Variable-Capacity Furnace
Replacement Control Center Kit
Cancels: IIK 320A-60-9
IIK 320A-60-10
3-96
Installation Instructions
Part No. 320729-752
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
SAFETY CONSIDERATIONS
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained personnel should
install or service heating equipment.
2. Firmly touch a clean, unpainted, metal surface of the furnace
chassis which is close to the control. Tools held in a person’s
hand during grounding will be satisfactorily discharged.
3. After touching the chassis you may proceed to service the
control or connecting wires as long as you do nothing that
recharges your body with static electricity (for example; DO
NOT move or shuffle your feet, DO NOT touch ungrounded
objects, etc.).
Untrained personnel can perform basic maintenance functions
such as cleaning and replacing filters. All other operations should
be performed by trained service personnel. When working on
heating equipment, observe precautions in the literature, on tags,
and on labels attached to the unit.
4. If you touch ungrounded objects (recharge your body with
static electricity), firmly touch furnace again before touching
control or wires.
Follow all safety codes. Wear safety glasses and work gloves.
Have a fire extinguisher available.
6. Before removing a new control from its container, discharge
your body’s electrostatic charge to ground to protect the
control from damage. If the control is to be installed in a
furnace, follow items 1 through 5 before bringing the control
or yourself into contact with the furnace. Put all used AND
new controls into containers before touching ungrounded
objects.
Recognize safety information. This is the safety-alert symbol
.
When you see this symbol on the furnace and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies a hazard which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which would result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
Turn off gas and electrical supplies to unit before beginning
any installation or modification. Follow operating instructions on label attached to furnace. Failure to follow this
warning could result in personal injury or death.
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
Electrostatic discharge can affect electronic components.
Take precautions during furnace installation and servicing to
protect the furnace electronic control. Precautions will prevent electrostatic discharges from personnel and hand tools
which are held during the procedure. These precautions will
help to avoid exposing the control to electrostatic discharge
by putting the furnace, the control, and the person at the same
electrostatic potential.
5. Use this procedure for installed and uninstalled (ungrounded)
furnaces.
7. An ESD service kit (available from commercial sources) may
also be used to prevent ESD damage.
INTRODUCTION
This instruction covers installation of the variable-capacity furnace
replacement control center kit Part No. 320729-752 in ALL
variable-capacity furnaces regardless of their ignition type, intermittent spark ignition (IID) or hot surface ignition (HSI), or
previous control center type.
See Table 1 for kit contents.
Table 1—Kit Contents
DESCRIPTION
PART NO.
QUANTITY
Harness
318843-401
1
Label Wiring
322295-101
1
Label Wiring
322297-101
1
Label Diagnostic
321223-101
1
Screw
No. 6D X 1/2-in. LG
4
Wire Tie
HY76TB125
2
Control Center
HK42FZ012
1
2-Sided Adhesive Tape
34410B160
1
Installation Instructions IIK 320A-60-10/58M-30SI
1
1. Disconnect all power to the furnace. DO NOT TOUCH THE
CONTROL OR ANY WIRE CONNECTED TO THE CONTROL PRIOR TO DISCHARGING YOUR BODY’S ELECTROSTATIC CHARGE TO GROUND.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Catalog No. 565-892
Printed in U.S.A.
Form 58M-30SI
Pg 1
3-96
Replaces: 58M-24SI
Tab 6a 8a
DESCRIPTION AND USAGE
of high voltage connections (L1/L2, P1/P2, B1/B2, I1/I2) may
have changed from the previous control center that is being
replaced. (See Fig. 1.) If replacing a control center HK42FZ003
(originally installed in Series A/B, 101/111 furnaces), the wiring
label 322295-101 has the updated location of high voltage connections on control center HK42FZ012. This label can be placed
over original wiring label in the furnace. DISCARD all other parts
except control center, and if used, wiring label 322295-101.
