Lennox MPA048S4S-*P, MCFA024S4-*P, MPB024S4S-*P, MPA036S4S-*P, MPB036S4S-*P Installation Instructions Manual

INSTALLATION

©

2017 Lennox Industries Inc.

Dallas, Texas, USA

Table of Contents

General ...........................................................................1

Included Parts.................................................................2

Indoor / Outdoor Unit Match-Ups....................................2

Model Number Identication ...........................................3

Typical Single-Zone System Components......................4

System Dimensions .......................................................5

Outdoor Units ..............................................................5

Indoor Units .................................................................6

System Clearances ........................................................6

Outdoor Unit ................................................................6

Indoor Unit ...................................................................7

Torque Requirements for Caps and Fasteners...............7

Indoor Unit Installation ....................................................7

Unit Placement Considerations ...................................7

Floor Installation ..........................................................8

Ceiling Installation .......................................................8

Indoor Unit Condensate Piping Connections ...............9

Outdoor Unit Installation ...............................................10

Placement Considerations .........................................10

Direct Sunlight, Rain, Snow and Ice Protection .........10

Prevailing Winds ........................................................11

Buried Refrigerant Pipe Protection ............................12

Outdoor Unit Condensate Piping ...............................12

Securing the Outdoor Unit .........................................12

Refrigerant Piping Connections ....................................13

Leak Test and Evacuation ............................................14

Leak Test ...................................................................14

Triple Evacuation Procedure......................................14

Wiring Connections ......................................................15

Outdoor Unit .............................................................15

Indoor Unit .................................................................15

Unit Start-Up .................................................................23

Adding Refrigerant for Longer Line Set ........................23

Troubleshooting ............................................................23

Test Run .......................................................................23

Pre-Checks ................................................................23

Procedure ..................................................................23

Dry Mode Operation (Dehumidication) .......................24

Procedure ..................................................................24

Sequence of Operation ..............................................24

INSTRUCTIONS

MLA/MPA/MPB and

MCFA/MCFB Series

SINGLE-ZONE MINI-SPLIT SYSTEMS
(208/230V) --
Ceiling / Floor Indoor Units
507548-06
4/2017
Supersedes 10/2016

THIS MANUAL MUST BE LEFT WITH THE OWNER

FOR FUTURE REFERENCE

WARNING

Improper installation, adjustment, alteration, ser vice or
maintenance can cause property damage, personal
injury or loss of life.

Installation and service must be performed by a li censed
professional HVAC installer (or equivalent) or a service
agency.

WARNING

The clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs, and HFCs) as of July, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for non-compliance.

WARNING

This product contains a chemical known to the State
of California to cause cancer, birth defects, or other
reproductive harm.

CAUTION

As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.

General

Refer to the Product Specications bulletin (EHB) for more

product information.
These instructions are intended as a general guide and

do not supersede local or national codes in any way.
Authorities having jurisdiction should be consulted before
installation.

The MCFA and MCFB Ceiling/Floor indoor units are

matched with an outdoor heat pump unit to create a mini­split system that uses HFC-410A refrigerant.

Included Parts

Package 1 of 1 contains the following:
1 - Assembled Indoor Unit

Parts Figure Quantity Parts Figure Quantity

M0STAT60Q-1
Wireless controller

Wireless control
holder with 2 mounting
screws

1

1 Batteries (AAA) 2

Installation and owner’s

manual

1 ea.

The assembled indoor unit will include the following items:

1 - Assembled Outdoor Unit and the following items:

