

FIGURE 17. Control (Field Wiring) – Heat Pump (Non-Communicating)

Page 16

N.C. CONDENSATE

FLOAT SWITCH

OPTIONAL DISCHARGE AIR

SENSOR (SEE DAS NOTE ON

PAGE 7)

FLOAT SW

REMOVE FACTORY-INSTALLED

JUMPER ON FLOAT SWITCH TERMINALS WHEN INSTALLING A FLOAT SWITCH

SOR (SEE OAS NOTE ON PAGE

COM

A B

BUS

B A

COM

- +

12VDC

S30 MAG

MOUNT

S30 SMART HUB

+ -

12VDC

iComfort

AIR

HANDLER (AHC)

OUTDOOR UNIT

(AC OR HP)

IComfort

ALL CONNECTIONS ON THE RSBUS ARE LIMITED TO 1500FT. WIRE GAUGE OF RSBUS WIRE IS 18.

FIGURE 18. iComfort® Communicating System Wiring

N.C. CONDENSATE FLOAT SWITCH

OPTIONAL DISCHARGE AIR SENSOR

(SEE DAS NOTE ON PAGE 7)

FLOAT SW

REMOVE FACTORY-INSTALLED

JUMPER ON FLOAT SWITCH TERMINALS WHEN INSTALLING A FLOAT SWITCH

OPTIONAL OUTDOOR AIR SENSOR (SEE OAS NOTE ON PAGE 7)

SETUP NOTES:

CUT Y1-Y2 ON-BOARD JUMPER FOR 2-STAGE OUT-

MUNICATING)

COM

A B

BUS

B A

COM

- +

12VDC

S30 MAG

MOUNT

LL CONNECTIONS ON THE RSBUS IS LIMITED TO 1500FT. WIRE GAUGE OF RSBUS WIRE IS 18.

S30 SMART

HUB

+ -

12VDC

iComfort

DLER (AHC)

CUT R-O ON-BOARD JUMPER FOR OUTDOOR HEAT

MUNICATING)

24VAC

HEAT PUMP UNIT

- 1 OR 2 STAGE

FIGURE 19. iComfort® Communicating Indoor / Non-Communicating Outdoor (HP) System Wiring

Page 17

Components

FIRST,

CUT YELLOW WIRE HERE.

FAN

SECOND,

Blue

Yellow

Black

REWIRE YELLOW WIRE AS SHOWN

Yellow

Use Wire nuts

*OUTDOOR RELAY — NOT REQUIRED WITH SINGLE‐SPEED OUTDOOR FAN

Purple

Yellow

Purple

Unit Type

Thermostat ComfortSense® 7000 or 7500

Indoor Conventional 24V

Outdoor Conventional 24V

XP19-024 UNITS COME FACTORY WIRED FOR LOW OUTDOOR FAN SPEED ONLY. HIGH SPEED Y2 (BLUE WIRE) IS NOT CONNECTED. BE SURE TO CONNECT BLUE Y2 WIRE TO TERMINAL OF OUTDOOR RELAY.

Y1—Y2 JUMPER - ONLY REMOVE IF

Black

OUTDOOR

SENSOR

(X2658)

2-STAGE COOLING

DS—Y1 JUMPER - MUST BE REMOVED FOR HUMIDITROL OPERATION

HEAT PUMP APPLICATIONS ONLY REMOVE R—O JUMPER.

EDA RELAY

7500 Thermostat

OUTDOOR UNIT DEFROST BOARD (HP)

WIRE

YELLOW

BROWN RED

BLUE

BLACK

NUTS

INDOOR UNIT 24 VOLT TERMINAL STRIP

ComfortSense 7000 or

1N4005 DIODE (shrink wrapped -

diode is concealed in the wire.)

OUTDOOR UNIT CONTROL WIRES (AC)

EDA RELAY

NUMBER OF WIRES REQUIRED—Indoor unit to: Thermostat to:

System type Humiditrol® EDA Comfort Sense 7000 or 7500

Thermostats

1 stage AC

2 stage AC 8* 4

1 stage HP 8* 5

7* 3

2 stage HP 9* 6

*Includes conductor for 2-stage heat

Outdoor Unit Outdoor Air Sensor

EARLIER MODEL VALVE ACTUATOR

BLACK

GREY

RED

LATER MODEL VALVE ACTUATOR

RED

ORANGE

VIOLET

EDA VALVE ACTUATOR

EDA VALV E ACTUATOR

FIGURE 20. Field Wiring (Non-Communicating Systems)

Page 18

Components

Operation sequence for dehumidification

1. REMOVE 24 VOLTS FROM DH AND/OR DS

2. THERMOSTAT CYCLES OUTDOOR UNITS TO Y2

3. INDOOR AND OUTDOOR FAN SPEEDS REDUCED

Unit Type

Thermostat ComfortSense® 7000 or 7500

Indoor Conventional 24V

Outdoor iComfort®-enabled

DS—R (W1) JUMPER - MUST BE CUT FOR HUMIDITROL OPERATION. SEE W1 JUMPER DETAIL.

OUTDOOR UNITS (A175)

SEE TRACE CUT DETAIL.

SEE W1 JUMPER DETAIL.

INDOOR UNIT 24 VOLT TERMINAL STRIP

RED

ORANGE

EDA RELAY

VIOLET

EDA VA LVE ACTUATOR

OUTDOOR

SENSOR

(X2658)

ComfortSense 7000 or

EARLIER MODEL VALVE ACTUATOR

7500 Thermostat

EDA RELAY

Clip W1 Jumper for

Humiditrol (EDA)

DS—R TRACE ON A175 - MUST BE CUT FOR HUMIDITROL OPERATION. SEE TRACE CUT DETAIL.

Trace intact

DS TO R ON A92 - ON-BOARD LINK MUST BE CUT FOR DEHUMIDIFICATION.

DS—Y1 JUMPER - MUST BE REMOVED FOR HUMIDITROL OPERATION

HEAT PUMP APPLICATIONS ONLY - REMOVE R—O JUMPER.

(2-STAGE ONLY ) FOR HUMIDITROL OPERATION (EDA), CONNECT FIELD PROVIDED WIRE FROM DS ON A92 TO DS ON A175.

application

Trace cut for

Humiditrol (EDA)

application

BLACK

GREY

RED

LATER MODEL VALVE ACTUATOR

EDA VALV E ACTUATOR

1N4005 DIODE (shrink wrapped -

diode is concealed in the wire.)

NUMBER OF WIRES REQUIRED—Indoor unit to: Thermostat to:

System Type Humiditrol

EDA

ComfortSense® 7000 or

Outdoor Unit Outdoor Air Sensor

7500 Thermostats

1-stage AC

7 4

2-stage AC 8 5

1-stage HP 9 6

2-stage HP 10 7)

FIGURE 21. 24V Field Wiring (Non-Communicating Systems)

Page 19

Components

Operation sequence for dehumidification

1. REMOVE 24 VOLTS FROM DH AND/OR DS

2. THERMOSTAT CYCLES OUTDOOR UNITS TO Y2

3. INDOOR AND OUTDOOR FAN SPEEDS REDUCED

CHARGE

DOOR

Unit Type

Thermostat

ComfortSense

Indoor iComfort®-enabled

Outdoor iComfort®-enabled

7000 or 7500

DS—R (W1) JUMPER - MUST BE CUT FOR HUMIDITROL OPERATION. SEE W1 JUMPER DETAIL.

OUTDOOR UNITS (A175)

SEE W1 JUMPER DETAIL.

SEE TRACE CUT DETAIL.

Air Sensors

(optional)

OUTDOOR

iComfort by Lennox

FURNACE (IFC) OR

AIR HANDLER (AHC)

SENSOR

(X2658)

DS—R TRACE - MUST BE CUT FOR HUMIDITROL OPERATION. SEE TRACE CUT DETAIL

7500

Thermostat

1N4005 DIODE (shrink wrapped -

ComfortSense 7000 or

diode is concealed in the wire.)

Clip W1 Jumper for

Humiditrol (EDA)

application

Trace intact

BLACK

GREY

RED

Trace cut for

Humiditrol (EDA)

application

EDA VALV E ACTUATOR

LATER MODEL VALVE ACTUATOR

EDA RELAY

RED

VIOLET

ORANGE

EDA VA LVE ACTUATOR

EDA RELAY

EARLIER MODEL VALVE ACTUATOR

NUMBER OF WIRES REQUIRED—Indoor unit to: Air Sensors (Optional)

ComfortSense

System Type Humiditrol

EDA

7000 or 7500 Thermostats

1-stage AC

2-stage AC 10 5

1-stage HP 8 6

2-stage HP 10 7

Outdoor unit Outdoor Discharge

8 4

2 2

FIGURE 22. Field Wiring (Non-Communicating Systems)

Page 20

Components

OUTDOOR UNITS (A175)

iComfort by Lennox FURNACE (IFC) OR AIR HANDLER (AHC)

Air Sensors

(optional)

CHARGE

DOOR

iComfort

THERMOSTAT (or

S30 Smart Hub)

Unit Type

Thermostat iComfort

Indoor iComfort®-enabled

Outdoor iComfort®-enabled

Operation sequence for dehumidification

1. REMOVE 24 VOLTS FROM DH AND/OR DS

2. THERMOSTAT CYCLES OUTDOOR UNITS TO Y2

3. INDOOR AND OUTDOOR FAN SPEEDS REDUCED

MAXIMUM TOTAL LENGTH OF ALL CONNECTIONS ON THE RSBUS IS LIMITED TO 1500FT. WIRE GAUGE OF RSBUS WIRE IS 18.

EDA RELAY

RED

VIOLET

ORANGE

EDA VA LVE ACTUATOR

EARLIER MODEL VALVE ACTUATOR

1N4005 DIODE (shrink wrapped -

diode is concealed in the wire.)

