Trane BAYECON101AA Assembly instructions

Installer’s Guide
March 2020 18-HE39D8-13
SAFETY WARNING
Only qualified personnel should install and service the equipment. The installation, starting up, and servicing of heating, ventilating,
and air-conditioning equipment can be hazardous and requires specific knowledge and training. Improperly installed, adjusted or
altered equipment by an unqualified person could result in death or serious injury. When working on the equipment, observe all pre-
cautions in the literature and on the tags, stickers, and labels that are attached to the equipment.
Model: Used with:
BAYECON101AA/AB 2/4TC*,WC*,YC*,DC* *018-036
BAYECON102AA/AB 2/4TC*,WC*,YC*, DC* *042-060
BAYRLAY004A (Relay required in WC* Units)
Note: “Graphics in this document are for
representation only. Actual model may differ
in appearance.”
Down Discharge Economizer and Rain Hood

2
INSTALLER’S GUIDE
18-HE39D8-13
ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
IMPORTANT-This Document is customer property and is to remain with this unit. Please return to service information pack
upon completion of work.
Install Economizer Kit
1. Remove Power
Disconnect and verify that power is off.
2. Remove Access Panels
Remove these four (4) access panels (see Figure 3, page 3):
• Control/Heat access panel
• Blower access panel
• Coil access panel
• Horizontal Return Air panel (discard or store)
3. Install Economizer Assembly
General
The economizer is a multi-damper design. It is installed in the
return air stream and is connected to the unit low voltage supply
through wire leads. The economizer is fully accessible through the
Coil access panel.
IMPORTANT: The Economizer installation requires that you
install an air filter rack ordered separately. Use:
BAYFLTR101B for 2/4YC*, WC*, TC*, DC* *018-3036
BAYFLTR201B for 2/4YC*, WC*, TC*, DC* *042-3060.
When the economizer is installed in WC* models, relay accessory
kit BAYRLAY004A is required. Refer to the drawing on page 9 to
make your relay wiring connections in the Control Box.
Identify Economizer Kit Contents
Refer to Figures 1 and 2 on page 3 to identify the kit contents.
Inspect Contents
You must report damage and make claims to the transportation
company immediately. Report missing parts to your supplier
immediately and replace with authorized parts only.
!WARNING:
HAZARDOUS VOLTAGE - DISCONNECT POWER BEFORE SERVICING
1. The economizer ships with the return air damper folded
up to allow the assembly to fit through the Coil opening
in the side of the unit, see Figures 1 and 2 on page 3.
Insert the economizer assembly into the unit through the
Coil access panel opening. See Figure 4 on page 4.
2. Swing the return air damper section down so that it rests
on the bottom of the unit. The economizer will sit com-
pletely over the return air opening in the bottom of the
unit. See Figures 5 on page 5. Screw the economizer
assembly together with one assembly screw in the side
of the economizer. Tighten the linkage rod between the
return air dampers.
3. Insert 2 screws through the holes in the front face of the
unit and into the matching attachment holes in the
economizer assembly. See Figure 6 on page 5.
4. Insert a screw through the pre-punched hole in the side
flange of the return air damper and into the mating hole
in the economizer assembly and tighten. See Figure 5
on page 5.
ELECTRIC SHOCK HAZARD
OPEN AND LOCK OUT ALL UNIT DISCONNECTS PRIOR TO
ACCESSORY INSTALLATION OR UNIT MAINTENANCE,TO PREVENT
INJURY OR DEATH FROM ELECTRICAL SHOCK OR CONTACTWITH
MOVING PARTS.
WARNING!
SAFETY HAZARD
DO NOT REMOVE END COVERS FROM ECONOMIZER ACTUATOR;
THE SPRING-RETURN ASSEMBLY MAY RELEASE AND CAUSE
PERSONAL INJURY.
!WARNING
Use care when inserting the economizer in the return air compart-
ment, to prevent damaging the foil faced insulation.
CAUTION
!