Parts Figure Quantity Parts Figure Quantity

Drain connector 1 Seal ring 1

Indoor / Outdoor Unit Match-Ups

Outdoor Unit Indoor Unit Voltage

MPA024S4S-*P or MPB024S4S-*P MCFA024S4-*P

MPA036S4S-*P or MPB036S4S-*P MCFA036S4-*P

MPA048S4S-*P or MPB048S4S-*P MCFA048S4-*P

208/230V

208/230V

208/230V

MPB018S4S-*P MCFB018S4-2P

MLA018S4S-*P MCFB018S4-2P

MLA024S4S-*P MCFA024S4-2P

208/230V

208/230V

208/230V

2

Model Number Identication

OUTDOOR SINGLE ZONE HEAT PUMP UNITS

M P A 009 S 4 S - 1 P

Series Type

M = Mini-Split

Unit Type

L = Low Ambient Heat Pump

P = Heat Pump

Major Design Sequence

A = 1st Generation

B = 2nd Generation

Nominal Cooling Capacity

018 = 1.5 tons

024 = 2 tons
036 = 3 tons
048 = 4 tons

CEILING/FLOOR NON-DUCTED INDOOR UNITS

M CF A 018 S 4 - 1 P

Series Type

M = Mini-Split

Voltage

P = 208/230V-1 phase-60hz

Minor Design Sequence

1 = 1st Revision

Refrigerant Circuits

S = Single Circuit

Refrigerant Type

4 = HFC-410A

Cooling Efciency

S = Standard Efciency

Voltage

P = 208/230V-1 phase-60hz

Unit Type

CF = Ceiling/Floor Non-Ducted

Major Design Sequence

A = 1st Generation

B = 2nd Generation

Nominal Cooling Capacity

018 = 1.5 tons

024 = 2 tons
036 = 3 tons
048 = 4 tons

Minor Design Sequence

1 = 1st Revision
2 = 2nd Revision

Refrigerant Type

4 = HFC-410A

Cooling Efciency

S = Standard Efciency

3

Typical Single-Zone System Components

IMPORTANT - Condensate drain line must always

be located at the bottom of the
bundle.)

Wiring

Line set
(wrapped in foam insulation)

Supply Air

Indoor unit wiring connections

Condensate drain line

(wrapped in foam insulation)

Refrigerant Line Set, Condensate Line

And Indoor / Outdoor Cable

Filter

Indoor Unit

Return Air

Wireless Remote

Control

Utility

Bundle

UV-rated tape (field-provided)

IMPORTANT - The refrigerant
metering device for this system is
located in the outdoor unit. This
makes it necessary to insulate the

Communication cable
036 and 048 only

Tape

(field-provided)

refrigerant lines individually to
prevent sweating.

Outdoor Unit

012-036 shown

208/230V Outdoor Unit

Terminal Block

1 2 3 L1 L2

Liquid and vapor shut off valves

Figure 1. Typical System Shown

4

Access cover
for valves

Condensate drain
from Indoor Unit

To Indoor

Unit

Communication Cable

036 and 048 only

TO INDOOR COMM. BUS

NOTE：

LLEY WO

ARG Y

S1

XT2

Use 2-conductor
shielded wire

S2

To Power

Supply

System Dimensions

A

E

D

B

C

TYPICAL APPEARANCE OF UNITS

Outdoor Units

Model

MPA024S4S-*P

MPA036S4S-*P

MPA048S4S-*P

MPB018S4S-*P

MPB024S4S-*P

MPB036S4S-*P

MPB048S4S-*P

MLA024S4S-*P

Unit of

Measurement

inches 40-5/8 25-1/4 31-7/8 15-1/8 16

mm 1032 641 810 384 406

inches 40-1/4 25 53-3/4 15-3/8 16

mm 1023 635 1365 391 406

inches 36 21-1/4 27-5/8 14-1/4 13-3/4

mm 914 540 702 363 350

inches 40-1/2 26-1/2 31-7/8 16-1/8 15-7/8

mm 1032 673 810 410 403

inches 41-1/8 25 52-1/2 16-1/8 15-7/8

mm 1045 634 1333 415 404

inches 40-3/4 26-1/2 31-7/8 15-1/8 16

mm 1035 673 810 384 406

A B C D E

Figure 2. Outdoor Unit Dimensions - Inches (mm)

5

Indoor Units

4

(222)

26-5/8

(676)

9-1/4
(235)

SIDE VIEW

FRONT VIEW

5-1/2

(139)

B

A

BACK VIEW

4-3/4

BOTTOM VIEW

(120)

6

(152)

8

9-1/2

(203)

(241)

Model No.

in. mm in. mm

A B

MCFA024S4S-*P 42-1/8 1070 39 991

MCFA036S4S-*P 50-5/8 1286 47-3/8 1203

MCFA048S4S-*P 65 1651 61-3/4 1568

8-3/

MCFB018S4S-*P 42-1/8 1070 39 991

Figure 3. MCFA and MCFB Indoor Unit Dimensions - Inches (mm)

System Clearances

Outdoor Unit

24 (610)

12

(305)

1

Minimum rear clearance can be 6 inches (152 mm) when mounted on brackets

and with no obstructions on the other three sides.