Furnaces originally installed with control center HK42FZ012 do
NOT need to replace the wiring label. See following tables in these
instructions for control center setup switch position:
- Table 2 for adjustment of air conditioning airflow (A/C)
- Table 3 for adjustment of continuous fan airflow (CF)
- Table 4 for adjustment of heating blower time delay off
(SW-7 and -8)
- Table 5 for adjustment of system setup switches (SW-1
through -6)
Use this variable-capacity furnace replacement control center kit
when replacement of the furnace control is required.
This replacement control center kit is designed to be used in IID or
HSI ignition type variable-capacity condensing furnaces. Refer to
appropriate section for your furnace model.
Section I: Models 355MAV and 58MVP 40-in. Tall VariableCapacity Multipoise Hot Surface Ignition (HSI) Condensing Gas
Furnaces
Section II: Models 320A, 321A, 398B, 58SXB, 58VCA, and
58VUA 46-3/16-in. Tall Variable-Capacity Intermittent Spark
Ignition (IID) Condensing Gas Furnaces
INSTALLATION
SECTION I: MODELS 355MAV AND 58MVP 40-IN. TALL
VARIABLE-CAPACITY MULTIPOISE HOT SURFACE
IGNITION (HSI) CONDENSING GAS FURNACES
This kit is designed to be used in 40-in. tall multipoise condensing
furnaces. The control center in this kit, HK42FZ012 is a direct
replacement for control center HK42FZ003. Note that the location
P/N HK42FZ003
HOT
SURFACE IGNITOR
CONNECTOR
PL4
P/N HK42FZ012
I2
B2
L2
P2
I1
B1
L1
P1
I1
B1
L1
P1
I2
B2
L2
P2
EAC-ELECTRONIC
AIR CLEANER
TERMINALS
(115-VAC 1 AMP MAX)
G HUM
115-V
CONNECTORS
(SEE DETAILS ABOVE)
W2 COM W/W2 Y/Y2 R
24V
MAIN HARNESS
CONNECTOR
PL1
MAIN BLOWER
CONTROL WIRE
CONNECTOR
PL3
TRANSFORMER
24-V
CONNECTORS
PRESSURE SWITCH
CONNECTOR PL2
HUM-HUMIDIFIER
TERMINAL
(24-VAC 0.5 AMP MAX)
24-V THERMOSTAT
TERMINALS
DEHUMIDIFIER (DH)
CONNECTOR
3-AMP FUSE
SEC-2
SEC-1
STATUS AND DIAGNOSTIC
LED LIGHTS
AIR CONDITIONING
(A/C) SETUP SWITCH
SETUP SWITCHES
(SW) AND BLOWER
OFF DELAY SETUP
SWITCHES
CONTINUOUS
FAN (CF) SETUP
SWITCHES
COMMUNICATION
CONNECTOR
PL6
MODEL PLUG
PL5
A95093
→ Fig. 1—Control Center
2
SECTION II: MODELS 320A, 321A, 398B, 58SXB, 58VCA,
AND 58VUA 46-3/16-IN. TALL VARIABLE-CAPACITY
INTERMITTENT SPARK IGNITION (IID)
CONDENSING GAS FURNACES
13. Replace screw in control box removed to disconnect main
blower wire harness ground wire.
Step 1—Remove Control Board
See Fig. 5 for installing replacement control center component
location.
Step 2—Install Replacement Control Center
See Fig. 2 for UPFLOW furnace or Fig. 3 for DOWNFLOW
furnace component location. See Fig. 4 for control box component
location.
1. Position replacement control center in control box.
1. Turn off gas and electrical supplies to unit.
2. Mark control center mounting holes and drill control box
using 1/8-in drill. See Fig. 5 for approximate location of holes.
2. Remove control access door.
3. Attach control center using screws supplied in kit.
3. Remove and discard control box enclosure cover.
4. Attach green ground wire on old main blower wire harness to
upper left hole inside control box using screw supplied in kit.
4. Disconnect all wires and connectors to old control board.
5. Install old 5-pin main blower harness connector to new control
center PL6. Location of 5-pin connector PL6 is approximately
in center of new control center.
