Lennox 505, 021 User Manual

INSTALLATION/

E2006 Lennox Industries Inc.

Dallas, Texas, USA

SERVICE
INSTRUCTIONS

®

Humiditrol
Accessory (EDA) Units

ACCESSORIES

505,021M
02/06
Supersedes 01/06

Humiditrol

The Dave Lennox Signaturet Collection Humiditrol® En­hanced Dehumidification Accessory (EDA) is designed for
installation with a Lennox R−410A split−system outdoor unit
and an air handler or a furnace with a variable speed blow­er. This accessory is designed for indoor installations in ei­ther upflow or horizontal air discharge applications. This

unit is for use only on R−410A systems with thermal
expansion valves.

Prior to installation, study the decision tree on page
16 to confirm that all application requirements for
EDA installation are met.

NOTE − For downflow application, refer to Installation In­struction Supplement, Installing EDA Unit in Downflow
Configuration 505,134M.

Shipping & Packing List

S 1 − Assembled EDA indoor unit
S 1 − Bag assembly (includes check/flow restrictor for

use on EDA coil, EDA notification label).

S 1 − Outdoor fan relay and wiring harness (used only

with outdoor units equipped with variable speed fan
motors)

Check the components for shipping damage. If any dam­age is found, immediately contact the last carrier.

Other Required Components

Separately-ordered components are restricted to those
listed in the Engineering Handbook and the price book:

S SignatureStat

included],

− Single-stage (81M26)

− Multi−stage (81M27)

− Multi−stage heat-pump (81M28)

S Twisted Pair Wire (84X49) for outdoor sensor to ther-

mostat − Required for use with SignatureStatt.

®

EDA Series Unit

t

thermostat [Outdoor Sensor (46M98)

Table of Contents

EDA Series Unit 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping & Packing List 1. . . . . . . . . . . . . . . . . . . . . . . .

Other Required Components 1. . . . . . . . . . . . . . . . . . . .

General Information 1. . . . . . . . . . . . . . . . . . . . . . . . . . .

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

Installation Dimensions and Arrangement 3. . . . . . . . .

Component Functions 4. . . . . . . . . . . . . . . . . . . . . . . . . .

General Installation Information 5. . . . . . . . . . . . . . . . .

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

EDA Installation Flow Chart & Procedures 5. . . . . . . .

Leak Testing, Evacuation, Charging 8. . . . . . . . . . . . . .

Insulating and Sealing the Unit 9. . . . . . . . . . . . . . . . . .

Other System Components 9. . . . . . . . . . . . . . . . . . . . .

How the EDA Unit Works 10. . . . . . . . . . . . . . . . . . . . . . .

Cooling Mode with Dehumidification ON 10. . . . . . . . . .

Cooling Mode (Dehumidification OFF) 11. . . . . . . . . . . .

Heating Mode (Heat Pump Applications) 11. . . . . . . . . .

Air Resistance Table 13. . . . . . . . . . . . . . . . . . . . . . . . . . .

Repair Parts List 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wiring Diagrams 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Decision Tree 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Information

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

The Humiditrol® EDA unit will operate to dehumidify, as re­quired, when ambient temperatures are below 95ºF. When
temperatures reach 95ºF, the cooling and dehumidification
requirements will both be satisfied by the increased sys­tem runtime. In applications that include a Humiditrol
EDA unit, a call to activate the dehumidification mode at or
above 95ºF is unnecessary and would not be issued or al­lowed by the SignatureStatt room thermostat.

Prior to system checkout, consider the outdoor ambient
temperature. REMEMBER, the EDA unit does NOT
function in temperatures at or above 95ºF. Plan testing
to be conducted when temperatures are between 65ºF and
95ºF to ensure proper EDA set up and checkout operation.

S 75VA 24VAC indoor unit transformer (12P61) − Re-

quired when EDA unit is installed with a two-stage heat
pump system.

S Humiditrol

plications information in Lennox Engineering Hand­book)

®

EDA Insulation and Piping Kit (refer to ap-

02/06 505,021M

The approved application for the EDA Series unit is
restricted to those listed in the Engineering Hand­book and price book.

*2P0206* *P505021M*

Enhanced Dehumidification

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

IMPORTANT

Litho U.S.A.

®

WARNING

11/16

20−3/4

11/16

This cased product contains fiberglass wool. Dis­turbing the insulation during installation, mainte­nance, or repair will expose you to fiberglass wool
dust. Breathing this may cause lung cancer. (Fiber­glass wool is known to the State of California to
cause cancer.)

Fiberglass wool may also cause respiratory, skin,
and eye irritation.

To reduce exposure to this substance or for further
information, consult material safety data sheets
available from address shown below, or contact
your supervisor.

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

Unit Dimensions

WARNING

Risk of explosion or fire. Can cause
injury or death. Recover all refrigerant
to relieve pressure before opening the
system.