IN COMMUNICATING SYSTEM, THERMOSTAT DS INPUT IS NOT USED AND DEHUMIDIFICATION IS CONTROLLED VIA DEHUMIDIFICATION RELAY THAT CONTROLS 24VAC OUTPUT ON DH TERMINAL.

EDA RELAY

BLACK

GREY

RED

EDA VALV E ACTUATOR

LATER MODEL VALVE

ACTUATOR

NUMBER OF WIRES REQUIRED—Indoor unit to: Air Sensors (Optional)

System Type Humiditrol

1-stage AC

2-stage AC

1-stage HP

3 4 4 2 2

2-stage HP

EDA

iComfort®

Thermostat

Outdoor unit Discharge Outdoor

FIGURE 23. Field Wiring (Communicating Systems)

Page 21

SENSOR CONNECTIONS AND WIRING REQUIREMENTS

The following are sensor connections and wiring requirements for the discharge air and outdoor air sensors.

Discharge Sensor (DAT)

The Air Handler Control has two screw terminals marked Discharge Air Sensor. The sensor is REQUIRED for

EVENHEAT operation and is eld mounted and ordered

separately using Lennox Catalog # 88K38. In the EVENHEAT mode, the discharge air sensor cy-

cles the electric heating elements as needed to maintain the Air Handler control EVENHEAT jumper selected discharge setpoint.

The discharge air sensor should be mounted downstream

of the electric heat elements as illustrated in gure 15,

detail A. It must be placed in a location with unobstructed

airow, where other accessories (such as humidiers, UV

lights, etc.) will not interfere with its accuracy. Wiring distance between the Control and the discharge air

sensor should not exceed 10 feet (3 meters) when wired with 18-gauge thermostat wire.

Outdoor Air Sensor

This is a two screw terminal for connection to a Lennox

X2658 outdoor temperature sensor. The Control takes no

action on the sensor status other than to communicate the temperature to the RSBus network. Wiring distance between the AHC and outdoor temperature sensor should not exceed 200 feet when wired with 18-gauge thermostat wire.

• Minimum temperature: -40ºF (-40ºC)

• Maximum temperature: 70ºF (158ºC)

Float Switch

IMPORTANT – The oat switch connection to monitor the condensate oat switch and shut down cooling when an open oat switch is detected, only applies to systems with

iComfort communicating thermostats. Air handlers controlled by a conventional 24VAC thermostat must have the

oat switched wired in series with the the "Y" wire to the

outdoor unit. The air handler control has two screw connections for con-

nection to a normally closed (N.C.) condensate drain oat switch. When the N.C. condensate oat switch contacts

open, the cooling will be disabled for systems controlled by an iComfort thermostat. Alert Code E371 "Float switch Sensed open" will be displayed indicating Maintainence is required on condensate drain line. After 10 minutes, the homeowner will be alerted with a critical alert message on thermostat home screen. The alert will automatically clear

when the oat switch contacts close.

AIR HANDLER CONTROL 9-PIN CONNECTOR (P8)

1 - Air Handler (no electric heat) – Two wire factory

harness (wired to pins 7 and 8) which provides 230 VAC power to Air Handler Control.

2 - Air Handler (with electric heat) – Eight wire factory

harness (all pin position are wired as noted in table

5).

NOTE - See gure 15, detail B for wire colors.

TABLE 5. Electric Heat Connection (P8)

Position Function / Description

1 Heat stage 1 relay coil

2 Heat stage 2 relay coil

3 Relay coil return

4 Heat stage 3 relay coil

5 Heat stage 4 relay coil

6 Heat stage 5 relay coil

7 L1 230VAC supply from heater kit

8 L2 230VAC supply from heater kit

9 Not used

CONTROL CONNECTIONS AND WIRING REQUIREMENTS

This section provides information on communicating and non-communicating control connections and wire run lengths.

TABLE 6. Air Handler Control Connections –

Communicating

Label Label Function

R 24VAC

Thermostat

Outdoor Unit

Float SW

i+ RSbus data high connection

i- RSbus data low connection

C 24VAC command (ground)

R 24VAC

i+ RSbus data high connection

i- RSbus data low connection

C 24VAC command (ground)

R N.C. condensate oat switch

connections

(Systems with iComfort communicating thermostats only)

TABLE 7. Run Length – Communicating

Wire Run Length AWG #Insulation / Core Types

Maximum length or wiring for all connections on the RSbus is limited to 1500 feet (457 meters)

Color-coded, temperature rating 95°F

(35°C) minimum, solid core. (Class II Rated Wiring)

TABLE 8. Run Length – Non-Communicating

Wire Run Length AWG #Insulation / Core Types

Less than 100’ (30m) 18 Color-coded,

temperature rating 95°F

More than 100’ (30m) 16

(35°C) minimum, solid core. (Class II Rated Wiring)

Page 22

TABLE 9. Air Handler Control Connections

Function

Indoor Control Terminal Label

W1 (Input)

W2 (Input)

W3 (Input)

Y1 & Y2 (Input/

Output)

G (Input)

R The R terminal shall be capable of providing the power to the thermostat and all the associated loads .

O (Input/Output)

DS (Input)

DH (Output) The DH terminal provides a 24VAC output for dehumidification needs in communicating systems .

H (Output) The H terminal provides a 24VAC output for humidification needs in both communicating and non-communicating mode .

L (Input)

Non-Communicating

Room Thermostat

(Indoor and Outdoor -24 volts)

Indicates a rst-stage heating demand. This input is an anticipator for the thermostat. Indicates a second-stage heating demand. W1 input must be active to recognize second-stage heat demand. Indicates a third-stage heating demand. W1 and W2 inputs must be active to recognize third-stage heat demand.

Room thermostat inputs 24 volts to the Y1 and Y2 terminals on the indoor con-

trol. The 24 volt signal is then passed through to the outdoor unit. During a second-stage demand, both Y1 and Y2 are active. The Y1 terminal is connected to Y2 by link (Solid jumper on control that would be cut for 2 stage applications)

Indicates a 24 volt indoor blower demand.

The C terminal shall interconnect the signal ground of the room thermostat with secondary transformer ground (TR) and chassis ground (GND )

Room thermostat inputs 24 volts to the O terminal on the indoor con trol. The O terminal is connected to R by link (Solid jumper on control that would be cut if unit was a heat pump)

Used for Harmony III zoning systems, or thermostat with dehumidication capability. The DS terminal is connected to R by link (Solid jumper on control that would be cut if for the above applications). Harmony III control - This will allow the control to vary the voltage signal to the indoor blower motor to control required CFM. Dehumidication - Allow a 24 volt signal on the DS to turn o and on the dehumidication mode.

The L terminal is provided for connection to devices with Lennox System Operation Monitor (LSOM) capabilities. The control interprets the fault signals and transmits them as an alarm message on the communication line. There are ten (10) identied LSOM fault codes. Each is mapped to the communication Alarm codes.

Indoor Communicating

Outdoor Non-Communicating

N/A N/A

The room thermostat communicated with the indoor control. The indoor control outputs 24 volts on its Y1 and Y2 ter- minals which are hard wired to the noncommunicating outdoor unit.

In a communicating system, ”G” input to indoor control is used by non-communicating IAQ devices (such as LVCS, HRV or ERV) to ensure indoor blower demand.

The room thermostat communicated with the indoor control. The indoor control outputs 24 volts on its O terminals which are hard wired to the non-communicating outdoor unit. If there is 24 volts on O , the reversing valve will be energized and the outdoor unit will run in the cooling mode. If O does not have 24 volts, the outdoor unit will run in heating mode.

N/A N/A

Full Communication

(Indoor & Outdoor)

In a full communicating system, no wiring is required on Y1 and Y2 terminals.

In communicating system “G” input to indoor control is used by non-communicating IAQ devices (such as L VCS, HRV or ERV) to ensure indoor blower demand .

In a full communicating system, O terminal is not wired.

Page 23

JUMPER & OPTION JUMPER

GUIDE

COOLING MODE

BLOWER SPEED

(COOLING & HP MODE)

HIGH

SPEED

MEDIUM-HIGH

SPEED

MEDIUM-LOW

SPEED

LOW

SPEED

HEATING MODE

BLOWER SPEED

(ELECTRIC HT MODE)

HIGH

SPEED

MEDIUM-HIGH

SPEED

MEDIUM-LOW

SPEED

LOW

SPEED

PUSH

BUTTON

2-STAGE

COMPRESSOR JUMPER

HEAT PUMP JUMPER

OPTION SELECTION

ON-BOARD JUMPER

HARMONY JUMPER

DEHUMIDIFICATION-

-CUT ON-BOARD OPTION JUMPER (WIRE LOOP)

1-STG COMPRESSOR

(JUMPERS Y1 to Y2)

(JUMPERS R to O)

(JUMPERS R to DS)

Y1-Y2

DO NOT CUT

COMPR

2 STAGE

A/C UNIT

DO NOT CUT

R-0

HEAT

PUMP

NO HARMONY ZONING

OR NO

COMFORTSENSE 7000

W/ DS CONNECTION

DO NOT CUT

R-DS

CUT JUMPER

DEHUM

HARMONY

HUMIDIFICATION MODE

2-STG COMPRESSOR

CUT JUMPER

Y1-Y2

COMPR

2 STAGE

HEAT PUMP UNIT

R-0

HEAT

PUMP

HARMONY ZONING

C0MFORTSENSE 7000

W/ DS CONNECTION

R-DS

DEHUM

HARMONY

BLOWER

ADJUST SELECTION

NORMAL

NORM

(+ 10%)

SETTING

NORM

(-10%)

SETTING

NORM+-

HUMIDIFICATION MODE

STANDARD HEAT MODE

(DEFAULT)

STANDARD

HEAT MODE

(STAGED BY TSTAT)

