Carrier WeatherMaker 38YDB User manual

38YDB
WeatherMaker™ Two-Speed Split System
Heat Pump with Puron® Refrigerant
Installation Start-Up and Instructions
NOTE: Read the entire instruction manual before starting the
installation.
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service, maintenance,
or use can cause explosion, fire, electrical shock, or other
conditions which may cause death, personal injury, or property
damage. Consult a qualified installer, service agency, or your
distributor or branch for information or assistance. The qualified
installer or agency must use factory-authorized kits or accessories
when modifying this product. Refer to the individual instructions
packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instructions thor-
oughly and follow all warnings or cautions included in literature
and attached to the unit. Consult local building codes and National
Electrical Code (NEC) for special requirements.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and CAU-
TION. These words are used with the safety-alert symbol. DAN-
GER identifies the most serious hazards which will result in severe
personal injury or death.
WARNING signifies hazards 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.
Before installing, modifying, or servicing system, main elec-
trical disconnect switch must be in the OFF position. There
may be more than 1 disconnect switch. Lock out and tag
switch with a suitable warning label. Electrical shock can
cause personal injury or death.
Puron® (R-410A) systems operate at higher pressures than
standard R-22 systems. Be certain that service equipment is
rated for R-410A. Some R-22 service equipment may not be
acceptable. Check with your distributor.
INSTALLATION RECOMMENDATIONS
NOTE: In some cases noise in the living area has been traced to
gas pulsations from improper installation of equipment.
1. Locate unit away from windows, patios, decks, etc. where unit
operation sound may disturb customer.
2. Ensure that vapor and liquid tube diameters are appropriate to
capacity of unit.
3. Run refrigerant tubes as directly as possible by avoiding
unnecessary turns and bends.
4. Leave some slack between structure and unit to absorb
vibration.
5. When passing refrigerant tubes through the wall, seal opening
with RTV or other pliable silicon-based caulk. (See Fig. 2.)
6. Avoid direct tubing contact with water pipes, duct work, floor
joists, wall studs, floors, and walls.
7. Do not suspend refrigerant tubing from joists and studs with a
rigid wire or strap which comes in direct contact with tubing.
(See Fig. 2.)
8. Ensure that tubing insulation is pliable and completely sur-
rounds vapor tube.
9. When necessary, use hanger straps which are 1 in. wide and
conform to shape of tubing insulation. (See Fig. 2.)
10. Isolate hanger straps from insulation by using metal sleeves
bent to conform to shape of insulation.
When outdoor unit is connected to factory-approved indoor unit,
outdoor unit contains system refrigerant charge for operation with
indoor unit of the same size when connected by 15 ft of
field-supplied or factory accessory tubing. For proper unit opera-
tion, check refrigerant charge using charging information located
on control box cover or in the Check Charge section of this
instruction.
IMPORTANT: Maximum liquid-line size is 3/8–in. O.D. for all
residential applications.
IMPORTANT: Always install the factory-supplied Puron® heat
pump (bi-flow) liquid line filter drier. Obtain replacement filter
driers from your distributor or branch.
Fig. 1—Model 38YDB
A98516
Visit www.carrier.com
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 5a 5a PC 101 Catalog No. 533-761 Printed in U.S.A. Form 38YDB-1SI Pg 1 12-00 Replaces: New

INSTALLATION
Step 1—Check Equipment and Job Site
UNPACK UNIT
Move to final location. Remove carton, taking care not to damage
unit.
INSPECT EQUIPMENT
File claim with shipping company prior to installation if shipment
is damaged or incomplete. Locate unit rating plate on unit corner
panel. It contains information needed to properly install unit.
Step 2—Install on a Solid, Level Mounting Pad
If conditions or local codes require the unit be attached to pad, tie
down bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 3
to determine base pan size and knockout hole location.
On rooftop applications, mount on level platform or frame. Place
unit above a load-bearing wall and isolate unit and tubing set from
structure. Arrange supporting members to adequately support unit
and minimize transmission of vibration to building. Consult local
codes governing rooftop applications.
Do not allow POE lubricant to come into contact with roofing
material. POE may deteriorate certain types of synthetic
roofing.
Roof mounted units exposed to winds above 5 mph may require
wind baffles. Consult the Application Guideline and Service
Manual for Residential Split System Air Conditioners and Heat
Pumps using Puron®Refrigerant for wind baffle construction
NOTE: Unit must be level to within ±2°(±3/8 in./ft) per
compressor manufacturer specifications.
Step 3—Clearance Requirements
When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 30-in. clearance to
service end of unit and 48 in. above unit. For proper airflow, a 6-in.
clearance on 1 side of unit and 12 in. on all remaining sides must
be maintained. Maintain a distance of 24 in. between units.
Position so water, snow, or ice from roof or eaves cannot fall
directly on unit.
On rooftop applications, locate unit at least 6 in. above roof
surface.
Step 4—Operating Ambient
The minimum outdoor operating ambient in cooling mode is 55°F,
and the maximum outdoor operating ambient in cooling mode is
125°F.
Fig. 2—Connecting Tubing Installation
A94028
INSULATION
VAPOR TUBE
LIQUID TUBE
OUTDOOR WALL INDOOR WALL
LIQUID TUBE
VAPOR TUBE
INSULATION
CAULK
Avoid contact between tubing and structureNOTE:
THROUGH THE WALL
HANGER STRAP
(AROUND VAPOR
TUBE ONLY)
JOIST
1″MIN.
SUSPENSION
Fig. 3—Mounting Unit to Pad
UNIT SIZE
MINIMUM
MOUNTING PAD
DIMENSIONS
TIEDOWN KNOCKOUT
LOCATIONS
Support Feet Snow Stand A B
024 19 X 24 26 X 32 2-13/16 6-15/16
030-060 26 X 32 31 X 35 4 9-3/4
A97548
C
LA
B
VIEW FROM TOP 83/16″
3/8-IN. DIA TIEDOWN
KNOCKOUTS IN BASEPAN
(2) PLACES
Fig. 4—Accessory Support Feet
A98533
2

Step 5—Elevate Unit
Accumulation of water and ice in base pan may cause
equipment damage.
Elevate unit per local climate and code requirements to provide
clearance above estimated snowfall level and ensure adequate
drainage of the unit. Fig. 4 shows unit with accessory support feet
installed. Use accessory snow stand in areas where prolonged
freezing temperatures are encountered. Refer to separate Installa-
tion Instructions packaged with accessories.
Step 6—Check Indoor Expansion Device
For proper unit operation and reliability, units must be
installed with factory-supplied balanced port hard shutoff
TXV specifically designed to operate with Puron®two-speed
unit. Do not install with evaporator coils having capillary tube
metering devices.
FURNACE COILS
Remove existing AccuRater piston from indoor coil and install
factory-supplied TXV.
IMPORTANT: The TXV should be mounted as close to the
indoor coil as possible and in a vertical, upright position. Avoid
mounting the inlet tube vertically down. Valve is more susceptible
to malfunction due to debris if inlet tube is facing down. A
factory-approved filter drier must be installed in the liquid line.
Install TXV kit to indoor coil as follows:
PROCEDURE 1—INSTALLING TXV IN PLACE OF
PISTON
1. Pump system down to 2 psig and recover refrigerant.
2. Remove indoor coil inlet tube at piston body inlet. Use
back-up wrench to prevent damage.
3. Remove piston retainer, being careful not to damage sealing
surface of O-ring.
4. Remove and discard factory-installed piston. Replace retainer
if O-ring is damaged.
NOTE: If the piston is not removed from the body, TXV will not
function properly.
5. Reinstall piston retainer in piston body.
6. Replace indoor coil inlet tube. Use back-up wrench to prevent
damage.
To prevent damage to the unit, use a brazing shiled and wrap
TXV with wet cloth or use heat sink material.
7. Sweat swivel adapter (See Fig. 6D) to inlet of indoor coil and
attach to TXV (See Fig. 6A) outlet. Use backup wrench to
avoid damage to tubing or valve. Sweat inlet of TXV, marked
“IN,”to liquid line. Avoid excesive heat which could damage
valve.
8. Install vapor elbow (See Fig. 6B) with equalizer adapter to
suction tube of line set and suction connection to indoor coil.
Adapter has a 1/4-in. male flare connector for attaching
equalizer tube.
9. Connect equalizer tube of TXV to 1/4-in. equalizer fitting on
vapor line adapter.
10. Attach TXV bulb to horizontal section of suction line using
nylon bulb clamps provided. (See Fig. 6C.) Insulate bulb with
field-supplied insulation tape. See Fig. 7 for correct position-
ing of sensing bulb.
11. Proceed with remainder of unit installation.
FAN COILS
Indoor unit (fan coil) does NOT contain a balanced port hard
shut-off TXV specifically designed for Puron®two-speed TXV.
Changeout is required.
PROCEDURE 2—REPLACING R-22 TXV OR NON-
BALANCED PORT PURON® TXV OR INDOOR COIL
1. Pump system down to 2 psig and recover refrigerant.
2. Remove coil access panel and fitting door from cabinet.
3. Remove and save TXV support clamp using a 5/16-in. nut
driver.
4. Remove TXV using a backup wrench on flare connections to
prevent damage to tubing.
5. Using wire cutters, cut equalizer tube off flush with vapor tube
inside cabinet.
6. Remove bulb from vapor tube inside cabinet.
7. Braze equalizer stub-tube closed. Use protective barrier as
necessary to prevent damage to drain pan.
IMPORTANT: Route the equalizer tube of approved factory
supplied Puron®TXV through suction line connection opening in
fitting panel prior to replacing fitting panel around tubing.
8. Install TXV (Fig. 6A) with 3/8-in. copper inlet tube through
small hole in service panel. Use wrench and backup wrench,
to avoid damage to tubing valve.
9. Reinstall TXV support clamp (removed in item 3).
10. Attach TXV bulb to vapor tube inside cabinet in same location
as original was removed using supplied nylon bulb clamps
(See Fig. 6C). See Fig. 7 for correct positioning of sensing
bulb.
11. Route equalizer tube through suction connection opening
(large hole) in fitting panel and install fitting panel in place.
12. Sweat inlet of TXV, marked “IN,”to liquid line. Avoid
excessive heat which could damage valve.
13. Install vapor elbow (See Fig. 6B) with equalizer adapter to
vapor line of line set and vapor connection to indoor coil.
Adapter has a 1/4-in. male flare connector for attaching
equalizer tube. (See Fig. 6B.)
14. Connect equalizer tube of TXV to 1/4-in. equalizer fitting on
vapor line adapter. Use backup wrench to prevent damage to
equalizer fitting.
Fig. 5—TXV Installed
A00426
THERMOSTATIC
EXPANSION
VALVE
EQUALIZER
TUBE
COIL SENSING
BULB
3