IMPORTANT

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

EDA Model Dimensions − Inches (mm)

Dimension EDA−024B EDA−036C EDA−060D

A 17−1/2 (445) 21 (533) 24−1/2 (622)

B 12−1/4 (311) 12−1/4 (311) 14 (356)

C 16−1/8 (422) 19−5/8 (498) 23−1/8 (587)

D 16−1/8 (422) 19-5/8 (498) 23−1/8 (587)

E 1−3/8 (35) 3−1/8 (79) 4−7/8 (124)

F 3−1/8 (79) 4−7/8 (124) 6−5/8 (168)

G 3 (76) 3−1/4 (83) 4−3/4 (121)

Check/Flow Restrictor
to Vapor Line Tee

Liquid Line to
Indoor TXV

Liquid Line
From Outdoor
Unit

E

1

(25)

To Charge Compensator
side connection

A

9−1/2
(241)

2−1/2

(64)

F

G

Electrical
Inlet

B

(17)

1−3/4

(44)

11/16 (17)

D

11/16 (17)

OUTLET

AIR

OPENING

(527)

22−1/4

(565)

(17)

EDA 01/06

11/16 (17)

INLET AIR OPENING INLET AIR OPENING

C

11/16 (17)

1−7/16 (37)

20−1/8

(511)

Page 2

11/16 (17)

Installation Dimensions and Arrangement

EDA UNIT

(TRANSITION
See Note 2)

INDOOR
COIL

EDA−024B: 12−1/2
EDA−036C: 12−1/2

EDA−060D: 14

Varies by indoor

coil model; see

LENNOX

Engineering

Handbook.

12" (min.)

TRANSITION
(See Note 1)

FURNACE

TYPICAL

UP−FLOW

POSITION

(Furnace Shown)

TYPICAL HORIZONTAL

POSITION (Furnace Shown)

AIR FLOW

UP-FLOW FURNACE

NOTES:

1. Transition is required for all air handlers; dimension
width and depth is dependent upon the air handler
and the EDA model used.

2. Transition is required between indoor coil and EDA
if 5 ton EDA unit is used with small profile furnace.

Figure 1

Varies by air

handler model; see

Handbook for

40

AIR FLOW

LENNOX

Engineering

dimensions.

UP-FLOW AIR
HANDLER

Page 3

EDA INSTALLATION/ SERVICE INSTRUCTIONS

Component Functions

Check/Flow Restrictor Operation

Charge CompensatorThe charge compensator

(shown in figure 5) serves to maintain the proper amount of
refrigerant circulating in larger systems. [Some systems
do not require a charge compensator, but do require a simi-

FROM

VAPOR

LINE

TEE

CHECK/FLOW
RESTRICTOR FLOATS IN
CHATLEFF CONNECTOR

GREATER

PRESSURE

lar kit to connect into the system (see Engineering Hand­book)]

The charge compensator stores excess refrigerant when
the EDA coil is active and returns it to the system during

FROM

VAPOR

LINE

TEE

GREATER

PRESSURE

O−RING SEALS
CHECK/FLOW
RESTRICTOR

normal cooling or heating operations. When the EDA coil is
active, less charge is required to obtain the proper amount
of subcooling because of the additional coil surface and
the cooler air which passes over the EDA coil.

Check/Flow RestrictorThe check function of the
check/flow restrictor (shown in figure 2) prevents refriger­ant from flowing into the inactive components during times
when the EDA coil is inactive. The flow restrictor controls
the rate of return of charge to the system from the charge
compensator and the EDA coil when the system changes
from "EDA coil active" to "EDA coil inactive."

Valve AssemblyThe first valve of the diverting valve as­sembly (figure 3, E) directs the flow of refrigerant to either
bypass the EDA coil (EDA coil is inactive) or pass through
the EDA coil (EDA coil is active).The second valve (figure 3
F) directs the flow of refrigerant back to the liquid line when
the first valve (E) allows flow through the EDA coil. When
the EDA coil is inactive, the second valve (F) provides a
vent path to the suction line, draining the EDA coil and
charge compensator of liquid refrigerant.

Figure 2

EDA Unit Parts Arrangement

AB CD A B CD A B C D

EDA−024B

EDA−036C EDA−060D

EDA

UNIT

EDA

UNIT

EFEF

3−WAY DIVERTING VALVE ASSEMBLY

A − Liquid Line From Outdoor Unit
B − Liquid Line to Indoor TXV
C − Check/Flow Restrictor to Vapor

Line Tee

EDA COIL

3−WAY DIVERTING VALVE ASSEMBLY

D − To Charge Compensator side connection (1/4" line must be brazed closed on systems that do not
require the installation of a charge compensator)

E − EDA inactive mode − bypasses the EDA EDA active mode − allows refrigerant flow through EDA
F − EDA inactive mode − vent path to suction line; EDA active mode − directs refrigerant flow back to

liquid line

EDA COIL

3−WAY DIVERTING VALVE ASSEMBLY

Figure 3

EF

EDA COIL

EDA 01/06

Page 4

General Installation Information

Releasing Air Charge

NOTE − EDA units use dry air as a holding charge.

WARNING

Improper installation, adjustment, alteration, ser­vice or maintenance can cause personal injury, loss
of life, or damage to property.

Installation and service must be performed by a
qualified installer or service agency.

The EDA unit may be used in upflow or horizontal dis­charge installations. Slots around the inlet end of the EDA
cabinet are provided to secure the EDA unit to the duct
flanges of indoor coil/air handler cabinets. Use field-pro­vided #8 x 1" long SDST screw (usually 6 required).

CAUTION

Physical contact with metal edges and corners
while applying excessive force or rapid motion can
result in personal injury. Be aware of, and use
caution when working nearby these areas during
installation or while servicing this equipment.

