Carrier 52S Wall Thermostat Interface Retrofit Kit User manual

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 132 Catalog No. 535-20060 Printed in U.S.A. Form 52S-67SI Pg 1 9-03 Replaces: 52S-66SI
Book 1 4
Ta b 9 a 1 1 a
Installation Instructions
INTRODUCTION
These instructions cover the installation of the 52S Wall
Thermostat Interface Retrofit Kit accessory with Indoor Coil
Freeze Thermostat (IFT) to be installed on 52S packaged termi-
nal air conditioner (PTAC) products. See Fig. 1. Indoor coil
freeze thermostat protection protects the indoor coil from
freezing.
SAFETY CONSIDERATIONS
Only trained, qualified personnel and service mechanics
should install electrical accessories on packaged terminal air
conditioners or heat pumps.
PACKAGE CONTENTS
INSTALLATION
Prepare Unit
1. Check to be sure unit is off and power to unit is
disconnected.
2. Remove front panel from the unit. See Fig. 2.
3. Remove the thermostat knob (grip and pull firmly) and
discard. See Fig. 3.
4. Remove the plastic control panel cover plate (by remov-
ing 2 attachment screws) and save. See Fig. 3.
5. Remove the temperature limiter off thermostat control
shaft (grip and pull firmly) and discard. See Fig 4.
6. Open control box by removing the 2 control box cover
screws shown in Fig. 3 and swing the cover down to
open. Save the screws.
7. Remove wire ties and discard, making sure not to damage
the wires.
8. Remove Push Button Switch from control box door (by
removing 2 attachment screws) and discard screws. See
Fig. 5.
9. Remove thermostat control from control box door (by
removing 2 attachment screws) and discard screws. See
Fig. 5.
ITEM QUANTITY
Wall Thermostat Control Panel 1
Indoor Coil Freeze Thermostat Clip 1
Control Panel Label 1
Wiring Schematic Label 1
Conversion Label 1
Hi Speed/Low Speed Label 1
Remote Wiring Access Cover 1
Wire Nut 1
Wire Ties 2
No. 10 Hex Head Screws 5
Disconnect all power to unit to avoid possible electrical
shock during installation.
52S Wall Thermostat Interface Retrofit Kit Accessory
For Use With
Packaged Terminal Air Conditioner
or Heat Pump
HI
LO
FAN SPEED
SWITCH
ASSY
PAR T
NUMBER:
WIRE
SCHEMATIC
WALL
THERMOSTAT
CONTROL
PANEL
REMOTE WIRING
ACCESS COVER
NO. 10 HEX
HEAD SCREWS
CONVERSION
LABEL CONTROL
PANEL LABEL
HI SPEED/LO SPEED
LABEL
WIRE TIES
WIRE NUT
INDOOR COIL FREEZE
THERMOSTAT CLIP
WIRING SCHEMATIC
LABEL
NOTICE: THIS UNIT HASBEEN
CONVERTEDTO A REMOTE
CONTROLLED (WALL THERMOSTAT)
UNIT USINGCONVERSIONKIT.
WALL THERMOSTAT COMFORT
Fig. 1 — Wall Thermostat Interface Retrofit Assembly Package Contents

2
NOTE: Wiring schematic for the unit is located in plastic bag
on front of control box door.
SELECT UNIT
For Cooling with Electric Heat units see below. For Heat
Pump units see page 5. For Cooling Only units see page 7.
COOLING WITH ELECTRIC HEAT UNITS
Remove Existing Controls
1. Remove ALL 3 wires (yellow, white and orange) from
the fan cycle switch. See Fig. 6.
2. Remove the following wires from the push button switch:
a. Power cord wire from L1.
b. Yellow compressor wire from COMP.
c. Violet heater wire from HTR.
d. Grey heater wire from LS.
e. Black fan motor wire from HI.
f. Red fan motor wire from LO.
g. Pink L2 wire from L2.
3. Remove the thermostat and push button switch controls
and all remaining attached wires and discard. Remove
thermostat bulb and mounting bracket from front of coil
and discard with the thermostat control. See Fig. 7.
Install New Wall Thermostat Controls
1. Remove knockout on control box cover for thermostat
wiring interface. See Fig. 8.