NOTE: Label thermostat wires to assist attachment to new
control center.
5. Remove and discard lower bracket (downflow furnaces only)
used to support control board to blower assembly. This
bracket was used for shipping support only.
6. Connect black wire in old blower wire harness to control
center B1 terminal. B1 terminal is located in lower right
corner of new control center.
6. Disconnect main furnace wire harness (15-pin connector)
from control box 15-pin connector.
NOTE: Loose black wire attached to wire terminal should have
an insulated 1/4-in. quick-connect terminal. Do not remove insulation if still intact. If wire was used for accessory attachment, use
field-supplied tape or wire nut to terminate wire and prevent
possible shorting. See Step 3 for accessory attachment.
7. Remove and discard 15-pin connector and wire assembly from
inside of control box.
8. Remove old control board from control box enclosure.
9. Remove wires from power connection block on right side of
control box.
7. Connect white wire in old main blower wire harness to control
center B2 terminal. B2 terminal is located in lower right
corner of new control center.
10. Remove power connection block from right side of control
box and discard. (Optional)
NOTE: Loose white wire attached to wire terminal should have
an insulated butt connector terminal. Do not remove butt connector
if still intact. If wire was used for accessory attachment, use
field-supplied tape or wire nut to terminate wire and prevent
possible shorting. See Step 3 for accessory attachment.
11. Remove main blower wire harness strain relief bushing from
left side of control box. Discard strain relief.
12. Disconnect main blower wire harness green ground wire
attached to outside upper left corner of control box.
MAIN
BLOWER
WIRE
HARNESS
15-PIN MAIN
FURNACE
WIRE
HARNESS
CONNECTOR
CONTROL
BOX
AUXILIARY
JUNCTION
BOX AND
DOOR
SWITCH
15-PIN MAIN
FURNACE
WIRE
HARNESS
CONNECTOR
AUXILIARY
JUNCTION
BOX AND
DOOR
SWITCH
MAIN
BLOWER
WIRE
HARNESS
CONTROL
BOX
CONDENSATE
DRAIN TRAP
CONDENSATE
DRAIN TRAP
A94295
A94296
Fig. 2—Upflow Condensing 46-3/16-in. Tall
Variable-Capacity Furnace
Fig. 3—Downflow Condensing 46-3/16-in. Tall
Variable-Capacity Furnace
3
15-PIN MAIN
FURNACE WIRE
HARNESS
CONNECTOR
CONTROL
BOARD
MAIN BLOWER
WIRE HARNESS
GROUND WIRE
15-PIN MAIN
FURNACE
CONTROL
BOARD WIRE
CONNECTOR
P1
CIRCUIT
BREAKER
TRANSFORMER
WIRES
CB1
P2
K1
I1
B1
B2
MAIN
BLOWER
WIRE
HARNESS
I2
P5
SETUP
P4
BLOWER OFF
TIME DELAY
SELECTOR
R
SET-UP
SWITCHES
A/C TON
AIRFLOW
SELECTOR
Y
W
G
THERMOSTAT
TERMINALS
C
POWER
CONNECTION
BLOCK
ACCESSORY RELAY
FURNACE MODEL
PROFILE PLUG
A94297
Fig. 4—Old Control Component Location in Old Control Box
8. Install 15-pin, large rectangular connector on new wire harness (supplied in kit) in top right corner of control box.
17. Locate circuit breaker on new control center, using 2-sided
adhesive tape. See Fig. 5 for location.
9. Secure 15-pin new wire harness wire tie to control box using
screw supplied in kit. See Fig. 5 for location.
18. Connect 2 red wire, 1/4-in. quick-connect terminals on new
wire harness to circuit breaker.
Wire tie must be secured as shown to ensure "drip leg" in
harness. This ensures any moisture near control will drip off
and not be deposited on control center.
The circuit breaker from old control MUST be used when
installing new control center. The 3-amp fuse on new control
center is used to protect all 24-vac wiring from external
shorting. The circuit breaker is used to protect new control
center internal components from an internal short condition.
