Carrier 38MHR series Installation Instructions Manual

38MHR
Outdoor Unit Single Zone Ductless System
Sizes 09 to 24

Installation Instructions

NOTE: Read the entire instruction manual before starting the

installation.

TABLE OF CONTENTS

PAGE

SAFETY CONSIDERATIONS 2.........................

PARTS LIST 3.......................................

SYSTEM REQUIREMENTS 4...........................

DIMENSIONS − OUTDOOR 5..........................

CLEARANCES − OUTDOOR 8.........................

INSTALLATION TIPS 9................................

OUTDOOR UNIT INSTALLATION 9.....................

ELECTRICAL DATA 11...............................

CONNECTION DIAGRAMS 11.........................

SYSTEM VACUUM AND CHARGE 12...................

START−UP 13........................................

OUTDOOR UNIT DIAGNOSTIC GUIDES 13..............

SAFETY CONSIDERATIONS

Installing, starting up, and servicing air−conditioning equipment
can be hazardous due to system pressures, electrical components,
and equipment location (roofs, elevated structures, etc.).

Only trained, qualified installers and service mechanics should
install, start−up, and service this equipment.

Untrained personnel can perform basic maintenance functions such
as coil cleaning. All other operations should be performed by
trained service personnel only.

When working on the equipment, observe the precautions in the
literature and on tags, stickers, and labels attached to the
equipment.

Follow all safety codes. W ear safety glasses and work gloves. Keep
a quenching cloth and a fire extinguisher nearby when brazing.
Use care in handling, rigging, and setting bulky equipment.

Read these instructions thoroughly 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
the unit and in instructions or manuals, be alert to the potential for
personal injury. Understand these signal words: DANGER,
WARNING, and CAUTION. These words are used with the
safety−alert symbol. DANGER identifies the most serious hazards
which will result in severe personal injury or death. WARNING
signifies hazards which could result in personal injury or death.
CAUTION is used to identify unsafe practices which may result in
minor personal injury or product and property damage.

NOTE is used to highlight suggestions which will result in
enhanced installation, reliability, or operation.

. When you see this symbol on

!

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal
injury or death.

Before installing, modifying, or servicing system, main
electrical 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.

!

EQUIPMENT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation.

Do not bury more than 36 in. (914 mm) of refrigerant pipe
in the ground. If any section of pipe is buried, there must be
a 6 in. (152 mm) vertical rise to the valve connections on
the outdoor units. If more than the recommended length is
buried, refrigerant may migrate to the cooler buried section
during extended periods of system shutdown. This causes
refrigerant slugging and could possibly damage the
compressor at start−up.

WARNING

!

WARNING

EXPLOSION HAZARD

Failure to follow this warning could
result in death, serious personal injury,
and/or property damage.

Never use air or gases containing
oxygen for leak testing or operating
refrigerant compressors. Pressurized
mixtures of air or gases containing
oxygen can lead to an explosion.

CAUTION

2

PARTS LIST

Table 1—Parts List

PART NO. PART NAME QTY.

1 Outdoor unit 1

- Literature package including installation instructions and warranty 1

- Grommet to secure the outdoor unit (helps with vibration prevention during unit operation) 4

- Drain Joint 1

- Drain Hose 1

■ Outdoor

1

Fig. 1 - Parts List

NOTE:

− If the outdoor unit is higher than the indoor unit, prevent rain from flowing into the indoor unit along the connection pipe by making
a downward arc in the connection pipe before it enters the wall to the indoor unit. This ensures that rain drips from the connection
pipe before it enters the wall.

− Piping and the interconnecting wiring are field supplied.

− The illustration above is only a sketch. Different models may be slightly different.

The following units are covered in these installation instructions.

Table 2—Unit Sizes

SYSTEM TONS BTUh VOLTAGE - PHASE OUTDOOR MODEL

0.75 9,000 115-1 38MHRC09A--1

1.00 12,000 115-1 38MHRC12A--1

Cooling Only

Heating Pump

0.75 9,000 208/230-1 38MHRC09A--3

1.00 12,000 208/230-1 38MHRC12A--3

1.50 18,000 208/230-1 38MHRC18A--3

2.00 24,000 208/230-1 38MHRC24A--3

0.75 9,000 115-1 38MHRQ09A--1

1.00 12,000 115-1 38MHRQ12A--1

0.75 9,000 208/230-1 38MHRQ09A--3

1.00 12,000 208/230-1 38MHRQ12A--3

1.50 18,000 208/230-1 38MHRQ18A--3

2.00 24,000 208/230-1 38MHRQ24A--3

A150766

3

SYSTEM REQUIREMENTS

Allow sufficient space for airflow and service of the unit. See Fig. 5 for the required minimum distances between the unit, walls or ceilings.

Piping
IMPORTANT: Both refrigerant lines must be insulated separately.

S Table 3 contains piping information for the product covered within this document.