2. Mount wall thermostat control panel to front control box
cover using 3 of the no. 10 hex head screws provided. See
Fig. 9-11.
NOTE: Be sure removable terminal block on control
board is lined up with hole in control box cover from
knockout in previous step.
3. Re-connect wiring to fan/cycle switch. See Fig. 6.
a. Black Hi Fan speed wire to top terminal on fan/
cycle switch.
b. Red Low Fan speed wire to bottom terminal on
fan/cycle switch.
c. Grey Fan wire (factory installed on printed circuit
board from Relay K3, see Fig. 12) to center termi-
nal on fan/cycle switch.
WIRING SCHEMATIC
STANDARD PTAC MODELS
CONTROL PANEL
COVER PLATE
PUSH BUTTON
SWITCH
THERMOSTAT
KNOB
CONTROL BOX
COVER SCREWS
CONTROL PANEL COVER
PLATE ATTACHMENT SCREWS
TEMPERATURE
LIMITER
PUSH BUTTON SWITCH
ATTACHMENT SCREWS
THERMOSTAT CONTROL
ATTACHMENT SCREWS
Fig. 2 — Removing Front Panel
Fig. 5 — Thermostat Control and
Push Button Switch
Fig. 3 — Control Panel Cover Plate
Fig. 4 — Temperature Limiter

3
OUTDOOR
FROST THERMOSTAT
FAN CYCLE
SWITCH
MOUNTING
BRACKET
THERMOSTAT
BULB
WIRING INTERFACE
KNOCKOUT
WALL THERMOSTAT CONTROL PANEL
MOUNTING SCREWS
WALL THERMOSTAT CONTROL PANEL
MOUNTING SCREW
Fig. 7 — Thermostat Bulb and Mounting Bracket
Fig. 6 — Fan Cycle Switch and
Outdoor Frost Thermostat
Fig. 9 — Wall Thermostat Control Panel
Fig. 8 — Thermostat Wiring Knockout Fig. 11 — Secure Control Panel (Front)
Fig. 10 — Secure Control Panel (Top)

4
4. Re-connect the following wires on control board. See
Fig. 12.
a. Violet heater wire to Heat2 on relay K2A1.
NOTE: The male piggy back terminal is not used. This
terminal may either be removed or pinched back to fit the
connector onto Heat2 relay terminal.
b. Grey heater wire to Heat1 on relay K2.
c. Pink L2 wire to L2 on relay K2Al.
d. Yellow compressor wire to COMP on relay Kl.
e. Power Cord wire (Ll) to L1 (brass post terminal)
on relay K2.
5. Secure control board ground wire (green) to ground
screw on control box door with power cord and chassis
ground wires. See Fig.13.
6. Remove coil filter. Install Indoor Coil Freeze Thermostat
(IFT) into coil.
a. Use a pen to make an opening in the fins 4-in. from
the right side of the coil between the second and third
tube from the top to install freeze sensor (Fig. 14).
b. Push freeze sensor into opening made in Step 6a.
c. Bend clip on scored line and install in fins (the curved
notches will lock clip in place) next to sensor to hold
sensor in place in the coil. See Fig. 15.
7. Replace filter (indoor coil freeze thermostat will be locat-
ed in the coil behind the filter).
8. Dress wires using wire ties provided.
9. Close the control box door and secure by re-attaching
screws saved earlier. See Fig. 3.
10. Reinstall plastic control panel cover using the 2 screws
removed earlier. See Fig. 3.
Install Labels and Schematics
1. Remove old wiring schematic label and install new wiring
schematic label in same location. See Fig. 16.
2. Install conversion label to front of control box. See
Fig. 16.
3. Install Hi speed/Low speed label next to fan cycle switch
on side of control box. See Fig. 17.
NOTE: Fan cycle switch now becomes a speed selector
switch and selects whether the fan runs in high speed or
low speed. It is recommended to set the switch to low fan
speed for maximum sound comfort.
4. Install new control panel label over the old control panel
label to cover holes left by removal of old controls and
refer guests to the wall-mounted thermostat. See Fig. 16.
Wiring of Thermostat
1. Refer to installation instructions included with thermostat
for thermostat installation.
2. Route thermostat wires through grommet in remote
wiring access cover (supplied with kit).