10. Install 4-pin, single row connector on new kit wire harness to
control center PL7B. Location of 4-pin connector PL7B is
adjacent to thermostat terminal block.
19. Connect black wire from furnace auxiliary junction box and
door switch to new control center L1 terminal. L1 terminal is
located in lower right corner of new control center.
11. Install 11-pin, single row connector on new kit wire harness to
control center PL7A. Location of 11-pin connector PL7A is
adjacent to thermostat terminal block, above 4-pin connector.
20. Connect white wire from furnace auxiliary junction box to
new control center L2 terminal. L2 terminal is located in lower
right corner of new control center.
12. Connect black wire, 1/4-in. quick-connect terminal on new kit
wire harness to control center I1 terminal. I1 terminal is
located in lower right corner of new control center.
21. Connect black wire from furnace transformer to new control
center P1 terminal. P1 terminal is located in lower right corner
of new control center.
13. Connect white wire, 1/4-in. quick-connect terminal on new kit
wire harness to control center I2 terminal. I2 terminal is
located in lower right corner of new control center.
22. Connect white wire from furnace transformer to new control
center P2 terminal. P2 terminal is located in lower right corner
of new control center.
14. Connect blue wire, 3/16-in. quick-connect terminal on new
wire harness to control center SEC-2 terminal. SEC-2 terminal
is located adjacent to thermostat block on new control center.
23. Connect 2 brown transformer wires to new kit wire harness
blue and red wires with 1/4-in. quick-connect terminals.
15. Connect red wire, 3/16-in. quick-connect terminal on new
wire harness to control center SEC-1 terminal. SEC-1 terminal
is located adjacent to thermostat block on new control center.
16. Remove circuit breaker from old control board.
4
MAIN BLOWER
WIRE HARNESS
GROUND WIRE
2-SIDED ADHESIVE TAPE
PL6
CONNECTOR
(5-PIN)
CIRCUIT
BREAKER
KIT WIRE
HARNESS
(15-PIN)
TRANSFORMER
CONNECTORS
EAC
TERMINAL
BLOCK
ADD WIRE
TIE SUPPLIED
WITH KIT
PL7A
SEC-1
PL6
POWER
TERMINAL
BLOCK
SEC-2
P4
P1
P3
MAIN
BLOWER
WIRE
HARNESS
W2 COM W/W1 Y/Y2 R
24V
FURNACE MODEL
PROFILE PLUG
(FROM OLD CONTROL BOARD)
SET-UP
SWITCHES A/C SET-UP
SWITCHES
G HUM
PL7B
THERMOSTAT
TERMINALS
24-V
PL7B
FUSE
CONNECTOR
CF SET-UP
(4-PIN)
SWITCHES
PL7A
CONNECTOR
(11-PIN)
WIRE TIE
ATTACHMENT
LOCATION
ADD WIRE TIE
SUPPLIED WITH KIT
A94298
Fig. 5—Component Location of New Control Center Kit
Step 3—Electronic Air Cleaner and Humidifier
Attachment
1. Connect 115-vac electronic air cleaner (EAC) wires to new
control center.
NOTE: The EAC terminals will accept 12 gage maximum solid
or stranded wire and are energized with 115vac (1.5-amp maximum) during main blower motor operation.
a. Strip approximately 1/8-in. of insulation off end of black
EAC power wire.
b. Connect stripped end into black EAC terminal on new
control center by depressing terminal arm with screwdriver
or finger and inserting wire as shown in Fig. 6. EAC
terminal is located on mid-right side of new control center.
c. Strip approximately 1/8-in. of insulation off end of white
EAC neutral wire.
A93053
Fig. 6—Depressing EAC Terminals on New
Control Center
d. Connect stripped end into white EAC terminal on new
control center by depressing terminal arm with screwdriver
or finger and inserting wire as shown in Fig. 6. EAC
terminal is located on mid-right side of new control center.
a. Connect 1 humidifier wire to new control center HUM
terminal. HUM terminal is located on thermostat terminal
block on bottom side of new control center.