24

(610)

79

(2007)

Air Outlet

Air Inlet

1

12

(305)

Figure 4. Outdoor Unit Clearances - Inches (mm)

6

Indoor Unit

CEILING APPLICATIONS

3/4

(19)

SIDE VIEW

59 (1499)

(Service Clearance

DROP CEILING

SUPPLY

AIR

WALL WALL

24

(610)

CEILING AND FLOOR APPLICATIONS

FLOOR APPLICATIONS

FRONT VIEW

Unit Flush with Wall

SUPPLY

AIR

59 (1499)

(Service Clearance

Front of Unit)

24

(610)

Figure 5. Indoor Unit Clearances - Inches (mm)

Torque Requirements for Caps and
Fasteners

When servicing or repairing HVAC components, ensure
the fasteners are appropriately tightened. “Table 1. Torque
Requirements” provides torque values for fasteners.

IMPORTANT

Only use Allen wrenches of sufcient hardness (50Rc -

Rockwell scale minimum). Fully insert the wrench into
the valve stem recess.

Service valve stems are factory-torqued from 9 ft.-lbs.
(12 N) for small valves, to 25 ft.-lbs. (34 N) for large
valves) to prevent refrigerant loss during shipping and
handling. Using an Allen wrench rated at less than 50Rc
risks rounding or breaking off the wrench, or stripping
the valve stem recess.

See the Lennox Service and Application Notes C-08-1
for further details and information.

Table 1. Torque Requirements

Parts

Service valve cap 8 ft.-lb. 11

Sheet metal screws 16 in.-lb. 2

Machine screws #10 27 in.-lb. 3

Compressor bolts 7 ft.-lb. 10

Gauge port seal cap 8 ft.-lb. 11

Recommended Torque

U.S. Newton-Meter- N

Indoor Unit Installation

CAUTION

In order to avoid injury, take proper precaution when
lifting heavy objects.

Unit Placement Considerations

AVOID

Do not install the unit in the following locations:

• Areas exposed to petrochemicals or petrochemical
products

7

• Areas exposed to salt or other corrosive materials or

Electrical
Connections

Refrigerant / Drain
Pipe Connections

caustic gases

• Areas exposed to extreme voltage variations (such as
factories

• Tightly enclosed areas that may impede service of the
unit

• Areas exposed to fossil fuels (such as oil or gas in
kitchens)

• Areas exposed to strong electromagnetic forces

• Areas exposed to acids or alkaline detergents

DO

• Place the unit so that it is not exposed to direct sunlight

• Ensure the structural ceiling can support the weight of
the unit

• Select a location where condensate line will have the
shortest run to a suitable drain per local codes.

• Allow sufcient space around unit for proper operation
and maintenance

• Install unit a minimum of 3 feet (1m) away from any
antenna, power cord (line) radio, telephone, security

system, or intercom. Electrical interference and radio

frequencies from any of these sources may affect op­eration

• Be sure to instruct customers how to properly operate
the unit (especially maintenance of air lter, and oper­ation procedure) by having them carry out operations
themselves while looking at the manual provided with
the controller

Side Panel

Factory Installed

Hanging Brackets

Grille

Side Panel

Figure 7. Remove Side Panel and Grille

2. Install four mounting bolts (appropriate for your
application) to the wall. See “Figure 3. MCFA and

MCFB Indoor Unit Dimensions - Inches (mm)” on

page 6 to ensure proper positioning of the bolts.

3. Upon conrming the four bolts are level, correctly
spaced and secured to the wall; lift the unit onto the

brackets. Conrm the unit is level before continuing.

Field-Installed

Mounting Bolts

Floor Installation

• Locate a suitable position within the space where
maintenance access and supply air will not be restrict­ed or affected by obstacles. See “Figure 5. Indoor Unit
Clearances - Inches (mm)” on page 7 for minimum
clearances

• Place the MCFA or MCFB on a wall which is both ca-
pable of supporting the unit’s weight and which is con-

structed to enable the unit to t ush on the wall. An

uneven wall may lead to vibration and subsequent unit
damage

Figure 6. Floor / Wall Applications

Units are wall mounted using factory-installed hanging
brackets.

1. Remove the side panels and grille to expose factory­installed hanging brackets on the sides of the unit.

Factory Installed

Hanging Brackets

Figure 8. Hang Unit on Mounting Bolts

Ceiling Installation

• Locate a suitable position within the space where
maintenance access and supply air will not be restrict­ed or affected by obstacles

• Suspend the unit from a ceiling which is capable of
supporting the unit’s weight

Units are suspended from the ceiling using factory-
installed hanging brackets.

1. Remove the side panels and grille to expose factory­installed hanging brackets on the sides of the unit

8

Grille

Side Panel

Threaded

T

8. Hang the unit by sliding the factory-installed hanging

DRAIN LINE

Slope at least 1/4”
per foot (18 mm per M)

3 ft. (1 m)

SUPPORT

STRAPS

brackets on to the threaded rods between the sets of
washers and nuts.