PINK (L2 ON K2A1)
VIOLET (HEAT2 ON K2A1) PLAIN POWER CORD
(L1 ON K2)
GREY WIRE
(HEAT1 ON K2)
YELLOW WIRE
(COMP ON K1)
GREY FAN WIRE
K1
K2
K2A1
Fig. 12 — Typical Wall Thermostat Interface Board Terminal Connections (Heat/Cool Control Board Shown)
Fig. 13 — Ground Wires and Ground Screw Fig. 14 — Location of Indoor Coil Freeze
Thermostat

5
3. Make thermostat wiring connection (5 wires) to remov-
able terminal block on control board, accessible through
the opening for thermostat wiring interface.
a. R to R (24 VAC)
b. C to C (common — must be connected for digital
thermostats)
c. Y to Y (compressor)
d. G to G (Fan)
e. W to W (electric heater)
4. Plug thermostat wiring terminal block back on to control
board.
5. Attach remote wiring access cover to control box cover
using 2 screws provided (where knockout was removed
for thermostat wiring interface). See Fig. 18.
Installation Completion
1. Replace front panel.
2. Restore power to unit.
HEAT PUMP UNITS
Remove Existing Controls
1. Remove ALL 3 wires (yellow, white and orange) from
the fan cycle switch. See Fig. 6.
2. Remove the following wires from the push button switch:
a. Power cord wire from L1.
b. Violet heater wire and Black Reversing Valve wire
from HTR and separate.
c. Other Black Reversing Valve wire from IT1.
d. Black fan motor wire from HI.
e. Red fan motor wire from LO.
f. Pink L2 wire from L2.
3. Remove the following wires from the Outdoor Frost
Thermostat (OFT) (See Fig. 6):
a. Black Wire from Terminal 2.
b. Blue wire that is multi-linked to the gray wire in
Terminal 1 is no longer needed. CUT Blue wire
from Terminal 1, allowing about 3 inches of wire,
and attach included wire nut to end of Blue wire.
See Fig. 19.
Fig. 15 — Sensor Clip for Indoor Coil Freeze
Thermostat (IFT) on Typical Unit
WIRING SCHEMATIC
WALL THERMOSTAT PTAC MODELS
CONVERSION LABEL WIRING SCHEMATIC LABEL
CONTROL PANEL LABEL
WALL THERMOSTAT COMFORT
NOTICE: THISUNIT HASBEENCONVERTED
TOA REMOTECONTROLLED(WALLTHERMOSTAT)
UNIT USINGCONVERSIONKIT.
Fig. 16 — Location of Labels and Schematic
VENT
HEAT
MODE
HEAT
PUMP
ELECTRIC
NOTE: ELECTRIC HEAT
MODE WILL DISABLE
COMPRESSOR OPERATION.
OPEN/CLOSED
FAN SPEED
SWITCH
HI
LO
CON
CYC
Fig. 17 —Location of Fan Speed Label
WIRING SCHEMATIC
WALL THERMOSTAT PTAC MODELS
WALL THERMOSTAT COMFORT
NOTICE: THIS UNIT HASBEENCONVERTED
TOA REMOTECONTROLLED(WALLTHERMOSTAT)
UNIT USINGCONVERSIONKIT.
WIRING TO
WALL THERMOSTAT
Fig. 18 —Remote Thermostat Wire and
Terminal Cover
INDOOR COIL FREEZE
THERMOSTAT AND CLIP
WIRING ACCESS
HOLE

6
4. Remove the thermostat and push button switch controls
and all remaining attached wires and discard. Remove
thermostat bulb and mounting bracket from front of coil
and discard with the thermostat control. See Fig. 7.
Install New Wall Thermostat Controls
1. Remove knockout on control box cover for thermostat
wiring interface. See Fig. 8.
2. Mount wall thermostat control panel to front control box
cover using 3 of the no. 10 hex head screws provided. See
Fig. 9-11.
NOTE: Be sure removable terminal block on control
board is lined up with hole in control box cover from
knockout in previous step.