15. Proceed with remainder of unit installation.
LONG-LINE APPLICATIONS, INSTALL LIQUID-LINE
SOLENOID VALVE (LSV)
For refrigerant piping arrangements with equivalent lengths
greater than 50 ft or when elevation difference between indoor
and/or outdoor unit is greater than ± 8 ft, follow all requirements
of the Long-Line Guideline section in the Application Guideline
and Service Manual for Residential Split-System Air Conditioners
and Heat Pumps Using Puron®Refrigerant. If required by
Long-Line Application Guideline, install LSV kit Part No.
KHALS0401LLS specifically designed for Puron®Heat Pump.
LSV should be installed between filter drier and indoor coil as
close as possible to filter drier. Follow the Installation Instructions
included with accessory kit.
IMPORTANT: Flow arrow must point toward outdoor unit.
Step 7—Make Piping Connections
Relieve pressure and recover all refrigerant before system
repair or final unit disposal to avoid personal injury or death.
Use all service ports and open all flow-control devices,
including solenoid valves.
Fig. 6—TXV Kit Contents
A00400
AB
C
D
INLET
COIL
Fig. 7—Positioning of Sensing Bulb
A00399
SENSING BULB
STRAP
8 O'CLOCK 4 O'CLOCK
4

Do not leave system open to atmosphere any longer than
minimum required for installation. POE oil in compressor is
extremely susceptible to moisture absorption. Always keep
ends of tubing sealed during installation.
To prevent compressor damage DO NOT bury more than 36
in. of refrigerant tubing. If ANY tubing is buried, provide
6-in. vertical rise at service valve.
Outdoor units may be connected to indoor section using accessory
tubing package or field-supplied refrigerant grade tubing of correct
size and condition. Tubing diameters listed in Table 1 are adequate
for equivalent lengths up to 50 ft For tubing requirements beyond
50 ft, substantial capacity and performance losses can occur.
Follow the recommendations in the Application Guideline and
Service Manual for Residential Split-System Air Conditioners and
Heat Pumps Using Puron®Refrigerant to minimize losses. Refer
to Table 1 for field tubing diameters. Refer to Table 2 for
accessory requirements.
If refrigerant tubes or indoor coil are exposed to atmosphere, they
must be evacuated to 500 microns to eliminate contamination and
moisture in the system. Do not leave system open to atmosphere
any longer than minimum required for installation. POE oil in
compressor is extremely susceptible to moisture absorption. Al-
ways keep ends of tubing sealed during installation.
OUTDOOR UNIT CONNECTED TO FACTORY-APPROVED
INDOOR UNIT
These outdoor units are carefully evaluated and listed with specific
indoor coils for proper system performance.
IMPORTANT: Do not apply indoor coils which are not factory
approved to these units.
INSTALL ADAPTER TUBE
1. Remove plastic retainer holding outdoor piston in liquid
service valve.
2. Check to be sure outdoor piston is properly installed in liquid
service valve.
3. Locate plastic bag taped to unit containing adapter tube.
4. Remove Teflon washer from bag and install on open end of
liquid service valve. (See Fig. 8.)
5. Remove adapter tube from bag and connect threaded nut to
liquid service valve. Tighten nut finger tight and then with
wrench an additional 1/2 turn (15 ft-lb). DO NOT OVER-
TIGHTEN!
REFRIGERANT TUBING AND FILTER DRIER
Installation of filter drier in liquid line is required.
Connect vapor tubing to fittings on outdoor unit vapor service
valve. Connect liquid tubing to filter drier. (See Table 1 and Fig.
9.) Use refrigerant grade tubing. Connect other end of filter drier
to adapter tube on liquid service valve.
SWEAT CONNECTION
To avoid valve damage while brazing, service valves must be
wrapped in a heat-sinking material such as a wet cloth.
Wrap service valves and filter drier with a wet cloth or heat-
sinking material. Braze connections using either silver bearing or
non-silver bearing brazing material. Do not use soft solder
(materials which melt below 800°F). Consult local code require-
ments.
To prevent damage to unit or service valves, observe the
following:
•Use a brazing shield.
•Wrap service valves with wet cloth or use a heat sink
material.
LEAK CHECKING
Leak test all joints in indoor, outdoor, and refrigerant tubing.
EVACUATE REFRIGERANT TUBING AND INDOOR COIL
Never use the system compressor as a vacuum pump.
Refrigerant tubes and indoor coil must be evacuated using the
recommended deep vacuum method of 500 microns. The alternate
triple evacuation method may be used if the procedure outlined
below is followed.
Table 1—Refrigerant Connections and
Recommended Liquid and Vapor Tube
Diameters (In.)
UNIT LIQUID VAPOR VAPOR (LONG-LINE)
SIZE Connection
Diameter Tube Diameter Connection Diameter Tube Diameter Connection Diameter Tube Diameter
024 3/8 3/8 5/8 5/8 5/8 3/4
036 3/8 3/8 3/4 3/4 3/4 7/8
048 3/8 3/8 7/8 7/8 7/8 7/8
060 3/8 3/8 7/8 1-1/8 7/8 1-1/8
Notes:
1. Tube diameters are for lengths up to 50 equivalent ft
2. Do not increase or decrease tubing sizes.
Fig. 8—Liquid Service Valve with Sweat Adapter
Tube
A97556
SWEAT/FLARE
ADAPTER
TEFLON
SEAL
PISTON BODY
LIQUID SERVICE VALVE
PISTON
5