EVENHEATER MODE

-ENABLED WITH OPTIONAL

FACTORY

JUMPER

7-SEGMENT LED

COOLING BLOWER RAMPING

(COOLING MODE UNLESS NOTED)

DELAYPROFILE #4

OFF-50%-82%-

100%-50%-OFF

DELAYPROFILE #3

OFF-82%-100%-OFF

DELAYPROFILE #2

CLG

OFF - 100% - DEMAND SATISFIED - 100% FOR 45 SECONDS - OFF

OFF - 30 SECOND DELAY 100% - DEMAND SATISFIED - 100% FOR 45 SECOND - OFF

DELAYPROFILE #1

OFF-100%-OFF

CONTINUOUS FAN

BLOWER SPEED

HIGH

SPEED

(100%)

MEDIUM-HIGH

SPEED

(70%)

* MEDIUM-LOW

SPEED

(38%)

LOW

SPEED

(28%)

DISCHARGE AIR SENSOR

DEGREE TARGET

DISCHARGE

TEMPERATURE

100 DEGREE TARGET

115 DEGREE TARGET

130

DEGREE

TARGET

* INDICATES FACTORY DEFAULT SETTING

110

115

130

100

115

100

115

130

100

115

130

100

115

130

24VAC OUTPUT ON ”H”

FOR HUMIDIFIER OR

ACCESSORY INTERLOCK

SMART MODE

- ”H” ENABLED WHEN HEAT ACTIVE

(HP or ELECT. HT)

AUTO MODE

- ”H” ENABLED WHEN

BLOWER ACTIVE

& NO CLG OR DEHUM

130

SMART

AUTO

FIGURE 24. Air Handler Conguration

Page 24

Air Handler Control Button, Display and

DEMAND

Jumpers

Use gure 24 as a reference for jumper settings. If any of

the referenced jumpers are missing, the Air Handler Control will display Error Code 130 as per table 10, and the Air Handler Control will automatically use the factory default

setting shown in gure 24.

IMPORTANT

Before changing any clippable links or jumper settings, make sure the motor has completely stopped. Any changes will not take place while the motor is running.

PUSH BUTTON

An on-board push button is provided for the purpose of

placing the Air Handler Control in di󰀨erent operation

modes and can be used to recall stored error codes. When button is pushed and held, Air Handler Control will cycle through a menu of options depending on current operating mode. Every three seconds a new menu item will be displayed. If the button is released while that item is shown on the display, Air Handler Control will enter displayed oper-

ating mode, or execute dened operation sequence for that

menu option. Once all items on menu have been displayed the menu resumes from the beginning (if button is still held).

1 - Press the diagnostic push button and hold it to cycle

through a menu of options. Every three seconds a new menu item will be displayed. Release the button when the desired mode is displayed.

2 - When the solid “E” is displayed, the control enters

the Error Code Recall mode. Error Code Recall mode menu options: Display will cycle through Error Codes and will automatically exit Error Code recall

once the last error code has been reached; solid “≡”

exits Error Code Recall mode; and solid “c” clears

the error history. Must press button while ashing

“c” is displayed to clear error codes. Cycling power to AHC will clear stored error codes.

3 - When the solid “-” is displayed, the control enters the

applicable mode. Field conguration mode menu

options: "H" electric heat stages detected; the AHC automatically detects the electric heat when power is applied and does not require "manual electric heat detection" using the push button, "A" Blower

Test Mode or "P" programming or conguring unit

size code. Releasing the button when solid “-” is displayed exits current active mode.

JUMPERS

Jumpers are used for non-communicating mode only.

1 - Humidication – Controls the status of H terminal

on the thermostat block. Congurations are as follows:

• If jumper is installed in SMART Humidication position (Default), H terminal is active if heat demand is present and indoor blower is running.

• If jumper is installed in AUTO Humidication posi-

tion, H terminal is energized whenever indoor blower is running.

2 - EvenHeat – Target Discharge Air Temperature

selection is used to set discharge air temperatures for EvenHeat operation.

NOTE - Optional Discharge Air Temperature Sensor, Len- nox Catalog # 88K38 is REQUIRED for EVENHEAT operation and must be ordered separately.

3 - Blower Only CFM – Used to select Indoor blower

CFM for continuous operation.

4 - Heat – Used to select Indoor blower CFM for electrical

heat by placing the jumper in proper position. Actual

CFM values for di󰀨erent air handler sizes are shown

in Targeted CFM tables starting on page 30.

5 - Cool – Used to select cooling indoor blower CFM by

placing the jumper in proper position. Actual CFM

values for di󰀨erent air handler sizes are shown in

Targeted CFM tables starting on page 30.

6 - Adjust - Used to select the indoor blower CFM

adjustment value by placing the jumper in appropriate position.

• If NORM is selected, indoor blower runs at normal speeds.

• If + is selected, indoor blower runs at approximately 10% higher speed than NORM setting.

• If - is selected, indoor blower runs at approximately 10% lower speed than NORM setting.

If the jumper is missing, the Air Handler Control will activate the Conguration Jumper is Missing alarm in and will automatically use the default factory setting in table

10. See gure 24 for jumper congurations. Actual CFM

values for di󰀨erent air handler sizes are shown in Targeted

CFM tables starting on page 26.

7 - Delay – Indoor blower cooling prole, delay for

cooling and heat pump operations.

• For heat pump heating operation only delay proles 1

and 2 are applicable. If proles 3 or 4 have been selected, heat pump operation will use prole 1 only.

• For heat pump cooling operation all 4 proles are op- erational.

If the jumper is missing, the Air Handler Control will activate the Conguration Jumper is Missing alarm and will automatically use the default factory setting in table 10.

See gure 24 for jumper congurations.

Delay Prole 1

A - When cool or heat demand is initiated, motor ramps up

to 100% and runs at 100% until demand is satised.

B - Once demand is met, motor ramps down to stop.

100%

CFM

COOLING

OFFOFF

Page 25

Delay Prole 2

Cooling – Air Conditioner and Heat Pump

OFF

100% CFM

COOLING DEMAND

100% CFM

45 SEC.

OFF

A - When cool demand is initiated, motor ramps up to

100% and runs at 100% until demand is satised.

B - Once demand is met, motor runs at 100% for 45 seconds.

C - Motor ramps down to stop.

Heating – Heat Pump Only

A - When cooling demand is initiated, motor ramps up

to 82%.

B - Motor runs at 82% for approximately 7.5 minutes

and then ramps up to 100% (unless the demand

has been satised) and motor runs at 100% until demand is satised.

C - Once demand is met, motor ramps down to stop.

Delay Prole 4

1/2 MIN 50% CFM

7 1/2 MIN 82% CFM

COOLING DEMAND

100%

CFM

1/2 MIN 50% CFM

30 sec

delay

100% CFM

HEATING DEMAND

100% CFM

45 SEC.

A - When heat demand is initiated, 30 seconds motor

on delay starts.

B - After the motor on delay expires, motor ramps up

to 100% and runs at 100% until demand is satised.

C - Once demand is met, motor runs at 100% for 45 seconds.

D - Motor ramps down to stop.

Delay Prole 3

OFF

7 1/2 MIN

82%CFM

COOLING DEMAND

100% CFM

TABLE 10. AHC System Status Codes

AHC Single Character

Display

Letter or Number

Action

Unit Size Code displayed represents air handler model size and capacity. See Configuring Unit Size Codes in gure

22.

If three horizontal bars are displayed, AHC does not recognize air handler model size and capacity. See Conguring

Unit Size Codes in Figure 22.

A - When cooling demand is initiated, motor ramps up to 50%.

B - Motor runs at 50% for 30 seconds and ramps up to

82%.

C - Motor runs at 82% for approximately 7.5 minutes

and then ramps up to 100% (unless the demand

has been satised) and motor runs at 100% until demand is satised.

D - Once demand is met, motor runs at 50% for 30

seconds.

E - Motor ramps down to stop.

DISPLAY

An on-board single character LED display (see gure 20

for LED display location) indicates general system status information such as mode of operation, indoor blower CFM and error codes. Multi-character strings are displayed with character ON for one second, OFF for 0.5 seconds and one second pause between the character groups.

Idle mode (decimal point / no unit operation)

Cubic feet per minute (cfm) setting for indoor blower (1 second ON, 0.5 second OFF) / cfm setting for current mode displayed . Example:

Cooling Compressor Capacity (1 second ON, 0.5 second OFF) / % of input rate displayed/Pause/cfm setting displayed/Pause/Repeat codes on systems with iComfort communicating outdoor unit. C1 or C2 displayed /Pause/cfm setting displayed/Pause/Repeat when installed with a non-communicating outdoor unit. Example C70 or C100 with communicating outdoor unit or C1 or C2 with non-communicating outdoor units

Dehumidication mode (1 second ON) / 1 second OFF) / cfm setting displayed / Pause / Repeat Codes)

Defrost mode. (Y, W and O call)

Electric Heat Stage (1 second ON, 0.5 second OFF) / 1 or 2 displayed / Pause / cfm setting displayed / Pause / Repeat codes. Example: H0 or H1 or H2 or H3

Compressor Heating Capacity (1 second ON, 0.5 second OFF) / % of input rate displayed/Pause/cfm setting displayed/Pause/Repeat codes on systems with iComfort communicating outdoor unit. h1 or h2 displayed /Pause/cfm setting displayed/Pause/Repeat when installed with a non-communicating outdoor unit. Example h70 or h100 with communicating outdoor unit or h1 or h2 with non-communicating outdoor units

Discharge air sensor temperature (indoor blower must be operating)

Page 26

TABLE 11. AHC Conguration, Test and Error Recall (Fault and Lockout) Function

NOTE — AHC MUST BE IN IDLE MODE)

Single Character LED

Display

Solid Push and hold button until solid appears, release button.

