Carrier SYNERGY 38YD Instruction manual

38YDA
Two-Speed Heat Pump
Installation and Start-Up 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 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 and work gloves. Use
quenching cloth for brazing operations. Have fire extinguisher
available. Read these instructions thoroughly and follow all
warnings or cautions attached to the unit. Consult local building
codes and the National Electrical Code (NEC) for special installation requirements.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on the unit or in instructions and
manuals, be alert to the potential for personal injury.
Understand the signal word DANGER, WARNING, or 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 hazards that 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 or servicing system, always turn off main
power to system. There may be more than 1 disconnect
switch. Turn off accessory heater power if applicable. Electrical shock can cause personal injury or death.
INSTALLATION
Step 1—Check Equipment and Jobsite
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. Check rating plate to be sure unit
matches job specifications.
Step 2—Install on a Solid, Level Mounting Pad
If conditions or local codes require the unit be attached to pad,
tiedown bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 2
to determine base pan size and knockout hole location.
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.
Fig. 1—Model 38YDA
A92446
clearance on 1 side of unit and 12 in. on all remaining sides must
be maintained. Maintain a distance of 24 in. between heat pumps.
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. Where possible, place unit above a load-bearing wall.
Arrange supporting members to adequately support unit and
minimize transmission of vibration to building. Consult local
codes governing rooftop applications.
For proper unit operation and reliability, the outdoor unit
must be installed with the accessory balance port, hard
shut-off TXV. Do not install with evaporator coils having
capillary tube metering devices.
Step 3—Elevate Unit
For proper drainage, the heat pump must be raised off the
mounting surface. Fig. 3 shows unit with accessory heat pump feet
installed. Use accessory heat pump rack in areas where prolonged
subfreezing temperatures or heavy snow occur. Refer to separate
Installation Instructions packaged with accessories.
Step 4—Remove Indoor AccuRater® Piston
NOTE: An accessory indoor thermostatic expansion valve (TXV)
is required. Refer to presale literature for proper part no.
After removing existing AccuRater from indoor coil, install
required accessory TXV kit. (See Fig. 4 and 5.) If unit is installed
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. 563-763
Printed in U.S.A.
Form 38YDA-1SI
Pg 1
1-94
Replaces: 38YD-3SI
Tab 5a 5a
3/8″
DIA TIEDOWN KNOCKOUTS
(2) PLACES IN BASEPAN
19 15/16″
NOTES:
1. ALLOW 30″ CLEARANCE TO SERVICE SIDE OF
UNIT, 48″ ABOVE UNIT, 6″ ON ONE SIDE, 12″
ON REMAINING SIDE, AND 24″ BETWEEN
UNITS FOR PROPER AIRFLOW.
2. MINIMUM OUTDOOR OPERATING AMBIENT IN
COOLING MODE IS 55° F AND MAX 125° F.
3. SERIES DESIGNATION IS THE 13TH POSITION
OF THE UNIT MODEL NUMBER.
4. CENTER OF GRAVITY
AIR IN
AIR DISCHARGE
13 1/2″
AIR IN
4″
C
L
9 3/4″
AIR DISCHARGE
8 3/16″
AIR IN
7/8″
FIELD POWER SUPPLY CONN
7/8″ DIA HOLE WITH
1 1/8″ DIA KNOCKOUT
AND
1 3/8″ DIA KNOCKOUT
DIA VAPOR
LINE CONN
FIELD CONTROL SUPPLY CONN
7/8″ DIA HOLE
34 15/16″
2 1/2″
3/8″ DIA LIQUID
LINE CONN
1 9/16″
AIR DISCHARGE
30″
39 13/16″
ACCESS
PANEL
33 7/8″
27 1/2″
10 1/2″
16 3/4″
4 3/16″
1 3/4″
2
1 1/4″
15/16″
A93262
Fig. 2—Unit Reference Drawing
with a FK4 or FC4 fan coil, no TXV change is necessary since
these fan coils are factory-equipped with proper TXV.
Install TXV kit to indoor coil as follows:
1. Install suction tube adapter.
2. Install liquid flare-to-sweat adapter.
3. Install TXV on liquid flare-to-sweat adapter.
4. Connect external equalizer tube to fitting on suction tube
adapter.
5. Position sensing bulb on horizontal portion of suction tube
adapter. Secure using supplied hardware. Insulate bulb after
installation.
6. Check all connections for leaks.
DO NOT BURY MORE THAN 36 IN. OF REFRIGERANT
TUBING IN GROUND. If any section of tubing is buried,
there must be a 6-in. vertical rise to the valve connections on
the outdoor unit. If more than the recommended length is
buried, refrigerant may migrate to cooler buried section
during extended periods of unit shutdown, causing refrigerant
slugging and possible compressor damage at start-up.
Step 5—Make Piping Connections
Outdoor units may be connected to indoor sections using accessory
tubing package or field-supplied refrigerant grade tubing of correct
size and condition. Tubing diameters listed with these instructions
are adequate for equivalent lengths up to 100 ft. Do not install
equivalent interconnecting tubing lengths greater than 100 ft. Do
not increase or decrease interconnecting tubing diameters.
2
In some cases noise in the living area has been traced to gas
pulsations from improper installation of equipment.
COIL
INSTALLATION RECOMMENDATIONS
SENSING
BULB
1. Locate the unit away from windows.
2. Ensure that vapor and liquid tube diameters are appropriate to
the capacity of the unit. (See Table 1.)
EQUALIZER
TUBE
3. Run refrigerant tubes as directly as possible by avoiding
unnecessary turns and bends.
4. Leave some slack between the structure and the unit to absorb
vibration.
THERMOSTATIC
EXPANSION
VALVE
5. When passing refrigerant tubes through the wall, seal the
opening with RTV or other pliable silicon-based caulk. (See
Fig. 6.)
Fig. 4—TXV Installed
6. Avoid direct lineset contact with water pipes, ductwork, floor
joists, wall studs, floors, and walls.
10 O'CLOCK
2 O'CLOCK
7. Do not suspend refrigerant tubing from joists and studs with a
rigid wire or strap which comes in direct contact with the
tubing. (See Fig. 6.)
SENSING BULB
STRAP
8. Ensure that tubing insulation is pliable and completely surrounds the vapor line.
9. When necessary, use hangar straps which are 1 in. wide and
conform to the shape of the tubing insulation. (See Fig. 6.)
SUCTION TUBE
10. Isolate the hangar straps from the insulation by using metal
sleeves bent to conform to the shape of the insulation.
8 O'CLOCK
7/8″ O.D. & SMALLER
If refrigerant tubes or indoor coil is exposed to atmospheric
conditions for longer than 5 minutes, it must be evacuated to 500
microns to eliminate contamination and moisture in the system.
036, 048
060
LIQUID
Connect
Tube
Diameter
Diameter
3/8
3/8
3/8
3/8
4 O'CLOCK
LARGER THAN 7/8″ O.D.
A81032
Fig. 5—Positioning of Sensing Bulb
Outdoor unit contains correct system refrigerant charge for operation with indoor unit of the same size when connected by 15 ft of
field-supplied or factory accessory tubing. Check refrigerant
charge for maximum efficiency. (See Step 9—Checking Charge.)
Table 1—Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters (In.)
UNIT
SIZE
A91277
VAPOR
Connect
Tube
Diameter
Diameter
7/8
7/8
7/8
1-1/8
REFRIGERANT TUBING — Connect tubing to fittings on outdoor unit vapor and liquid service valves. (See Fig. 2.)
Notes: 1. Tube diameters are for lengths up to 100 equivalent ft.
2. Do not increase or decrease tubing sizes.
A brazing shield MUST be used when tubing sets are being
brazed to the service valves to prevent damage to the painted
unit surface.
Relieve all pressure before refrigerant system repair or final
disposal to avoid personal injury or death. Use all service
ports and open all flow-control devices, including solenoid
valves.
To avoid valve damage while brazing, service valves must be
wrapped with a heat-sinking material such as a wet cloth.
Fig. 3—Accessory Heat Pump Feet
SWEAT CONNECTION — Use refrigerant grade tubing. Service
valves are closed from factory and ready for brazing. After
wrapping the service valve with a wet cloth, the tubing set can be
brazed to the service valve using either silver bearing or non-silver
bearing brazing material. Consult local code requirements. Refrigerant tubing and indoor coil are now ready for leak testing. This
check should include all field and factory joints.
A93567
OUTDOOR UNITS CONNECTED TO FACTORY-APPROVED
INDOOR UNITS
See Product Data Digest for factory-approved indoor units.
3
ROUTE GROUND AND POWER WIRES
NOTE:
AVOID CONTACT BETWEEN TUBING AND STRUCTURE
INDOOR WALL
According to NEC, ANSI/NFPA 70, and local codes, the
cabinet must have 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 could result in electrical shock,
fire, or death.
OUTDOOR WALL
CAULK
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. (See Fig. 2.) Size wires per
NEC but not smaller than minimum wire size shown in Product
Data Digest.
INSULATION
VAPOR LINE
LIQUID LINE
THROUGH THE WALL
CONNECT GROUND AND POWER WIRES — Connect ground
wire to ground connection in control box for safety. Connect
power wiring to leads provided. (See Fig. 7.)
JOIST
HANGER STRAP
(AROUND VAPOR
LINE ONLY)
DISCONNECT
PER N.E.C. AND/OR
LOCAL CODES
CONTACTOR
VAPOR LINE
FIELD POWER
WIRING
3 PHASE ONLY
BLUE
FIELD GROUND
INSULATION
1″
MIN
WIRING
LIQUID
LINE
SUSPENSION
GROUND
LUG
Fig. 7—Line Power Connections
A92469
A94025
CONNECT CONTROL WIRING — Route 24-v control wires
through control wiring grommet and connect to leads provided in
unit control box. (See Fig. 7.)
Fig. 6—Piping Installation
Step 6—Make Electrical Connections
Use No. 18 AWG color-coded, insulated 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.
To avoid personal injury or death, do not supply power to unit
with compressor terminal box cover removed.
The outdoor unit requires a minimum of 27-va, 24-vac control
power.
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 or Product Data Digest for
recommended circuit protection device.
NOTE: Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate.
NOTE: Use copper wire only between disconnect switch and
unit.
NOTE: Install branch circuit disconnect per NEC of adequate
size to handle unit starting current. Locate disconnect within sight
from and readily accessible from unit, per Section 440-14 of NEC.
AIRFLOW SELECTION FOR 58MVP FURNACE — The
58MVP provides high- and low-speed blower operation to match
the heat pump/cooling heating capacities of the compressor at high
and low speeds. To select the recommended airflow, refer to Table
2 and the 58MVP Installation Instructions. The 58MVP utilizes a
control center that allows the installing technician to select proper
airflows. For adjustments to the manual switches labeled A/C and
CF and recommended switch positions, refer to Table 2. Highspeed 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 high and low blower operation.
AIRFLOW SELECTION FOR FK4B FAN COILS — The FK4B
provides high- and low-speed blower operation to match the
capacities of the compressor at high and low speeds. To select the
recommended airflow, refer to Table 3 and the FK4B Installation
Instructions. The FK4B utilizes an EASY SELECT control board
that allows the installing technician to select proper airflows. For
adjustments to the control board and recommended H/P SIZE and
CFM ADJUST selections, refer to Table 3. It is recommended
4
Table 2—58MVP Airflow Selection
38YDA
036
048
060
HIGH-SPEED
A/C SETUP
SWITCH POSITION
A/C-1
A/C-2
A/C-3
OFF
OFF
ON
OFF
ON
ON
OFF
ON
ON
LOW-SPEED
CF SETUP
SWITCH POSITION
CF-1
CF-2
CF-3
OFF
ON
OFF
ON
ON
OFF
ON
ON
OFF
FURNACE MODEL/HEATING SIZE
060
High
1200
—
—
080
Low
800
—
—
High
1200
—
—
100
Low
800
—
—
High
1200
1600
1600*
Low
800
1000
1000
* Efficiency rating obtained at 1600 CFM. If 2000 CFM is desired, adjust airflow per 58MVP Installation Instructions.
Table 3—FK4B Airflow Selection
38YDA
036
048
060
FK4B
001
002
003
004
005
006
006
006
EASY SELECT CONTROL BOARD
H/P SIZE
CFM ADJUST
Blue Wire
Black Wire
036
MED
036
MED
036
MED
036
MED
036
MED
036
MED
048
MED
060
MED
CFM (HP-EFF)
Cool
High
1250
1250
1120
1150
1200
1180
1575
1865
Heat
Low
770
770
710
690
775
825
1100
1300
High
1365
1365
1220
1260
1310
1285
1710
2050
Low
835
835
770
755
835
900
1195
1435
to Fig. 8C or 8E and the humidity rises, the humidistat contacts
open and de-energize the relay. If the relay is de-energized, the
system will operate on high-speed compressor and high-speed
airflow until the humidistat closes.
HP-EFF be used for the TYPE selection to maximize efficiency.
Refer to the FK4B Installation Instructions for other TYPE
selections. This fan coil has an adjustable blower off delay factory
set at 90 sec for high and low operation.
LCC Operation For Fig. 8D
Step 7—Install Electrical Accessories
Due to the indoor control logic, the standard blower operation of
systems is covered in Fig. 8D. The blower runs in high or low
speed in conjunction with compressor high- or low-speed operation. When the LCC is wired according to Fig. 8D and the
humidity rises, the humidistat contacts open and de-energize the
relay. If the relay is de-energized, the system will operate on
high-speed compressor and low-speed airflow until the humidistat
closes.
Refer to the individual instructions packaged with the kits or
accessories when installing.
Available electrical accessories include latent capacity control.
Consult Product Data Digest for proper kit part no. and application. See Fig. 8 and Table 4 for typical accessory wiring diagrams.
Table 4—Wiring Diagram Reference
Low-ambient kits are not available for 2-speed units. Do not
attempt to operate in cooling below 55°F or modify control
system for low-ambient operation. Compressor damage may
occur.
OUTDOOR
UNIT
LATENT CAPACITY CONTROL (LCC)
The purpose of an LCC is to provide a dehumidification mode,
assuring a 75 percent or less system sensible heat ratio. If the
indoor unit installed contains an ICM blower, such as FK4 or
58MVP, no LCC is required. The indoor products which contain
ICM blowers have enough CFM range to provide proper airflow
for low-speed cooling. If the indoor unit installed has a standard
PSC blower motor, the low-speed airflow available will be 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 24-v coil.
38YDA
WIRING DIAGRAM
C
D
E
F
Indoor Units Covered
58EJA
58MCA
FA4A 58MXA 58DFA
58TMA
FK4B 58MVP FB4A 58PAV 58EFA
58TUA
FC4B 58RAV 58GFA
58WAV
58ZAV
A
B
Step 8—Start-up
1. The outdoor unit is equipped with a crankcase heater which
operates at temperatures less than 75°F. If the outdoor
temperature is less than 75°F, energize crankcase heater 24 hrs
before starting unit. To energize heater only, set indoor
thermostat at the OFF position and close the power disconnect
to the unit.
NOTE: If an LCC is desired, the low-speed airflow must be
maintained so that a minimum of 300 CFM/ton can be supplied
during high-speed LCC operation.
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 refrigerant flow (back seated). Replace caps finger tight and tighten
additional 1/12 turn (20 ft-lb torque) with wrench.
LCC Operation For Fig. 8C and 8E
The standard blower operation of systems is covered in Fig. 8C
and 8E. The blower runs in high speed regardless if compressor
operation is high or low speed. When the LCC is wired according
4. Close electrical disconnects to energize system.
5
TWO SPEED
HEAT PUMP
TWO SPEED
THERMOSTAT
R
R
C
C
C
G
G
W2
W2
W2
Y2
Y/Y2
Y2
E
E
R
TRANS.
TWO SPEED
HEAT PUMP
TWO SPEED
THERMOSTAT
R
R
R
C
C
C
G
G
W2
W2
Y2
W3
L
L
L
O
O
O
Y1
Y1
Y1
Y2
Y/Y2
E
W3
W2
W/W1
L
L
O
O
Y1
Y1
B
A93570
A
A93106
TWO SPEED
HEAT PUMP
TWO SPEED
THERMOSTAT
R
R
TRANS.
C
TWO SPEED
HEAT PUMP
TWO SPEED
THERMOSTAT
R
R
C
C
C
TRANS.
R
R
C
C
G
G
W2
W
W2
Y
Y1
G
G
W2
W2
W2
Y1
Y1
Y
Y1
E
E
E
W3
W3
W3
L
L
L
L
L
O
O
O
O
O
Y2
Y2
Y2
Y2
H
H
C
R1
D
R1
A93573
Fig. 8—Typical Circuit Connections
6
A93574
R
TRANS.
C
TWO SPEED
HEAT PUMP
TWO SPEED
HEAT PUMP
TWO SPEED
THERMOSTAT
R
R
C
C
G
G
W2
W
W2
Y1
Y
Y1
TWO SPEED
THERMOSTAT
R
C
O
O
Y2
Y2
C
C
G
W2
W/W1
W2
W2
Y1
Y/Y2
E
L
R
G
Y1
E
L
R
TRANS.
O
O
L
L
Y2
Y2
H
H
F
R1
R1
E
A93575
A93571
R1 = Relay, SPDT, pilot duty 24-v coil (HN61KK324) or equivalent
R2 = Relay, SPDT, pilot duty 24-v coil (HN61KK040) or equivalent
H = Humidistat, Opens on humidity rise (HL38MG026).
Use separate humidistat for humidifier control.
Fig. 8—Typical Circuit Connections (Continued)
5. Set room thermostat at desired temperature. The factory
accessory indoor thermostats are 2-stage, with approximately
2°F difference between stages. Be sure the set point is below
indoor ambient and is low enough to energize desired speed.
6. Set room thermostat at COOL or HEAT and fan switch at
FAN or AUTO, as desired. Wait for the appropriate time
delay(s) and for the 2-minute minimum low-speed run time.
Operate unit for 15 minutes. Check refrigerant charge.
Step 9—Checking 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.
Adjust charge in both heating and cooling by following procedure
shown on the charging tables located on unit information plate on
back side of access panel.
Do not vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.
Compressor damage may occur if system is overcharged.
Factory charge is shown on unit rating plate. (See Fig. 2.)
NOTE: When the 2-speed unit is operating at low speed cooling,
the system’s vapor (suction) pressure will be higher than a
standard single-speed system or high-speed cooling operation.
This normal operation is due to the reduced capacity operating
with typically larger indoor and outdoor coils.
SYSTEM FUNCTIONS
The outdoor unit control system has special functions. The
following is an overview of the 2-speed control functions.
Cooling Operation
This product utilizes a 2-stage cooling indoor thermostat. With a
call for first stage (Y1), the outdoor fan and low-speed compressor
are energized. If low speed cannot satisfy the cooling demand,
high speed will be energized (Y1 and Y2) by the second stage of
the indoor thermostat. The thermostat has a 2°F differential
7
3-Sec Time Delay
between first and second stages. After second stage is satisfied, the
unit will return to low-speed operation until first stage is satisfied
or until second stage is required again.
Any time the control receives a 24-v input, such as Y1 or Y2, there
is a 3-sec time delay before the control function is initiated. This
helps prevent nuisance trips and thermostat jiggling.
Heating Operation
This product utilizes a 2-stage heating indoor thermostat. The first
stage of heating is heat pump operation (Y1), while auxiliary or
back up heat is controlled by second stage (W2). There is a 2°F
differential between first and second stage. The control board
determines the speed of heat pump operation. See Table 5 for
ambients at which high-speed and low-speed operations occur.
When high-speed heat pump is required, the control will provide a
Y2 (24-vac) signal back to the thermostat to energize high-speed
indicator LED.
1-Minute Speed Change Time Delay
When the compressor changes speeds from high to low or low to
high, there is a 1-minute time delay before the compressor will
restart. The outdoor fan motor remains running.
5-Minute Time Delay
The 2-speed control logic contains a 5-minute time delay that
prevents the unit from short cycling after a thermostat off cycle or
power interruption. The unit can be forced to operate immediately
by momentarily touching a jumper between the speed-up terminals
of the control board. (See Fig. 9.) The speed-up feature will not
bypass any other function or time delay.
Table 5—Ambient Temperatures for High- and
Low-Speed Operation
AMBIENT TEMPERATURE (°F)
High Speed
Low Speed
30 or less
31 or greater
33 or less
34 or greater
40 or less
41 or greater
LM1 LM2
DFT1 DFT2 T1
T2
1
LED Function Lights
When using the factory-authorized indoor thermostats with the
2-speed outdoor units, there are 2 locations where system function
LED indicator lights are available. The indoor thermostat provides
indicator lights for high- and low-speed operation, system malfunction, and auxiliary heat. The 2-speed control board has a LED
which provides signals for several system operations. See Table 6
which provides LED functions, indicator locations, and definitions. Table 6 also provides the order of signal importance if more
than 1 signal should occur. The signal to the indoor thermostat is
supplied by the low-voltage L lead.
S2
S1
PW2 PW1
P1
18
K7
FURN INT
OFF
ON
50
35
40
45
105 OFF
90
100
20
30
15
25
10
95
30
SPEED-UP
90
85
036
048
060
ZONE
UNIT
SIZE
STAGE 2 DEFROST BALANCE
LATCH
TIME
POINT
NOTE: A signal (code) will not be sent through the L lead to the
thermostat unless unit failure has occurred. (See Table 6.)
Fig. 9—Two-Speed Control Board
Table 6—Function Light Code
and Display Location
A93568
2-Minute Low-Speed Minimum
CODE
T’STAT
UNIT
DEFINITION
*
Constant flash
No pause
—
X
No demand
Stand by
9
1 flash
w/pause
—
X
Low-speed operation
8
2 flashes
w/pause
—
X
High-speed operation
7
3 flashes
w/pause
X
X
Outdoor thermistor failure
6
The 2-speed control will energize the crankcase heater during the
unit’s off cycle when the outdoor ambient is below 75°F.
4 flashes
w/pause
X
X
Coil thermistor failure
5
Outdoor Fan Motor Operation
3 flashes
pause
4 flashes
X
X
Thermistor out of range**
4
5 flashes
w/pause
X‡
X
Pressure switch trip (LM1/LM2)
3
6 flashes
w/pause†
X
X
Compressor PTC’s out of limit
2
Constant light
No pause
No flash
X
X
Board failure
If the unit has not operated within the past 30 minutes, the unit will
operate for a minimum of 2 minutes in low speed upon the next
thermostat high or low demand.
Crankcase Heater Operation
The 2-speed control will energize the outdoor fan any time the
compressor is operating. The outdoor fan will remain energized
during the 1-minute speed change time delay and if a pressure
switch or positive temperature coefficient (PTC) overload should
trip.
After termination of a defrost cycle, the outdoor fan will delay
coming on for 20 sec. This allows the refrigerant system to recover
the outdoor coil heat and minimize the "steam cloud" effect.
1
* Function light signal order of importance in case of multiple signal request; 1
is most important.
† Signal at thermostat will occur after 3 consecutive attempted restarts and
lockout has occurred.
‡ Will be energized if pressure switch remains open for 1 hr.
** Check both thermistors to determine which is faulty.
The unit is equipped with an integrated control motor (ICM) which
varies its speed by receiving a pulse width modulated (PWM)
signal. The control provides the ICM with a PWM signal based on
high- or low-speed unit operation and outdoor ambient.
Factory Defaults
The outdoor ICM motor runs at high speed whenever the compressor runs at high speed. When the compressor operates at low
speed and the outdoor ambient is less than 87°F, the ICM reduces
speed to conserve energy.
Factory defaults have been provided in the event of failure of the
ambient thermistor, outdoor coil thermistor, and/or furnace interface jumper. Refer to Table 7 for default and function.
8
Table 7—Factory Defaults
FAILED COMPONENT
FUNCTION
Crankcase Heater
Outdoor ICM Speed
Second-Stage Latching
DEFAULT
Energized during any off cycle
Run motor at maximum speed
Does not function
Balance point does not function,
but interface still energizes furnace and locks out heat pump
with a call for W2
Unit only runs in high compressor speed
Defrost is initiated based on coil
temperature only
Anytime there is a call for W2,
W3 is also energized
Defrost occurs at each time interval, but terminates after 5 minutes
Does not function
Furnace Interface
Ambient Thermistor
Heating Switchover Speed Point
Defrost Initiation
Outdoor Thermostat for Auxiliary
Heat
Outdoor Coil Thermistor
Defrost Initiation and Termination
Furnace Interface Jumper
Furnace Interface
Second-Stage Latching
HIGH VOLTAGE
During normal operation, the compressor operates at low speed to
satisfy first stage of the indoor thermostat. If the indoor thermostat
temperature increases 2 degrees, the compressor shifts into highspeed operation. When the indoor thermostat temperature is
satisfied, the compressor returns to low-speed, first-stage operation.
L2
HI
CCH
ODF
LM1 LM2
O
DFT1 DFT2 T1
K2
K3
K4
K5
T2
S2
S1
PW2 PW1
C
1
K1
K6
P1
18
K7
FURN INT
OFF
ON
SPEED-UP
The installing technician can select high-speed compressor operation until the first stage of the indoor thermostat is satisfied. This
eliminates the temperature droop of the indoor thermostat between
first- and second-stage operation and holds the room temperature
closer to set point when load requirements are high. To select this
option, rotate the STAGE 2 LATCH potentiometer (pot) to the
desired temperature. (See Fig. 11.) The pot is factory set at OFF,
however, a temperature of 85°, 90°, 95°, 100°, or 105°F can be
selected. The selected temperature is the outdoor temperature at
which the structure’s cooling load will require high-speed operation.
STAGE 2 DEFROST BALANCE
LATCH
TIME
POINT
LED 1
A93569
Fig. 11—LED And Potentiometer Location
cooling load must be taken from the structure’s heat gain/loss
calculations. The selected temperature is the point at which
high-speed capacity is needed and is just above the low-speed
balance point. (See Fig. 10.)
After the temperature is selected, the unit will operate in high
speed during first-stage demand at any temperature at or above the
setting.
70
Zoning Selection
60
HIGH
SPEE
HIGH SPEED
BALANCE POINT
D CA
50
BTU (1000'S)
LO
LOW VOLTAGE
If the STAGE 2 LATCH pot is set to ZONE position, the
compressor operating speed in either heat or cool mode is
determined by the Y1 and/or Y2 inputs. The system operates in
low speed with a Y1 input and high speed with a Y2, or Y1 and Y2
input. This allows the multistage zoning system to determine what
heating speed is needed regardless of outdoor temperature or
switchover point.
PACIT
Y
40
LOW S
PEED
30
CAPA
STRUCTURE
BALANCE POINT
CITY
Defrost Time Selection
20
The defrost interval can be field selected, dependent on local or
geographical requirements. It is factory set at 90 minutes and can
be changed to either 30 or 50 minutes by rotating the defrost time
pot. (See Fig. 9.)
LOW SPEED
BALANCE POINT
10
50
60
70
80
90
100
110
Defrost
120
The 2-speed control logic for the 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 the outdoor coil thermistor is 30°F (±
2°) or less, and the selected defrost time (interval) has been
accumulated during unit operation. Termination occurs when the
coil thermistor reaches 80°F (± 5°) or the defrost period reaches a
maximum of 10 minutes.
TEMPERATURE (°F)
A91282
Fig. 10—Typical Cooling Balance Points
The unit’s capacities should be plotted versus the cooling load
(heat gain) of the structure to accurately determine the STAGE 2
LATCH temperature to be selected . The unit’s capacities versus
the outdoor temperature can be found in the presale literature. The
9
indoor thermostat to W3 of the control, and W2 of the control to
W2 of the indoor unit. When the outdoor ambient is less than the
setting of the balance point pot, the 24-vac signal will energize the
auxiliary heat (W2) of the indoor unit.
Defrost will always be done in high speed, regardless if unit
operation requires low speed unless zoning is selected. During
defrost, the unit operates in high speed, energizes the reversing
valve O and auxiliary heat W2, and de-energizes the outdoor fan.
Upon termination, there is be a 20-sec delay in the outdoor fan
being energized.
Emergency Heat
If the 2-speed control receives a call for auxiliary heat (W2)
without a heat pump heating (Y1) call, the second auxiliary stage
(W3) will be energized. This ensures all available heat is energized
if the indoor thermostat is switched to emergency heat.
Field-Initiated Forced Defrost
By placing a jumper across the speed-up terminals for a minimum
of 5 sec and then removing it, the unit will initiate a defrost cycle.
(See Fig. 9.) The cycle will occur only if the outdoor ambient is
less than 50°F, regardless of outdoor coil temperature. The cycle
will terminate when the coil thermistor reaches 80°F (± 5° ) or the
defrost period reaches a maximum of 10 minutes.
Compressor PTC Overload Protection
The control senses the resistance of the compressor internal PTC
overloads. If the resistance of the PTC’s is out of range, the control
will shut off the unit until the resistance range is acceptable. See
Table 8 for compressor PTC ranges.
Furnace Interface
This feature provides a heat pump lockout upon a demand for
auxiliary heat W2 and must be used when interfacing a heat pump
with a gas/oil furnace. Field selection of the furnace interface,
FURN IN, option is done by connecting the factory-supplied
jumper to the ON position of the 3 terminal connector. (See Fig. 9.)
Table 8—Compressor PTC Ranges
COMPRESSOR INTERNAL PTC RESISTANCE
Safe Range (77°F)
1.5k to 7.8k ohms
To trip
26k to 34k ohms
To reset
8.4k to 10k ohms
When the option is selected, the heat pump is locked out of
operation any time there is a thermostat call for W2, or the outdoor
ambient is below the balance point pot setting. (See Fig. 9.) When
the unit requires defrost, auxiliary heat W2 energizes the furnace.
After defrost is terminated, the heat pump shuts down and the
furnace satisfies the thermostat. To utilize this function, the
economic and/or thermal balance point must be determined. See
the appropriate heat pump balance point worksheet available from
your local distributor or branch.
When the control turns off the outdoor unit due to out of range
PTC’s, the unit will remain off for 15 minutes with the outdoor fan
running. After 15 minutes the control will check the resistance
every 5 minutes until it reaches the reset range. During this time,
a malfunction signal will appear on the control board. If a PTC trip
occurs 3 times without 12 minutes of normal operation, the control
will lock out the outdoor unit operation and provide a malfunction
signal at the control and indoor thermostat.
Balance Point
Pressure Switch Protection
This feature can be used in 2 different options: furnace interface or
electric heat staging. Refer to the Furnace Interface section for its
application. If the heat pump is installed with a fan coil with
multistages of electric heat, this option can be used to stage the
banks of heat by outdoor ambient. This eliminates the need for
accessory outdoor thermostats.
The outdoor unit is equipped with high- and low-pressure
switches, wired in series. If a control senses an opening of a
pressure switch, the control will provide a 5-minute time delay in
outdoor unit operation with the outdoor fan running. A malfunction signal will appear on the control when a pressure switch
opens. If the switch remains open for 1 hr or longer, a malfunction
signal will be provided at L terminal of the indoor thermostat.
When using this option to stage electric heat, the first stage will be
energized by a W2 demand, and second stage will be energized by
a W3 demand. Select the W3 desired temperature by rotating the
balance point pot. (See Fig. 9 or 11.) Temperatures that may be
selected are 10°, 15°, 20°, 25°, 30°, 35°, 40°, and 45°F. The pot is
factory set at 45°F.
MAJOR COMPONENTS
2-Speed Control
The 2-speed control board controls the following functions:
- High- and low-compressor contactor operation
- Outdoor fan motor operation
- Crankcase heater operation
- Compressor protection
- Pressure switch monitoring
- Second-stage latching
- Time delays
- Time/temperature defrost
- Defrost interval selection
- Zoning
- Furnace interface
- Electric heat staging
Low-Speed Heating With Auxiliary Heat
If the system is operating in low-speed heating and there is a
demand for auxiliary heat (W2), the system will change to
high-speed operation. W2 will be energized, unless the lowvoltage control wiring is configured as described in Fig. 12.
TWO SPEED
THERMOSTAT
FAN
COIL
TWO SPEED
HEAT PUMP
W2
W2
W2
CONTROL
LOGIC
W3
W3
Refer to the System Functions section for individual function
information.
Header Pin Housing
A93572
Fig. 12—Low-Voltage Control Wiring
The header pin housing is the plastic assembly which holds the
stripped lead ends for field connections. The 2-speed control
receives the 24-vac low-voltage control system inputs through the
housing and pins. The housing also contains jumpers which the
control uses for system configuration, such as heat pump versus air
conditioning. Refer to Fig. 13 for header pin housing configuration.
Auxiliary Heat (W2) Lockout
In some areas, it is necessary to disable the auxiliary heat, except
for defrost, until the outdoor ambient is less than the structure’s
balance point. This is accomplished by using the wiring lowvoltage as shown in Fig. 12. Wire the 24-vac W2 signal from the
10
1
C - TRANSFORMER COMMON
2
R - TRANSFORMER LINE
The 2-speed control provides the electrical interlock. The contactors are supplied with 240-v coils, which reduces the va requirements of the low-voltage (24-vac) control system.
3
Temperature Thermistors
4
5
W2 - FIRST STAGE AUXILIARY HEAT
6
O - REVERSING VALVE
7
Y2 - SECOND STAGE COOLING/HEAT PUMP
8
Y1 - FIRST STAGE COOLING/HEAT PUMP
9
W3 - SECOND STAGE AUXILIARY HEAT
10
L - MALFUNCTION LIGHT
Thermistors are electronic devices which sense temperature. As
the temperature increases, the resistance decreases. A thermistor is
used to sense outdoor ambient and coil temperature. Refer to Fig.
14 for resistance values versus temperature.
11
12
4 - TON
13
14
5 - TON
THERMISTOR CURVE
IF NO JUMPER IS
INSTALLED, DEFAULT
IS 3 - TON
90
80
RESISTANCE (KOHMS)
15
16
17
18
JUMPER FOR
HEAT PUMP ONLY
A93576
Fig. 13—Header Pin Housing Configuration
2-Speed Compressor
4 TON
0.70
2.20
1.00
2.20
50
40
30
20
0
0
20
40
60
80
TEMPERATURE (DEG. F)
100
120
A91431
Table 9—Two-Speed Compressor
(Winding Resistance at 70°F ± 20°)
3 TON
0.80
3.20
1.30
3.10
60
10
The 2-speed compressor contains motor windings that provide
low-speed 4-pole (1750 rpm) and high-speed 2-pole (3500 rpm)
operation. Refer to Table 9 for appropriate winding resistances.
Refer to unit wiring label for winding configuration.
WINDING
T1-T2
T1-T3
T1-T7
T1-T8
70
Fig. 14—Resistance Values Versus Temperature
5 TON
0.60
1.80
1.00
2.00
ICM Outdoor Fan Motor
The outdoor integrated control motor (ICM) is a variable-speed
motor which can operate from 400 to 900 rpm. The motor is a DC
permanent magnet-type motor with the electronic controls integrated into its rear cover. The speed at which the motor operates
and thus commutated is determined by a PWM signal which is
received from the control board.
The 2-speed compressor is protected by an internal pressure relief
(IPR) which will relieve discharge gas into the compressor shell
when the differential between suction and discharge pressures
exceed 500 psi.
EMI Filter
The compressor is also protected by 3 PTC devices attached to the
motor windings. The PTC’s resistance is sensed by the 2-speed
control. See Table 8 for PTC resistance ranges.
An electromagnetic interference (EMI) filter is installed on the
high-voltage input to the ICM to prevent electromagnetic signals
generated by the ICM from interfering with other home appliances
such as radios or televisions.
Mechanically Interlocked Contactors
CARE AND MAINTENANCE
Do not bypass interlocks of contactors as compressor damage
will occur.
For continuing high performance and to minimize possible equipment failure, it is essential that periodic maintenance be performed
on this equipment. Consult your servicing contractor or User’s
Manual for the proper frequency of maintenance. Frequency of
maintenance may vary depending upon geographic areas, such as
coastal applications.
Interlocked contactors coils are 240v, high voltage. Electrical
shock can cause personal injury or death.
Step 1—Leave User’s Manual With Homeowner
The 2-speed products are equipped with mechanically interlocked
contactors. Each contactor has interconnecting linkage, providing
independent interlocks.
Explain system operation and maintenance procedures outlined in
User’s Manual.
11
Copyright 1993 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
13131
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. 563-763
Printed in U.S.A.
Form 38YDA-1SI
Pg 12
1-94
Replaces: 38YD-3SI
Tab 5a 5a