IMPORTANT: Never open system under vacuum to atmosphere
without first breaking it open with nitrogen.
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of
pulling a vacuum of 500 microns and a vacuum gage capable of
accurately measuring this vacuum depth. The deep vacuum
method is the most positive way of assuring a system is free of air
and liquid water. (See Fig. 10.)
Triple Evacuation Method
The triple evacuation method should only be used when vacuum
pump is only capable of pumping down to 28 in. of mercury and
system does not contain any liquid water. Refer to Fig. 11 and
proceed as follows:
1. Pump system down to 28 in. of mercury and allow pump to
continue operating for an additional 15 minutes.
2. Close service valves and shut off vacuum pump.
3. Connect a nitrogen cylinder and regulator to system and open
until system pressure is 2 psig.
4. Close service valve and allow system to stand for 1 hr During
this time, dry nitrogen will be able to diffuse throughout the
system, absorbing moisture.
5. Repeat this procedure as indicated in Fig. 11. System will then
contain minimal amounts of contaminants and water vapor.
FINAL TUBING CHECK
IMPORTANT: Check to be certain factory tubing on both indoor
and outdoor unit has not shifted during shipment. Ensure tubes are
not rubbing against each other or any sheet metal. Pay close
attention to feeder tubes, making sure wire ties on feeder tubes are
secure and tight.
Table 2—Accessory Usage
ACCESSORY REQUIRED FOR LOW-AMBIENT APPLICATIONS
(BELOW 55°F)
REQUIRED FOR LONG-LINE
APPLICATIONS
*
(OVER 50 FT)
Wind Baffle See Low-Ambient Instructions No
Support Feet Recommended No
Puron®Balanced-Port Hard Shutoff TXV Yes† Yes†
Puron®Liquid-Line Solenoid Valve for Heating No See Long-line
ApplicationGuideline
* For tubing line sets between 50 and 175 ft, for 20 ft vertical differential refer to Application Guideline and Service Manual for Residential Split-System Air Conditioners
and Heat Pumps using Puron® Refrigerant.
†Required for all applications. Factory supplied with outdoor unit.
Fig. 9—Filter Drier with Sweat Adapter Tube and
Liquid Tube
A97555
R
-
4
1
0
A
LIQUID
SERVICE
VALVE
LIQUID-LINE
FILTER-DRIER
Fig. 10—Deep Vacuum Graph
A95424
500
MINUTES
01234567
1000
1500
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
A95424 Fig. 11—Triple Evacuation Method
A95425
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
CHARGE SYSTEM
BREAK VACUUM WITH DRY NITROGEN
EVACUATE
WAIT
6

Step 8—Make Electrical Connections
To avoid personal injury or death, do not supply power to unit
with compressor terminal box cover removed.
Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown
on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit
protection device.
NOTE: Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate. Do not
install unit in system where voltage may fluctuate above or below
permissible limits.
NOTE: Use copper wire only between disconnect switch and
unit.
NOTE: Install branch circuit disconnect of adequate size per
NEC to handle unit starting current. Locate disconnect within sight
from and readily accessible from unit, per Section 440-14 of NEC.
ROUTE GROUND AND POWER WIRES
Remove access panel and control box cover to gain access to unit
wiring. Extend wires from disconnect through power wiring hole
provided and into unit control box. Size wires per NEC but not
smaller than minimum wire size shown in Product Data Digest.
The unit cabinet must have as uninterrupted or unbroken
ground to minimize personal injury if an electrical fault
should occur. The ground may consist of electrical wire or
metal conduit when installed in accordance with existing
electrical codes. Failure to follow this warning can result in an
electric shock, fire, or death.
CONNECT GROUND AND POWER WIRES
Connect ground wire to ground connection in control box for
safety. Connect power wiring to leads provided as shown in Fig.
12.
CONNECT CONTROL WIRING
Route 24v control wires through control wiring grommet and
connect to leads provided in control box. (See Table 3 and Fig. 13.)
Use No. 18 AWG color-coded, insulated (35°C minimum) wire. If
thermostat is located more than 100 ft from unit, as measured
along the control voltage wires, use No. 16 AWG color-coded wire
to avoid excessive voltage drop.
All wiring must be NEC Class 1 and must be separated from
incoming power leads.
The outdoor unit requires a minimum of 27-va, 24v control power.
FINAL WIRING CHECK
IMPORTANT: Check factory wiring and wire connections to
ensure terminations are secured properly. Check wire routing to
ensure wires are not in contact with tubing, sheet metal, etc.
Step 9—Install Electrical Accessories
GENERAL
Refer to the individual instructions packaged with kits or acces-
sories when installing. The liquid line solenoid valve accessory is
available on these units. See Fig. 14 for wiring diagram.
Available electrical accessories include latent capacity control. See
Table 3 and Fig. 13 for typical accessory wiring diagrams.
LATENT CAPACITY CONTROL (LCC)
The purpose of an LCC is to provide a dehumidification mode to
assure a 75 percent or less system sensible heat ratio. If indoor unit
installed contains an ICM blower (such as an FK4, FV4, or 40FK
fan coil or a 58UHV, 58UXV, or 58MVP gas furnace), no LCC is
required. Indoor products with ICM blowers have enough CFM
range to provide proper airflow for low-speed cooling. If indoor
unit installed has a standard PSC blower motor, the low-speed
airflow available is too great to assure 75 percent or less system
sensible heat ratio. The LCC for standard blower products consists
of a standard humidistat which opens contacts on humidity rise and
a pilot duty relay with 24v coil.
NOTE: If an LCC is desired, low-speed airflow must be main-
tained so that a minimum of 300 CFM/ton can be supplied during
high-speed LCC operation.
LCC Operation for Typical PSC Fan Coils
The standard blower connections for systems with typical PSC fan
coils is covered in Fig. 13A, B, and D. The blower runs in high
speed regardless if compressor operation is high or low speed.
When the LCC is wired according to Fig. 13A, B, or D and
humidity rises, the humidistat contacts open and de-energize the
relay. If relay is de-energized, the system operates on high-speed
compressor and high-speed airflow until humidistat closes. Fig.
l3C shows the wiring with a Carrier Thermidistat Control which
controls temperature and humidity level without the need for an
additional humidistat and relay.
LCC Operation for Typical PSC Furnaces
The standard blower connections of systems with typical PSC
furnaces is covered in Fig. 13J, K, N, P, Q, or S. The blower runs
in high or low speed in conjunction with compressor high- or
low-speed operation. When the LCC is wired according to Figs.
l3J, K, N, P, Q, or S and humidity rises, the humidistat contacts
open and de-energize the relay. If relay is de-energized, the system
operates on high-speed compressor and low-speed airflow until
humidistat closes. Figs. l3L and 13R show the wiring with a
Carrier Thermidistat Control which controls temperature and
humidity level without the need for an additional humidistat and
relay.
Step 10—Make Airflow Selections
AIRFLOW SELECTION FOR 58UHV, 58UXV FURNACES
The 58UHV, 58UXV Non-Condensing Variable-Speed Furnaces
provide high- and low-speed blower operation to match the
capacities of compressor high and low speeds. To select recom-
mended airflow, refer to Table 4 and the 58UHV, 58UXV
Installation Instructions. These settings are made on the furnace
airflow selector board by moving the appropriate color-coded
jumper wires. The ORANGE jumper wire should be set to the
HP—EFFY position for heat pump best efficiency or HP—CMFT
for heat pump enhanced comfort. The YELLOW COOL SIZE
Fig. 12—Line Power Connections
A91306
CONTACTOR
DISCONNECT
PER N. E. C. AND/ OR
LOCAL CODES
FIELD POWER
WIRING
FIELD GROUND
WIRING GROUND
LUG
7