3. Re-connect wiring to fan/cycle switch. See Fig. 6.
a. Black Hi Fan speed wire to top terminal on fan/
cycle switch.
b. Red Low Fan speed wire to bottom terminal on
fan/cycle switch.
c. Grey Fan wire (factory installed on printed circuit
board from Relay K3, see Fig. 20) to center termi-
nal on fan/cycle switch.
4. Re-connect the following wires to control board. See
Fig. 20.
a. Violet heater wire to Heat2 on relay K2A1.
NOTE: The male piggy back terminal is not used. This
terminal may either be removed or pinched back to fit the
connector onto Heat2 relay terminal.
b. Pink L2 wire to L2 (brass post terminal) on relay
K2Al.
c. Power Cord wire (Ll) to L1 (brass post terminal)
on relay K2.
d. One of the 2 black reversing valve wires to RVS
(no polarity).
e. Remaining black reversing valve wire to L2 (brass
post terminal) on relay K2A1.
NOTE: Black reversing valve wires are molded together
in a 2-wire bundle.
5. Connect the following wires from the control board to the
Outdoor Frost Control (OFT):
a. Red wire from Heat1 on relay K2 to terminal 2 of
OFT.
b. Yellow wire from COMP of relay K1 (with piggy
back male terminal) to yellow wire already
attached to terminal 3 of OFT. Attach both wires
back on to terminal 3 of OFT.
6. Secure control board ground wire (green) to ground
screw on control box door with power cord and chassis
ground wires. See Fig. 13.
7. Remove coil filter. Install Indoor Coil Freeze Thermostat
(IFT) into coil.
a. Use a pen to make an opening in the fins 4-in. from
the right side of the coil between the second and third
tube from the top to install freeze sensor (Fig. 14).
b. Push freeze sensor into opening made in Step 7a.
c. Bend clip on scored line and install in fins (the curved
notches will lock clip in place) next to sensor to hold
sensor in place in the coil. See Fig. 15.
8. Replace filter (indoor coil freeze thermostat will be locat-
ed in the coil behind the filter).
9. Dress wires using wire ties provided.
10. Close the control box door and secure by re-attaching
screws saved earlier. See Fig. 3.
11. Reinstall plastic control panel cover using the 2 screws
removed earlier. See Fig. 3.
Install Labels and Schematics
1. Remove old wiring schematic label and install new wir-
ing schematic label in same location. See Fig. 16.
2. Install conversion label to front of control box. See
Fig. 16.
3. Install Hi Speed/Low Speed label next to fan cycle switch
on side of control box. See Fig. 17.
NOTE: Fan cycle switch now becomes a speed selector
switch and selects whether the fan runs in high speed or
low speed. It is recommended to set the switch to low fan
speed for maximum sound comfort.
Fig. 19 —Cut Blue Wire from Terminal 1
PINK (L2 ON K2A1)
VIOLET (HEAT2 ON K2A1) PLAIN POWER CORD
(L1 ON K2)
RED WIRE
(HEAT1 ON K2)
YELLOW WIRE
(COMP ON K1)
GREY FAN WIRE
BLACK WIRE FROM
REVERSING VALVE
TO RVS
(NO POLARITY)
BLACK WIRE FROM REVERSING
VALVE TO L2 ON K2A1
(NO POLARITY)
K1
K2
K2A1
Fig. 20 —Typical Wall Thermostat Interface Board Terminal Connections (Heat Pump Control Board Shown)

7
4. Install new control panel label over the old control panel
label to cover holes left by removal of old controls and
refer guests to the wall-mounted thermostat. See Fig. 16.
Wiring of Thermostat
1. Refer to installation instructions included with thermostat
for thermostat installation.
2. Route thermostat wires through grommet in remote wir-
ing access cover (supplied with kit).
3. Make thermostat wiring connection (6 wires) to remov-
able terminal block on control board, accessible through
the opening for thermostat wiring interface.
a. R to R (24 VAC)
b. C to C (common — must be connected for digital
thermostats)
c. Y to Y (compressor)
d. O to O (reversing valve)
e. G to G (Fan)
f. W to W (electric heater)
4. Plug thermostat wiring terminal block back on to control
board.
5. Attach remote wiring access cover to control box cover
using 2 screws provided (where knockout was removed
for thermostat wiring interface). See Fig. 18.