Solid

Action

Press and hold Solid “-” until required symbol displays . or

CONFIGURING ELECTRIC HEAT SECTIONS – AHC will automatically congure electric heat when 240V power is applied.

Air Handler Control has been enhanced to automatically congure electric heat when the electric heat harness in connected to the air handler and 240 volt power is applied. The air handler will not energize the blower and heat stages during the

Solid

automatic electric heat detection process. Releasing the push button when "H" is displayed will display the stages of electric heat that were automatically detected upon power up. Example HO, H1, H2, H3, H4, H5. H2 indicates 2 stage of electric heat were detected.

INDOOR BLOWER TEST

Solid

Release push button - control cycles indoor blower on for ten seconds at 70% of maximum air for selected capacity size unit. Control will automatically exit current active mode. .

CONFIGURING UNIT SIZE CODES

Single Character LED

Display

Solid

Blinking

Action

RELEASE push button - This mode allows the eld to select a unit size code (number or letter) that matches the air

handler model size and capacity.

IMPORTANT — All eld replacement controls may be manually congured to conrm air handler model size and capacity.

1. When the correct Unit Size Code is displayed, RELEASE push button. Selected code will ash for 10 second period.

2. During ten second period, HOLD push button until code stops blinking (three seconds minimum).

3. Air Handler Control will store code in memory and exit current active mode. LED display will go blank and then the Unit Size Code will display for 2 to 5 seconds.

NOTE - If ten second period expires, or push button is held less than 3 seconds, control will automatically exit current active mode and go into IDLE Mode without storing unit size code. If this occurs, then Unit Size Code conguring procedure must be repeated.

ERROR CODE RECALL MODE (NOTE — CONTROL MUST BE IN IDLE MODE)

Solid

Blinking Push and hold for one (1) second, release button. Seven-segment will display 0000 and exit error recall mode.

To enter Error Code Recall Mode — PUSH and HOLD button until solid E appears, then RELEASE button.

Control will display up to ten error codes stored in memory. If E000 is displayed, there are no stored error codes.

Error Code Recall will automatically exit after the last stored code is displayed.

To exit Error Code Recall Mode — PUSH and HOLD button until solid three horizontal bars appear, then RELEASE button.

NOTE - Error codes are not cleared

To clear error codes stored in memory, continue to HOLD push button while the three horizontal bars are displayed. Release push button when solid c is displayed. Error codes are automatically cleared when 240V power is cycled o and then back on.

Page 27

TABLE 12. AHC Single Character Display Alert Codes (Communicating and Non-Communicating)

Alert

Code

Priority

Critical

Moderate

Critical

Moderate

Critical

Minor The indoor blower motor is over heating.

Critical

Minor

Alert How to Clear

The air-handler has lost communication with the rest of the system.

There is a frequency/distortion problem with the power to the air-handler.

The 24VAC to the air-handler control is lower than the required range of 18 to 30VAC.

There is a delay in the air-handler responding to the system.

The iComfort™ thermostat has lost communication with the air-handler for more than 3 minutes.

There is a hardware problem with the air-handler control.

An air-handler conguration jumper is missing.

The air-handler control parameters are corrupted.

The air-handler control software is corrupted.

The iComfort™ thermostat has found a problem with the air-handler outdoor sensor.

The system has lost communication with the air-handler indoor blower motor.

The unit size code for the air-handler and the size of blower motor do not

match.

The unit size code for the air-handler has not been selected.

The air-handler's blower motor will not start.

There is a problem with air-handler discharge air sensor.

The blower cannot provide the requested CFM due to high static.

The indoor and outdoor unit capacities do not match.

Equipment is unable to communicate. This may indicate the existence of other alarms / codes. In most cases errors are related to electrical noise. Make sure high voltage power is separated from RSBus. Check for mis-wired and/or loose connections between the thermostat, indoor unit and outdoor unit. Check for a high voltage source of noise close to the system. Generally, this is a self-recoverable error.

This alarm/code may indicate transformer overloading. Check the voltage and line power frequency. Check the generator operating frequency, if the system is running on back-up power. Correct voltage and frequency problems. System resumes normal operation 5 seconds after fault recovered.

24-volt power low (range is 18 to 30 volts). Check and correct voltage. Check for additional power-robbing equipment connected to system. This alarm / code may require the installation of an additional or larger VA transformer.

Typically, this alarm/code does not cause any issues and will clear on its own. The alarm/code is usually caused by a delay in the outdoor unit responding to the thermostat. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.

Equipment lost communication with the icomfort ™ thermostat. Check the wiring connections, ohm wires and cycle power. The alarm stops all associated HV AC operations and waits for a heartbeat message from the unit that's not communicating. The alarm/ fault clears after communication is re-established.

There is a control hardware problem. Replace the control if the problem prevents operation and is persistent. The alarm / fault is cleared 300 seconds after the fault recovers.

Conguration jumper(s) missing on control (applicable in non-communicating applications only). Replace the jumper or put wire between terminals on control. Cleared after jumper is connected.

Recongure the system. Replace the control if heating or cooling is not available.

Recycle power. If failure re-occurs, replace the control. System reset is required to recover.

In normal operation after control recognizes sensors, the alarm will be sent if valid temperature reading is lost. Compare outdoor sensor resistance to temperature/resistance charts in unit installation instructions. Replace sensor pack if necessary. At the beginning of (any) conguration, the air-handler control will detect the presence of the sensor(s). If detected (reading in range), appropriate feature will be set as installed and shown in the ’About’ screen. The alarm / fault will clear upon conguration, or sensing normal values.

Lost communication with indoor blower motor. Possible causes include power outage, brown-out, motor not powered, loose wiring, condensation on air handler control without cover on breaker. Problem may be on control or motor side. Cleared after communication is restored.

Incorrect appliance unit size code selected. Check for proper conguring under unit size codes for air handler on conguration guide or in installation instructions. The alarm / fault clears after the correct match is detected following a reset. Remove the thermostat from the system while applying power and reprogramming.

No appliance unit size code selected. Check for proper conguring under: Unit size codes for air handler on conguration guide or in installation instructions. Critical Alert. The alarm /fault clears after the correct match is detected following a reset. Remove the thermostat from the system while applying power and reprogramming.

The system will go into watchguard mode. Indoor blower motor unable to start. This could be due to seized bearing, stuck wheel, obs truction etc. Replace motor or wheel if assembly does not operate or meet performance standards. The alarm / fault clears after the indoor blower motor starts successfully.

Indoor blower motor over temperature (motor tripped on internal protector). Check motor bearings and amps. Replace if necessary. The alarm / fault clears after blower demand is satised.

Compare outdoor sensor resistance to temperature/resistance charts in installation instructions. Replace sensor if necessary. The alarm/fault is cleared 30 seconds after fault is detected as recovered.

Warning Only. Restricted airow - Indoor blower is running at a reduced CFM (cutback mode). The variable-speed motor has pre-set speed and torque limiters to protect the motor from damage caused by operating outside of design parameters (0 to 0.8” e.g.. total external static pressure). Check lter and duct system. To clear, replace lter if needed or repair/add duct. The alarm/fault is cleared after the current service demand is satised.

Check for proper conguring in installation instructions. Alarm is just a warning. The system will operate, but might not meet efciency and capacity parameters. The alarm will clear after commissioning is complete.

Page 28

TABLE 13. AHC Single Character Display Alert Codes (Communicating and Non-Communicating) (cont'd)

Alert Code

E371

Priority

Critical

Moderate

Moderate/ Critical

Moderate

Alert How to Clear

The O relay on the air-handler has failed. Either the pilot relay contacts did not close or the relay coil did not energize.

The R to O jumper was not removed on the air-handler control.

The Y1 relay on the air-handler has failed. Either the pilot relay contacts did not close or the relay coil did not energize.

The Y2 relay on the air-handler has failed. Either the pilot relay contacts did not close or the relay coil did not energize.

The air-handler's electric heat is not congured.

There is a problem with the air-handler's rst stage electric heat. Either the pilot relay contacts did not close, or the relay coil in the electric heat section did not energize.

There is a problem with the air-handler's second stage electric heat. Either the pilot relay contacts did not close, or the

relay coil in the electric heat section did not energize. The air-handler will operate on rst stage electric heat until the is-

sue is resolved.

There is a problem with the air-handler's third stage electric heat. Either the pilot relay contacts did not close, or the relay

coil in the electric heat section did not energize. The air-handler will operate on rst stage electric heat until the issue is resolved.

There is a problem with the air-handler's fourth stage electric heat. Either the pilot relay contacts did not close, or the relay

coil in the electric heat section did not energize. The air-handler will operate on rst stage electric heat until the issue is resolved.

There is a problem with the air-handler's fth stage electric heat. Either the pilot relay contacts did not close, or the relay

coil in the electric heat section did not energize. The air-handler will operate on rst stage electric heat until the issue is resolved.

Float switch sensed open. The cooling is disabled when installed with an iComfort communicating thermostat. The condensate drain line needs maintenance. The condensate drain pan oat safety switch is open.

The secondary voltage for the air-handler has fallen below 18VAC. If this continues for 10 minutes, the icomfort™ thermostat will turn o the air-handler.

O relay failed. Pilot relay contacts did not close or the relay coil did not energize. Replace control. The alarm clears after a reset

Conguration link(s) not removed on control. Cut / remove R to O jumper. Applicable with non communicating outdoor unit with communicating indoor unit. The fault clears after the R to O jumper is cut/removed.

Operation stopped. Y1 relay failed. Pilot relay contacts did not close or the relay coil did not energize. The indoor unit cannot verify that the relay is closed. The alarm clears after a reset and Y1 input sensed.

Operation stopped. Y2 relay failed. Pilot relay contacts did not close or the relay coil did not energize. The indoor unit cannot verify that the relay is closed. The alarm clears after a reset and Y2 input sensed.