jumper is used to select airflow to match the needed tons of
cooling. The BLUE CFM/TON jumper wire is used to select slight
adjustments to airflow of 400, 350, or 315 CFM per ton. (See
Table 4.)
AIRFLOW SELECTION FOR 58MVP FURNACES
The 58MVP Condensing Variable-Speed Furnaces provide high-
and low-speed blower operation to match the capacities of com-
pressor at high and low speeds. To select recommended airflow,
refer to Table 5 and the 58MVP Installation Instructions. The
58MVP utilizes a control center that allows the installing techni-
cian to select proper airflows. For adjustments to the manual
switches labeled A/C and CF and recommended switch positions,
refer to Table 5. High-speed airflow is determined by the position
of the A/C switches, and low-speed airflow is determined by the
position of the CF switches. This furnace has a built-in, non-
adjustable 90 sec. off delay for cooling mode blower operation.
AIRFLOW SELECTION FOR FK4, FV4, OR 40FK FAN COILS
The FK4, FV4, and 40FK provides high- and low-speed blower
operation to match the capacities of compressor at high and low
speeds. To select recommended airflow, refer to Table 6 and the
FK4, FV4, or 40FK Installation Instructions. The FK4, FV4, and
40FK utilizes an EASY SELECT control board that allows the
installing technician to select proper airflows. The ORANGE
SYSTEM TYPE JUMPER wire should be set to HP—EFF or
HP—COMFORT. The BLUE AC/HP SIZE JUMPER is used to
select airflow to match the outdoor unit nominal size in tons of
cooling. The BLACK AC/HP CFM ADJUST jumper is used to
make slight adjustments to the selected airflow tonnage. (See
Table 6.) This fan coil has an adjustable blower off delay factory
set at 90 sec. for high- and low-speed blower operation.
Step 11—Start-Up
To prevent compressor damage or personal injury, observe
the following:
•Do not overcharge system with refrigerant.
•Do not operate unit in a vacuum or at negative pressure.
•Do not disable low-pressure switch.
To prevent personal injury wear safety glasses, protective
clothing, and gloves when handling refrigerant and observe
the following:
•Back seating service valves are not equipped with Schrader
valves. Fully back seat (counter clockwise) valve system
before removing gage port cap.
Do not vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.
Follow these steps to properly start up the system:
1. The outdoor unit is equipped with a crankcase heater which
operates when the compressor is OFF. Energize crankcase
heater 24 hr before starting unit. To energize heater only, set
indoor thermostat to OFF position and close power disconnect
to unit.
2. Fully back seat (open) liquid and vapor tube service valves.
3. Unit is shipped with valve stem(s) front seated and caps
installed. Replace stem caps after system is opened to refrig-
erant flow (back seated). Replace caps finger tight and tighten
additional 1/12 turn (20 ft-lb torque) with wrench.
Table 3—Wiring Diagram Reference
INDOOR PRODUCT THERMOSTAT CONTROLS DIAGRAM LETTER
IN FIG. 13
Standard Fan Coil
Carrier Programmable (Model 2S) Latent Capacity A
Carrier Non-Programmable (Model 2S) Latent Capacity B
Carrier Thermidistat™Control (Model RH) Humidifier and Outdoor Sensor C
Other Brand Models Latent Capacity D
FK4, FV4, or 40FK Fan Coil
Carrier Programmable (Model 2S) —E
Carrier Non-Programmable (Model 2S) —F
Carrier Thermidistat™Control (Model RH) Humidifier and Outdoor Sensor G
Other Brand Models —H
Single-Stage Furnace
Carrier Programmable (Model 2S) Latent Capacity J
Carrier Non-Programmable (Model 2S) Latent Capacity K
Carrier Thermidistat™Control (Model RH) Humidifier and Outdoor Sensor L
Carrier Dual Fuel Thermostat (Model DF) Outdoor Sensor M
Other Brand Models Latent Capacity N
Two-Stage Furnace with PSC Blower Motor
Carrier Programmable (Model 2S) Latent Capacity P
Carrier Non-Programmable (Model 2S) Latent Capacity Q
Carrier Dual Fuel Thermostat (Model DF) Outdoor Sensor V
Carrier Thermidistat™Control (Model RH) Humidifier and Outdoor Sensor R
Other Brand Models Latent Capacity S
Two-Stage Furnace with ICM Blower Motor
Carrier Programmable (Model 2S) —T
Carrier Non-Programmable (Model 2S) —U
Carrier Dual Fuel Thermostat (Model DF) Outdoor Sensor V
Other Brand Models —W
Variable-Speed 80 percent
Non-Condensing Furnace Carrier Thermidistat™Control (Model RH) Humidifier and Outdoor Sensor X
Carrier Dual Fuel Thermostat (Model DF) Outdoor Sensor Y
Variable-Speed Condensing Furnace Carrier Thermidistat™Control (Model RH) Humidifier and Outdoor Sensor Z
8

4. Close electrical disconnects to energize system.
5. Set room thermostat at desired temperature. Be sure the set
point is below indoor ambient and is set low enough to
energize desired speed.
NOTE: Carrier electronic thermostats are equipped with a 15-
minute staging timer. This timer prevents the dual capacity system
from operating at high capacity until unit has been operating in low
capacity for 15 minutes unless there is at least a 5°F difference
between room temperature and thermostat set point. To force high
capacity, adjust the set point at least 5°below room ambient for
cooling or 5°above room ambient for heating.
6. Set room thermostat to COOL or HEAT and fan control to
AUTO or ON as desired. Wait for appropriate time delay(s).
Operate unit for 15 minutes. Check refrigerant charge.
Step 12—Check Charge
Service valve gage ports are not equipped with Schrader
valves. To prevent personal injury, make sure gage manifold
is connected to the valve gage ports before moving valves off
fully back seated position. Wear safety glasses and gloves
when handling refrigerant.
UNIT CHARGE
Factory charge is shown on unit rating plate. To check charge in
cooling mode, refer to Cooling Only Procedure. To check charge
in heating mode, refer to Heating Check Chart Procedure.
Adjust charge in both heating and cooling by following procedure
shown on charging tables located on unit information plate on back
side of access panel.
NOTE: Unit is to be charged in high capacity only. Charging in
low capacity may cause compressor chattering and possible
damage to the compressor.
COOLING ONLY PROCEDURE
1. Operate unit a minimum of 10 minutes before checking
charge.
Table 4—Airflow Selection for 58UHV, 58UXV Furnaces (CFM)
38YDB
UNIT
SIZE
FURNACE
MODEL/HEATING
SIZE
FURNACE AIRFLOW SELECTION BOARD SETTINGS
Cool Size
Jumper
Position
AC/HP
Jumper
Position
Cool CFM Per Ton Jumper Position
400 350 315
Heat Pump Heating Airflow
*
High Low High Low High Low
024 060 M-LO HP—EFFY 865 510 735 500 660 500
HP—CMFT 780 500 660 500 595 500
036
060 HI HP—EFFY 1260 780 1100 680 990 585
HP—CMFT 1135 700 990 610 895 555
080 M-LO HP—EFFY 1260 790 1100 700 990 625
HP—CMFT 1135 715 990 630 895 560
100 LO HP—EFFY 1260 780 1090 775 990 700
HP—CMFT 1130 700 980 700 890 700
120 LO HP—EFFY 1195 865 1085 785 985 785
HP—CMFT 1075 780 975 750 885 750
048
080 HI HP—EFFY 1635 1040 1470 915 1325 820
HP—CMFT 1510 940 1325 825 1190 740
100 M-HI HP—EFFY 1680 1040 1465 915 1325 820
HP—CMFT 1510 935 1320 825 1190 740
120 M-HI HP—EFFY 1650 1070 1465 975 1315 930
HP—CMFT 1485 965 1320 880 1185 835
060 100 HI HP—EFFY 2085 1300 1840 1150 1655 1025
HP—CMFT 1890 1170 1655 1035 1490 920
120 HI HP—EFFY 2110 1300 1865 1140 1640 1080
HP—CMFT 1900 1170 1650 1025 1475 970
*
Heat Pump Cooling Airflow always matches HP—EFFY Heat Pump Heating Airflow
Table 5—Airflow Selection for 58MVP Furnaces (CFM)
38YDB
UNIT
SIZE
HIGH-SPEED
A/C SETUP
SWITCH POSITION
FURNACE MODEL/HEATING SIZE LOW-SPEED
CF SETUP
SWITCH POSITION
040 060 080 100 120
A/C-1 A/C-2 A/C-3 High Low High Low High Low High Low High Low CF-1 CF-2 CF-3
024 OFF ON OFF 800 565 800 515 ——————OFF OFF OFF
036 OFF OFF ON 1200 800 1200 800 1200 800 1200 800 ——OFF ON OFF
048 OFF ON ON ——————1600 1000 1600 1000 ON ON OFF
060 ON ON ON ——————2000 1200 2000 1200 OFF OFF ON
9