T able 3—Piping and Refrigerant Information

System Size 9K (115V) 12V (115V) 9K (208-230V) 12K (208-230V) 18 (208-230V) 24K (208-230V)

Min. Piping Length ft. (m) 10(3) 10(3) 10(3) 10(3) 10(3) 10(3)

Piping

Refrigerant

Standard Piping Length

Max. outdoor-indoor
height difference (OU
higher than IU)

Max. outdoor-indoor
height difference (IU higher
than OU)

Max. Piping Length with
no additional refrigerant
charge per System
(Standard Piping length)

Total Max. Piping
Length per system

Additional refrigerant
charge (between Standard
– Max piping length)

Suction Pipe
(size - connection type)

Liquid Pipe
(size - connection type)

Refrigerant Type Type R410A R410A R410A R410A R410A R410A

Cooling Only Models
Charge Amount

Heat Pump Models
Charge Amount

ft. (m)

ft. (m)

ft. (m)

ft. (m) 25(7.5) 25(7.5) 25(7.5) 25(7.5) 25(7.5) 25(7.5)

ft. (m) 82(25) 82(25) 82(25) 82(25) 98(30) 164(50)

Oz/ft

(g/m)

In (mm) 3/8(9.52) 1/2(12.7) 3/8(9.52) 1/2(12.7) 1/2(12.7) 5/8(15.9)

In (mm) 1/4(6.35) 1/4(6.35) 1/4(6.35) 1/4(6.35) 1/4(6.35) 3/8(9.52)

Lbs (kg) 1.06(0.48) 1.30(0.59) 1.06(0.48) 1.30(0.59) 2.09(0.95) 2.65(1.2)

Lbs (kg) 1.76(0.8) 2.12(0.96) 1.76(0.8) 2.12(0.96) 3.30(1.5) 3.968(1.8)

25(7.5) 25(7.5) 25(7.5) 25(7.5) 25(7.5) 25(7.5)

33(10) 33(10) 33(10) 33(10) 33(10) 33(10)

33(10) 33(10) 33(10) 33(10) 33(10) 33(10)

0.161(15) 0.161(15) 0.161(15) 0.161(15) 0.161(15) 0.322(30)

All outdoor units have an electronic expansion valve to manage the refrigerant flow of the fan coil connected.

Wiring

All wires must be sized per NEC (National Electrical Code) or
CEC (Canadian Electrical Code) and local codes. Use the Electrical
Data table MCA (minimum circuit amps) and MOCP (maximum
over current protection) to correctly size the wires and the

Communication Wiring:

A separate shielded stranded copper conductor only, with a 600
volt rating and double insulated copper wire, must be used as the
communication wire from the outdoor unit to the indoor unit.
Please use a separate shielded 16GA stranded control wire.

disconnect fuse or breakers respectively.
Per the caution note, only stranded copper conductors with a 600

!

CAUTION

volt rating and double insulated copper wire must be used. The use
of BX cable is not recommended.

Recommended Connection Method for Power and
Communication Wiring − Power and Communication Wiring:

The main power is supplied to the outdoor unit. The field supplied
14/3 power/communication wiring from the outdoor unit to the
indoor unit consists of four (4) wires and provides the power for
the indoor unit. Two wires are high voltage AC power, one is

EQUIPMENT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation.

S Wires should be sized based on NEC and local codes.
S Use copper conductors only with a minimum 600 volt

rating and double insulated copper wire.

communication wiring and the other is a ground wire.

Recommended Connection Method for Power and
Communication Wiring (To minimize communication wiring
interference) Power Wiring:

The main power is supplied to the outdoor unit. The field supplied
power wiring from the outdoor unit to the indoor unit consists of
three (3) wires and provides the power for the indoor unit. Two
wires are high voltage AC power and one is a ground wire. To
minimize voltage drop, the factory recommended wire size is 14/2
stranded with a ground.

4

DIMENSIONS − OUTDOOR

System Size Height (H) in. (mm) Width (W) in. (mm) Depth (D) in. (mm) Weight-Net lbs. (kg)

9K (115) 21.85(555) 30.31(770) 11.81(300) 57.3(26)

Cooling

Only

Heat

Pump

12K (115V) 21.85(555) 30.31(770) 11.81(300) 57.8(26.2)

9K (208/230V) 21.85(555) 30.31(770) 11.81(300) 54.7(24.8)

12K (208/230V) 21.85(555) 30.31(770) 11.81(300) 53.8(24.4)

18K (208/230V) 21.81(554) 31.50(800) 13.11(333) 70.1(31.8)

24K (208/230V) 27.64(702) 33.27(845) 14.29(363) 88.6(40.2)

System Size Height (H) in. (mm) Width (W) in. (mm) Depth (D) in. (mm) Weight-Net lbs. (kg)

9K (115) 21.85(555) 30.31(770) 11.81(300) 61.5(27.9)

12K (115V) 21.85(555) 30.31(770) 11.81(300) 65.0(29.5)

9K (208/230V) 21.85(555) 30.31(770) 11.81(300) 57.1(25.9)

12K (208/230V) 21.85(555) 30.31(770) 11.81(300) 60.6(27.5)

18K (208/230V) 21.81(554) 31.50(800) 13.11(333) 94.6(42.9）

24K (208/230V) 27.64(702) 33.27(845) 14.29(363) 105.2(47.7)

T able 4—Dimensions and Weights

30.66(779) W3

11.81(300) D

H

21.85(555)

0.47(12)

19.17(487) W1

30.31(770) W

2.76(70) W

0.98(25) B1

D3

D2

3.54(90) B2

D1

11.26(286)

13.07(322)

2.36(60)

2.42(61.5) A2

11.73(298)

H1

H2

Unit: inch(mm)

3.66(93)

R

.24(6)

0

0.47(12) A1

Fig. 2 - Sizes 9K and 12K

5