9. Use the leveling nut (beneath hanging brackets)
to adjust the unit to the correct height. Remove the
electrical tape holding the upper washers and nuts
in place and tighten each of the four nuts above the
brackets down onto the brackets. This will ensure that
the unit remains level.

Indoor Unit Condensate Piping Connections

Figure 9. Remove Side Panel and Grille

2. Install suspension rods in the structural
ceiling or concrete slab in a suitable location.
If the structural ceiling is constructed of concrete,
install anchors to accept four suitably sized threaded
rods to suspend the indoor unit. If the structural ceiling
includes wooden joists, use angle iron or Unistrut

channel xed securely in place to accept the threaded

rods.

3. Slide one nut and one washer onto each threaded rod.

Rod

CONCRETE CEILING

USING ANCHORS

Anchor

Angle Iron Bolted

in Place Across

Wooden Joists

Threaded

Rod

ANGLE IRON

ACROSS WOODEN

JOISTS

Wooden
Joist

Figure 10. Locate Threaded Rods

4. Use electrical tape to keep the washer from falling off.
Position the nuts

5. Slide a second washer and then a second nut onto

each rod slightly above the nal resting place of the

hanging brackets.

6. If necessary, install a eld-provided isolation grommet
to prevent transmission of vibration from unit to
structural ceiling.

hreaded Rod

IMPORTANT

Make sure that drain piping is properly routed and
insulated to prevent both leaks and condensation.

1. Use a eld-provided hose clamp to secure the drain

line stub on the side of the cassette base to a eld-

supplied 1” (25 mm) drain line.

NOTE: Take care not to over-tighten the hose clamp as

this may damage the drain line stub.

NOTE: Connection between stub and drain line must be

watertight. Apply non hardening plumbing joint
compound if needed to ensure a watertight seal.

2. Conrm proper slope (not less than 1/4 inch per foot
(18 mm per m)) and routing of condensate lines to
ensure moisture is drained away from the indoor unit.

3. Drain should be as short as possible and should
not have any droops or kinks that would restrict
condensate ow and shall be approved resistant pipe.

There must be a 2-inch (51 mm) space between

the end of the condensate drain and the nal

termination point (ground, open drain, etc.) to
ensure that the line will drain freely.

4. After the system installation is complete, the
condensate drain line must be checked for leaks and

proper drainage. If a eld-provided condensate pump

has been installed, it must be checked to ensure proper
operation. This check is part of the start-up process
which must be done by the installing contractor.

IMPORTANT

Drain should have a slope of at least ¼ inch per foot and

should be approved corrosion-resistant pipe. You must
conrm operation of every drain and pump in the system

as part of the commissioning procedure.

Field-Provided

Isolation

Grommet

Washer

Leveling

Nut

Figure 11. Locate Bracket on Threaded Rod

7. Use either a mechanical lifting device or a minimum of
two people to raise the unit.

Suspension
Bracket

Figure 12. Indoor Unit Suspended from Ceiling

using a Properly Sloped Gravity Drain

9

Outdoor Unit Installation

Placement Considerations

CAUTION

In order to avoid injury, take proper precaution when
lifting heavy objects.

Consider the following when positioning the unit:

• In coastal areas or other places with salty atmosphere
of sulfate gas, corrosion may shorten the life of the
unit. In coastal areas, the coil should be cleaned with
potable water several times per year to avoid corrosive
buildup (salt)

• Some localities are adopting sound ordinances based
on the unit’s sound level registered from the adjacent
property, not from the property where the unit is in­stalled. Install the unit as far as possible from the prop­erty line

• When possible, do not install the unit directly outside
a window. Glass has a very high level of sound trans­mission

• Install unit level

Building Structure

Ground
Level

Figure 13. Install Unit Level

• Since water drains from the outdoor unit during vari­ous stages of operation, do not place anything which
may be damaged by moisture under the unit

Direct Sunlight, Rain, Snow and Ice Protection

• If the outdoor unit is subjected to prolong exposure to
direct sunlight with temperatures over 100°F (38°C) a
canopy is recommended as illustrated in “Figure 14.
Outdoor Unit on Pedestal (Stand) and Protective Can­opy” or “Figure 19. Dog House-Style Shelter” on page

11.

IMPORTANT

The construction of a canopy or shade is necessary
because of an ambient limit control set to 122°F (50°C)
to protect the electronics. If the outdoor unit is placed in
direct sunlight it is possible that the limit may activate
and shut down the unit.