2. Measure liquid service valve pressure by attaching an accurate
gage to service port.
3. Measure liquid line temperature by attaching an accurate
thermistor type or electronic thermometer to liquid line near
outdoor coil.
4. Refer to charging label for required subcooling temperatures.
5. Refer to Table 7. Find the point where required subcooling
temperature intersects measured liquid service valve pressure.
6. To obtain required subcooling temperature at a specific liquid
line pressure, add refrigerant if liquid line temperature is
higher than indicated or reclaim refrigerant if temperature is
lower. Allow a tolerance of ± 3°F.
HEATING CHECK CHART PROCEDURE
To check system operation during heating cycle, refer to the
Heating Pump Charging Instructions on outdoor unit. This chart
indicates whether a correct relationship exists between system
operating pressure and air temperature entering indoor and outdoor
units. If pressure and temperature do not match on chart, system
refrigerant charge may not be correct. Do not use chart to adjust
refrigerant charge.
NOTE: In heating mode, check refrigerant charge only when
pressures are stable. If operating conditions cause vapor pressure
switch and thereby outdoor fan to cycle, check refrigerant charge
in cooling or lower indoor dry bulb temperature. If in doubt,
remove charge and weigh in correct refrigerant charge.
NOTE: When charging is necessary during heating season,
charge must be weighed in accordance with unit rating plate ±0.6
oz/ft of 3/8-in. liquid line above or below 15 ft respectively.
EXAMPLE:
To calculate additional charge required for a
25-ft line set:
25 ft - 15 ft = 10 ft X 0.6 oz/ft=6ozof
additional charge
Step 13—System Functions and Sequence of Operation
The outdoor unit control system has special functions. The
following is an overview of the two-speed control functions:
COOLING OPERATION
This product utilizes a 2-stage cooling indoor thermostat. With a
call for first stage cooling (Yl), the outdoor fan and low capacity
compressor are energized. If low capacity cannot satisfy cooling
demand, high capacity is energized (Yl and Y2 or just Y2) by the
second stage of indoor thermostat. After second stage is satisfied,
the unit returns to low-capacity operation until first stage is
satisfied or until second stage is required again. When both one
stage and two stage cooling are satisfied, the compressor will shut
off.
NOTE: Outdoor fan motor will continue to operate for one
minute after compressor shuts off, when outdoor ambient is greater
than 100°F.
NOTE: When two-speed unit is operating in low-capacity cool-
ing, system vapor (suction) pressure will be higher than a standard
single-speed system or high-speed operation. This normal opera-
tion is due to the reduced capacity operating with typically larger
indoor and outdoor coils.
HEATING OPERATION
This product utilizes a 3-stage heating indoor thermostat. With a
call for first stage heating (Y1), the outdoor fan and low capacity
compressor are energized. If low capacity cannot satisfy heating
demand, high capacity is energized (Y1 and Y2) by the second
stage of the indoor thermostat. Auxiliary or back up heat is
controlled by third stage (W1). After second stage of heat is
satisfied, the unit returns to low capacity operation until first stage
is satisfied or until second stage is required again. When both one
stage and two stage heating are satisfied, the compressor will shut
off.
Table 6—Airflow Selection for FK4, FV4, or 40FK Fan Coils (CFM)
38YDB
UNIT
SIZE
40FK/FK4/FV4
UNIT
SIZE
EASY SELECT CONTROL BOARD HEATING CFM
*
COOLING CFM
*
AC/HP
SIZE
(Blue Wire)
AC/HP
CFM ADJUST
(Black Wire) SYSTEM TYPE
(Orange Wire) High Low High Low
024
FK4C 001 024 NOM HP—EFF 735 440 735 440
HP—COMFORT 630 410
002 024 NOM HP—EFF 735 440 735 440
HP—COMFORT 630 410
003 024 NOM HP—EFF 735 440 735 440
HP—COMFORT 630 410
036
FK4C 001 036 NOM HP—EFF 1100 660 1100 660
HP—COMFORT 990 615
002 036 NOM HP—EFF 1100 660 1100 660
HP—COMFORT 990 615
003 036 NOM HP—EFF 1100 660 1100 660
HP—COMFORT 990 615
005 036 NOM HP—EFF 1100 660 1100 660
HP—COMFORT 990 615
006 036 NOM HP—EFF 1100 660 1100 660
HP—COMFORT 990 670
048 005 048 NOM HP—EFF 1470 880 1470 880
HP—COMFORT 1320 820
006 048 NOM HP—EFF 1470 880 1470 880
HP—COMFORT 1325 895
060 006 060 NOM HP—EFF 1835 1100 1835 1100
HP—COMFORT 1655 1120
* Airflow CFMs are given with AC/HP CFM ADJUST jumper set at NOM. Airflow can be adjusted 15 percent or −10 percent by selecting HI or LO, respectively.
10

HEAT STAGE 3
RVS COOLING
FAN
O/W2
W/W1
Y1/W2
E
W3
24 VAC COMM
N/A
OUTDOOR
SENSOR
CONNECTION
C
G
R
B
S1
S2
C
Y1
C
Y2
PROGRAMMABLE
THERMOSTAT
MODEL 2S TYPICAL
FAN COIL TWO-SPEED HEAT PUMP
See notes 7, 8, 9 and 11
W2
G
W1
O
RR
H
R1
COOL/HEAT
STAGE 1
COOL/HEAT
STAGE 2
24 VAC HOT
Y/Y2
A00360
A
CA00362
O/W2
Y1/W2
W/W1
G
R
E
W3
TYPICAL
FAN COIL TWO-SPEED
HEAT PUMP
W2
G
C
W1
Y2
R
O
Y1
C
DHUM
HUM
B
S1
S2
R
C
RVS COOLING
HEAT STAGE 3
COOL/HEAT
STAGE 2
COOL/HEAT
STAGE 1
FAN
24 VAC HOT
24 VAC COMM
N/A
HUMIDIFY
N/A
OUTDOOR
SENSOR
CONNECTION
Y/Y2
HUMIDIFIER
(24 VAC)
OUTDOOR
SENSOR
See notes 7, 8, 11, 16, and 17
THERMIDISTAT
CONTROL
MODEL RH
HEAT STAGE 3
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING
RVS HEATING
Y1
B
S1
S2
Y1
Y2
O
NON-PROGRAMMABLE
THERMOSTAT
MODEL 2S TYPICAL
FAN COIL TWO-SPEED
HEAT PUMP
See notes 7, 8, 10 and 11
G
O/W2
W2
W1
R
C
E
W3
H
R1
COOL/HEAT
STAGE 2
FAN
COOL/HEAT
STAGE 1
OUTDOOR
SENSOR
CONNECTION
24 VAC HOT
24 VAC COMM
A00361
B
R
CC
Y1
O
TYPICAL
FAN COIL TWO-SPEED
HEAT PUMP
See notes 8 and 11
W3
G
W2
R
E
Y2
H
R1
24 VAC HOT
24 VAC COM
HEAT STAGE 3
R
C
G
W2
Y2
Y1
OTHER BRAND
TWO-SPEED
THERMOSTAT
COOL/HEAT
STAGE 1
W1
COOL/HEAT
STAGE 2
FAN
O
E
EMERGENCY
HEAT
RVS COOLING
A00363
D
Fig. 13—Typical 24-V Circuit Connections
11

24 VAC HOT
FAN
R
G
R
G
24 VAC COMM
N/A
OUTDOOR
SENSOR
CONNECTION
C
B
S1
S2
C C
R
PROGRAMMABLE
THERMOSTAT
MODEL 2S
40FK/FV4
FK4
FAN COIL
J1
JUMPER
J2 JUMPER
TWO-SPEED
HEAT PUMP
See notes 7, 8, 9, 11 and 23
DH
Y1
Y1
W/W1
O/W2
Y1/W2
O
W1
Y/Y2 Y2
W1
Y/Y2
O
W2
COOL/HEAT
STAGE 1
COOL/HEAT
STAGE 2
HEAT STAGE 3
RVS COOLING
A00328
E
GA00330
O/W2
W/W1
Y1/W2
G
R
O
Y1
40FK/FV4
FK4
FAN COIL TWO-SPEED
HEAT PUMP
W1
G
W2
C
Y2
R
W1
Y1
O
C
DHUM
HUM
B
S1
S2
Y/Y2
R
C
DH
COOL/HEAT
STAGE 1
HEAT STAGE 3
COOL/HEAT
STAGE 2
RVS COOLING
FAN
24 VAC HOT
24 VAC COMM
DEHUMIDIFY
HUMIDIFY
N/A
OUTDOOR
SENSOR
CONNECTION
Y/Y2
HUMIDIFIER
(24 VAC)
OUTDOOR
SENSOR
See notes 7, 8, 11, 13, 16, 17, and 23
J2 JUMPER
REMOVE J1
THERMIDISTAT
CONTROL
MODEL RH
R
Y/Y2
R
Y2
CCC
R
W1
O
Y1
NON-PROGRAMMABLE
THERMOSTAT
MODEL 2S
40FK/FV4
FK4
FAN COIL TWO-SPEED
HEAT PUMP
J1 JUMPER
J2 JUMPER
See notes 7, 8 ,10, 11 and 23
GG
Y/Y2
DH
W/W1 W1
Y1
O/W2
Y1
W2
O
B
S1
S2
24 VAC HOT
24 VAC COMM
FAN
RVS COOLING
OUTDOOR
SENSOR
CONNECTION
HEAT STAGE 3
COOL/HEAT
STAGE 2
COOL/HEAT
STAGE 1
N/A
A00329
F
R
Y2
R
Y2
CCC
OO
W1
R
Y1
OTHER BRAND
TWO-SPEED
THERMOSTAT
40FK/FV4
FK4
FAN COIL TWO-SPEED
HEAT PUMP
J1 JUMPER
J2 JUMPER
GG
Y/Y2
DH
W2 W1
Y1
O
Y1
W2
24 VAC HOT
24 VAC COM
FAN
RVS COOLING
COOL/HEAT
STAGE 2
HEAT STAGE 3
E
EMERGENCY
HEAT
COOL/HEAT
STAGE 1
See notes 8, 11, and 23
A00331
H
Fig. 13—Typical 24-V Circuit Connections (Cont’d)
12