Installation Completion
1. Replace front panel.
2. Restore power to unit.
COOLING ONLY UNITS
Remove Existing Controls
1. Remove ALL 3 wires (yellow, white and orange) from
the fan cycle switch. See Fig. 6.
2. Remove the following wires from the push button switch:
a. Power cord wire from L1.
b. Black fan motor wire from HI.
c. Red fan motor wire from LO.
3. Remove Yellow compressor wire from thermostat,
terminal 1.
4. Remove the thermostat and push button switch controls
and all remaining attached wires and discard. Remove
thermostat bulb and mounting bracket from front of coil
and discard with the thermostat control. See Fig. 7.
Install New Wall Thermostat Controls
1. Remove knockout on control box cover for thermostat
wiring interface. See Fig. 8.
2. Mount wall thermostat control panel to front control box
cover using 3 of the no. 10 hex head screws provided. See
Fig. 9-11.
NOTE: Be sure removable terminal block on control
board is lined up with hole in control box cover from
knockout in previous step.
3. Re-connect wiring to fan/cycle switch. See Fig. 6.
a. Black Hi Fan speed wire to top terminal on fan/
cycle switch.
b. Red Low Fan speed wire to bottom terminal on
fan/cycle switch.
c. Grey Fan wire (factory installed on printed circuit
board from Relay K3, see Fig. 12) to center termi-
nal on fan/cycle switch.
4. Connect one end of Pink wire (included in plastic bag
labeled “For cooling only installations”) to the C terminal
on the capacitor. Connect the other end to L2 on relay
K2A1.
5. Re-connect the following wires on control board. See
Fig. 12.
a. Yellow compressor wire to COMP on relay Kl.
b. Power Cord wire (Ll) to L1 (brass post terminal)
on relay K2.
6. Secure control board ground wire (green) to ground
screw on control box door with power cord and chassis
ground wires. See Fig. 13.
7. Remove coil filter. Install Indoor Coil Freeze Thermostat
(IFT) into coil.
a. Use a pen to make an opening in the fins 4-in. from
the right side of the coil between the second and third
tube from the top to install freeze sensor (Fig. 14).
b. Push freeze sensor into opening made in Step 7a.
c. Bend clip on scored line and install in fins (the curved
notches will lock clip in place) next to sensor to hold
sensor in place in the coil. See Fig. 15.
8. Replace filter (indoor coil freeze thermostat will be locat-
ed in the coil behind the filter).
9. Dress wires using wire ties provided.
10. Close the control box door and secure by re-attaching
screws saved earlier. See Fig. 3.
11. Reinstall plastic control panel cover using the 2 screws
removed earlier. See Fig. 3.
Install Labels and Schematics
1. Remove old wiring schematic label and install new wir-
ing schematic label in same location. See Fig. 16.
2. Install conversion label to front of control box. See
Fig. 16.
3. Install Hi Speed/Low Speed label next to fan cycle switch
on side of control box. See Fig. 17.
NOTE: Fan cycle switch now becomes a speed selec-
tor switch and selects whether the fan runs in high
speed or low speed. It is recommended to set the
switch to low fan speed for maximum sound comfort.
4. Install new control panel label over the old control panel
label to cover holes left by removal of old controls and
refer guests to the wall-mounted thermostat. See Fig. 16.
Wiring of Thermostat
1. Refer to installation instructions included with thermostat
for thermostat installation.
2. Route thermostat wires through grommet in remote wir-
ing access cover (supplied with kit).
3. Make thermostat wiring connection (4 wires) to remov-
able terminal block on control board, accessible through
the opening for thermostat wiring interface.
a. R to R (24 VAC)
b. C to C (common — must be connected for digital
thermostats)
c. Y to Y (compressor)
d. G to G (Fan)
4. Plug thermostat wiring terminal block back on to control
board.
5. Attach remote wiring access cover to control box cover
using 2 screws provided (where knockout was removed
for thermostat wiring interface). See Fig. 18.
Installation Completion
1. Replace front panel.
2. Restore power to unit.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 132 Catalog No. 535-20060 Printed in U.S.A. Form 52S-67SI Pg 8 9-03 Replaces: 52S-66SI
Book 1 4
Ta b 9 a 1 1 a
Copyright 2003 Carrier Corporation