2. Connect 24-vac humidifier (HUM) wires to new control
center.
b. Connect other humidifier wire to new control center COM
24V terminal. COM 24V terminal is located on thermostat
terminal block on bottom side of new control center.
NOTE: The HUM terminal on control center is energized with
24vac (0.5-amp maximum) when gas valve is energized.
NOTE: A field-supplied 115-vac controlled relay connected to
EAC terminals may be added if humidifier operation is desired
only during main blower operation. Otherwise, humidifier is
energized approximately 35 sec before main blower operates.
5
Table 2—Air Conditioning (A/C) Airflow Setup Switch Position on New Control Center
AIR
CONDITIONER
(TONS)
Default
1-1/2
2
2-1/2
3
3-1/2
4
5
AIRFLOW
(CFM)
1200 or
2000
600
800
1000
1200
1400
1600
2000
A/C SETUP SWITCH POSITION
A/C-1
A/C-2
ALLOWABLE FURNACE MODEL SETUP
A/C-3
OFF
OFF
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
ON
ON
040
060
080
100
3 Tons
1200 CFM
X
X
X
X
X
—
—
3 Tons
1200 CFM
X
X
X
X
X*
—
—
3 Tons
1200 CFM
X
X
X
X
X
—
—
5 Tons
2000 CFM
—
X
X
X
X
X
X
* Invalid selection on 320A, 321A, 398B, 58SXB, 58VCA, and 58VUA models.
X—Indicates allowable selection.
Step 4—Setup Adjustments of New Control Center
4. Adjust Setup (SW) switches.
1. Transfer furnace model profile plug.
a. Observe setup switch selections on old control board.
NOTE: The setup switches are labeled on old control board as to
their function. The location of switches on switch bar may be in
different locations on new control center.
a. Remove furnace model profile plug, located approximately
in middle bottom of old control board. (See Fig. 4.)
b. Install furnace model profile plug in lower left corner of
new control center. (See Fig. 5.)
b. Adjust system setup switches. See Fig. 5 for location of
SW switches on new control center. See Fig. 7 and Table
4 for SW switch positions and descriptions.
NOTE: The LP/NAT gas selection setup switch has been removed from new control center because emergency heat operation
does not need to be disabled when operating with propane as
previously designed.
2. Adjust air conditioning (A/C) setup switches.
a. Observe A/C setting on old control board. The switch is
located in bottom left corner. (See Fig. 4.)
The A/C selection is the number indicated on control board
and not the switch. Each dot indicates 1/2-ton setting.
b. Adjust A/C selection on new control center. See Fig. 5 for
location of A/C setup switches and Table 2 for position of
A/C setup switches.
5. Adjust heating blower off time delay switches.
a. Observe heating blower off time delay setting of old
control board. The switch is located in bottom left corner.
(See Fig. 4.)
3. Adjust continuous fan (CF) setup switches.
a. The old control board did not have the ability to set
continuous airflow selection.
The off delay time selection is determined by the numbers
indicated on switch. Each number represents 20 sec increments starting at 60 sec.
b. Adjust heating blower off time delay selection on new
control center. See Fig. 5 for location of heating blower off
time delay switches and Table 5 for position of switches for
desired heating blower off time delay.
b. The new control center allows continuous fan airflow to be
adjusted. This feature may be used when higher continuous
fan airflow is desired. Continuous fan airflow will be the
same as low-heat airflow unless otherwise selected. See
Fig. 5 for location of CF setup switches and Table 3 for
position of CF setup switches.
Table 3—Continuous Fan (CF) Airflow Setup Switch Position
CONTINUOUS
FAN
(CFM)
Default HSI
Default IID
600
800
1000
1200
1400
1600
2000
CF SETUP SWITCH POSITION
CF-1
CF-2
ALLOWABLE FURNACE MODEL SETUP
CF-3
OFF
OFF
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
ON
ON
* Add 15% additional CFM when Bypass Humidifier switch SW-3 on control center is used.