Heat call with no congured or mis-congured electric heat. Congure electric heat in the air-handler. The fault clears electrical heat is successfully detected.

Heat section / stage 1 failed. Pilot relay contacts did not close, or the relay coil in the electric heat section did not energize. The alarm clears after stage 1 relay is detected.

Heat section / stage 2 failed (same as code 351). Pilot relay contacts did not close, or the relay coil in the electric heat section did not energize. The air-handler will operate on stage 1 heat only. The alarm clears after stage 2 relay is detected.

Heat section / stage 3 failed (same as code 351). Pilot relay contacts did not close, or the relay coil in the electric heat section did not energize. The air-handler will operate on stage 1 heat only. The alarm clears after sage 2 relay is detected.

Heat section / stage 4 failed (same as code 351). Pilot relay contacts did not close, or the relay coil in the electric heat section did not energize. The air-handler will operate on stage 1 heat only. The alarm clears after stage 2 relay is detected.

Heat section / stage 5 failed (same as code 351). Pilot relay contacts did not close, or the relay coil in the electric heat section did not energize. The air-handler will operate on stage 1 heat only. The alarm clears after stage 2 relay is detected.

The oat switch terminals on the AHC control sensed an open oat switch and will shut o cooling when installed with an iComfort Communicating thermostat. After 10 minutes the Alert Code will escalate from a moderate code to a Critical code and will be displayed on the thermostat home screen. Alert clears when oat switch contacts close.

Secondary voltage is below 18VAC. After 10 minutes, operation is discontinued. Check the indoor line voltage, transformer output voltage. The alarm clears after the voltage is higher than 20VAC for 2 seconds or after a power reset.

Page 29

Target CFM Tables

BLOWER DATA

CBA38MV-018/024 BLOWER PERFORMANCE

0 through 0.80 in. w.g. External Static Pressure Range

“ADJUST”

Jumper

Setting

1 2 3 4 1 2 3 4

“HEAT” Speed “COOL” Speed

cfm cfm cfm cfm cfm cfm cfm cfm

+ 460 685 885 1050 460 685 885 1050

NORM 400 575 795 940 400 575 795 940

– 365 515 715 830 365 515 715 830

NOTES - The e󰀨ect of static pressure, lter and electric heater resistance is included in the air volumes listed.

First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the same second-stage COOL speed selected, minimum 250 cfm. Lennox iHarmony® Zoning System applications - minimum blower speed is 250 cfm.

BLOWER DATA

CBA38MV-030 BLOWER PERFORMANCE

0 through 0.80 in. w.g. External Static Pressure Range

“ADJUST”

Jumper

Setting

1 2 3 4 1 2 3 4

cfm cfm cfm cfm cfm cfm cfm cfm

+ 630 875 1095 1315 630 875 1095 1315

NORM 545 785 995 1195 545 785 995 1195

– 510 700 890 1075 510 700 890 1075

NOTES - The e󰀨ect of static pressure, lter and electric heater resistance is included in the air volumes listed.

“HEAT” Speed “COOL” Speed

Jumper Speed Positions

BLOWER DATA

CBA38MV-036 BLOWER PERFORMANCE

0 through 0.80 in. w.g. External Static Pressure Range

“ADJUST”

Jumper

Setting

1 2 3 4 1 2 3 4

“HEAT” Speed “COOL” Speed

cfm cfm cfm cfm cfm cfm cfm cfm

+ 920 1255 1410 1580 920 1255 1410 1580

NORM 815 1165 1315 1435 815 1165 1315 1435

– 720 1010 1155 1285 720 1010 1155 1285

NOTES - The e󰀨ect of static pressure, lter and electric heater resistance is included in the air volumes listed.

Jumper Speed Positions

Page 30

Target CFM Tables (cont'd)

BLOWER DATA

CBA38MV-042 BLOWER PERFORMANCE

0 through 0.80 in. w.g. External Static Pressure Range

“ADJUST”

Jumper

Setting

1 2 3 4 1 2 3 4

“HEAT” Speed “COOL” Speed

cfm cfm cfm cfm cfm cfm cfm cfm

+ 1100 1320 1540 1760 1100 1320 1540 1760

NORM 1000 1200 1400 1600 1000 1200 1400 1600

– 900 1080 1260 1440 900 1080 1260 1440

NOTES - The e󰀨ect of static pressure, lter and electric heater resistance is included in the air volumes listed.

First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the same second-stage COOL speed selected, minimum 450 cfm. Lennox iHarmony® Zoning System applications - minimum blower speed is 450 cfm.

BLOWER DATA

CBA38MV-048 BLOWER PERFORMANCE

0 through 0.80 in. w.g. External Static Pressure Range

“ADJUST”

Jumper

Setting

1 2 3 4 1 2 3 4

cfm cfm cfm cfm cfm cfm cfm cfm

+ 1670 1870 2100 2200 1670 1870 2100 2200

NORM 1460 1670 1870 2100 1460 1670 1870 2100

– 1230 1410 1600 1800 1230 1410 1600 1800

NOTES - The e󰀨ect of static pressure, lter and electric heater resistance is included in the air volumes listed.

First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the same second-stage COOL speed selected, minimum 450 cfm. Lennox iHarmony® Zoning System applications - minimum blower speed is 450 cfm.

“HEAT” Speed “COOL” Speed

Jumper Speed Positions

BLOWER DATA

CBA38MV-060 BLOWER PERFORMANCE

0 through 0.80 in. w.g. External Static Pressure Range

“ADJUST”

Jumper

Setting

1 2 3 4 1 2 3 4

“HEAT” Speed “COOL” Speed

cfm cfm cfm cfm cfm cfm cfm cfm

+ 1695 1890 2140 2210 1695 1890 2140 2210

NORM 1525 1680 1850 2075 1525 1680 1850 2075

– 1300 1450 1630 1800 1300 1450 1630 1800

NOTES - The e󰀨ect of static pressure, lter and electric heater resistance is included in the air volumes listed.

First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the same second-stage COOL speed selected, minimum 450 cfm. Lennox iHarmony® Zoning System applications - minimum blower speed is 450 cfm.

Jumper Speed Positions

Page 31

Unit Operating Sequences

This section details unit operating sequence for non-communicating systems. NOTE - For communicating systems, see the iComfort thermostat installation instruction.

TABLE 14. CBA38MV with ComfortSense™ 7500 Thermostat and Single-Stage Outdoor Unit

Operating Sequence

Operating Sequence System Demand System Response

System

Condition

Normal Operation 1 On On On Acceptable 24 VAC High 100%

Dehumidication Call

Normal Operation 1 On On On Acceptable 24 VAC High 100%

Dehumidication call

Dehumidication call ONLY

Step

2 On On On Demand 0 VAC High 70%

1 On On On Demand 0 VAC High 70%

Thermostat Demand Relative Humidity

Comp

Y1 Y2 O G W1 W2 Status D

NO CALL FOR DEHUMIDIFICATION

BASIC MODE (Only active on a Y1 thermostat demand)

PRECISION MODE (Operates independent of a Y1 thermostat demand)

Air

Handler

CFM

(COOL)

Comments

Compressor and indoor air handler follow thermostat demand

ComfortSense 7500 thermostat energizes Y1 and de-energizes D on a call for dehumidication.

NOTE - No over cooling.

Dehumidication mode begins when humidity is greater than set point

ComfortSense 7500 will keep outdoor unit energized after cooling temperature setpoint has been reach in order to maintain room humidity setpoint.

NOTE - Allow to over

F from cooling set

cool 2 point.

Page 32

TABLE 15. CBA38MV with ComfortSense™ 7500 Thermostat and Two-Stage Outdoor Unit

Operating Sequence

Operating Sequence System Demand System Response

Thermostat Demand Relative Humidity

System Condition

Step

Y1 Y2 O G W1 W2 Status D

Compre

ssor

No Call for Dehumidication

Normal Operation

- Y1

Normal Operation

- Y2

1 On On On Acceptable 24 VAC Low 70%

2 On On On On Acceptable 24 VA C High 100%

Room Thermostat Calls for First-Stage Cooling

BASIC MODE (Only active on a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable 24 VAC Low 70%

Dehumidication Call

2 On On On On Demand 0 VAC High 70%

PRECISION MODE (Operates independent of a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable 24 VAC Low 70%

Dehumidication call

Dehumidication call ONLY

2 On On On On Demand 0 VAC High 70%

1 On On On On Demand 0 VAC High 70%

Room Thermostat Calls for First- and Second-Stage Cooling

BASIC MODE (Only active on a Y1 thermostat demand)

Normal Operation 1 On On On On Acceptable 24 VAC High 100%

Dehumidication Call

2 On On On On Demand 0 VAC High 70%

PRECISION MODE (Operates independent of a Y1 thermostat demand)

Normal Operation 1 On On On On Acceptable 24 VAC High 100%

Dehumidication call

Dehumidication call ONLY

2 On On On On Demand 0 VAC High 70%

1 On On On On Demand 0 VAC High 70%

Air

Handler

CFM

(COOL)

Comments

Compressor and indoor air handler follow thermostat demand

ComfortSense 7500 thermostat energizes Y2 and deenergizes D on a call for dehumidication

NOTE - No over cooling.

Dehumidication mode begins when humidity is greater than set point

ComfortSense 7500 thermostat will keep outdoor unit energized after cooling temperature setpoint has been reached in order to maintain room humidity setpoint.

NOTE — Allow to over cool 20F from cooling set point.

ComfortSense 7500 thermostat energizes Y2 and deenergizes D on a call for dehumidication

NOTE — No over cooling.

Dehumidication mode begins when humidity is greater than set point

ComfortSense 7500 thermostat will keep outdoor unit energized after cooling temperature setpoint has been reached in order to maintain room humidity setpoint.