STATUS FUNCTION LIGHTS
A system control STATUS function light is located on the outdoor
unit control board (See Fig. 15). The STATUS light provides
signals for several system operations. See Table 8 for codes and
definitions. Table 8 also provides the order of signal importance.
NOTE: Only one code will be displayed on the outdoor unit
control board (the most recent, with the highest priority).
FACTORY DEFAULTS
Factory defaults have been provided in the event of failure of
outdoor air thermistor and/or outdoor coil thermistor. Refer to
Table 9 for default and function.
ONE MINUTE SPEED CHANGE TIME DELAY
When compressor changes speeds from high to low or low to high,
there is a 1-minute time delay before compressor restarts. The
outdoor fan motor remains running.
COMPRESSOR OPERATION
When the compressor operates in two capacity operation, the
motor rotates clockwise. Both the lower and upper pistons are
eccentric with the rotating crankshaft, and both compress refrig-
erant. When the compressor operates in single capacity the motor
reverses direction (rotates counter-clockwise). The lower piston
becomes idle since it is not eccentric with the compressor
crankshaft and the upper piston which is eccentric with the rotating
crankshaft compresses refrigerant. The start and run windings are
reversed.
FIVE-MINUTE HIGH-SPEED MINIMUM
If unit has not operated within the past 12 hours, or following a
unit power-up, upon the next thermostat high- or low-speed
demand, unit operates for a minimum of 5 minutes in high speed.
CRANKCASE HEATER OPERATION
The two-speed control energizes crankcase heater during unit’s off
cycle.
OUTDOOR FAN MOTOR OPERATION
The two-speed control energizes outdoor fan any time compressor
is operating. The outdoor fan remains energized during the
1-minute speed change time delay and if a pressure switch or
compressor overload should trip. Outdoor fan motor will continue
to operate for one minute after the compressor shuts off when the
outdoor ambient is greater than 100°F.
After termination of a defrost cycle, the outdoor fan delays coming
on for 20 sec. This allows refrigerant system to recover outdoor
coil heat and minimize the “steam cloud”effect.
DEFROST TIME SELECTION
The defrost interval can be field selected, dependent on local or
geographical requirements. It is factory set at 90 minutes but can
be changed to either 30, 60, or 120 minutes. To select defrost time,
set dip switches located on the left side of the unit board (See Fig.
15). See Table 9 for Defrost Dip Switch Settings.
COOL/HEAT
STAGE 1
COOL/HEAT
STAGE 2
R
W/W1
Y/Y2
O/W2
Y1/W2
G
24 VAC COMM
N/A
OUTDOOR
SENSOR
CONNECTION
C
B
S1
S2
C
Y2
C
PROGRAMMABLE
THERMOSTAT
MODEL 2S SINGLE-STAGE
FURNACE TWO-SPEED HEAT PUMP
See notes 7, 9, 11,14 and 24
W
R
Y1
R
O
W1
G
Y
H
R1
FAN
HEAT STAGE 3
RVS COOLING
24 VAC HOT
A00364
J
24 VAC HOT
24 VAC COMM
HEAT STAGE 3
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING
Y1
B
S1
S2
C
O
NON-PROGRAMMABLE
THERMOSTAT
MODEL 2S SINGLE-STAGE
FURNACE TWO-SPEED
HEAT PUMP
See notes 7, 10, 11, 14 and 24
G
O/W2
W
R
Y
Y2
Y1
H
R1
COOL/HEAT
STAGE 2
FAN
COOL/HEAT
STAGE 1
N/A
OUTDOOR
SENSOR
CONNECTION
W1
A00365
K
Fig. 13—Typical 24-V Circuit Connections (Cont’d)
13

O/W2
W/W1
Y1/W2
G
R
THERMIDISTAT
CONTROL
MODEL RH SINGLE-STAGE FURNACE TWO-SPEED
HEAT PUMP
W
G
Y
C
Y2
W1
R
Y1
O
C
DHUM
HUM
B
S1
S2
R
C
HEAT STAGE 3
COOL/HEAT
STAGE 2
RVS COOLING
FAN
24 VAC HOT
24 VAC COMM
N/A
HUMIDIFY
See notes 7, 11, 14, 15, 16, 17, 18 and 25
N/A
OUTDOOR
SENSOR
CONNECTION
Y/Y2
HUMIDIFIER
(24 VAC)
OUTDOOR
SENSOR
COOL/HEAT
STAGE 1
A00366
L
24 VAC HOT
24 VAC COM
HEAT STAGE 3
R
C
G
R
C
Y1
C
W1
O
OTHER BRAND
TWO-SPEED
THERMOSTAT SINGLE-STAGE
FURNACE TWO-SPEED
HEAT PUMP
G
W
R
Y2
W2
O
EY
Y2
Y1
H
R1
COOL/HEAT
STAGE 2
FAN
EMERGENCY
HEAT
RVS COOLING
COOL/HEAT
STAGE 1
See notes 11, 14, and 24
A00332
N
W/W1
G
R
SINGLE-STAGE
FURNACE TWO-SPEED
HEAT PUMP
W
G
Y
C
Y2
W1
C
L
B
S1
S2
R
R
C
HEAT STAGE 3
(FURNACE)
COOL/HEAT
STAGE 2
(COMPRESSOR HI)
FAN
24 VAC HOT
24 VAC COM
O
O/W2
RVS COOLING
RVS SENSING
N/A
OUTDOOR
SENSOR
CONNECTIONS
Y/Y2
Y1
COOL/HEAT
STAGE 1
(COMPRESSOR LO)
Y1/W2
OUTDOOR
SENSOR
See notes 7, 11, 14, 15, and 26
PROGRAMMABLE
DUAL FUEL
THERMOSTAT
MODEL DF
A00367
M
Fig. 13—Typical 24-V Circuit Connections (Cont’d)
14

G
C
Y2
C
TWO-STAGE
FURNACE WITH PSC
BLOWER MOTOR TWO-SPEED
HEAT PUMP
See notes 6, 7, 9, 11, 12,
14, 21, and 24
R
Y1
R
O
W1
W/W1
Y/Y2
W2
Y1 *
COOL/HEAT
STAGE 1
R
W/W1
Y/Y2
O/W2
Y1/W2
24 VAC COMM
N/A
OUTDOOR
SENSOR
CONNECTION
C
B
S1
S2
PROGRAMMABLE
THERMOSTAT
MODEL 2S
G
H
R1
FAN
HEAT STAGE 3
COOL/HEAT
STAGE 2
RVS COOLING
24 VAC HOT
A00368
P
RA00370
O/W2
W/W1
Y1/W2
G
R
TWO-STAGE
FURNACE
WITH PSC
BLOWER MOTOR TWO-SPEED
HEAT PUMP
W/W1
G
Y/Y2
C
Y2
W1
R
Y1
O
C
DHUM
HUM
B
S1
S2
Y1 *
W2
R
C
HEAT STAGE 3
COOL/HEAT
STAGE 1
COOL/HEAT
STAGE 2
RVS COOLING
FAN
24 VAC HOT
24 VAC COMM
N/A
HUMIDIFY
N/A
OUTDOOR
SENSOR
CONNECTION
Y/Y2
HUMIDIFIER
(24 VAC)
OUTDOOR
SENSOR
See notes 7, 11, 12, 14, 15, 16,
17, 18, 21, and 25
THERMIDISTAT
CONTROL
MODEL RH
24 VAC HOT
24 VAC COMM
HEAT STAGE 3
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING
Y1
B
S1
S2
C
W1
O
NON-PROGRAMMABLE
THERMOSTAT
MODEL 2S
TWO-STAGE
FURNACE WITH PSC
BLOWER MOTOR TWO-SPEED
HEAT PUMP
See notes 6, 7, 10, 11, 12,
14, 21, and 24
G
O/W2
R
Y2
W/W1
Y/Y2
W2
Y1
Y1 *
H
R1
COOL/HEAT
STAGE 2
FAN
COOL/HEAT
STAGE 1
N/A
OUTDOOR
SENSOR
CONNECTION
A00369
Q
24 VAC HOT
24 VAC COM
HEAT STAGE 3
R
C
G
W2
Y2
E
O
R
C
Y1
C
W1
OTHER BRAND
TWO-SPEED
THERMOSTAT
TWO-STAGE
FURNACE WITH PSC
BLOWER MOTOR TWO-SPEED
HEAT PUMP
See notes 6, 11, 12, 14, 21, and 24
G
R
Y2
W/W1
Y/Y2
W2
Y1
O
Y1 *
H
R1
COOL/HEAT
STAGE 2
FAN
EMERGENCY
HEAT
RVS COOLING
COOL/HEAT
STAGE 1
A00371
S
Fig. 13—Typical 24-V Circuit Connections (Cont’d)
15