Refrigeration

All EDA coils are shipped with a combination check/flow
restrictor. The restrictor is provided in the bag assem-
bly and must be installed. Refer to the appropriate high
and/or low side installation instructions for information on
the appropriate line sets. Refer to Lennox Refrigerant Pip­ing guide (Corp. 9351−L9) for proper size, type, and ap­plication of field−fabricated lines.

CAUTION

The EDA coil is shipped from the factory pressur­ized with dry air. Pierce a hole in the coil’s rubber
plug vapor line seal to relieve the pressure before re­moving the seals.

Ensure that the coil is void of pressure. Remove the rubber
plug from the lines.

NOTE − If there is no pressure when the plugs are pierced,
check the unit for leaks before continuing with the installa­tion.

Refrigerant Line Connections

NOTE − When connecting lines, be careful to avoid damag­ing the 3−way diverting valve access panel. Place a wet rag
against the piping plate and around the EDA unit line con­nections. A wet rag heat shield must be in place during
brazing to guard against damage to the paint.

Electrical Wiring

Electrical wiring diagrams are provided in figures 12 and 13
(see pages 14 and 15). Some modifications to certain units
may be necessary. Review the diagrams before installa­tion to ensure all necessary components are on hand at
time of installation.

EDA Installation and Checkout Flow Chart

Follow the procedures in the flow chart in figure 4 while re­ferring to the illustration in figure 5 to install the EDA: and
associated components.

Page 5

EDA INSTALLATION/ SERVICE INSTRUCTIONS

EDA Installation & Checkout Flow Chart

start

ARE

ALL REQUIRED

PARTS

AVAILABLE

?

YES

Installation Process

ENSURE ALL POWER IS OFF

INSTALL EDA UNIT IN DUCT

SYSTEM

INSTALL THE CHARGE

COMPENSATOR (IF REQUIRED)

IN CONVENIENT LOCATION

(SEE FIGURE 5)

NO

Required Parts (all applications)

EDA Unit, with check/flow restrictor & label
Appropriate SignatureStatt Thermostat
46M98 − Outdoor Sensor
84X49 − Twisted Pair Wire
Appropriate Insulation and Piping Kit

PROCURE

MISSING PARTS

MAKE WIRING CONNECTIONS

AS SHOWN IN FIGURES 12 & 13

(SEE PAGES 14 AND 15)

INSTALL EDA" LABEL ON

OUTDOOR UNIT

POWER UP THE INDOOR UNIT

Required Parts (2−Stage Heat Pump appl.)

12P61 − 75VA Transformer (for HP applications)

Check Dehumidification Operation

SET COOLING SETPOINT ON ROOM THERMOSTAT
TO 2 DEGREES ABOVE INDOOR TEMPERATURE
(OUTDOOR UNIT WILL TURN OFF)

NOTE − A Humiditrol® EDA−equipped system is allowed
to operate and cool room temperature below set point
(but only by 2ºF) when trying to satisfy a persisting hu­midity set point.

SET DEHUMIDIFICATION SETPOINT TO 5% BELOW
CURRENT ROOM RELATIVE HUMIDITY

MAKE ALL REFRIGERATION

CONNECTIONS, BEING SURE

TO INSTALL THE CHECK/FLOW

RESTRICTOR (SEE FIGURE 5)

LEAK CHECK THE SYSTEM

WITH 3−WAY VALVE ASSEMBLY

SET TO EVACUATE" (SEE

FIGURE 7)

INSULATE ALL REFRIGERANT

LINES

EVACUATE THE SYSTEM AS

DESCRIBED IN THE OUTDOOR

UNIT INSTALLATION

INSTRUCTIONS

INSTALL OUTDOOR SENSOR

CHECK THAT 3−WAY VALVE

ASSEMBLY IS SET TO

COOLING" POSITION AS

SHOWN IN FIGURE 7

ENABLE HUMIDITROL ON

ROOM THERMOSTAT (SEE

FIGURE 8)

SET THERMOSTAT FOR

MAXIMUM COOLING

OPEN REFRIGERANT VALVES

TURN OUTDOOR UNIT MAIN

POWER ON

CHECK CHARGE AND CHARGE

AS NEEDED (SEE PAGE 8)

DEHUMIDIFICATION

IS

THE

OUTDOOR

TEMPERATURE

BELOW

95ºF

?

YES

OUTDOOR UNIT:
COMPRESSOR IN HIGH STAGE;
FAN IN LOWEST SPEED;

EDA:
3−WAY VALVE ASSEMBLY TO DEHUMIDIFICATION"
POSITION

INDOOR UNIT:
FAN IN DEHUMIDIFICATION SPEED

CHECK THE TEMPERATURE DIFFERENCE
ACROSS THE EDA COIL AND THE LIQUID LINE
TEMPERATURES AS NOTED IN FIGURE 9 ON
PAGE 10

IS DE−ACTIVATED;

NO

OPERATION AT A

TEMPERATURE IS

CHECK FOR

CORRECT

TIME WHEN

AMBIENT

BELOW 95ºF.