NOTE — Allow to over cool

F from cooling set point.

Page 33

Unit Operating Sequences

This section identies the requirements for conguring the air handler unit for unit size, heat mode selection and EvenHeat.

Air Handler Control Checkout

Power-up - Unit Size Code (Number or letter) displayed represents air handler model size and capacity. If three horizontal bars displays, Air Handler Control (AHC) does not recognize unit size code (air handler model size and capacity).

Finished

The AHC has been enhanced to automatically detect and configure electric heat when the electric heat harness is plugged into the unit AHC and 240v power is applied to the air handler. Manual electric heat detection using the push button is no longer required

Refer to Heat Pump or Cooling Sequence of Operation flow

diagrams, Air Handler or ECB38 Electric Heat installation instructions.

T-STAT CALL

ONE (H1)

Electric

heat

Installed?

Ye s

W1 Call?

Ye s

NUMBER OF HEAT SECTIONS DETECTED

TWO (H1-H2)

THREE (H1-H3)

Ye sNo

Standard

FOUR (H1-H4)

H1 AND H2

AHC

recognizes

Unit Size

Code?

Which Heat

Mode?

FIVE (H1-H5)

H1 AND H2

H3 AND H4

No (Display Alarm

Code 203)

Refer to Configuring Unit Size Codes flow diagram, Air Handler or ECB38 Electric Heat installation instructions.

IMPORTANT — Field replacement controls may need to be manually configured to validate air handler unit size code.

EVENHEAT

Refer to EVENHEAT Operation flow diagram, Air Handler or ECB38 Electric Heat installation instructions.

Pilot relays on AHC are energized one at a time. There is a minimum of 10 seconds delay between pilot relay activations.

NOTE - AHC will not recognize higher heat sections

calls if lower heat section is not present.

At the completion of each heat section demand (W1, A call for electric heating first, second or third stage is initiated when 24 VAC (R) is detected on W1, W2 and W3 inputs on AHC. (Factory mounted metal jumpers connect W1/2 and W2/W3.)

Indoor blower will immediately start to delivery CFM as set by heating mode jumper on AHC with activation of first electric heat pilot relay.

RECOMMENDED — USE FIGURE 24 AS A REFERENCE FOR SETTING JUMPER CONFIGURATIONS ON THE AIR HANDLER CONTROL.

W2, and W3), the AHC will immediately de-energize

the corresponding pilot relay(s).

NOTE — If the call for lower heat section is removed, AHC will automatically de-energize higher heat sections.

At the completion of all heating demands, the indoor blower will run for an additional 10 seconds before

de-energizing.

FIGURE 25. Air Handler Control Checkout

Page 34

Configuring Unit Size Codes (Model Number)

Power-up — Unit Size Code (number or letter) displayed represents unit size code (air handler model size and capacity). If three horizontal bars display, then Air Handler Control (AHC) does not recognize unit size code.

To enter unit size code

configuration mode ; PUSH and

HOLD button next to single

character LED display until dash

symbol appears, RELEASE button.

Solid dash “-” will remain

on continuously, without

PUSH and HOLD button until the solid P

symbol is displayed on the single

character LED display, then RELEASE

button. This mode allows the user to

select a unit size code (number or letter)

that matches the air handler model size

blinking.

and capacity.

Ye s

(No heating, cooling or indoor fan operation)

AHC in IDLE mode

Turn room thermostat to

OFF

AIR HANDLER MODELUNIT SIZE CODE

A C

CBA38MV-018/024 CBA38MV-030

CBA38MV-036

CBA38MV-042

CBA38MV-048

CBA38MV-060

IMPORTANT — Field replacement controls may need to be manually configured to validate air handler unit size code.

Solid P starts

blinking on single

character LED

display.

PUSH and HOLD button to allow AHC to display unit size

code

(letter or number) for each different air handler model

for three seconds.

FIGURE 26. Congure Unit Size Codes

Page 35

1. When the correct Unit Size Code is displayed, RELEASE

push button. Selected code will flash for 10 second period.

2. During that 10 second period, HOLD push button until code

stops blinking (three seconds minimum).

3. Air Handler Control will store code in memory and exit current

active mode. LED display will go blank and then the Unit Size Code will display for 2 to 5 seconds.

NOTE - If 10 second period expires, or push button is held less than

three seconds, control will automatically exit current active mode and go into IDLE Mode without storing unit size code. If this occurs, then Unit Size Code configuring procedure must be repeated.

LED displays correct

Unit Size Code.

YES

Unit enters IDLE

Mode.

Conguring/Detecting Electric Heat Sections

The AHC control in the air handler has been enhanced to automatically detect and congure the electric heat when the electric heat harness is connected to the AHC control and 240 Volt power is applied. The air handler no longer requires manual detection using the push button on the AHC Control.

RECOMMENDED — USE FIGURE 24 AS A REFERENCE FOR SETTING

JUMPER CONFIGURATIONS ON THE AIR HANDLER CONTROL.

Standard EVENHEAT

Which Heat

Mode?

Set desired Heating Mode Blower Speed jumper pin.

Electric heat is staged by room thermostat. (AHC comes with factory jumper between W1 to W2 and W2 to W3)

Refer to Air Handler Control Checkout ow diagram for operation.

The AHC control has been enhanced to automatically detect the electric heat. Electric heat is detected/congured when the electric harness is connected to the AHC control 9-pin jack plug and 240 volt power is applied. Manual detection of electric heat using the push button is no longer required.

Automatic Electric Heat Detection/Conguration Notes

Conguration

Finished

Set desired Heating Mode Blower Speed jumper pin.

Install and wire discharge air temperature sensor.

Set desired Target Discharge Temperature jumper pin. If jumper pin is missing or discharge air temperature sensor is not detected, AHC defaults to Standard Heat Mode . Target settings are 85, 100, 115 and 130ºF) .

Refer to EVENHEAT Operation ow diagram for operation.

1. The AHC has been enhanced to automatically detect/congure the electric heat heat. Automatic electric heat detection occurs when the electric heat harness is connected to the AHC 9-pin jack plug and 240V power is applied to the air handler.

2. During automatic electric heat detection/conguration process, the AHC will NOT bring on the blower or electric heat relays.

3. Manual electric heat detection using the push button is no longer required.

4. The number of electric heat stages automatically detected can be veried by pressing the push button until "H" is displayed and then releasing the button. The display will show HO, H1, H2, H3, H4 or H5 which is the number of electric heat stages detected. Example H2 indicates 2-stages of electric heat were detected. The electric heat stages automatically detected can also be veried using iComfort thermostat> advanced settings,>dealer control center>equipment>air handler>about>Number of heating stages

5. On iComfort systems, if the air handler was installed and connected to an iComfort thermostat prior to electric heat installation, the system may need to be recongured using the icomfort thermostat to recognize the change in the electric heat installation.

FIGURE 27. Heat Mode Selection

Page 36

INPUTS OUTPUTS

Room Thermostat Demand

Target Discharge Air Temperature Set at 85ºF

Y1 Heat Pump First Stage Heat Pump First Stage

Y1 + Y2

Y1 + W1 and/or W2

Heat Pump First and Second Stage

Heat Pump First Stage + First Electric Heat Section (H1)

Heat Pump First and Second

Y1 and Y2 + W1 and/or W2

Stage+ First Electric Heat Section (H1)

W1 and/or W2 First Electric Heat Section (H1)

EVENHEAT OPERATION

Target Discharge Air Temperature Set at 100ºF

Heat Pump First and Second Stage + First Electric Heat Section (H1)

Heat Pump First Stage + First Electric Heat Section + Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

Heat Pump First and Second Stage + First Electric Heat Section + Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

First Electric Heat Section (H1) + Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

Target Discharge Air Temperature Set at 115ºF/130ºF

Heat Pump First + First Electric Heat Section (H1)

Heat Pump First and Second Stage + First Electric Heat Section (H1) + Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

Heat Pump First Stage + First Electric Heat Section (H1) Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

Heat Pump First and Second Stage + First Electric Heat Section (H1) Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

First Electric Heat Section (H1) + Second Electric Heat Section (H2) if number of electric heater sections detected is more than two.

Heat pump rst or second stage or electric heat demand will start the Air Handler Control (AHC) indoor blower at CFM value based on tables found in installation instructions.

Timer delays for

120 seconds

Heat Pump and electric heat

demand?

One Stage More than one stage

Ye s

Last room thermostat Heat

up- staging action

Increase target discharge air temperature by 15Fº

Timer delays for 150

seconds

FIGURE 28. EVENHEAT Operation (1 of 2)

Page 37

Note 1 Activation delay

120 seconds if one heat stage is or deactivated

150 seconds if more than one stage is activated or deactivated.

EVENHEAT Operation

Start Timer Delay

(Note 1)

Ye s

Adjust Target Discharge Air

Temperature

Delay Timer

Finished or last

change was up-

stage

Ye s

Electric heat ON

Ye s

W call with one

Electric Heat

Section ON

Above

Change in Heat

demand from

room thermostat?

Stop Delay Timer

Increase heat demand.

Y1 (with or without Y2) +

W1 and W2

Adjust Target Discharge Air

Temperature

Heat Pump OFF

Discharge air temperature sensor setting on the Air Handler Control will remain at set point on W1 demand and be increased 15ºF for W2 demand.

Heat Pump ON

Discharge air temperature sensor setting on Air Handler Control will remain at set point. W1 demand will increase set point 15ºF. W2 demand will increase set point an additional 15ºF. (Total of 30ºF)

Below

Delay Timer

Finished or last

change was

down-

stage

Ye s

Y1 ON and

Y2 OFF

More Electric

Heat

available

Ye s

Activate Y2

Ye s

Adjust Target

Discharge Air

Temperature

Turn OFF Electric

Heat Section

Discharge air

temperature is

within target range?

Measured discharge air

temperature is above or

below

target range?