† Invalid selection on 320A, 321A, 398B, 58SXB, 58VCA, and 58VUA models.
X—Indicates allowable selection.
6
040
060
080
100
565*
—
X
X
X
X
X
—
—
515*
500
X
X
X
X
X†
—
—
690*
667
X
X
X
X
X
—
—
860*
835
—
X
X
X
X
X
X
Table 5—Heating Blower Off Time Delay Setup
Switch Position
DESIRED HEATING SETUP SWITCH (SW-7 AND -8) POSITION
MODE BLOWER
SW-7
SW-8
OFF DELAY (SEC)
90
OFF
OFF
135
ON
OFF
180
OFF
ON
225
ON
ON
P4
P1
P3
W2 COM W/W1 Y/Y2 R
24V
G HUM
Step 5—Miscellaneous Accessory Kits Used
The following items are detailed to assist in modifying the existing
system modifications when using new control center. This information is important since new control center has incorporated
many features the old control board did not have. If you have any
questions on the following or have any other field modification
you are not sure of, please contact your distributor service
department.
ON
FLT (FAULT CODE RECALL)
1
LOW HEAT ONLY
2
BPH (BYPASS HUMIDIFIER)
3
EMERGENCY HEAT
4
MZ (MULTI ZONE)
5
6
HEATING BLOWER
OFF TIME DELAY
7
1. Two-Stage Thermostat Interface Kit
If previous application used a 2-stage thermostat kit to allow
THERMOSTAT to control furnace high- and low-heat operation instead of FURNACE controlling high- and low-heat
operation, do the following:
8
COMPONENT TEST
a. Remove and discard 2-stage thermostat interface kit.
A94299
Fig. 7—Setup Switches (SW) on New
Control Center
This kit can be identified by a relay mounted to left side of
control box and wired as shown in Fig. 8.
b. The new control center can be controlled directly by the
2-stage thermostat without use of relay.
Table 4—Setup Switch (SW) Description on New
Control Center
SETUP
SWITCH NO.
NORMAL
POSITION
SW-1
(FLT)
OFF
SW-2
(LOW)
OFF
SW-3
(BPH)
OFF
SW-4
(EMER HEAT)
OFF
SW-5
(MZ)
OFF
SW-6
(COMP TEST)
OFF
SW-7 and -8
(Blower
Off Delay)
See
Table
5
(1.) Connect 2-stage thermostat W1 to new control center
W/W1 thermostat terminal. (See Fig. 5.)
DESCRIPTION OF USE
(2.) Connect 2-stage thermostat W2 to new control center
W2 thermostat terminal. (See Fig. 5.)
Turn switch to ON for fault history display. No thermostat signal can be
present for fault history display.
Turn switch to ON to lock furnace in
low-heat mode only.
Turn switch to ON when a bypass humidifier is used. This will compensate
for higher return-air temperature and
provide 5 percent more airflow in lowheat mode only.
Turn switch to ON to bypass microprocessor control. Furnace will operate at
high heat only with main blower and
inducer motor operating at maximum
RPM. NO safeties are bypassed.
Turn switch to ON when modulating
dampers are used. In this mode, main
blower speed is recalculated once every minute while furnace is in low-heat
or continuous fan mode.
Turn switch to ON to initiate component
test. Furnace will operate inducer motor
20 sec low speed, 20 sec high speed,
HSI 15 sec or IID 0 sec, blower 20 sec
low speed, and blower 20 sec high
speed. SW-1 must be in OFF position.
No thermostat signal can be present for
component test to be initiated.
Adjust switches to provide desired heating mode blower off delay time, 90,
135, 180, or 225 sec.
(3.) Turn setup switch SW2 to ON position. (See Fig. 7.)
2. Two-Speed Outdoor Condensing Unit Interface Kit
The purpose of the interface kit was to allow furnace to
operate 2 blower speeds in cooling modes, matching airflow
requirements of the 2-speed outdoor condensing unit.