EDA 01/06

Figure 4

Page 6

Electrical Inlet

To Charge

Compensator side

connection (some

applications)

Check/Flow

Restrictor to Vapor

Line Tee

Liquid Line to

Indoor TXV

Liquid Line From

Outdoor Unit

EDA

Typical Installation (Horizontal Air Handler shown)

EDA UNIT

Check/Flow-

Restrictor

Details

FITTING IN
EDA UNIT

AIR

FLOW

IMPORTANT!
RESTRICTOR MUST BE INSERTED WITH O−RING
END OF RESTRICTOR TOWARD EDA UNIT FITTING.
TORQUE CHATLEFF CONNECTION TO 20 FT. LBS.

MUST BE INSULATED

Liquid

TXV

Line

INDOOR

UNIT

air−flow

Vapor
Line

TEFLON SEAL

1/4" PORT MUST

BE BRAZED

CLOSED

CHECK/FLOW
RESTRICTOR
AND O−RING

System without

compensator

NO CHARGE

COMPENSATOR

OR 1/4" LINE

Liquid Line from

Outdoor Unit

Liquid Line to

Indoor TXV

ELECTRICAL
INLET

LIQUID LINE FROM
OUTDOOR UNIT

6 ft. max.

BETWEEN CHARGE
COMPENSATOR AND EDA USING
1/4" LINE PROVIDED IN CHARGE
COMPENSATOR KIT

TYPICAL HORIZONTAL POSITION INSTALLATION

MUST BE
INSULATED

TO CHARGE
COMPENSATOR SIDE
CONNECTION

CHECK/FLOW
RESTRICTOR TO
VAPOR LINE TEE

LIQUID LINE
TO INDOOR
TXV

2 ft. max.

DROP TO CHARGE
COMPENSATOR

TO CHECK/FLOW
RESTRICTOR ON EDA

Compensator

USE REDUCER(S) FROM

CHARGE COMPENSATOR KIT

(WHEN REQUIRED)

VAPOR LINE
FROM
OUTDOOR
UNIT

7/8 X 7/8 X

1/4" TUBING
CONNECTION − MUST
BE AT LOWEST POINT
OF THE COMPENSATOR

Liquid

Line

Charge

Details

3/8 TEE

CHARGE
COMPENSATOR

Vapor
Line

VAPOR
LINE
FROM
INDOOR
COIL

OUTDOOR

UNIT

VAPOR LINE FROM

INDOOR COIL

1/4" TUBING
CONNECTION −
MUST BE ON
BOTTOM OF
COMPENSATOR

TO CHECK/FLOW
RESTRICTOR ON EDA

7/8 X 7/8 X
3/8 TEE

UPFLOW POSITION

CHARGE

COMPENSATOR

VAPOR LINE FROM
OUTDOOR UNIT

USE REDUCER(S)

FROM CHARGE

COMPENSATOR KIT

(WHEN REQUIRED)

USE REDUCER(S)

FROM CHARGE

COMPENSATOR KIT

(WHEN REQUIRED)

Figure 5

Page 7

EDA INSTALLATION/ SERVICE INSTRUCTIONS

Leak Testing, Evacuating, Charging

IMPORTANT

The 3−way diverting valve actuator shaft setscrew
(see figure 7) is factory set and is not to be adjusted.

3−way Diverting Valve Operation

NOTE − During system operation, the 3-way valve requires
24-volt power to drive between cooling and dehumidifica­tion.

The 3−way diverting valve is actually two valves connected
by a common shaft, designed to open one valve while clos­ing the other, and vice versa. For evacuating (with power
off), the diverting valve can be REPOSITIONED using its
actuator lever, a long setscrew that has been factory-set to
a precise point on the common shaft. Do not loosen (un­screw) the setscrew. Should the setscrew become

loose, carefully follow the note in figure 6 to position
and tighten it.

Re−aligning Setscrew

NOTE − Actuator shaft setscrew is factory set and must not be ad­justed. If the set screw should become loose, use a pliers to grip the
shaft where shown (1) and rotate the shaft (in direction of the black
arrow) until the pin stops (inset shows pin and stops). Press the red
button (2) in the direction of the white arrow and move the lever (3)
to the forward position and tighten setscrew to 60 in-lbs torque.

2

1

IMPORTANT

Prior to starting the outdoor unit for charging, be
sure the 3-way valve is energized and in the cool­ing" (forward) position (see figure 7).

3. Very little charge is required for the additional volume
of the EDA unit. When in normal cooling, the compo­nents will all be occupied by vapor that has very little
weight. At most (depending on the model) an addition­al 1/4 pound of refrigerant may be required.

4. When shifting from dehumidify mode to cooling, or
vice versa, wait at least 10 minutes for the system to
reach stable operating pressure before checking tem­peratures and pressures, or adjusting refrigerant
charge.

NOTE − Prior to starting the outdoor unit for charging,
set the thermostat to call for cooling (dehumidification
OFF). It will take about 90 seconds for the 3−way di­verting valve to energize and shift to the cooling posi­tion. To ensure that the 3-way diverting valve is ener­gized and in the cooling" (forward) position, observe
the position of the 3-way diverting valve actuator shaft
setscrew in figure 7; if properly shifted, the setscrew
will be in the forward position.

Setting 3−Way Diverting Valve to

Evacuate Position

1. PUSH RED TAB IN DIRECTION INDICATED.

2. PUSH ACTUATOR SHAFT DOWN TOWARD THE
CENTER−OF−TRAVEL POSITION

1

3

STOP

PIN

SHAFT

STOP

Figure 6

Leak Testing, Evacuating, Charging

1. Set the 3−way diverting valve actuator shaft to the cen­ter (evacuate) position for leak testing and evacuation
(see figure 7). IMPORTANT! The actuator shaft

must be set as described to allow the EDA to evac­uate more quickly.

2. Refer to instructions provided with the outdoor unit for
leak testing, evacuating and charging procedures.

EDA 01/06

2

COOLING

(FORWARD)

EVACUATE

(CENTER)

DEHUMIDIFICATION

(REARWARD)

Figure 7

5. The charge must be checked with the system in cool­ing operation (dehumidification OFF). After testing
and charging as required, set the thermostat to force
a demand for dehumidification.

Page 8

Insulating and Sealing the Unit

IMPORTANT

All piping, metering devices, and connections must
be insulated to prevent moisture damage caused by
sweating.

Seal the unit so that warm air is not allowed into the cabi­net. This is especially important when the unit is installed in
an unconditioned area. Make sure the liquid line entry
points are sealed with either refrigerant tube insulating ma­terial or with Permagum (see figure 5 on page 7).

Then, select HUMIDITROL mode from the DEHUMIDIFY
menu (follow the path: MENU −> DEHUMIDIFY). The user
control sequence is also shown in figure 8, C through H;
specifically:

S Turn on Humiditrol − D & E
S Set level of dehumidification − F through H (adjustment

range is from 45% to 60% and is factory set to 50%)

If HUMIDITROL is enabled and the outdoor sensor is dis­connected, operation is NOT allowed in dehumidification
mode. This is indicated by the display of "OUTSIDE ERR"
on the SignatureStatt thermostat Home screen.

Other System Components

Blower Control

EDA units are to be applied with an indoor unit that has a
variable speed motor (VSM). Refer to the indoor unit instal­lation instruction for setting blower speed.

Thermostat and Sensor

IMPORTANT

A SignatureStatt thermostat and properly-
connected outdoor sensor is REQUIRED for the
EDA unit to function properly. Twisted pair wire
(84X49 or equivalent) is REQUIRED between the
SignatureStat and the outdoor sensor.

Install the remote sensor on the outside of a northern wall
of the home, away from direct sunlight or other heat
sources that may affect its sensitivity.

Refer to the SignatureStatt thermostat Installation
Instructions for installation, wiring, and setup. Also refer to
the SignatureStatt Thermostat Programming Guide for
programming and settings.

To configure the thermostat for operation with a Humidi-

®

trol

system, first enable HUMIDITROL in the thermostat’s

installer settings (follow the path: MENU −> INSTALLER
SETTINGS −> HUMIDITROL − see figure 8, A and B).

Setting Thermostat

Installer Setup

INSTALLER SETTINGS Y
AUTO CHANGEOVER ON
EER ON
DEADBAND 4.0°F

HUMIDITROL OFF

MAIN MENU SELECT B

AB

User Controls

MAIN MENU
PROGRAM
HEAT / COOL
HUMIDIFY ↓

DEHUMIDIFY

HOME SELECT

CD

DEHUMIDIFY MODE
OFF

HUMIDITROL

DEHUM MENU SELECT

EF

DEHUMIDIFY

CONTROL

%

50

DEHUM MENU SELECT

↑
↓

GH

Figure 8

HUMIDITROL

DISABLE

ENABLE

INSTALL MENU SELECT

DEHUMIDIFY MENU

MODE OFF

DEHUMIDIFY 50%

MAIN MENU SELECT

DEHUMIDIFY MENU
MODE HUMIDITROL

DEHUMIDIFY 50%

MAIN MENU SELECT

DEHUMIDIFY MENU
MODE HUMIDITROL

DEHUMIDIFY 55%

MAIN MENU SELECT

Page 9

EDA INSTALLATION/ SERVICE INSTRUCTIONS

EDA Unit Operation

The EDA coil is added to an HVAC system downstream of
the indoor coil. In dehumidification mode, the coil becomes
an extension of the condenser coil and injects heat into the
indoor air stream.

This dehumidification mode allows significantly improved
control of the humidity in the conditioned space without
overcooling the space. The assembly includes a set of
3−way diverting valves which will either route refrigerant
through the EDA coil, or cause the refrigerant to bypass
the EDA coil, depending on the mode of operation.

Operation Notes

1. IMPORTANT REMINDER! Dehumidification will not
occur when the outside temperature is at or above
95ºF.

2. When operating in cooling (or heat pump heating)
mode, all temperatures and pressures will be as in a
normal system.

3. When the thermostat is in HUMIDITROL mode, and
after a cooling demand has been satisfied but a dehu­midification demand persists and the room tempera­ture is not more than 2°F below the setpoint, the air
handlers will operate at reduced airflow with the com­pressor at high speed.

4. When the unit is in the dehumidification
mode, the display will show a raindrop"
icon with an imbedded negative sign and
the current relative humidity to its right.

Cooling Mode (Dehumidification ON)

If the room thermostat’s cooling demand has been satis­fied but the dehumidification setting has not been satisfied,
the unit continues to run in dehumidification mode. The
room thermostat sends a signal to the EDA unit’s 3−way di­verting valve assembly to begin operating in the dehumidi­fication mode.

Figure 9 shows refrigerant flowing from the outdoor unit,
entering the EDA, passing through the first 3−way diverting
valve, then entering the EDA coil. There, heat from the
warm refrigerant is transferred into the indoor air stream.
The refrigerant exits the coil through the second 3−way di­verting valve and into the indoor coil expansion valve.

During dehumidification, the indoor air blower (and outdoor
fan, if an outdoor relay is used) operates at a lower air vo­lume. The cool, dehumidified air leaving the indoor coil is
warmed as it passes over the EDA coil. Air temperature
rise across the EDA coil can be from 10° to 25°F, depend­ing on the operating ambient and air-conditioned space
conditions.

The warm vapor−liquid−refrigerant mixture entering the
EDA unit from the outdoor unit will be subcooled in the EDA
unit and enter the expansion valve at a lower-than-normal
temperature. Liquid temperatures can be in the 65° to 70°F
range, with a 10° to 40°F temperature change across the
EDA.

OUTDOOR UNIT

Cooling Cycle with EDA Coil Active (Model EDA−036C shown)

VAPOR
LINE VALVE

LIQUID
LINE
VALV E

7/8 x 7/8 x
3/8 TEE

CHECK/FLOW

RESTRICTOR

(flow permitted)

See note 2 See note 2

NOTE 1. With EDA Coil Active, expect a 10 to 25ºF air temperature rise across EDA coils.
NOTE 2. With EDA Coil Active, expect a 10 to 40ºF liquid line temperature change across EDA coils.
NOTE 3. Charge compensator and 1/4" line not required on all systems. See Engineering Handbook.

CHARGE COMPENSATOR
(holding some refrigerant)
See note 3.

3−WAY
DIVERTING
VALV E

See note 1See note 1

CHECK/

EXPANSION

VALV E

Figure 9

air flow

INDOOR COIL

INDOOR
BLOWER

INDOOR

UNIT

EDA 01/06

Page 10

Cooling Mode (Dehumidification OFF)

Figure 10 illustrates refrigerant flow in cooling mode (dehu­midification mode OFF),

Cooling Cycle with EDA Coil Inactive (Model EDA−036C shown)

The liquid refrigerant from the outdoor unit enters the EDA
module . Since there is no demand for dehumidification,
the 3−way diverting valve assembly directs the flow back
out of the EDA module to the indoor unit expansion valve.

VAPOR
LINE VALVE

LIQUID
LINE
VALV E

OUTDOOR UNIT INDOOR UNIT

NOTE 1. In Cooling Mode, no air temperature change across EDA coils.
NOTE 2. In Cooling Mode, no liquid line temperature change across EDA coils.
NOTE 3. Charge compensator and 1/4" line not required on all systems. See Engineering Handbook.

7/8 x 7/8 x
3/8 TEE

CHECK/FLOW

RESTRICTOR

(flow restricted)

See note 2 See note 2

CHARGE COMPENSATOR
(NOT holding refrigerant)
See note 3.

3−WAY
DIVERTING
VALV E

See note 1See note 1

EXPANSION

air flow

CHECK/

VALV E

Figure 10

Heating Mode (Heat Pump Applications)

Figure 11 illustrates refrigerant flow in the heating mode.

In heat pump application heating mode, a system that in­cludes an EDA unit will operate as a conventional heat
pump. The EDA unit does not operate in this mode.

INDOOR COIL

INDOOR
BLOWER

Heat Pump Heating Cycle with EDA Coil Inactive (Model EDA−036C shown)

OUTDOOR UNIT

VAPOR
LINE VALVE

LIQUID
LINE
VALV E

NOTE 1. In Heating Mode, no air temperature change across EDA coils.
NOTE 2. In Heating Mode, no liquid line temperature change across EDA coils.
NOTE 3. Charge compensator and 1/4" line not required on all systems. See Engineering Handbook.

7/8 x 7/8 x
3/8 TEE

CHECK/FLOW

RESTRICTOR

(flow restricted)

See note 2 See note 2

CHARGE COMPENSATOR
See note 3.

See note 1See note 1

CHECK/

EXPANSION

VALV E

Figure 11

air flow

INDOOR COIL

INDOOR
BLOWER

INDOOR UNIT

Page 11

EDA INSTALLATION/ SERVICE INSTRUCTIONS

Check List

instructions; also, see figure 5)

p

gp

(but only by 2F) when try

n Checkpoint What to Check Action

Thermostat and
Sensor

Thermostat Humiditrol® Installer Settings Confirm HUMIDITROL is enabled (see figure 8)

Thermostat Humiditrol® User Settings Confirm HUMIDITROL − Dehumidify − ON is selected (see figure 8)

Thermostat Humiditrol® User Settings Confirm Relative Humidity setting (see figure 8)

Indoor Unit Variable-Speed Blower Settings Confirm Settings for D": CFM = 60% to 65% of 2nd-stage cool

Insulation Charge Compensator

Insulation Liquid Line

Insulation Vent Line to Suction Line

Charge Compen­sator

Check/Flow Re­strictor

System Charge Refrigerant With unit running in cooling mode, check and confirm system is

Outdoor Unit Fan Relay Confirm (if unit has variable speed outdoor fan) relay is installed

Outdoor Unit EDA Label Confirm label is installed in prominent location and will be easily

NOTE − System will NOT operate in dehumidification mode with outdoor temperature at or above 95ºF.

Operational Status Dehumidification Mode Record supply air temperature and confirm temperature that it is

Operational Status Dehumidification Mode On units with variable speed outdoor fan, check that fan operates

Wiring Confirm Sensor connected to SignatureStatt using twisted pair

wire (see wiring diagram figure 13)

(see indoor unit installation instructions and table 1, below)

Confirm insulation is properly installed (see charge compensator kit

1/4"Line Confirm 1/4" port oriented downward (see charge compensator

details, figure 5)

3/8" Line Confirm restrictor installed/oriented properly (see check/flow restric-

tor details figure 5)

properly charged (see outdoor unit installation instructions).

properly (see wiring diagram figures 12 and 13)

visible during servicing.

higher than in cooling mode.

at approximately 250 rpm (lowest speed).

Table 1

®

Demand Signals − Humiditrol

Operating Sequence System Demand System Response

Thermostat Demand Relative Humidity

System Type Step

Cooling Operation − No call for dehumidification

Single-stage outdoor unit 1 ON (na) ON ON Acceptable 24 VAC High 100
Two-stage outdoor unit Y1 1 ON − ON ON Acceptable 24 VAC Low 70
Two-stage outdoor unit Y2 2 ON ON ON ON Acceptable 24 VAC High 100

Demand for Dehumidification and Cooling

Single-stage outdoor unit 1 ON (na) ON ON Demand 24 VAC High 100
Two-stage outdoor unit Y1 1 ON − ON ON Demand 24 VAC Low 70
Two-stage outdoor unit Y2 2 ON ON ON ON Demand 24 VAC High 100

Dehumidification Mode Only − No Cooling Demand

Single-stage outdoor unit 1 ON (na) ON ON Demand 0 VAC High 50 − 70*

Two-stage outdoor unit Y2 2 ON ON ON ON Demand 0 VAC High 50 − 70*

* NOTE − Blower CFM speed (percentage) will vary depending on selected indoor equipment (furnace, coil blower, etc.).

Y1 Y2 O G Status D

EDA Enabled

Com-

pressor

Blower

CFM

(Cool) %

Comments

Compressor and indoor

blower follow thermostat

demand

Cooling operation has

priority

A Humiditrol® EDA−
equipped system is allowed
to operate and cool room
temperature below set point
(but only by 2ºF) when try­ing to satisfy a persisting
humidity set point; it is not
allowed to operate at all
when outdoor temperature
is >95ºF.

EDA 01/06

Page 12

Air Resistance

Si

(twisted

3

Table 2 shows air volume and total air resistance for the
available EDA models.

Table 2

Air Resistance

Air Volume Total Air Resistance

Model No.
EDA−024B

EDA−036C

EDA−060DB

cfm L/s in. w.g. Pa

400 190 0.05 12

600 285 0.10 25

800 380 0.15 37

1000 470 0.22 55

600 285 0.05 12

800 380 0.08 20

1000 470 0.11 27

1200 565 0.15 37

1400 660 0.20 50

1000 470 0.05 12

1200 565 0.06 15

1400 660 0.08 20

1600 755 0.10 25

1800 850 0.11 27

2000 945 0.13 32

2200 1040 0.15 37

Repair Parts

S 3−way diverting valve assembly
S Check/flow restrictor
S EDA Relay
S Outdoor unit relay
S Teflon seals

Wiring Diagrams

Typical condensing unit and heat pump wiring diagrams
are provided in figures 12 and 13. Some modifications to
certain units may be necessary.

Connect the EDA unit with the indoor and outdoor units,
and to the thermostat. Be sure the outdoor sensor is
installed and connected to the SignatureStatt thermo­stat’s outdoor sensor terminal block. Table 3 shows the re­quirements for control wiring.

Table 3

Control Wiring Requirements

Units: (all) (with LSOM) (without LSOM)

Indoor unit to:

Signatu­reStatt

10* 8 9* 7

Out-

Signatu-

door

reStatt

unit

9* 6 8* 4

8* 5 7* 3

9* 7 8* 6

Out­door
unit

System
type

2 stage

AC

1 stage

AC

2 stage

HP

1 stage

HP

gna­tureS­tatt to
Sensor

pair)

Humidi­trol®
EDA

2

*Includes conductor for 2−stage heat

Page 13

EDA INSTALLATION/ SERVICE INSTRUCTIONS

1st, cut yellow
wire here.

Typical EDA/Condensing Unit Wiring Diagram

*OUTDOOR RELAY 

NOT REQUIRED WITH SINGLE-

SPEED OUTDOOR FAN

2nd, rewire yellow
wire as shown

Blue

B4

Yellow

FAN

Black

2

75

Yellow

Yellow

Use Wirenuts

Purple

K1

Black

Black

BLACK

BLACK

RED

YELLOW

BLUE

BLACK

BROWN

Purple

PURPLE

RED

5

1

INDOOR

UNIT

3

Orange

EDA

Red

Violet

VALV E
ACTUATOR

SEE CONTROL WIRING BELOW
FOR THERMOSTAT WIRING

DSY1 JUMPER − MUST BE
REMOVED FOR HUMIDITROL
OPERATION

Y1Y2 JUMPER − ONLY
REMOVE IF 2−STAGE COOLING

OUTDOOR

UNIT

FAN RELAY (NOT REQUIRED
WITH SINGLE-SPEED
OUTDOOR FAN)

RED (NOT REQUIRED FOR

APPLICATIONS WITHOUT LSOM)

PURPLE

BLACK

YELLOW

BLUE (NOT REQUIRED FOR SINGLE STAGE)

BLACK

BROWN (NOT REQUIRED FOR

APPLICATIONS WITHOUT LSOM)

OUTDOOR WIRING

(VSM APPLICATION

ONLY)

EDA

UNIT

Control Wiring

RED

BLACK

PURPLE

Figure 12

INDOOR

UNIT

SignatureStatt
THERMOSTAT

TWISTED PAIR

Y1Y2 JUMPER − IN FOR
SINGLE− STAGE COOLING;
REMOVED FOR 2−STAGE
COOLING

OUTDOOR

SENSOR

(46M98)

EDA 01/06

Page 14

Typical EDA/Heat Pump Wiring Diagram

*OUTDOOR RELAY 

NOT REQUIRED WITH SINGLE-

SPEED OUTDOOR FAN

2nd, rewire
yellow wire

as shown
1st, cut
yellow wire
here.

OUTDOOR

WIRING

(VSM

APPLICATION

ONLY)

B4

FAN

Blue

Yellow

Black

Use Wirenuts

Yellow

2

75

Yellow

Purple

K1

Black

Black

BLACK

BLACK

Purple

PURPLE

RED

5

1

BLUE

BROWN

BLUE

3

Orange

EDA

Violet

INDOOR

UNIT

VALV E
ACTUATOR

DSY1 JUMPER − MUST BE
REMOVED FOR HUMIDITROL
OPERATION

SEE CONTROL WIRING BELOW
FOR THERMOSTAT
WONNECTIONS

RO JUMPER − MUST BE
REMOVED FOR HEAT PUMP
APPLICATION

Y1Y2 JUMPER − ONLY
REMOVE IF 2−STAGE COOLING

OUTDOOR

UNIT

RED

FAN RELAY (NOT REQUIRED
WITH SINGLE-SPEED
OUTDOOR FAN)

PURPLE

BLACK

YELLOW

BLUE

BROWN (NOT REQUIRED FOR APPLICATIONS WITHOUT LSOM)

BLUE (NOT REQUIRED FOR SINGLE STAGE)

EDA

UNIT

Control Wiring

Figure 13

RED

BLACK

PURPLE

INDOOR

UNIT

SignatureStatt
THERMOSTAT

OUTDOOR

SENSOR

TWISTED PAIR

Y1Y2 JUMPER − IN FOR
SINGLE− STAGE COOLING;
REMOVED FOR 2−STAGE
COOLING

(46M98)

Page 15

EDA INSTALLATION/ SERVICE INSTRUCTIONS

START

Is

dealer

R−410A & EDA

trained

?

YES

Zoning

application?

YES

Humiditrol

NO

NO

Obtain R−410A &
EDA training

matchup listed in
EDA Engineering

®

Enhanced Dehumidification Accessory (EDA)

Desired

equipment

Handbook?

YES

Decision Tree

Must use one of

NO

Must use one of
these outdoor units:

XC21, XP19, XC13, XP13

ONLY!

these variable
speed indoor
units:

CBX32MV, CBWMV,

G60UHV, G60DFV,

G61MPV ONLY!

Must be valid ARI rated match (refer to outdoor unit Engineering Handbook)

[If furnace]
Select indoor
coil

MUST BE TXV ONLY

Application

Not Approved

DO NOT

INSTALL

NOTE − Lennox warranties do
not cover damage or defect
resulting from operation with
system components (indoor unit,
outdoor unit, and refrigerant
control devices) which do not
match or meet the specifications
recommended by Lennox. This
unit intended to operate with
variable speed air handlers − see
Lennox Engineering Handbook
for approved matches.

Upflow/horizontal

NOTE − AIR HANDLER REQUIRES
FIELD−FABRICATED TRANSITION
BETWEEN BLOWER OUTLET
AND EDA COIL.

(REFER TO EDA ENGINEERING HANDBOOK)
X = PREFERRED MATCH−UP
A = ALLOWED FOR PHYSICAL MATCH−UP TO EVAPORATOR

CAPACITY −024B −036C −060D

−018 X A

−024 X A

−030 X A

−036 X A

−042 X

−048 X

−060 X

HUMIDITROL® EDA

94M41 94M42 94M43

Select Piping Kit

(REFER TO EDA ENGINEERING HANDBOOK AND
INSULATION & PIPING KIT INSTRUCTIONS 505,021M)

CAPACITY OUTDOOR UNIT MODEL PIPING KIT

Select EDA

−018 XC13 98M62

−024 XC13 98M62

−030 XC13, XP13 98M22

−036 XC13 98M22

−042 XC13 98M22

−048 XC13 98M22

−060 XC13 98M22

Upflow/
Horizontal

XP13 94M44

XP13, XP19, XC21 94M44

XP13, XP19, XC21 94M44

XP13 94M44

XP13, XP19, XC21 94M44

XP13, XP19, XC21 94M44

How

installed

?

Downflow

NOTE − REQUIRES ADDITIONAL
FIELD−FABRICATED SUPPORT
FRAME & TRANSITION; SEE
INSTALLATION SUPPLEMENT
505,134M

Downflow

EDA 01/06

INSTALL
SYSTEM

Figure 14

Page 16