COOL/HEAT
STAGE 1
R
W/W1
Y/Y2
O/W2
Y1/W2
G
24 VAC COMM
N/A
OUTDOOR
SENSOR
CONNECTION
C
B
S1
S2
C
Y2
C
W1
PROGRAMMABLE
THERMOSTAT
MODEL 2S
TWO-STAGE
VARIABLE-SPEED
FURNACE WITH ICM
BLOWER MOTOR TWO-SPEED
HEAT PUMP
See notes 6, 7, 9, 11, 12, 14, 21 and 24
R
Y1
R
O
G
W/W1
Y/Y2
W2
Y1 *
COOL/HEAT
STAGE 2
FAN
HEAT STAGE 3
RVS COOLING
24 VAC HOT
A00372
T
VA00374
W/W1
G
R
TWO-STAGE
OR VARIABLE
SPEED FURNACE TWO-SPEED
HEAT PUMP
G
C
Y2
W1
C
L
B
S1
S2
R
R
C
W2
*
HEAT STAGE 3
(FURNACE)
COOL/HEAT
STAGE 2
(COMPRESSOR HI)
FAN
24 VAC HOT
24 VAC COMM
O
O/W2
RVS COOLING
RVS SENSING
N/A
OUTDOOR
SENSOR
CONNECTIONS
W/W1
Y/Y2 Y/Y2
Y1
Y1
COOL/HEAT
STAGE 1
(COMPRESSOR LO)
Y1/W2
OUTDOOR
SENSOR
See notes 7, 11, 12, 14, 15, 21 and 26
PROGRAMMABLE
DUAL FUEL
THERMOSTAT
MODEL DF
24 VAC HOT
24 VAC COMM
HEAT STAGE 3
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING
Y1
B
S1
S2
C
NON-PROGRAMMABLE
THERMOSTAT
MODEL 2S
TWO-STAGE
VARIABLE-SPEED
FURNACE WITH ICM
BLOWER MOTOR TWO-SPEED
HEAT PUMP
See notes 6, 7, 10, 11,12, 14, 21, and 24
G
O/W2
R
Y2
W1
O
W/W1
Y/Y2
W2
Y1
Y1 *
COOL/HEAT
STAGE 2
FAN
COOL/HEAT
STAGE 1
N/A
OUTDOOR
SENSOR
CONNECTION
A00373
U
R
CC
W1
TWO-STAGE
VARIABLE-SPEED
FURNACE WITH ICM
BLOWER MOTOR TWO-SPEED
HEAT PUMP
See notes 6, 7, 11, 12, 14, 21 and 24
G
R
Y2
O
W/W1
Y/Y2
W2
Y1
Y1 *
OTHER BRAND
TWO-SPEED
THERMOSTAT
24 VAC HOT
24 VAC COM
HEAT STAGE 3
R
C
G
Y1
Y2
W2
O
E
COOL/HEAT
STAGE 2
FAN
EMERGENCY
HEAT
RVS COOLING
COOL/HEAT
STAGE 1
A00375
W
Fig. 13—Typical 24-V Circuit Connections (Cont’d)
16

O/W2
W/W1
Y1/W2
G
R
FURNACE
BOARD
AFS
BOARD
TWO-SPEED
HEAT PUMP
VARIABLE SPEED 80%
NON-CONDENSING FURNACE
W/W1
G
Y/Y2
C
Y2
W1
O
C
DHUM
HUM
B
S1
S2
R
W2
O
Y1
R
COM
HUM
PL9-10
DEHUM
HEAT STAGE 3
HEAT/COOL
STAGE 1
HEAT/COOL
STAGE 2
RVS COOLING
FAN
24 VAC HOT
24 VAC COM
DEHUMIDIFY
HUMIDIFY
N/A
OUTDOOR
SENSOR
CONNECTIONS
Y/Y2
HUMIDIFIER
(24 VAC)
OUTDOOR
SENSOR
See notes 7, 11, 12, 14, 15, 16, 17,
18, 20, 21, and 25
Y1
THERMIDISTAT
CONTROL
MODEL RH
A00376
X
O/W2
W/W1
Y1/W2
G
R
VARIABLE-SPEED
CONDENSING
FURNACE TWO-SPEED
HEAT PUMP
W/W1
G
Y/Y2
C
Y2
R
Y1
W1
O
C
DHUM
HUM
B
S1
S2
W2
R
C
HEAT STAGE 3
COOL/HEAT
STAGE 1
COOL/HEAT
STAGE 2
RVS COOLING
FAN
24 VAC HOT
24 VAC COMM
DEHUMIDIFY
HUMIDIFY
N/A
OUTDOOR
SENSOR
CONNECTION
Y/Y2
HUMIDIFIER
(24 VAC)
OUTDOOR
SENSOR
See notes 7, 11, 12, 14, 15, 16, 17,
18, 19, 22, and 25
HUM
THERMIDISTAT
CONTROL
MODEL RH
DEHUM
DE Notes 27
A00378
Z
O/W2
W/W1
Y1/W2
G
R
FURNACE
BOARD
AFS
BOARD
TWO-SPEED
HEAT PUMP
VARIABLE SPEED 80%
NON-CONDENSING FURNACE
W/W1
G
Y/Y2
C
Y2
W1
O
C
L
B
S1
S2
R
W2
O
Y1
R
COM
HUM
PL9-10
DEHUM
HEAT STAGE 3
(FURNACE)
COOL/HEAT
STAGE 1
(COMPRESSOR LO)
COOL/HEAT
STAGE 2
(COMPRESSOR HI)
RVS COOLING
FAN
24 VAC HOT
24 VAC COMM
RVS SENSING
N/A
OUTDOOR
SENSOR
CONNECTIONS
Y/Y2
OUTDOOR
SENSOR
See notes 7, 11, 12, 14, 15, 21, and 26
Y1
PROGRAMMABLE
DUAL FUEL
THERMOSTAT
MODEL DF
A00377
Y
17

A97466
LEGEND
24-V FACTORY WIRING
24-V FIELD WIRING
FIELD SPLICE CONNECTION
RELAY SPDT, PILOT DUTY
24-V COIL (HN61KK324)
OR EQUIVALENT
HUMIDISTAT, OPENS ON
HUMIDITY RISE (HL38MG026)
AIRFLOW SELECTOR
R1
H
AFS
WIRING DIAGRAM NOTES:
1. Carrier thermostat wiring diagrams are only accurate for model numbers TSTAT _______.
2. Wiring must conform to NEC or local codes.
3. Connect 24v field wiring to factory-provided stripped leads.
4. Thermostats are factory configured with 5-minute compressor cycle protection and 4 cycles per hr limit. See thermostat Installation
Instructions for details.
5. To stage electric resistance heat, consult outdoor thermostat Installation Instructions.
6. Terminals marked with an * may not be present on equipment.
7. Underlined letter on dual terminal indicates its usage. For example: O/W2 means O is energized in cooling mode.
8. Refer to fan coil Installation Instructions for features and additional wiring information.
9. Programmable model 2S, when used in heat pump installations (Switch C OFF), uses O/W2 to control reversing valve.
10. Non-Programmable model 2S, when used in heat pump installations (Jumper R19 NOT cut), uses O/W2 to control reversing valve.
11. Select the ZONE position on two-speed heat pump control board. In heating mode, this allows Y1 to control low-speed compressor
operation and Y2 to control high-speed compressor operation.
12. Furnace must control its own second-stage operation via furnace control algorithm. Refer to furnace Installations Instructions for proper
setup.
13. To activate dehumidify function on FK4, FV4, or 40FK, remove J1 jumper at fan coil control board.
14. Heat pump MUST have a high-pressure switch for dual fuel applications.
15. Outdoor air temperature sensor must be attached in all dual fuel applications.
16. Thermidistat Dip Switch 1 should be set in ON position for heat pump installations.
17. Thermidistat Dip Switch 2 should be set in the ON position for dual capacity compressor operation.
18. Thermidistat Configuration Option No. 10 “Dual Fuel Selection”must be turned on in all dual fuel applications.
19. To activate dehumidify feature on current style 58MVP variable-speed furnaces, a pilot duty, 24v relay must be used.
20. To activate dehumidify feature on current style 58UHV, 58UXV variable-speed 80 percent non-condensing furnaces, disconnect green
(dehum) wire from G on furnace control board and connect to dehumidify terminal dhu on thermidistat.
21. See Table 3-Airflow Selection for 58UHV, 58UXV Furnaces.
22. See Table 4-Airflow Selection for 58MVP Furnaces.
23. See Table 5-Airflow Selection for FK4, FV4, or 40FK Fan Coil.
24. Select Defrost Time on dual capacity heat pump control board.
25. Thermidistat controls dual fuel operation; do not select Furnace Interface Option on dual capacity heat pump control board.
26. Dual fuel thermostat Dip Switch D should be set in the ON position for dual capacity compressor operation. This thermostat controls dual
fuel operation.
27. The DE jumper located next to the DEHUM terminal must be removed to enable the DEHUM input.
18

DEFROST
The dual capacity control logic for defrost function is the standard
time and temperature initiated, time or temperature terminated.
Defrost only occurs at outdoor temperatures less than 50°F. The
control initiates defrost when outdoor coil thermistor is 30°F (±2°)
or less, and selected defrost time (interval) has been accumulated
during unit operation. Termination occurs when coil thermistor
reaches 80°F (±5°) or defrost period reaches a maximum of 10
minutes. Defrost will occur at the compressor capacity that is being
called for. During defrost, unit operates in high or low capacity,
energizes reversing valve O and auxiliary heat W2, and de-
energizes outdoor fan. Upon termination, there is a 20-sec delay in
outdoor fan being energized.
FIELD-INITIATED FORCED DEFROST
By placing a jumper across forced defrost terminals (See Fig. 15)
for a minimum of 5 sec and then removing it, a defrost cycle can
be initiated. The cycle occurs only if outdoor ambient is less than
50°F, regardless of outdoor coil temperature. The cycle terminates
when coil thermistor reaches 80°F (±5°) or defrost period reaches
a maximum of 10 minutes.
COMPRESSOR VOLTAGE FAILURE (6 FLASHES)
The control senses the voltage of the compressor run winding. If
compressor voltage (Vc) is out of range (less than 90v or greater
than 600v), control shuts compressor off for 15 minutes with
outdoor fan running. After 15 minutes (provided there is a call for
Y1 or Y2), control attempts to start compressor. During this time,
a code of 6 flashes appears at control board. If Vc trip occurs 3
consecutive times during a Y1 request, then low capacity operation
is locked out and control responds to Y2 requests until a reset
occurs. If 3 consecutive trips occur in a combination of Yl and Y2
or all Y2 requests, then both low and high capacity operation will
be locked out. The compressor voltage failure (6 flashes) can be
caused by:
•compressor internal overload trip (refer to Table 10 for correct
winding resistance)
•no 208/230 volt power supply to outdoor unit
•failed compressor contactor(s)
•failure of start relay to pick-up properly.
•improper wiring
PRESSURE SWITCH PROTECTION
The outdoor unit is equipped with high- and low-pressure
switches. If the control senses the opening of the high or low
pressure switch, it will respond as follows:
1. De-energize the compressor hi or low speed contactor.
2. Keep the outdoor fan operating for 15 minutes.
3. Display the appropriate error code on the status light (see
Table 8).
4. After a 15 minute delay, if Yl or Y2 inputs are on and the LPS
or HPS is reset, energize appropriate compressor contactor,
either low or high.
5. If LPS or HPS has not closed after 15 minute delay, outdoor
fan is turned off. If the open switch closes anytime after the
15-minute delay, then resume operation on call for Y1 and/or
Y2.
HEATING VAPOR PRESSURE SWITCH
(PressureGuard™)
This outdoor unit is equipped with a heating vapor pressure
limiting device which cycles the outdoor fan at high ambient
heating conditions. The exact ambient at which outdoor fan cycles
depends on indoor and outdoor unit sizing. The effect of outdoor
fan cycling on HSPF (Heating Seasonal Performance Factor) is
insignificant, due to its occurrence at outdoor ambient where
building load is very low. Puron®is a high-pressure refrigerant.
The purpose of this switch is to provide maximum flexibility and
minimum cost for the installer/owner by not requiring special
thicker wall vapor tubing and indoor coils, thus allowing limited
retrofit. The use of this switch also allows the maximum number
of indoor coil choices at minimum cost for the installer/owner,
since it can use standard refrigerant tubing.
NOTE: Due to the presence of a vapor pressure switch in outdoor
unit fan circuit and the possibility of fan cycling, this unit may go
into brief defrost at high ambient heating conditions.
Fig. 14—Typical Solenoid Valve Wiring
A00333
LLS
R
Y2
CC
OO
W1
R
Y1
NON-PROGRAMMABLE
THERMOSTAT
MODEL 2S
40FK
FK4/FV4
FAN COIL TWO-SPEED
HEAT PUMP
J1 JUMPER
J2 JUMPER
G
Y/Y2
DH
W1
Y1
W2
24 VAC HOT
24 VAC COM
FAN
RVS COOLING
COOL/HEAT
STAGE 2
HEAT STAGE 3
COOL/HEAT
STAGE 1
R
Y/Y2
C
G
W/W2
Y1
B
O/W2
S1
S2
N/A
OUTDOOR
SENSOR
CONNECTION
Y2
Y1
Y2
Y1
19

MAJOR COMPONENTS
Two-Speed Control
The two-speed control board controls the following functions:
Low- and high-compressor contactor operation
•Outdoor fan motor operation
•Crankcase heater operation
•Enhances compressor reliability
•Pressure switch monitoring
•Time delays
•Time/temperature defrost
•Defrost interval selection
•Electric heat operation
Field Connections
The two-speed control received 24vac low-voltage control system
inputs through the screw connections on the left side of the control
board.
Dual Capacity Compressor
The dual capacity compressor contains motor windings that
provide 3500 RPM operation. Refer to Table 10 for correct
winding resistance.
Compressor Internal Relief
The compressor is protected by an internal pressure relief (IPR)
which relieves discharge gas into compressor shell when differen-
tial between suction and discharge pressures exceeds 525 psi. The
compressor is also protected by an internal overload attached to
motor windings.
Table 7—Required Liquid-Line Temperature (°F)
LIQUID PRESSURE AT
SERVICE VALVE
(PSIG)
REQUIRED SUBCOOLING TEMPERATURE
(°F)
5 101520
174 56 51 46 41
181 58 53 48 43
188 61 56 51 46
195 63 58 53 48
202 65 60 55 50
209 67 62 57 52
216 69 64 59 54
223 71 66 61 56
230 73 68 63 58
237 75 70 65 60
244 77 72 67 62
251 79 74 69 64
258 81 76 71 66
265 82 77 72 67
272 84 79 74 69
279 86 81 76 71
286 88 86 78 73
293 89 84 79 74
300 91 86 81 76
307 93 88 83 78
314 94 89 84 79
321 96 91 86 81
328 97 92 87 82
335 99 94 89 84
342 100 95 90 85
349 102 97 92 87
356 103 98 93 88
363 105 100 95 90
370 106 101 96 91
377 107 102 97 92
384 109 104 99 94
391 110 105 100 95
398 112 107 102 97
405 113 108 103 98
412 114 109 104 99
419 115 110 105 100
426 117 112 107 102
433 118 113 108 103
440 119 114 109 104
447 120 115 110 105
454 122 117 112 107
461 123 118 113 108
468 124 119 114 109
475 125 120 115 110
482 126 121 116 111
489 127 122 117 112
496 129 124 119 114
503 130 125 120 115
510 131 126 121 116
517 132 127 122 117
524 133 128 123 118
531 134 129 124 119
538 135 130 125 120
545 136 131 126 121
552 137 132 127 122
559 138 133 128 123
566 139 134 129 124
573 140 135 130 125
580 141 136 131 126
587 142 137 132 127
594 143 138 133 128
601 144 139 134 129
608 145 140 135 130
Table 8—LED Control Function Light Code
CODE DEFINITION *
Constant flash
No pause No demand Stand by 10
1 flash
w/pause Low-speed operation 9
2 flashes
w/pause High-speed operation 8
3 flashes
w/pause Outdoor ambient thermistor failure 7
4 flashes
w/pause Outdoor coil thermistor failure 6
3 flashes
pause
4 flashes Thermistor out of range†5
5 flashes
pause
1 flash Low pressure switch trip 4
5 flashes
w/pause
2 flashes High pressure switch trip 3
6 flashes
w/pause Compressor V
C
/V
H
trip 2
Constant light
No pause
No flash Board failure 1
*Function light signal order of importance in case of multiple signal request; 1
is most important.
†Check both thermistors to determine which is faulty.
Table 9—Defrost Dip Switch Settings
TIME DIP SWITCH #1 DIP SWITCH #2
30 up down
60 down up
90 down down
120 up up
20