If previous application used a kit to interface furnace control
with a 2-speed outdoor condensing unit (models 38TD,
38TDA, 38YD, 38YDA, 598A, or 698A), do the following:
a. Remove and discard relay and harness assembly from
motor. (See Fig. 9.)
(1.) The relay and harness assembly are mounted to blower
housing adjacent to motor.
(2.) To remove relay, remove wire on relay. Using a small
screw driver, pry retaining clip from lower side of
relay. Remove relay after clip is removed. See Fig. 10
for thermostat wiring of 38TD, 38TDA, or 598A Air
Conditioning units or Fig. 11 for thermostat wiring of
38YD, 38YDA, or 698A Heat Pump units.
b. Adjust continuous fan (CF) setup switches for low-cool
airflow. The new control center allows continuous fan
airflow to be adjusted to meet desired airflow requirements.
The "G" (continuous fan mode) thermostat terminal on
control center is used to provide low-cool fan airflow. See
Step 4, item 3 for adjusting CF switches.
NOTE: See Table 6 for CF switch setting for low-cool airflow
operation.
7
CONTROL BOX
COVER
EDGE
GUARD
Q1
GREEN WIRE
P1
CB1
CONTROL BOX
COVER
MOUNTING
SCREW
P5
K2
REMOVE
AND
DISCARD
C24
R59
P2
K1
SETUP
P4
R
Y
W
G
C
TO W1 OF THERMOSTAT
RELAY
SETUP SWITCHES
WIRE UNIT
BROWN WIRE
BLACK WIRE
TO W2 OF THERMOSTAT
A94300
Fig. 8—Two-Stage Thermostat Kit
NOTE: See Table 6 for A/C switch setting for high-cool airflow
operation.
BLOWER
HOUSING
REMOVE AND
DISCARD
KIT RELAY
3. Single-Speed Heat Pump
If previous application used a relay to open thermostat Y
signal during defrost mode, the relay is no longer required.
a. Remove and discard relay and all wires attached to relay.
Typical wiring would have been as indicated in Fig. 12.
b. Connect thermostat Y to furnace control Y/Y2. Connect
furnace Y/Y2 to heat pump interface terminal GF. (See Fig.
13.)
4. Variable-Speed Outdoor Unit
If previous application used a variable-speed outdoor unit, an
interface control was used. This interface control can be
identified by a large control box attached to side of furnace
(with a model and serial number plate, model 38TV900001)
and an RS-485 interface board installed on cover of furnace
control box. The RS-485 interface board is no longer required.
It was used to convert the RS-485 computer signal for old
control board. This feature is now incorporated into new
control center. To modify interface components for use with
new control center, do the following:
ICM
MOTOR
PLUG
SOCKET
REMOVE AND
DISCARD
HARNESS
ASSEMBLY
a. Contact your distributor service department for a new
communication wire harness, Part No. 322224-701.
b. Remove and discard RS-485 interface board located on
inside of old control box cover. (See Fig. 14.)
A94301
Fig. 9—Two-Speed Outdoor Condensing Unit
Interface Relay and Harness Assembly
c. Remove and discard all wires and cables previously attached to RS-485 interface board. (See Fig. 15.)
c. Adjust air conditioning (A/C) setup switches for high-cool
airflow. The "Y1" (cooling mode) thermostat terminal on
control center is used to provide high-cool fan airflow. See
Step 4, item 2 for adjusting A/C switches.
d. Install new interface cable obtained from Residential Product Engineering.