NOTE — Optional Outdoor Thermostat (Wired between R and W3) will lockout electric elements 3, 4 and 5.

FIGURE 29. EVENHEAT Operation ((2 of 2)

Page 38

Turn ON one Electric Heat

section

Heat Pump Operation (Heating and Cooling)

Air Handler Control AHC) Indoor Blower Mode Speed and Proles settings

1. Set Cooling Mode Blower Speed jumper pin . (Low and high indoor blower CFM settings are identical for cooling and heat pump)

2. Set Blower Adjust Selection jumper pin.

3. Set Cooling Mode Blower Ramping jumper pin (Cooling calls - All ramping proles are active) (Heating calls Only ramping proles 1 and 2 are active. If proles 3 or 4 are selected, AHC will default to prole 1)

A Prole 1 does not provide any ramping proles.

B Prole 2 provides a 30 second indoor blower ON delay at the start of a heat pump heating demand. (45

4. Simultaneous Heat Pump and electric heat call: Indoor Blower will operate at the highest CFM requested by

Single or Two-Stage Unit

1. AHC on-AHC jumper must be cut between Y1 and Y2 to allow two stage cooling operation.

2. AHC on-AHC jumper must be cut between R and O to allow heat pump operation.

RECOMMENDED — USE FIGURE 20 AS A REFERENCE FOR SETTING

second indoor blower OFF delay)

the heat pump or the electric heat blower speed selection.

JUMPER CONFIGURATIONS ON THE AIR HANDLER CONTROL.

CUT ON-BOARD JUMPER Y1-Y2 FOR TWO-STAGE A/C

CUT ON-BOARD JUMPER R -O.

IMPORTANT — USE CARE WHEN CUTTING JUMPERS TO

PREVENT DAMAGE TO CONTROL. SEE FIGURE 24,

CBA38MV JUMPER AND OPTION JUMPER GUIDE FOR FURTHER

DETAILS.

Y1-Y2

2-STAGE

COMPR

R-O

HEAT

PUMP

R-DS

DEHUM

HARMONY

CUT FOR OPTION

Heating

Air Handler Control (AHC) receives inputs on Y1 terminal

Y1 terminal on AHC is congured as input and passes signal from room thermostat to outdoor unit.

NOTE — The outdoor unit control directly controls the outdoor unit operation.

Y1 input to the AHC will control the indoor blower according to the cooling or heating mode blower speed adjust selection jumper pins.

Room thermostat calls for

second stage?

Ye s

, ramping and

Room thermostat

calls for rst

stage?

Cooling

Air Handler Control (AHC) receives inputs on Y1 and O

terminals

Y1 terminal on AHC is congured as input and passes signal from room thermostat to outdoor unit.

NOTE — The outdoor unit control directly controls the outdoor unit operation.)

Y1 input to the AHC. Will control the indoor blower according to the cooling mode blower speed selection jumper pins.

, ramping and adjust

Ye s

De-energize Y2 terminal on AHC. Indoor blower speed will reset to Y1 demand.

NOTE — The outdoor unit control directly controls the outdoor unit operation.)

Ye s

Y2 terminal on AHC is congured as input and passes signal from room thermostat to outdoor unit.

NOTE — The outdoor unit control directly controls the outdoor unit operation.)

Still calling for second

Y2 terminal is an input to the AHC. The indoor blower will be controlled according to the jumper pin selections.

stage?

Ye s

Page 39

Still calling for rst

stage?

De-energize Y1 (and O in cooling) terminals on AHC.

NOTE — The outdoor unit control directly controls the outdoor unit operation.

De-energize indoor blower per ramping prole.

Cooling Operation

CUT FOR OPTION

- Use care when cutting jumpers to prevent damage to

Air Handler Control AHC) Indoor Blower Mode Speed and Proles settings

1. Set Cooling Mode Blower Speed jumper pin.

2. Set Cooling Mode Blower Ramping jumper pin.

3. Set Blower Adjust Selection jumper pin. Single or Two-Stage Unit

AHC on-board jumper must be cut between Y1 and Y2 to allow 2 stage cooling operation.

Room thermostat

calls for rst

stage?

Air Handler Control (AHC) receives inputs on Y1 terminal .

Y1 terminal on AHC is congured as input and passes signal from room thermostat to outdoor unit.

NOTE - The outdoor unit control directly controls the outdoor unit operation.

CUT ON-BOARD JUMPER Y1-Y2 FOR TWO-STAGE A/C

RECOMMEND — USE FIGURE 20 AS A REFERENCE FOR SETTING JUMPER CONFIGURATIONS ON THE AIR HANDLER CONTROL.

IMPORTANT

control. See figure 20, CBA38MV jump and link guide for further details.

Y1-Y2

2-STAGE

COMPR

R-O

HEAT

PUMP

R-DS

DEHUM

HARMONY

Y1 input to the AHC will control the indoor blower according to the cooling or heating mode blower speed , ramping and adjust selection jumper pins.

Room thermostat calls for

second stage?

Ye sYe s

Y2 terminal on AHC is congured as input and passes signal from room thermostat to outdoor unit.

NOTE - The outdoor unit control directly controls the outdoor unit operation.

Y2 terminal is an input to the AHC. The indoor blower will be controlled according to the jumper pin selections.

Ye s

Still calling for second

stage?

Ye s

De-energize Y2 terminal on AHC. Indoor blower speed will reset to Y1 demand.

NOTE - The outdoor unit control directly controls the outdoor unit operation.

Still calling for rst

stage?

De-energize Y1 (and O in cooling) terminal on AHC.

NOTE - The outdoor unit control directly controls the outdoor unit operation.

De-energize indoor blower per ramping

prole.

Ye s

Page 40

Error Code / Recall Mode

Ye s No

To enter Error Code Mode , push and hold button next to single character LED display until solid E symbol appears, release button.

Control will display up to ten error codes stored in memory. If E 0 0 0 is displayed, there are no stored error codes.

The AHC will automatically exit after the last error code is displayed.

To exit Error Code Recall Model, push and hold button next to single character LED display until solid three horizontal bars appears, then release button.

AHC in Idle Mode

(No heating cooling or indoor

fan operation)

To clear error codes stored in memory, continue to hold push button while the solid three horizontal bars are displayed.

Release button when solid is displayed.

Error codes are also cleared when 240V power is cycled o and then back on.

Solid c starts blinking on

single character LED

display.

Turn room thermostat to OFF

NOTE — Error Codes are not cleared from memory. The AHC will automatically exit after the last error code is displayed.

IMPORTANT NOTE – Error Codes will be automatically cleared when unit power is cycled off. Cleared error code history will be stored in the iComfort thermostat under Notifications.

The display will blink for up to ten seconds. During this time, press the button and release to conrm deletion of the error code history. As conrmation, AHC will display 0 0 0 0 . (If ten second period expires or push button is not released, control will automatically exit Error Code Mode and go into mode without deleting error code history.

NOTE — Once the error code history is deleted, it cannot be recovered.

Page 41

Indoor Blower Test

To indoor blower test mode , push and hold button next to single character LED display until — (Solid bar), then release button.

Ye s

Indoor Blower Test Mode

AHC in Idle Mode

(No heating cooling or indoor

fan operation)

Turn room thermostat to

OFF

Display will show a continuous solid bar “-” .

Control will cycle the indoor blower motor for ten seconds at 70% of maximum air for selected capacity size unit. Control will indoor blower test mode.

Operation

COOLING (COOLING ONLY OR HEAT PUMP)

When the thermostat calls for cooling, 24 volts is applied to the blower time-delay relay coil. After a delay, the indoor blower relay energizes. The normally open contacts close, causing the indoor blower motor to operate. The circuit

between R and Y is completed, closing the circuit to the

contactor in the outdoor unit, starting the compressor and outdoor fan motor.

On heat pumps, circuit R and O energizes the reversing valve, switching the valve to the cooling position. (The reversing valve remains energized as long as the thermostat selector switch is in the COOL position.)

At the completion of the cooling demand and after the relay's time-delay, the compressor and outdoor fan will cycle

o󰀨.

HEATING (ELECTRIC HEAT ONLY)

When the thermostat calls for heat, the circuit between R and W is completed, and the heat sequencer is energized. A time delay follows before the heating elements and the

Push and hold button until the solid A symbol is displayed on the single character LED display, then release button.

indoor blower motor come on. Units with a second heat

sequencer can be connected with the rst sequencer to W

on the thermostat subbase, or they may also be connected to a second stage on the subbase.

HEATING (HEAT PUMP)

When the thermostat calls for heating, 24 volts is applied to the blower time-delay relay coil. After a delay, the normally open contacts close, causing the indoor blower motor to operate. The circuit between R and Y is completed, closing the circuit to the contactor in the outdoor unit, starting the compressor and outdoor fan motor. Circuit R and G energizes the blower relay, starting the indoor blower motor.

If the room temperature continues to decrease, the circuit between R and W1 is completed by the second-stage heat room thermostat. Circuit R-W1 energizes a heat sequencer. The completed circuit will energize supplemental electric heat (if applicable). Units with a second heat

sequencer can be connected with the rst sequencer to

W1 on the thermostat. They may also be connected to a second heating stage W2 on the thermostat subbase.

Page 42

EMERGENCY HEAT (HEATING HEAT PUMP)

If the selector switch on the thermostat is set to the emergency heat position, the heat pump will be locked out of the heating circuit, and all heating will be electric heat (if applicable). A jumper should be placed between W2 and E on the thermostat subbase so that the electric heat control

will transfer to the rst-stage heat on the thermostat. This will allow the indoor blower to cycle on and o󰀨 with the

electric heat when the fan switch is in the AUTO position.

Repairing or Replacing Cabinet Insulation

IMPORTANT

DAMAGED INSULATION MUST BE REPAIRED OR REPLACED before the unit is put back into operation. Insulation loses its insulating value when wet, damaged, separated or torn.