3
INSTALLER’S GUIDE
18-HE39D8-13
Mixed Air Sensor
Economizer Assembly
Rainhood Assembly
Figure 1. Economizer Kit Components
YC*, TC*, WC*, DC* *018A to *036
Figure 2. Economizer Kit Components
YC*, TC*, WC*, DC* *042A to *060
Figure 3. Remove Panels
DC, TC, WC,
or YC Unit
Horizontal
Return Air
Panel
Down Flow
Return Air
Panel
Blower Access Panel
Control Box Access
Panel
Coil Access
Panel
Mixed Air Sensor
Economizer Assembly
Rainhood Assembly
Mist Eliminator
(Filter)
Mist Eliminator
(Filter)
Return Air Damper
Flange Screw and
two (2) Mixed Air
Sensor
Sheetmetal Screws
(not shown)
Top Sealing
Flange
Return Air Damper
Flange Screw and
two (2) Mixed Air
Sensor
Sheetmetal Screws
(not shown)

4
INSTALLER’S GUIDE
18-HE39D8-13
4. Install Rain Hood Assembly
1. Locate the rainhood assembly, which includes the relief
damper and the mist eliminator. The back of the hood side
mating flanges need to be gasketed (gaskets included in
kit). Loosen the right two (2) screws on the unit’s top sealing
flange above the economizer. See Figure 3 on page 3.
2. Slide the top flange of the hood up underneath the unit’s top
sealing flange. Drive two self tapping screws into the keyhole
openings on the side flanges of the hood. Tighten the two (2)
screws on the top sealing flange and the screws on the hood
side flanges. See Figures 8 and 9.
5. Mount Mixed Air Sensor
1. Mount the Mixed Air sensor (with wiring) to the left Blower
partition using two sheetmetal screws. See Figure 10. The
male tabs on the two (2) yellow wires will connect to the
Economizer wiring harness in a later step.
2. Enthalpy and/or CO2 Sensor-If used, install these
options at this time per instructions provided.
Figure 4. Insert Economizer in Shipping Position
DC, TC, YC, or WC
Unit
Dry bulb outside air
temperature sensor
Insert economizer
in folded shipping
position
Economizer
actuator and
controller
6. Route Main Wiring
1. From the Economizer assembly, pass the wire harness
through the coil grommet. See Figure 10 (view A) on page
8. Continue routing the harness behind the Compressor
compartment and into the Blower compartment.
2. Continue routing the remaining harness through the grom-
met in the Control Box partition and into the Control Box.
7. Complete Installation
1. In the Control Box, complete the wiring connections per the
appropriate wiring diagram on pages 9 and 10. Secure all
wires so that there is no interference with any moving parts
in the unit.
2. Power the economizer and run the checkout procedure on
page 13. Make desired adjustments to the controller setting
the minimum occupied damper position, the outside air
setting (if enthalpy used), and the IAQ sensor (if used).
3. Replace the unit Coil access panel, the Blower access
panel, and the Control/Heat access panel.

5
INSTALLER’S GUIDE
18-HE39D8-13
Figure 5. Swing Down and Set Economizer Return Air Damper
Economizer
2.) Insert Assembly
screw
1.) Swing
Down
Return Air
Damper
Return Air Damper
3.) Tighten Linkage rod
Figure 6. Start Economizer’s Front Mounting Screws
Economizer outline
Install two (2)
screws into holes.
Leave extended
from unit 1/2”.
Economizer and
Return Air Damper
Apply gasket between damper assembly and hood.

6
INSTALLER’S GUIDE
18-HE39D8-13
1. Loosen the two
(2) screws to allow
hood to slide under
top sealing flange of
the unit.
Detail
Economizer rain
hood
Figure 7. Mounting Rain Hood
Top flange of hood
slides under HVAC
unit’s top sealing
flange HVAC unit’s top
sealing flange
Hood HVAC unit
2. Drive six (6) self
tapping screws into the
keyhole openings
on each side of hood
flanges.
Unit’s top sealing
flange
3. Tighten the two
(2) top screws and
the two (2) side
screws.

7
INSTALLER’S GUIDE
18-HE39D8-13
Figure 8. Rain Hood, Economizer, and Filter
Figure 9. Mount Mixed Air Sensor in Blower Compartment
View ‘A’ Approximate
Mounting Dimension
See View ‘A’
Return Duct Roofcurb
Relief damper
Mist eliminator
(filter)
Economizer rain
hood
Outside air
dampers
Return air
dampers Required filter
kit, order separately
Mount the Mixed Air
Sensor to the partition
using two (2) sheetmetal
screws. See View A for
approximate positioning.
1.80”
2.82”
A
Economizer Unit Application Models A
BAYECON101AA/AB 2/4TC*,WC*,YC*,DC*
*018-036 20.125”
BAYECON102AA/AB 2/4TC*,WC*,YC*,DC*
*042-060 24.375”

8
INSTALLER’S GUIDE
18-HE39D8-13
Figure 10. Main Wire Harness Routing
1.) From Economizer-
Assembly, Pass Wire
Harness Through Coil
Grommet. See View A.
View ‘A’
2.) Continue
Routing Behind
Compressor
Compartment
and into Blower
Compartment.
3.) Pull the two (2) Mixed Air
Sensor Wires (with female
quick connects) from the
Harness and Route Down
Near the Mixed Air Sensor.
Connect to sensor
pigtail wire leads.
Location of
Mixed Air Sensor
4.) Continue Routing
the Remaining Harness
Through the Grommet and
into the Control Box.
Coil Grommet

9
INSTALLER’S GUIDE
18-HE39D8-13
A A A A
Figure 11. TC*/YC* Economizer Connection Diagram
Wiring Diagram for Economizer Using a Honeywell W7459 Logic

10
INSTALLER’S GUIDE
18-HE39D8-13
Figure 12. WC* Economizer Connection Diagram
Wiring Diagram for Economizer Using a Honeywell W7459 Logic

11
INSTALLER’S GUIDE
18-HE39D8-13
B B B B
Wiring Diagram for Economizer Using a Honeywell W7212 Logic Only
TC*/YC* Economizer Connection Digram (“*” May Be “C”, “X”, “Y”)

12
INSTALLER’S GUIDE
18-HE39D8-13
B
2AB
B
B
Wiring Diagram for Economizer Using a Honeywell W7212 ONLY
WC* Economizer Connection Digram (“*” May Be “C”, “X”, “Y”)

13
INSTALLER’S GUIDE
18-HE39D8-13
5A. Checkout - For Units with a Honeywell W7459 Control, Only.
See 5B for W7212
SINGLE ENTHALPY CHANGEOVER SET POINT
Single enthalpy: The enthalpy changeover set
point is set to return the outdoor air damper to
minimum position when the
enthalpy rises above its set point. The enthalpy
set point scale markings, located on W7459,
are A,B,C,D; see table for the corresponding
control point. The factory-installed R4 WHITE
620-ohm jumper must be in place across ter-
minals + and SR.
Operate the motor through its complete open-close stroke.
If necessary, release one of the previously tightened linkage
connections to prevent damage. Check for proper operation,
making sure that the linkage does not bind and that the motor
travels smoothly throughout its fully open and closed position.
Table 1 describes how to drive the motor to the full open and full
closed positions (power connected). If there is excess length of
linkage rod, cut it to size. Make necessary minor adjustments until
desired operation is obtained, and tighten all nuts and set screws.
This motor checkout ensures that:
1. The motor operates the load.
2. The motor responds properly to the controller.
3. There is no binding of the linkage or motor stalling at any point
of travel.
If motor does not operate properly, check for proper voltage or
mechanical binding in linkage or damper.
If questions arise regarding this product, contact your distributor
or representative.
12 14 16 18 20 22
90
100
80
70
44 46
60
50
40
30
36
Y AI
3
R
8 40 42
20
10
85
(29)
90
(32)
95
(35)
100
(38)
105
(41) (43)
110
35
(2)
35
(2)
40
(4)
40
(4)
(41)
105110
(43)
45
24 26
ENTHALPY—BTU
28 30 32
PER POUND
34
DR
(7)
45
(7)
50
50
(10)
(10)
55
55
(13)
(13)
60
(16)
60
(16)
65
65
(18)
(18)
70
70
(21)
(21)
75
(24)
75
(24)
80
80
(27)
(27)
85 90
(29) (32)
95
(35)
100
APPROXIMATE DRY BULB TEMPERATURE— F ( C)
(38)
A
A
B
B
C
C
D
D
M11681
RELATIVE HUMIDITY (%)
1
1
HIGH LIMIT CURVE FOR W7459D.
CONTROL
CURVE
A
CONTROL POINT
APPROX. F (C)
AT 50% RH
73 (23)
B70 (21)
C67 (19)
D63 (17)
Table 1. Motor Operation Checkout
MODEL DRIVE MOTOR OPEN DRIVE MOTOR CLOSED SPRING RETURN
M7415 Power to TR and TR1, jumper
T and T1
Disconnect jumper at T or T1 and disconnect
P or P1, if connected Disconnect power at TR and TR1

14
INSTALLER’S GUIDE
18-HE39D8-13
1
1
2
2
M9097
ENTHALPY CHANGEOVER
SETPOINT
LED LIGHTS WHEN
OUTDOOR AIR IS SUITABLE
FOR FREE COOLING
JUMPER USED FOR SINGLE ENTHALPY CONTROL.
TR
INSERT DC MULTIMETER BETWEEN SOAND S FOR CHECKOUT
AND TROUBLESHOOTING.
TR1
A
BC
D
SO+
SR+
+
C7400
620 OHM
JUMPER
DC
W7459
S
+
1
1
M9098B
ENTHALPY
CHANGEOVER
SETPOINT
MINIMUM
DAMPER
POSITION
SETTING
LED LIGHTS
WHEN OUTDOOR
AIR IS SUITABLE
FOR FREE COOLING
MINIMUM DAMPER POSITION ADJUSTMENT
IS PRESENT ONLY ON W7459A,D MODELS.
MULTIMETER
Meter Location for Checkout and Troubleshooting
Location of Enthalpy Set Point, Minimum
Position and LED
Table 2. Enthalpy Checkout Procedure - W7459 Control
Figure 13. Enthalpy LEDs and Checkout
Checkout Procedure Response
A
LED is off.
Motor is in closed position.
B1. Disconnect factory-installed 620 ohm resistor from terminals Sr and
+LED turns on, motor drives toward open.
C
1. Disconnect power at TR and TR1.
2. Disconnect jumper P to P1.
3. Jumper TR to 1.
4. Jumper T1 to T.
5. If connected, remove C7400 Solid State Enthalpy Sensor from ter-
minals S0 and +. Ensure factory-installed 620 ohm resistor is connect-
ed to terminals Sr and +.
6. Apply power (24Vac) to terminals TR and TR1
―
1. To simulate high and low enthalpy (single enthalpy sensor) re-
connect factory-installed 620 ohm resistor from terminals Sr and +.
Connect 1.2K ohm 4074EJM Checkout Resistor across terminals So
and +.
2. Turn enthalpy setpoint potentiometer to "A". LED turns on, indicating low enthalpy.
Motor drives toward open.
3. Turn enthalpy setpoint potentiometer to "D". LED turns off, indicating high enthalpy.
Motor drives toward closed.
4. Disconnect the 1.2K ohm checkout resistor ―
D1. To verify sensor operation, reconnect the + lead of the outdoor
enthalpy sensor to the + terminal of W7459. ―
2. Connect a DC multimeter between terminal So of the W7459A and
terminal S of the enthalpy sensor. See Fig. 13 (positive meter lead to
terminal S of the enthalpy sensor).
Multimeter indication is between 3 and 25 mA if
sensor is operating properly.
If multimeter indicates zero, the sensor may be
wired backward.
3. When using differential enthalpy, check the return air enthalpy
sensor by connecting a DC multimeter between terminal Sr of the
W7459A and terminal S of the return air enthalpy sensor. (positive
meter lead to terminal S of the enthalpy sensor).
Multimeter indication is between 3 and 25 mA if
sensor is operating properly.
If multimeter indicates zero, the sensor may be
wired backward.

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INSTALLER’S GUIDE
18-HE39D8-13
Temp vs. OHM for MAS (Mixed Air Sensor)
Temp FTemp C R(K OHMS) DC Volts
33.8 19.576 3.910
35.6 29.092 3.882
37.4 38.636 3.894
39.2 48.204 3.863
41.0 57.796 3.829
42.8 67.412 3.790
44.6 77.048 3.749
46.4 86.705 3.713
48.2 96.380 3.674
50.0 10 6.0733.634
51.8 11 5.7823.590
53.6 12 5.5073.550
55.4 13 5.2473.507
57.2 14 5.0003.420
59.0 15 4.7673.373
60.8 16 4.5453.328
62.6 17 4.3353.283
64.4 18 4.1363.239
66.2 19 3.9483.180
68.0 20 3.7693.157
69.8 21 3.5993.118
71.6 22 3.4373.080
73.4 23 3.2843.034
75.2 24 3.1383.007
77.0 25 3.0002.971
78.8 26 2.8692.932
80.6 27 2.7442.896
82.4 28 2.6252.860
84.2 29 2.5122.824
86.0 30 2.4042.787
87.8 31 2.3012.750
89.6 32 2.2042.714
91.4 33 2.111 2.676
93.2 34 2.0232.639
95.0 35 1.9382.600
96.8 36 1.8582.561
98.6 37 1.7812.526
100.4381.708 2.484
Table 3. Temp vs. OHM Values for MAS (Mixed Air Sensor)

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INSTALLER’S GUIDE
18-HE39D8-13
5B. Checkout - For Units with a Honeywell W7212 Control, Only. See 5A for W7459
Table 4. Checkout for W7212, W7213, W7214 Economizer Connected to Honeywell Actuator
Figure 18. Meter location for checkout and
troubleshooting (W7212 shown).
CHECKOUT AND TROUBLESHOOTING
Checkout requires a 9V battery, 620 ohm, 1.2K ohm, 5.6K ohm,
and 6.8K ohm resistors. Use Table 4 and Fig. 18 for checkout.
W7212
M20612
N1
P1
T1
N2V
2V
2V
B
A
SR
SO
AQ
C
D
Free
Cool
10V
EXH
DCV
EXH
Set
10V
DCV
Max
10V
DCV
Set
Min
Pos
Open
P
T
AQ1
SO+
SR+
1
2
DC VOLTMETER
+
S
+
C7400
1
2
620 OHM RESISTOR
INSERT DC VOLTMETER BETWEEN AQ AND AQ1 FOR
CHECKOUT AND TROUBLESHOOTING.
JUMPER USED FOR SINGLE ENTHALPY CONTROL.
CAUTION
Equipment Damage Hazard.
Excessive force can damage potentiometer
controls.
Use a small screwdriver when adjusting enthalpy
changeover and minimum damper position controls.
!
Step Checkout Procedure Proper Response
1. CHECKOUT PREPARATION FOR ECONOMIZING ONLY
Disconnect power at TR and TR1All LED are off; Exhaust Fan contacts are open
Disconnect devices at P and P1
Jumper P to P1 (defaults to on board MIN POS potentiometer).
Jumper TR to 1 (call for cooling from the thermostat).
Place 5.6K ohm resistor across T and T1 (Blue sleeve-provides input to
economizer that the MAT is between 50-55F).
W7212 only jumper TR to N (places economizer in occupied mode).
If connected, remove C7400 Enthalpy Sensor from terminals SOand +.
Connect 1.2K ohm, from 4074EJM Checkout Resistor kit, (purple sleeve)
across terminals SOand + (makes OA enthalpy high).
Place 620 ohm resistor (white sleeve) across SRand + (makes return
enthalpy lower than OA).
Set MIN POS and DCV MAX potentiometers fully CCW.
Turn DCV setpoint potentiometer mid position (this sets the DCV
ventilation at approximately 1000 ppm).
Turn exhaust potentiometer to mid position (motor will be approximately
50% open when the exhaust fan contacts make).
Set enthalpy potentiometer to D.
W7214 only Jumper TR to O.
Apply power (24 Vac) to terminals TR and TR1

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INSTALLER’S GUIDE
18-HE39D8-13
Table 4. Checkout for W7212, W7213, W7214 Economizer Connected to Honeywell Actuator (Cont.)
Step Checkout Procedure Proper Response
2. DIFFERENTIAL ENTHALPY
Execute stop one, Checkout Preparation. ―
Turn DCV MAX to mid position.
Place 620 ohm resistor across SOand + (white sleeve resistor
makes OA enthalpy low).
Place 1.2K ohm resistor across SRand + (purple sleeve resistor
makes RA enthalpy high).
Free cool LED turn on; motor drives to approximately 45
degrees (half) open.
Remove 620 ohm resistor from SOand +. Free cool LED turn off; motor drives closed
3. SINGLE ENTHALPY
Execute stop one, Checkout Preparation. ―
Turn DCV MAX to mid position.
Set enthalpy potentiometer to A (fully CCW). Free cool LED turns on; motor drives to approximately 45
degrees (half) open.
Set enthalpy potentiometer to D or E for W7212C (fully CW). Free cool LED turns off; motor drives closed.
4. DCV AND EXHAUST
Execute step one, Checkout Preparation. ―
LED for both DCV and Exhaust should be off.
Turn DCV MAX to mid position. Motor drives to mid position, 45 degrees open.
Turn MIN POS fully CW.Motor drives fully open.
Turn MIN POS and DCV MAX to fully CCW.Motor drives closed.
Turn DCV MAX to mid position.
Connect 9V battery positive to AQ and negative to AQ1.
LED for both DCV and Exhaust turn on.
Actuator drives to 45 degrees open.
Remove jumper from N terminal (economizer goes into not occu-
pied mode).
Motor remains at 45 degrees open.
Adjust DCV MAX towards CW.Motor will move to position set by DCV MAX pot.
Adjust DCV MAX to fully CCW.Motor will drive closed.
Reconnect jumper to N terminal.
Adjust DCV MAX and MIN POS pots. Motor will drive to the most open position of the pots.
Adjust DCV MAX and MIN POS pots to fully CCW.
Remove power from N terminal adjust MIN POS towards CW.Motor should not move.
Adjust DCV MAX towards CW.Motor will move to position set by DCV MAX pot.
5. MINIMUM AND MAXIMUM POSITION
Execute stop one, Checkout Preparation. ―
Connect 9V battery positive to AQ and negative to AQ1. Adjust
DCV MAX potentiometer to mid position.
DCV LED turns on. Actuator drives to 45 degrees open.
Turn DCV maximum position potentiometer to fully CCW. Actuator drives fully closed.
Turn minimum position potentiometer to midpoint. Actuator drives to 45 degrees open.
Turn minimum position potentiometer fully CW. Actuator drives fully open.
Turn MIN POS to fully CCW. Actuator drives fully closed.
W7212: Remove jumper from TR and N. Actuator drives fully closed.
W7214: Jumper TR to O.
6. MIXED AIR INPUT
Execute stop one, Checkout Preparation. ―
Turn DCV MAX to mid position; set enthalpy potentiometer to A. Free cool LED turns on.
Actuator drives to 45 degrees open.
Actuator drives to 45 degrees open.Remove 5.6K ohm resistor (green sleeve) and place jumper from
T and T1.
Remove jumper from T and T1 and leave open. Actuator drives fully closed.

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INSTALLER’S GUIDE
18-HE39D8-13
Minimum Fresh
Air Damper will
not open
Locate Minimum
Position
Potentiometer on
Logic Module
Gently rotate
potentiometer fully
clockwise.
Does Actuator
begin to rotate
linkage arm?
Is resistor
Remove R3
resistor located
across P and P1
terminals on logic
module.
"open" or 130
ohms?
Replace resistor with 130
ohms 1 watt resistor
Replace Actuator and
logic module
Adjust linkage to
properly drive
dampers.
Check for 24 volts
across TR and
TR1 terminals on
Logic Module.
24 volts No voltage No
Yes
Yes
Yes
Yes
130 ohmsOpen
No
No
No
"G" must have 24V
applied to energize
the minimum
position damper
Black wire must be
connected to "G"
lead in unit.
Black wire must be
connected to "TR"
terminal at econ.
Blue wire from
TR1 must be
connected to "BL"
lead in unit.
Is 24V present to
Green "G" lead at
connection in unit?
Is the economizer's
Black wire
connected to "G"?
Is the economizer's
Black wire
connected to TR at
econ?
Is BL at TR1
connected to BL at
unit's low voltage
connection
You now should have 24V
between TR and TR1 at the
econ logic module
Honeywell W7459 Only - Troubleshooting - No Minimum Fresh Air

19
INSTALLER’S GUIDE
18-HE39D8-13
Is OD ambient
Dampers will not open
beyond minimum
position during 1
st
stage cooling.
below 70F?
Wires are
Ensure wires from
"1" and "TR1" are
correctly wired to
unit's low voltage
leads.
correctly
applied?
Remove wires
from "T" and "T1" Replace MAS
Correct wiring.
Ambient must be below 70F to activate
economizer beyond minimum position fresh
air opening.
Is OAS closed?
Is 24V present
between
terminals "1" and
"TR1"
Is resistance
Remove OAS
wire from "S0"
and "+" terminals
on the Logic
module
What is
620 ohms?
No
Replace the 620 ohm
1 watt resistor.
resistance of
MAS
2-4 ohms
Replace Actuator and Logic
Module
Measure
resistance across
wire leads
Jumper across the
OAS terminals to
close circuit
Does economizer
now operate?
Replace OAS
Yes
YesYes
Yes
NoNo
No No
No
Yes
Honeywell W7459 Only - Troubleshooting - Unit Will Not Economize

20
INSTALLER’S GUIDE
18-HE39D8-13
Is a 2-stage
Compressor will not
energize when
space conditions
rise.
thermostat
applied?
Is thermostat's Y2
connected to unit's YL
Yes
Is 24V present at YL
Troubleshoot unit. Problem
is not in economizer.
Troubleshoot why
thermostat is not calling
for 2nd stage.
Wire per Installer's
Guide.
Install a 2 stage thermostat and
wire according to economizer
Installer's Guide
No
No
No
Yes
Honeywell W7459 Only - Troubleshooting - 2nd Stage Inoperable