8
2-SPEED
THERMOSTAT
R
VARIABLE
SPEED
THERMOSTAT
R
C
C
G
G
W
W/W1
Y2
Y/Y2
2-SPEED AIR
CONDITIONER
2-SPEED
THERMOSTAT
VARIABLE
SPEED
THERMOSTAT
R
R
R
C
C
C
G
G
W2
W/W1
W2
Y2
Y/Y2
Y2
2-SPEED
HEAT PUMP
R
C
Y2
L
L
Y1
Y1
E
W3
L
L
O
O
Y1
Y1
A96098
A94303
→ Fig. 10—Thermostat Wiring for 38TD, 38TDA,
or 598A Air Conditioning Units
Fig. 11—Thermostat Wiring for 38YD, 38YDA,
or 698A Heat Pump Units
Table 6—A/C and CF Switch Position
FURNACE
CAPACITY
Airflow (Tons)
060
080
100 (1/2 HP)
100 (1 HP)
3
3-1/2
3-1/2
3-1/2
060
080
100 (1/2 HP)
100 (1 HP)
—
—
—
4
060
080
100 (1/2 HP)
100 (1 HP)
—
—
—
5
A/C SETUP
Airflow (CFM)
A/C-1
A/C-2
A/C-3
Airflow (CFM)
Outdoor Unit Capacity—036
1200
OFF
OFF
ON
800
1400
ON
OFF
ON
800
1400
ON
OFF
ON
800
1400
ON
OFF
ON
800
Outdoor Unit Capacity—048
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1600
OFF
ON
ON
1000
Outdoor Unit Capacity—060
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
2000
ON
ON
ON
1000
CF SETUP
CF-1
CF-2
CF-3
OFF
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
OFF
OFF
—
—
—
ON
—
—
—
ON
—
—
—
OFF
—
—
—
ON
—
—
—
ON
—
—
—
OFF
— Not used
Step 6—Clean-Up and Check Out
4. Use wire ties supplied in kit to dress wires as shown in Fig. 5.
After all components are installed and switches adjusted, finish
installation per the following:
5. Turn on electrical power to unit.
6. Turn on gas supply to unit.
1. Apply new diagnostic label over existing diagnostic label.
7. Check furnace operation through 2 complete cycles.
2. Apply new wiring label, Part No. 322297-101 over existing
wiring label.
8. Reinstall furnace access doors.
3. Locate 15-pin wiring harness wire tie (attached to harness).
Attach to control box using screw supplied in kit. (See Fig. 5.)
9
FURNACE THERMOSTAT TERMINALS
R
Y
W
G
FURNACE THERMOSTAT
TERMINALS
C
R
Y/Y2
W/W1
RF
GF
WF
RELAY
RF
GF
WF
HEAT PUMP INTERFACE
CONTROL TERMINALS
HEAT PUMP INTERFACE
CONTROL TERMINALS
A94304
A94305
Fig. 12—Previous Single-Speed Heat Pump Wiring
Fig. 13—Correct Single-Speed Heat Pump Wiring
P1
FURNACE OLD
CONTROL BOARD
C
5-WIRE
CABLE
C1
U5
R
SEC-1
SEC-2
R7
P2
A90245
Fig. 14—Remove RS-485 Interface Board on Inside of
Old Control Box Cover
RC
38TV900001
INTERFACE
CONTROL BOX
3-WIRE
CABLE
RS-485 INTERFACE
BOARD MOUNTED
TO INSIDE OF OLD
CONTROL BOX COVER
A94306
Fig. 15—Remove and Discard Wires and Cables to
RS-485 Interface Board
10
SERVICE TRAINING
Packaged Service Training programs are an excellent way to increase your
knowledge of the equipment discussed in this manual, including:
• Unit Familiarization
• Maintenance
• Installation Overview
• Operating Sequence
A large selection of product, theory, and skills programs is available, using popular
video-based formats and materials. All include video and/or slides, plus companion
book.
Classroom Service Training plus "hands-on" the products in our labs can mean
increased confidence that really pays dividends in faster troubleshooting, fewer
callbacks. Course descriptions and schedules are in our catalog.
CALL FOR FREE CATALOG 1-800-962-9212
[ ] Packaged Service Training
[ ] Classroom Service Training
A94328
11
Copyright 1996 Carrier Corporation
320a6010
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Catalog No. 565-892
Printed in U.S.A.
Form 58M-30SI
Pg 12
3-96
Replaces: 58M-24SI
Tab 6a 8a