WARNING

Electric Shock Hazard. Can cause injury or death. Foil-faced insulation has conductive

characteristics similar to metal. Be sure there

are no electrical connections within 1/2ʺ

of the insulation. If the foil-faced insulation comes in contact with electrical voltage, the foil could provide a path for current to pass through to the outer metal cabinet. While the current produced may not be enough to trip existing electrical safety devices (e.g., fuses or circuit breakers), the current can be enough to cause an electrical shock hazard that could cause personal injury or death.

Matte- or foil-faced insulation is installed in indoor equipment to provide a barrier between outside air conditions (surrounding ambient temperature and humidity) and the varying conditions inside the unit. If the insulation barrier is damaged (wet, ripped, torn or separated from the cabinet walls), the surrounding ambient air will a󰀨ect the inside surface temperature of the cabinet. The temperature/

humidity di󰀨erence between the inside and outside of the

cabinet can cause condensation on the inside or outside of the cabinet which leads to sheet metal corrosion and subsequently, component failure.

REPAIRING DAMAGED INSULATION

Areas of condensation on the cabinet surface are an indication that the insulation is in need of repair.

If the insulation in need of repair is otherwise in good con-

dition, the insulation should be cut in an X pattern, peeled

open, glued with an appropriate all-purpose glue and placed back against the cabinet surface, being careful to not overly compress the insulation so the insulation can retain its original thickness. If such repair is not possible, replace the insulation. If using foil-faced insulation, any cut, tear, or separations in the insulation surface must be taped with a similar foil-faced tape.

Homeowner Maintenance

IMPORTANT

Do not operate system without a lter. A lter is required

to protect the coil, blower, and internal parts from

excessive dirt and dust. The lter is placed in the return

duct by the installer.

• Inspect air lters at least once a month and replace or clean as required. Dirty lters are the most common

cause of inadequate heating or cooling performance.

• Replace disposable lters. Cleanable lters can be

cleaned by soaking in mild detergent and rinsing with cold water.

• Install new/clean lters with the arrows on the side pointing in the direction of airow. Do not replace a cleanable (high velocity) lter with a disposable (low velocity) lter

unless return air system is properly sized for it.

• If water should start coming from the secondary drain line, a problem exists which should be investigated and

corrected. Contact a qualied service technician.

Professional Maintenance

GLUE -make sure there is full coverage of glue on the metal or insulation so there are no areas where air pockets may form which can lead to sweating.

1. CUT INSULATION IN X PATTERN

2. APPLY GLUE

3. PRESS GLUED TABS AGAINST CABINET

FIGURE 30. Repairing Insulation

NOTICE !

Failure to follow instructions will cause damage to the unit.

This unit is equipped with an aluminum coil. Aluminum coils may be damaged by exposure to solutions with a pH below 5 or above 9. The aluminum coil should be cleaned using potable water at a moderate pressure (less than 50psi). If the coil cannot be cleaned using water alone, Lennox recommends use of a coil cleaner with a pH in the range of 5 to 9. The coil must be rinsed thoroughly

after cleaning.

In coastal areas, the coil should be cleaned with potable water several times per year to avoid corrosive buildup (salt).

Page 43

Check-out Procedures

IMPORTANT

During installation, service or maintenance, make sure that copper tubing does not rub against metal edges or other copper tubing. Care should also be taken to ensure that tubing does not become kinked. Use wire ties to secure tubing to prevent movement.

Do not secure electrical wires to tubing that carries hot refrigerant gas. Heat from the tubing may melt the wiring insulation, causing a short circuit.

NOTE – Refer to outdoor unit installation instructions for system start-up instructions and refrigerant charging instructions.

PRE-START-UP CHECKS

• Is the air handler properly and securely installed?

• If horizontally congured, is the unit sloped up to 1/4 inch toward drain lines?

• Will the unit be accessible for servicing?

• Has an auxiliary pan been provided under the unit with

separate drain for units installed above a nished ceiling or in any installation where condensate overow

could cause damage?

• Have ALL unused drain pan ports been properly plugged?

• Has the condensate line been properly sized, run, trapped, pitched, and tested?

• Is the duct system correctly sized, run, sealed, and insulated?

• Have all cabinet openings and wiring been sealed?

• Is the indoor coil factory-installed TXV properly sized for the outdoor unit being used?

• Have all unused parts and packaging been disposed of?

• Is the lter clean, in place, and of adequate size?

• Is the wiring neat, correct, and in accordance with the wiring diagram?

• Is the unit properly grounded and protected (fused)?

• Is the thermostat correctly wired and in a good location?

• Are all access panels in place and secure?

CHECK BLOWER OPERATION

• Set thermostat to FAN ON.

• The indoor blower should come on.

CHECK COOLING OPERATION

• Set thermostat to force a call for cooling (approximately 5ºF lower than the indoor ambient temperature).

• The outdoor unit should come on immediately and the indoor blower should start between 30 - 60 seconds later.

• Check the air ow from a register to conrm that the system is moving cooled air.

• Set the thermostat 5ºF higher than the indoor temperature. The indoor blower and outdoor unit should cycle

o󰀨.

CHECK ELECTRIC HEAT (IF USED)

• Set thermostat to call for auxiliary heat (approximately 5°F above ambient temperature). The indoor blower and auxiliary heat should come on together. Allow a minimum of 3 minutes for all sequencers to cycle on.

• Set the thermostat so that it does not call for heat. Allow

up to 5 minutes for all sequencers to cycle o󰀨.

Use of Air Handler During Construction

Lennox does not recommend the use of its air handler unit during any phase of construction. Very low return air temperatures, harmful vapors and operation of the unit with

clogged or misplaced lters will damage the unit.

Air handler units may be used for heating (heat pumps) or cooling of buildings under construction, if the following conditions are met:

• A room thermostat must control the air handler. The use

of xed jumpers is not allowed.

• Air lter must be installed in the system and must be maintained during construction.

• Air lter must be replaced upon construction comple- tion.

• The air handler evaporator coil, supply fan assembly and duct system must be thoroughly cleaned following

nal construction clean-up.

• All air handler operating conditions must be veried ac- cording to these installation instructions.

Page 44

Installing Contractor’s Name_______________________ Installing

Contractor’s Phone_______________________

Job

Installing Date_______________________________

Address____________________________________

Temperature

Duct

System

Duct Static

Air Handler Model #__________________________

Thermostat

SUPPLY

AIR

Disconnect

Switch

Line Voltage

Integrated Control

Blower Motor Amps

Electric Heat Amps

RETURN

AIR

DUCT SYSTEM

SUPPLY AIR DUCT

Sealed

Insulated (if necessary)

Registers Open and Unobstructed

RETURN AIR DUCT

Sealed

Filter Installed and Clean

Registers Open and Unobstructed

INTEGRATED CONTROL

Jumpers Configured Correctly (if applicable)

Appropriate Links in Place (if applicable)

VOLTAGE CHECK

Supply Voltage ___________

Low Voltage _____________

Electrial Connections Tight

DRAIN LINE

Leak Free

Filter

TOTAL EXTERNAL STATIC (dry coil)

Supply External Static ______ ______

Return External Static ______ ______

Total External Static = ______ ______

ELECTRIC HEAT AMPS____________

INDOOR BLOWER AMPS___________

INDOOR BLOWER CFM____________

TEMPERATURE DROP (Cooling Mode)

Return Duct Temperature ___________

Supply Duct Temperature − ___________

TEMPERATURE RISE (Heating Mode)

Return Duct Temperature __________

Supply Duct Temperature − __________

THERMOSTAT

Adjusted and Programmed

Operation Explained to Owner

Drain Line

dry coil wet coil

Temperature Drop = ___________

Temperature Rise = __________

Explained Operation of System to Homeowner

Technician’s Name:_______________________Date Start−Up & Performance Check Completed__________

FIGURE 31. Start-up and Performance Checklist (Upow Conguration)

Page 45

Technician’s Name:_______________________Date Start−Up & Performance Check Completed__________

Installing Contractor’s Name_______________________ Installing

Contractor’s Phone_______________________

Job

Installing Date_______________________________

Address____________________________________

Thermostat

Duct System

Integrated

Control

Filter

Air Handler Model #__________________________

Disconnect

Switch

Line Voltage

Duct System

DUCT SYSTEM

SUPPLY AIR DUCT

Sealed

Insulated (if necessary)

Registers Open and Unobstructed

RETURN AIR DUCT

Sealed

Filter Installed and Clean

Registers Open and Unobstructed

INTEGRATED CONTROL

Jumpers Configured Correctly (if applicable)

Appropriate Links in Place (if applicable)

VOLTAGE CHECK

Supply Voltage ___________

Low Voltage _____________

Electrial Connections Tight

DRAIN LINE

Leak Free

RETURN

Drain Line

AIR

Duct Static

SUPPLY

AIR

Electric Heat Amps

Blower motor Amps

Temperature

TOTAL EXTERNAL STATIC (dry coil)

dry coil wet coil

Supply External Static ______ ______

Return External Static ______ ______

Total External Static = ______ ______

ELECTRIC HEAT AMPS____________

INDOOR BLOWER AMPS___________

INDOOR BLOWER CFM____________

TEMPERATURE DROP (Cooling Mode)

Return Duct Temperature ___________

Supply Duct Temperature − ___________

Temperature Drop = ___________

TEMPERATURE RISE (Heating Mode)

Return Duct Temperature __________

Supply Duct Temperature − __________

Temperature Rise = __________

THERMOSTAT

Adjusted and Programmed

Operation Explained to Owner

Explained Operation of System to Homeowner

FIGURE 32. Start-Up and Performance Checklist (Horizontal Conguration)

Page 46

Lennox CBA38MV User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual