Carrier 38VMH Series User manual

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 20-38VMH002-01 Printed in U.S.A. Form 38VMH-1P-2SI Pg 1 01-20 Replaces: 38VMH-1P-1SI
Installation and Maintenance Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Step 1 — Unpack and Inspect Units . . . . . . . . . . . . 4
Step 2 — Position the Unit . . . . . . . . . . . . . . . . . . . . 4
Step 3 — Connect Refrigerant Piping and Wiring 5
Step 4 — Pressure and Vacuum Test System . . . 8
Step 5 — Adjust Refrigerant Charge . . . . . . . . . . . . . 8
Step 6 — Complete Electrical Connections. . . . . . . . 8
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Trial Run. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Error Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Unit Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Pre-Start Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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. The qualified installer or agency must use
factory-authorized kits or accessories when modifying this
product.
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 thoroughly and follow all warnings or cautions
included in literature and attached to the unit. Consult local
building codes and the current editions of the National
Electrical Code (NEC) ANSI/NFPA (American National
Standards Institute/National Fire Protection Association) 70. In
Canada, refer to the current editions of the Canadian Electrical
Code CSA (Canadian Standards Association) C22.1.
Understand the signal words — DANGER, WARNING, and
CAUTION. 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.
Recognize safety information. This is the safety-alert
symbol ( ). When this symbol is displayed on the unit and in
instructions or manuals, be alert to the potential for personal
injury. Installing, starting up, and servicing equipment can be
hazardous due to system pressure, electrical components, and
equipment location.
WARNING
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation. There
may be more than one disconnect switch. Tag all
disconnect locations to alert others not to restore power
until work is completed.
38VMH036-060
Outdoor Unit for
Single-Phase Variable Refrigerant Flow (VRF) Heat Pump Systems

2
GENERAL
The VRF (variable refrigerant flow) heat pump system offers a
variety of indoor unit types and sizes, ranging from 0.5 to 6
tons. The 38VMA single-phase heat pump outdoor units are
available in three capacities (3, 4, and 5 tons). The system has
the capability to operate between 50% and 130% connected
capacity, allowing the system to be tailored to the needs of the
customer and the application.
The equipment is initially protected under the manufacturer’s
standard warranty; however, the warranty is provided under the
condition that the steps outlined in this manual for initial
inspection, proper installation, regular periodic maintenance,
and everyday operation of the unit be followed in detail. This
manual should be fully reviewed in advance before initial
installation, start-up, and any maintenance. Contact your local
sales representative or the factory with any questions BEFORE
proceeding.
See Fig. 1 for model number nomenclature. Table 1 shows
components that may or may not be used for a particular
installation. Table 2 lists physical data for each unit size. Figure
2 shows unit dimensions.
Fig. 1 —Model Number Nomenclature
Table 1 — Components Shipped with Unit
WARNING
When installing the equipment in a small space, provide
adequate measures to avoid refrigerant concentration
exceeding safety limits due to refrigerant leak. In case of
refrigerant leak during installation, ventilate the space
immediately. Failure to follow this procedure may lead to
personal injury.
WARNING
DO NOT USE TORCH to remove any component. The
system contains oil and refrigerant under pressure.
To remove a component, wear protective gloves and
goggles and proceed as follows:
a. Shut off electrical power to unit.
b. Recover refrigerant to relieve all pressure from the
system using both high-pressure and low pressure
ports.
c. Traces of vapor should be displaced with nitrogen,
and the work area should be well ventilated.
Refrigerant in contact with an open flame produces
toxic gases.
d. Cut component connection tubing with a tubing
cutter and remove component from unit. Use a pan to
catch any oil that may come out of the lines and as a
gage for how much oil to add to the system.
e. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to a torch
flame.
Failure to follow these procedures may result in personal
injury or death.
CAUTION
DO NOT re-use compressor oil or any oil that has been
exposed to the atmosphere. Dispose of oil per local codes
and regulations. DO NOT leave refrigerant system open to
air any longer than the actual time required to service the
equipment. Seal circuits being serviced and charge with
dry nitrogen to prevent oil contamination when timely
repairs cannot be completed. Failure to follow these
procedures may result in damage to equipment.
NAME SHAPE QUANTITY FUNCTION
Main Drain Connection 1 For maintenance
Adapter 1 For suction pipe connection (3/4 in. to 5/8 in.)
Equipment Type
38 —Outdoor Unit
VM — VRF
Product Type Voltage (V-Ph-Hz)
3 — 208/230-1-60
Blank
Model Number Modifier
A— Revision Number— Revision Number
Capacity (Btuh)
036 — 36,000
048 — 48,000
060 — 60,000
38 VM A 036 H DS3 -1
System Type
H — Heat Pump
Cabinet Type
S — Standard
Variations
D — Domestic
Packaging
1 — USA & Canada
B— Revision Number

3
Table 2 — 38VMH Physical Data
* The source voltage must not fluctuate more than ± 10%.
† Rated conditions:
Cooling: Indoor air temperature 80°F dry bulb / 67°F wet bulb,
Outdoor air temperature 95°F dry bulb
Heating: Indoor air temperature 70°F dry bulb,
Outdoor air temperature 47°F dry bulb / 43°F wet bulb
** The amount does not consider extra piping length. Refrigerant
must be added on site in accordance with the actual piping
length.
†† In case the diversity exceeds 135%, the type of indoor unit is
limited and the maximum number of indoor unit is reduced.
*** These values, measured in anechoic chamber at a point 1 m in
front of the unit at a height of 1.4 m. During actual operation,
these values are normally somewhat higher as a result of
ambient conditions.
****Unit may operate in Heating mode in outdoor ambient temperatures
down to -13°F wb as long as unit was started when ambient
temperature was 5°F wb or warmer.
UNIT 036 048 060
NOMINAL TONS (Ton) 3 4 5
POWER SUPPLY (V-Ph-Hz)* 208/230-1-60
COOLING CAPACITY WITH NON-DUCTED & DUCTED INDOOR UNITS†
Nominal (kBtu/h) 36 48 60
Rated (kBtu/h) 36 48 60
HEATING CAPACITY WITH NON-DUCTED & DUCTED INDOOR UNITS†
Nominal (kBtu/h) 40 52.5 66
Rated (kBtu/h) 40 52.5 66
ELECTRICAL CHARACTERISTICS WITH NON-DUCTED INDOOR UNITS
Cooling
Power Consumption (kW) 3.10 4.60 6.10
EER (Btu/Wh) 12.10 11.00 9.50
SEER (Btu/Wh) 19.20 19.20 18.60
Heating
Power Consumption (kW) 3.10 4.30 5.80
COP (W/W) 3.62 3.42 3.19
HSPF (Btu/Wh) 9.20 9.20 10.00
ELECTRICAL CHARACTERISTICS WITH DUCTED INDOOR UNITS
Cooling
Power Consumption (kW) 2.90 4.70 6.10
EER (Btu/Wh) 11.90 9.80 9.30
SEER (Btu/Wh) 17.80 17.80 18.20
Heating
Power Consumption (kW) 3.00 4.20 5.70
COP (W/W) 3.68 3.54 3.26
HSPF (Btu/Wh) 9.60 9.60 10.00
UNIT DIMENSIONS (W x H x D) (in.) 35 1/2 x 52 1/4 x 15 3/4
UNIT NET WEIGHT (lb) 220
COMPRESSOR TYPE Hermetic Rotary DC Inverter Compressor
FAN UNIT
Air Volume (cfm) 4100
Motor Output (W) 90+90
REFRIGERANT SHIPPING CHARGE (lb)** 8.6
REFRIGERANT CONNECTING PORT DIAMETER
Suction Side (in.) 5/83/4
Liquid Side (in.) 3/8
OPERATION TEMPERATURE RANGE
Cooling (F db) 5~118
Heating (F wb)**** -13~64
MAX NUMBER OF CONNECTED INDOOR
UNITS 579
MAXIMUM CAPACITY OF COMBINED INDOOR
UNITS †† 50%~130%
SOUND PRESSURE LEVEL (db(A))*** 58.7 60.1 60.7
LEGEND
COP —Coefficient of Performance
db —Dry Bulb
EER —Energy Efficiency Ratio
ESP —External Static Pressure
wb —Wet Bulb

4
Fig. 2 —38VMAH Dimensions
INSTALLATION
Step 1 — Unpack and Inspect Units — Units are
packaged for shipment to avoid damage during normal transit
and handling. It is the receiving party’s responsibility to inspect
the equipment upon arrival. Any obvious damage to the carton
and/or its contents should be reported on the bill of lading, and
a claim should be filed with the transportation company and the
factory. The unit should always be stored in a dry place and in
the proper orientation as marked on the carton.
After determining the condition of the unit exterior, carefully
remove the packaging and inspect for hidden damage. Check
to make sure that items (thermostats, controllers, etc.) are
accounted for whether packaged separately or shipped at a later
date. Any hidden damage should be recorded, a claim should
be filed with the transportation company, and the factory
should be notified. In the event a claim for shipping damage is
filed; the unit, shipping carton, and all packing must be retained
for physical inspection by the transportation company. All units
should be stored in the factory shipping carton with internal
packaging in place until installation.
PROTECTING UNITS FROM DAMAGE — Do not apply
force or pressure to the coil, piping, or drain stub-outs during
handling. All units should be handled using proper forklift holes
or lifting locations.
Unit must always be properly supported. Temporary
supports used during installation or service must be adequate to
hold unit securely. To maintain warranty; protect units
against hostile environments, theft, vandalism, and debris on
jobsite. Do not allow foreign material to fall into unit. Failure to
do so may have serious adverse effects on unit operation.
Failure of any unit caused by deposits of foreign material
inside unit will not be covered by manufacturer’s warranty.
Some units and/or job conditions may require some form of
temporary covering during construction.
PREPARING JOBSITE FOR UNIT INSTALLATION —
To save time and to reduce the possibility of costly errors, set
up a complete sample installation in a typical location at
jobsite. Check all critical dimensions such as pipe and wire
connection requirements. Refer to job drawings and product
dimension drawings as required. Instruct all trades in their
parts of the installation. Units must be installed in compliance
with all applicable local code requirements.
IDENTIFYING AND PREPARING UNITS — Be sure
power requirements match the available power source. Refer to
unit nameplate and wiring diagram. In addition:
• Check all tags on the unit to determine if shipping screws
are to be removed. Remove screws as directed.
• Rotate the fan blade by hand to ensure that the fan is
unrestricted and can rotate freely. Check for shipping
damage and fan obstructions.
Step 2 — Position the Unit — Units are
recommended for outdoor use. To ensure there is enough space
for installation and maintenance of single, multiple, or parallel
unit installation, see Figs. 3 and 4. The unit should be mounted
on concrete and fastened to anchor bolts to prevent the unit
from tipping. Units installed in areas that are exposed to
ambient temperatures below freezing (32F) should be
installed on a snow/ice stand as defined by local codes.
NOTE: All dimensions shown in inches.

5
HANDLING THE UNIT — To avoid overturning the unit,
the angle of inclination should not be more than 15 degrees
when carrying the unit.
LIFTING UNIT WITH CABLES — Make sure the lifting
cables can withstand the weight of the unit. Use 2 cables.
Make sure each cable is at least 26.3 feet long to avoid
excess tension and force on the surfaces of the unit. To
avoid damage while lifting the unit, do not remove the
original packaging or unscrew from its original pallet.
Connect lifting cables diagonally as shown in Fig. 5 below.
Note the center of gravity in Fig. 5 below, which results
from the weight of the compressor and other components
located within the right-end section of the unit.
CONCRETE BASE REQUIREMENTS
• The unit’s base must be made of solid concrete.
• Ensure that the base is level and that the weight of the
unit is distributed evenly. See Fig. 6 below for reference.
Fig. 6 —Concrete Base
• Create an outlet near the base for drainage. Refer to
Fig. 7 below for main drain connection.
Fig. 7 —Drain Connections
• Ensure the roof can handle the unit weight if mounted on
the roof.
Step 3 — Connect Refrigerant Piping and
Wiring — Refrigerant pipe connections are made on the side
of the unit. Remove the L-shaped metal plate, and route piping
through the exposed opening. Route power and control wiring
through the two separate, adjacent knockouts. See Fig. 8 for
details.
INSULATION — Liquid lines and suction lines must be
insulated separately. Closed-cell insulation with fire-retardant
properties is recommended.
• For copper pipes less than 1/2 inch. OD, recommended
insulation thickness is 1/2 inch.
• For copper pipes equal to or greater than 5/8 inch. OD,
the recommended insulation thickness is 3/4 inch.
DANGER
DO NOT stand below unit while it is suspended in the air.
If unit were to fall, it may lead to personal injury or death.
Fig. 3 — Single Unit Installation
NOTE: All dimensions shown in inches.
Fig. 4 — Multiple or Parallel Unit Installation
NOTE: All dimensions shown in inches.
Fig. 5 — Lifting the Unit

6
PIPING CONNECTIONS BETWEEN OUTDOOR AND
INDOOR UNITS
Indoor units are connected to the outdoor units using branch
piping. See Fig. 8 and 9. Table 3 lists main pipe sizes. Branch
pipe sizing depends on the size of the indoor unit selected, see
Table 4. Table 5 lists the maximum number of indoor units and
connected capacity range per 38VMA outdoor unit.
REFRIGERANT PIPING MEASUREMENTS
Table 3 — Main Pipe Sizing
Table 4 — Branch Pipe Sizing
Table 5 — Maximum Indoor Unit Connections
* Use pipe adapter (Components Shipped with Unit - Page 2)
when main pipe diameter for suction line is 5/8 inch.
CAUTION
During brazing, keep nitrogen in pipes to avoid oxidation
inside the pipes. Use soapy water or refrigerant leak
detector to verify every joint in the refrigeration piping.
Fig. 8 — Piping and Control Wiring Connections
Fig. 9 — Piping and Control Wiring Locations
38VMH UNIT CAPACITY
(tons)
MAIN PIPE SIZE
SUCTION SIDE
(in.)
LIQUID SIDE
(in.)
036 3 5/83/8
048 4
060 5 3/4 *
INDOOR UNIT SIZE
(Btuh)
SUCTION SIDE
(in.)
LIQUID SIDE
(in.)
7,000 to 15,000 1/21/4
18,000 to 48,000 5/83/8
38VMH UNIT MAXIMUM NUMBER
OF INDOOR UNITS
CONNECTED
CAPACITY (%)
036 5
50 to 130048 7
060 9

7
Figures 10 and 11 and Tables 6 and 7 show allowable piping lengths and elevation differentials when connecting the outdoor units to
indoor units.
Table 6 — Permitted Pipe Lengths and Drop Heights
* Branch joints are field supplied.
NOTE: When the length "L1" is greater than 230 ft, the gas pipe
should be increased from 5/8 in to 3/4 inch or from 3/4 in to 7/8 inch.
The pipe adapter must be as close as possible to ODU.
Fig. 11 —Branch Joint Layout
Table 7 — Connection Method
BRANCH JOINT INSTALLATION — The branch joint
must be installed parallel to the ground; the angle of the joint
should not be greater than 10 degrees. Positioning the branch
joint more than 10 degrees from parallel can cause
malfunctions. See Fig. 12 for correct positioning of the joint.
Fig. 12 —Correct Branch Joint Positioning
Install the branch joints properly to avoid oil accumulating in
the system.
DESCRIPTION ALLOWABLE VALUE (ft) PIPES
Piping Length
Total Pipe Length ≤ 492 L1 + L2 + L3 + L4 + L5 + L6 + A +
B + C + D + E
Maximum Piping Length (L) Actual Length ≤ 296 L1 + L3 + L4 + L5 + L6 + E
Equivalent Length ≤ 328
First Branch to Farthest Indoor Unit ≤ 131 L3 + L4 + L5 + L6 + E
Height
Difference
Indoor Unit to Outdoor Unit Outdoor Unit Above ≤ 164 —
Outdoor Unit Below ≤ 131 —
Indoor Unit to Indoor Unit ≤ 49 —
First Branch to Farthest Indoor Unit* ≤ 49 —
Fig. 10 — Piping Lengths and Drop Height
UNIT TYPE SUCTION SIDE LIQUID SIDE
Outdoor Unit Flaring Flaring
Indoor Unit Flaring Flaring
Branch Pipe Brazing or Flaring Brazing or Flaring
LEGEND
1 — Main outdoor pipe, from outdoor unit to first branch pipe.
2 — Main indoor pipe, from branch pipe to first branch pipe.
3 — Branch pipe, from branch pipe to indoor unit.
◄—Branch joint.

8
Step 4 — Pressure and Vacuum Test
System — After completing the refrigerant piping, perform
the following pressure test:
1. Connect nitrogen canister to the system through the high-
pressure gas side valve from the meter connector.
2. Apply nitrogen pressure gradually to 500 psig.
3. If rapid pressure decrease is apparent; locate and repair
the leak, and pressurize the system again.
4. Repeat Steps 1-3 until the system remains at 500 psig for
24 hours.
After completing the pressure test, perform the following
vacuum test:
1. Relieve the system of the nitrogen gas.
2. Connect a vacuum pump capable of at least 85 cfm to the
system.
3. Vacuum the system to 500 microns or lower, and check
for rapid pressure change.
4. Repeat Steps 1-3 until the system remains at 500 microns
or lower for one hour.
When finished, replace the vacuum pump with the R-410A
refrigeration canister.
Step 5 — Adjust Refrigerant Charge —
Calculate the amount of refrigerant (R-410A) to add using
Table 8 and Fig. 13.
Table 8 — Refrigerant to Add Using Liquid Pipe
Size
All service valves on the outdoor units should remain fully
closed.
R-410A refrigerant should be added (in liquid state) at the
liquid line service port on the header unit.
If the total calculated amount of refrigerant can be added to the
system, the charging process is finished.
If the total calculated amount of refrigerant cannot be added to
the system, close the valve on the refrigerant bottle, move the
charging house from the liquid line service port to the suction
line service port.
Open the suction and liquid service valves on the header unit
and start the system in cooling mode.
Slowly open the valve on the refrigerant bottle and carefully re-
lease liquid refrigerant into the suction service port.
If the total calculated charge amount is added completely to the
system, the charging process is finished.
Step 6 — Complete Electrical Connections —
See Fig. 14 for a diagram of the unit’s internal power and
control wiring.
PIPE SIZE ON LIQUID SIDE
(in.)
REFRIGERANT TO BE
ADDED PER FOOT (lb/ft)
1/40.015
3/80.040
1/20.080
5/80.120
3/40.181
7/80.255
WARNING
Electrical shock can cause personal injury and death.
Disconnect power supply before making wiring
connections. There may be more than one disconnect
switch. Tag all disconnect locations to alert others not to
restore power until work is completed.
WARNING
All units must be wired strictly in accordance with the
wiring diagram furnished with the unit. Any wiring
different from the wiring diagram could result in personal
injury and property damage.
CAUTION
Any original factory wiring that requires replacement must
be replaced with wiring material having a temperature
rating of at least 105C.
Ensure supply voltage to the unit, as indicated on the serial
plate, is not more than 10% over the rated voltage or 10%
under the rated voltage.
Failure to follow these recommendations may result in
equipment damage.
Fig. 13 — Calculating the Amount of Refrigerant
to Add
* R = Amount of refrigerant to add.
R*=
Total length (ft)
of liquid piping
Size at
ဨ7/8 in.
x 0.225 +
(lb/ft)
Total length (ft)
of liquid piping
Size at
ဨ3/4 in.
x 0.181 +
(lb/ft)
Total length (ft)
of liquid piping
Size at
ဨ5/8 in.
x 0.120 +
(lb/ft)
Total length (ft)
of liquid piping
Size at
ဨ1/2 in.
x 0.080 +
(lb/ft)
Total length (ft)
of liquid piping
Size at
ဨ3/8 in.
x 0.040 +
(lb/ft)
Total length (ft)
of liquid piping
Size at
ဨ1/4 in.
x 0.015 +
(lb/ft)
IDU Model
40VMF012~036A--3
40VMM012~036A--3
Others
Charged amount per unit (lbs.)
1.10
1.10
0
+
x 0.22 (lbs/item)
Y-joints or headers
number in liquid side

9
Fig. 14 — Typical Wiring Diagram

10
POWER SUPPLY — Electrical characteristics of the
available power supply must agree with the unit nameplate
rating. Circuit breaker size and supply voltage must be as
shown in Table 9.
Table 9 — 38VMH Electrical Data
POWER WIRING — Installation of wiring must conform
with local codes and with NEC ANSI/NFPA 70, current
edition. Units must be electrically grounded in conformance
with the code. In Canada, wiring must comply with CSA
C22.1, Electrical Code.
General Wiring Notes
• Separate power sources are required for indoor and
outdoor units.
• Control circuit does NOT require separate power source.
• Power entry is on the right side of the unit when facing
the fan grille or front of the unit.
• Terminals for field power supply are suitable for copper
conductors.
• See Fig. 15 and 16 for power wiring.
Main Power — Bring wires from the disconnect switch
through the knockout hole at the bottom right corner of the unit
to the control box.
CAUTION
Operating the unit on improper supply voltage or with
excessive phase imbalance may result in equipment
damage and can affect the manufacturer’s warranty.
SUPPLY
VOLTAGE
POWER
SUPPLY
(V-Ph-Hz)
38VMH UNIT
SIZE
POWER SUPPLY
MCA* MOPD
208/230-1-60
036 36 40
048 38 40
060 40 45
LEGEND
MCA —Minimum Circuit Amps
MOPD —Maximum Overcurrent
Protective Device
* Select wire size based on larger value of MCA.
Fig. 15 — Power Wiring
Fig. 16 — Individual Power Wiring

11
WIRING THE COMMUNICATION TERMINAL
BLOCK — Figure 17 is the communication port diagram for
the outdoor unit.
Fig. 17 —Outdoor Unit Communication Port
Diagram
COMMUNICATION CABLE — The type of
communication cable used is a 2-core stranded shielded cable.
The diameter of the wire should be AWG 18. The maximum
wire length should be less than or equal to 3,937 feet between
outdoor and indoor units and less than or equal to 820 feet
between the wired controller and indoor units. Communication
wires are sold separately but can be obtained through Carrier.
Figure 18 below shows a typical communication wire from
Carrier.
Fig. 18 —Typical Communication Wire
CONTROL CONNECTIONS — Control power comes from
the control board in the outdoor unit and does NOT require a
separate source.
Use of 2-core stranded shielded cable is required. Shield is
used to protect the signal from interference. The control wire
between outdoor and indoor units is bus type. See Fig. 19 for
communication wiring.
COMMUNICATION WIRING — Communication wire
must be wired as shown in Fig. 8 and 19. Do not route
communication wire with high voltage power wire or allow it
to come in contact with non-insulated piping and sharp edges.
LEGEND
K1, K2 Reserved
O, A To pulse meter
X, Y To indoor unit centralized controller
P, Q To indoor units communication bus
H1, H2 Reserved
IMPORTANT: Wiring for communication shall be 2
inches. or more apart from power source wiring to avoid
electric noise. Do not insert control/communication and
power source wire in the same conduit.
Pay attention to the polarity of communication wire.

12
Legend
IDU - Indoor Unit
Fig. 19 — Connecting Communication Wire to Outdoor Unit Communication Terminal
P Q X Y
X Y
Outdoor Unit Centralized controller
HA HB
P Q
P Q
P Q
P Q
P Q
wired controller
HA HB
L1
L3
L5
L6
L7
L8
L9
L10
L11
L3
L3
L3
L3
Indoor unit 1#
Indoor unit 2#
Indoor unit 4#
Indoor unit 5#
Indoor unit 6#
Indoor unit 3#
P Q
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
HA HB
NOTE: Power from IDU
NOTE: 24 v. AC Power
Maximum wiring length
L1+L3< 3937 ft 18AWG, 2-Core Stranded Shield
L5 < 3937 ft 18AWG, 2-Core Stranded Shield
L6+L7+L8+L9 < 820 ft 18 AWG, 2-Core Stranded Shield
L10+L11 < 820 ft 18 AWG, 2-Core Stranded Shield

13
OPTION/EXTENSIONS OF COMMUNICATION
WIRING — To extend control wiring or make terminal
connections, use the PQE connection wire supplied in the
accessory kit and follow the steps below.
1. Cut connector on outdoor unit side as shown in Fig 20.
Fig. 20 —Shearing Outdoor Connector
2. Strip a suitable length of the insulation layer as shown in
Fig. 21.
Fig. 21 —Stripping the Wire
3. Use a suitable screwdriver to fix the communication wire
on the outdoor unit communication terminal as shown in
Fig. 22.
Fig. 22 —Connecting Communication Wire to
Outdoor Unit Communication Terminal
If communication wires are used to connect between indoor
units, find the corresponding port and plug it directly as shown
in Fig. 23.
Fig. 23 —Connecting the Communication Wires
START-UP
Trial Run — Set a different address for each indoor unit.
Addresses can range from 0 to 63. Address can be set
randomly using “Automatic Search Address” function, or set
addresses manually using wireless remote or wired controller.
Select and assign an indoor unit as 63. This unit will be in
“priority mode” and will control whether the system is in
heating or cooling.
Error Codes — Error codes are shown on the LED
display on the main control board. Press the CHECK button on
the main control board to scroll sequentially through error
codes. Refer to Fig. 14 for LED display location (DIS1), and
CHECK button location. Refer to Table 10 for an explanation
of error codes.
Table 10 — List of Error Codes
CAUTION
NEVER CONNECT the main power source to the control
or communication terminal block.
USE AN APPROPRIATE SCREWDRIVER for
tightening the terminal screws. Do not over tighten the
terminal screws.
Failure to follow these procedures may result in personal
injury or damage to equipment.
ERROR
CODE EXPLANATION
E2 Communication error between indoor unit and outdoor
unit
E4 T3 or T4 temperature sensor error
E5 Power voltage protection
E6 DC Fan error
E7 Discharge temperature sensor error
E9 EEPROM error
E.9. Mismatched main chip with EEPROM
EA DC Fan error more than 5 minutes in heating mode
Eb E6 error more than 2 times in 10 minutes
P1 High pressure protection
P2 Low pressure protection
P3 Input current overload
P4 Discharge temperature (T5) protection
P5 Condenser temperature (T3) protection
P8 Fan speed exceeds setpoint for 5 seconds or more.
PE High indoor coil temperature
PP Liquid slugging protection; indoor evaporator superheat
too low
F1 DC bus voltage is too low for 5 seconds
H0 Communication error between power driver board and
main board
H4 L0 or L1 error more than 3 times in 60 minutes
L0 Fault in compressor module
L1 DC bus under-voltage protection
L2 DC bus over-voltage protection
L4 Compressor MCE error
L5 Low compressor speed (Reserved)
L7 Compressor wrong phase protection (Reserved)
L8 Compressor speed difference is one second more than
15 rps
L9 Compressor speed difference between setting speed
and running speed more than 15 rps
LEGEND
EEPROM —Electrically Erasable Programmable Read-Only Memory
MCE —Motion Control Engine

14
Unit Settings
Table 11: SW3 and SW4 Function Definition
Table 12: ENC1 and ENC2
SW3 Function Definition SW4 Function Definition
Heating priority mode Automatic addressing
Cooling priority mode Non-automatic addressing (factory default)
First running priority mode Clear IDU address
Heating mode only Fahrenheit temperature (factory default)
Cooling mode only Celsius temperature
ENC1 Function Definition (factory use only) ENC2 Function Definition
For factory use only ODU network address dial-up
Only 0-7 used

15
Pre-Start Check
• Check that the refrigerant pipe line and communication
wire with indoor and outdoor units have been connected
to the same refrigeration system.
• Outdoor units require 208/230-1-60 power. Verify that
the power and phase requirements are correct and both
legs are present.
• Check that the power source’s voltage is within 10% of
the rated voltage.
• Check and confirm that the power and control wire are
correctly connected.
• Check that the wired controllers are properly connected.
• Before powering on, confirm there is no short circuit for
each line.
• Check that all units have passed a nitrogen pressure test
for 24 hours.
• Provide the customer accurate “as-built” drawings and
documents, including actual piping lengths and
locations, unit addresses, settings, etc.
• Ensure additional refrigerant charge calculations are
correct and that the system is charged accordingly.
• Energize outdoor units for at least 24 hours before
system start-up to ensure proper oil temperature has been
achieved.
• Ensure all refrigerant valves on outdoor units are fully
open. If these valves are not fully open, equipment
damage may occur.
MAINTENANCE
The following are recommended guidelines. Jobsite conditions
may say that maintenance schedule be performed more often
than recommended here.
EVERY 3 MONTHS:
• Check coil condition. Clean the coil if necessary.
EVERY 6 MONTHS — Follow the 3-month maintenance
schedule. In addition:
• Check for and remove debris that may have settled
around the base of the outdoor unit.
• Check for proper condensate drainage (clear basepan).
• Eliminate any standing water inside the outdoor unit.
EVERY 12 MONTHS — Follow the 6-month maintenance
schedule. In addition:
• Be sure all electrical connections are secure.
• Check heating and cooling action to confirm proper
operation.
CAUTION
When servicing or repairing this unit, use only factory-
approved service replacement parts. Refer to the rating
plate on the unit for complete unit model number, serial
number, and company address. Any substitution of parts or
controls not approved by the factory will be at the owner’s
risk and may result in equipment damage.
CAUTION
To avoid equipment damage, do not attempt to reuse any
mechanical or electrical controllers that have been wet.
Replace defective controller.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 20-38VMH002-01 Printed in U.S.A. Form 38VMH-1P-2SI Pg 16 01-20 Replaces: 38VMH-1P-1SI
© Carrier Corporation 2020