• Place unit away from overhanging roof lines which
would allow water or ice to drop on, or in front of, coil
or into unit. Construct a canopy as illustrated in “Figure

14. Outdoor Unit on Pedestal (Stand) and Protective

Canopy”

• The unit base should be elevated above the depth of

average snows as illustrated in “Figure 15. Outdoor
Unit on Brackets above Snow Line”

• In heavy snow areas, do not place the unit where drift-

ing will occur as illustrated in “Figure 16. Outdoor Unit
Air Flow Obstructed by Snow” on page 11

• Carefully consider how to manage defrost water dis­posal to prevent ice from blocking walkways or creat­ing a safety hazard near the outdoor unit as illustrat­ed in “Figure 17. Avoid Defrost Water Ice Hazard” on
page 11

Protective canopy

Protective canopy

• Choose a place solid enough to bear the weight and
vibration of the unit, where the operation noise will not

be amplied

• Choose a location where the hot air discharged from
the unit or the operation noise will not be a nuisance
to neighbors

• Avoid installing the outdoor unit near a bedroom or
other places where noise may cause a problem

• There must be sufcient space to carry the unit into
and out of the site

• There must be unobstructed air ow around the air in­let and the air outlet

• The unit must not be installed in areas where a am­mable gas leak may occur

• Install the outdoor unit a minimum of 3 feet (1m) away
from any antenna, power cord (line), radio, telephone,

security system, or intercom. Electrical interference

and radio frequencies from any of these sources may
affect operation

24 in

610 mm

12 in

305 mm

Air Inlet

Air Outlet

Pedestal

(stand)

Side View

Front View

Figure 14. Outdoor Unit on Pedestal (Stand) and

Protective Canopy

10

Pedestal
(stand)

Air Inlet

Air Outlet

Air Outlet

Air Inlet

12 in

305 mm

79 in

2007 mm

mm) from the unit as illustrated in “Figure 18. Wind

Barrier”

• When prevailing wind is into the discharge side, then
position the wind barrier a minimum 79 inches (2007
mm) from the front of the unit as illustrated in “Figure

18. Wind Barrier”

• Outdoor unit can be installed in a dog house style
shelter as illustrated in “Figure 19. Dog House-Style
Shelter”

• a roof overhang as illustrated in “Figure 20. Unit in­stalled in Alcove”

Prevailing Winter Winds from Air Inlet Side

Figure 15. Outdoor Unit on Brackets above Snow

Line

Figure 16. Outdoor Unit Air Flow Obstructed by

Snow

Wind Barrier

Inlet Air

Discharge Air

Wind Barrier

Prevailing Winter Winds From Air Discharge Side

Figure 18. Wind Barrier

24 in

12 in

305 mm

610 mm

24 in

610 mm

12” (305mm)
Min. Distance

79” (2007mm)
Min. Distance

12 in

305 mm

Figure 17. Avoid Defrost Water Ice Hazard

Prevailing Winds

Normally wind bafes are not required for a outdoor unit.

However, in order to maximize reliability and performance,
the following best practices should be followed.

If unit coil cannot be installed away from prevailing winter
winds, some method of protecting the coil is recommended.
However, minimum clearances as reference in “Figure 4.

Outdoor Unit Clearances - Inches (mm)” on page 6

must be observed at all times.
Common application examples are:

• When prevailing winds are from the air inlet side, then

position the wind barrier a minimum of 12 inches (305

NOTE - Minimum clearances shown.

Figure 19. Dog House-Style Shelter

11

12 in

305 mm

24 in

610 mm

12 in

305 mm

24 in

610 mm

NOTE - Minimum clearances shown.

Figure 20. Unit installed in Alcove

Four Field-provided Anchor Bolts

Buried Refrigerant Pipe Protection

• All refrigerant lines must be insulated regardless of if

it is buried

• In addition to insulating each line of piping, buried lines
must rest inside a sealed, watertight conduit

• The conduit must be designed so it cannot collect and
retain water

Outdoor Unit Condensate Piping

Condensate formed during the heating and defrost
processes must be drained from heat pump units. Drain
holes are provided in the base of the units to ensure proper
drainage. Heat pumps must be raised when installed on a
concrete pad or the ground to allow drainage to occur. If
the heat pump unit is installed on wall mounting bracket,
insert the provided drain connector into one of the 1

inch (25 mm) drain holes and attached a eld-provided
insulated drain hose to the connector. Use eld-provided

rubber plugs to cover any unused drain holes.

CAUTION

Roof Damage!
This system contains both refrigerant and oil. Some

rubber roong material may absorb oil. This will cause

the rubber to swell when it comes into contact with oil.
The rubber will then bubble and could cause leaks.
Protect the roof surface to avoid exposure to refrigerant
and oil during service and installation. Failure to follow
this notice could result in damage to roof surface.

Securing Outdoor Unit to Slab, Frame, or Rails

If the outdoor unit is installed on a eld-provided slab or

frame, use lag bolts or equivalent to secure the outdoor
unit to the slab or frame.

Figure 22. Securing Outdoor Unit to Slab

Four Field-Provided

Anchor Bolts

Figure 23. Securing Outdoor Unit to Rails

Securing Outdoor Unit To Hanging Brackets

If the outdoor unit is installed on eld-provided wall

mounting brackets, use lag bolts or equivalent to secure
the outdoor unit to the bracket. Minimum rear clearance
can be reduced to 6 inches (152 mm) when mounted
on brackets and with no obstructions on the other three
sides. Allow for condensate disposal when placing units
above one another.

Drain
Connector

Chassis

Condensate Drain
(location varies per model)

Figure 21. Condensate Drain

Securing the Outdoor Unit

Install the unit a minimum of 4 inches (102 mm) above the

Slab or Roof Mounting

roof or ground surface to avoid ice build-up around the
unit. Place the unit above a load bearing wall or area of
the roof that can adequately support the unit. Consult local
codes for rooftop applications.

12

6 in

152 mm

Air Inlet

Air Outlet

Figure 24. Securing Outdoor Unit to Brackets

Refrigerant Piping Connections

Field piping consists of two copper lines connecting the
outdoor unit to the indoor unit. “Table 2. Refrigerant Piping
and Indoor Unit Connection Sizes” lists the connection
sizes. The connections are made using the provided brass

are nuts at the end of the refrigerant piping connections.

Both lines must be individually insulated.

1. The seal on the unit refrigerant piping connections
should remain in place until the last possible moment.
This will prevent dust or water from getting into the
refrigerant piping before it is connected.

2. CAREFULLY adjust refrigerant piping connections to
suit the application.

3. Slowly loosen one of the are nuts to release the
factory nitrogen charge from the indoor units only.

4. Remove the are nuts from the connections on the
unit and discard the seal from each of the piping
connections.

5. Slide the are nuts onto the ends of the eld-provided

refrigerant piping before using a suitable aring tool to
are the end of the copper pipe.

6. Apply recommended HFC-410A refrigerant lubricant

to the outside of the ared refrigerant lines.

A

B

TO INDOOR

CANT ON THE OUTSIDE OF

THE FLARE

Figure 25. Making Connections

(Male to Female Connection)

TORQUE WRENCH

UNIT

TO OUTDOOR UNIT

Figure 26. Tighten Flare Nut

MALE FLARE

CONNECTION

BACKUP

WRENCH

IMPORTANT

The compressor in this unit contains PVE
oil (Polyvinylether). PVE oil is formulated for
hydro-uorocarbon (HFC) refrigerants, such as HFC-

410A, which this system contains. While it may have
some miscibility properties with mineral-based oil and

POE oil (Polyolester), it is not recommended to mix PVE

oil with any other type of refrigerant oil.

7. Align the threaded connections with the

ared refrigerant lines. Tighten the are nuts
lightly at rst to obtain a smooth match as

illustrated in “Figure 25. Making Connections
(Male to Female Connection)”.

8. Once snug, continue another half-turn on each nut
which should create a leak-free joint. A torque wrench

may be used to tighten are nuts using “Table 3. Flare

Nut Torque Recommendations”. Do not over-tighten

a ared joint. Flared connections should always

be accessible and must be insulated to prevent
condensation.

9. After refrigerant piping has been installed and checked

for leaks, apply insulation over all ared connections.

Table 2. Refrigerant Piping and Indoor Unit

Connection Sizes

Size

(Btuh)

18000 1/4 1/2

24000, 36000 &

48000

Liquid Line

in.

3/8 5/8

Gas Line

in.

Table 3. Flare Nut Torque Recommendations

Outside

Diameter

Inches

1/4 15 ft.-lb. (20 N) 1/4 turn

3/8 26 ft.-lb. (35 N) 1/2 turn

1/2 41 ft.-lb. (56 N) 7/8 turn

5/8 48 ft.-lb. (65 N) 1 full turn

Recommended

Torque

No torque wrench available

Finger tighten and use an

appropriately sized wrench to

turn an additional:

13

Table 4. Refrigerant Line Set Requirements

OUTDOOR UNIT

OUTDOOR UNIT

INDOOR UNIT

INDOOR UNIT

Maximum Line Set
Length

Maximum Line Set

Length

Maximum

Elevation -

Outdooor

Unit BELOW

Indoor Unit

Maximum

Elevation -

Outdooor

Unit ABOVE

Indoor Unit

Minimum Line Set
Length - 10 ft. (3m)

Minimum Line Set
Length - 10 ft. (3m)

Outside Unit BELOW Indoor Unit Outside Unit ABOVE Indoor Unit

Do not allow for excess length of line sets to be left rolled up as part of the
required distance, or in general. This will also cause additional performance issues.

IMPORTANT

Each system size has a line set length and vertical elevation parameters.

Line Set Diameters (in.)

System Size (KBtu)

Liquid Gas

024 3/8 5/8 82 ft. (25 m) 82 ft. (25 m) 164 ft. (50 m)

036/048 3/8 5/8 98 ft. (30 m) 98 ft. (30 m) 213 ft. (65 m)

Maximum Elevation

Outdoor Unit BELOW

Indoor Unit - Feet

(Meter)

Maximum Elevation

Outdoor Unit ABOVE

Indoor Unit - Feet

(Meter)

Set Length - Feet

Maximum Line

(Meters)

Leak Test and Evacuation

Air and moisture remaining in the refrigerant system will
have undesirable effects as indicated below:

• Pressure in the system rises

• Operating current rises

• Cooling or heating efciency drops

• Moisture in the refrigerant circuit may freeze

• Water may lead to corrosion of parts in the refrigera­tion system

• Relieve the nitrogen pressure by: loosening the
charge hose connector at the nitrogen cylinder

• When the system pressure is reduced to normal,
disconnect the hose from the cylinder

Table 5. Pressure Test Specications

Bar Psig kPa Duration

1 3 44 303 Minimum of 10 minutes

2 15 220 1517 Minimum of 10 minutes

3 32 470 3241 Minimum of 10 minutes

4 45 650 4482

The line set between the indoor and outdoor units
must be leak tested and evacuated to remove any non­condensables and moisture from the system.

5 32 470 3241

Leak Test

Use the following procedure to test for system leaks:

1. Connect the manifold gauge set and dry nitrogen gas
cylinder to the liquid and gas service ports.

2. Open valve on nitrogen cylinder.

3. Pressurize the system per the pressure test

specications in “Table 5. Pressure Test Specications”.

4. Check that the system pressure remains stable. If
there is any movement check system for leaks.

5. After the system is found to be free of leaks:

• Close valve on nitrogen cylinder

Use only oxygen-free nitrogen (OFN).

Triple Evacuation Procedure

A Micron or Torr gauge must be used for this procedure.

1. Discharge the oxygen-free nitrogen and evacuate the
system to a reading of 8000 Microns (8 Torr) using all
service valves.

2. Break the vacuum by allowing nitrogen into the port
connections (liquid and gas line pipes) until a positive
pressure is achieved.

3. Evacuate the system to a reading of 5000 Microns (5

14

1 hour. Stress test to prove the
integrity of the complete installation.

24 hours. Lower system pressure

test, after conrmation No. 4 was

successfully completed.

IMPORTANT

Torr).

4. Break the vacuum by allowing nitrogen into the port
connections (liquid and gas line pipes) until a positive
pressure is achieved

5. Evacuate the system to a minimum reading of 500
Microns (0.5 Torr).

6. For a moisture-free system, ensure the vacuum is held
without movement for a minimum of 4 hours.

7. If vacuum fails to hold, carry out steps 2 through 6 until
vacuum holds.

Wiring Connections

WARNING

Electric Shock Hazard. Can cause injury or death. Unit

must be rounded in accordance with national and local
codes.

Line voltage is present at all components when unit is
not in operation. Disconnect all remote electric power
supplies before opening access panel. Unit may have
multiple power sources.

IMPORTANT

This unit must be properly grounded and protected by a
circuit breaker. The ground wire for the unit must not be
connected to a gas or water pipe, a lightning conductor
or a telephone ground wire.

Do not connect power wires to the outdoor unit until
all other wiring and piping connections have been
completed.

Do not install the unit near a lighting appliance that
includes a ballast. The ballast may affect remote control
operation.

IMPORTANT

Install unit so that unit disconnect is accessible.

Use specied wiring and cable to make electrical

connections. Clamp cables securely and make sure that
connections are tight to avoid strain on wiring. Insecure
wiring connections may result in equipment failure and

risk of re.

Wiring must be installed so that all cover plates can be
securely closed.

CAUTION

All terminal connections must be made as illustrated
in the following diagrams. Improperly connected wiring
could damage unit or cause communication errors
between indoor and outdoor units.

In the U.S.A., wiring must conform with current local codes

and the current National Electric Code (NEC). In Canada,

wiring must conform with current local codes and the

current Canadian Electrical Code (CEC).

Outdoor Unit

• Refer to unit nameplate for minimum circuit ampacity
and maximum over-current protection size

• Make all electrical power wiring connections at the out­door unit

• Be sure to reattach all electrical box covers after con­nections are complete

Indoor Unit

• All indoor units are powered by the outdoor unit.

• Communication Wiring (Indoor Units 30K and Below):
Use one stranded 4-conductor wire to provide power
and communication

• Communication Wiring (Indoor Units 36K and Above):
Use one stranded 3-conductor wire to provide power
and one stranded 2-conductor wire to provide commu­nication

• Use minimum of 18 GA stranded wiring

• When installing a condensate pump, wire in-line with

the CN5 oat switch

15

IMPORTANT

208/230V Outdoor Unit

Terminal Block

From Power

Supply

1 2 3 L1 L2

Terminal Block

1 2 3

208/230V Indoor Unit

Outdoor Unit Indoor Unit

From Power

Supply

Indoor Unit

CommunicationTerminal Block

L1 L2

Power Terminal Block

208/230V Outdoor Unit

L1 L2

L1 L2

Power Terminal Block

208/230V Outdoor Unit

Power Terminal Block

208/230V Indoor Unit

S1 S2

Communication Terminal Block

Outdoor Unit

E Y XYQS1E P

S2

Outdoor Unit

Indoor Unit

All diagrams (Figure 29 through Figure 39) are typical wiring diagrams. Refer to the wiring diagram on the unit for actual
wiring.

Figure 27. Single-Zone Wiring 30K and Below

Figure 28. Single-Zone Wiring 36K and Above

16

0

8

4

1

2

3

5

6

7

C

9

A

B

D

E

F

1

2

ON

0

8

4

1

2

3

5

6

7

C

9

A

B

D

E

F

1

2

ON

0

8

4

1

2

3

5

6

7

C

9

A

B

D

E

F

1

2

ON

0

8

4

1

2

3

5

6

7

C

9

A

B

D

E

F

1

2

ON

S1+S 2

0~F 0~F 0~F 0~F

ADDRESS

CODE

0~15

16~31

32~47

48~63

FOR

CCM UNIT ADDR ESS

DC MOTOR

DRIVER MODULE

CN13

CN3

3

CN1 5

5

M

CN6

T2

T1

4

INDO OR COIL TEMP. SENS OR

ROOM TEMP. SENSOR

BLACK

WHITE

INDOOR UNIT MAINBOARD

CN3

RED

CN2

C N1

Y/G

BLACK

CN41

YELLOW

CN5

WATER LEVE L SWITCH

Inductor

CN8

CN18

RED

RED

1

ON

1

ON

COOLING
PRIORITY

HEATING
PRIORITY

FACTORY
SETTING

MODE

CN19

BLUE

BLACK

To LVM

Comm.Bus

WHITE

X Y E

Y/G

1

23

FILTER-BOARD

BLACK

RED

•••••••••••••••••••••• ••••••••

1

ON

1

ON

SW2

1

2

ON

1

2

ON

1

2

ON

1

2

ON

SW6

CODE

FOR TEMP. COMP ENSATION(HEATING)

FACTORY
SETTING

EEPROM

default

1

2

ON

1

2

ON

1

2

ON

1

2

ON

SW1

TEL0

EEPROM

default

FACTORY
SETTING

FOR ANTI-COLD WIND

1

ON

1

ON

FACTORY
SETTING

FOR SETTING AUTO-R ESTART

SW3

MODE

AUTO-RESTART

NOT AUTO-RESTART

CN2 3

ON/O FF

CN33

ALARM

Alarm
Output

Remote
Control

Ceiling-Floor Type

CN21

M

5

5

VSWING(INACTIVE)

CN24

M

5

SWING

FAN

FOR MODE CONFLICT SETTING

DISPLAY

BOARD

10

CN10A

TO WIRED

CONTROLLER

2

CN40

TO

PROGRA MMABL E

WIRED

CONTRO LLE R

4

2

•••••

COMPONENT IN DASH
LINE IS OPTIONAL
OR FIELD WIRING.

Note: The
programmable
wired controller
and regular
wired controller
use the same
wiring connector

(VRF only)

(VRF only)

32˚F (0˚C)36˚F (2˚C)39˚F (4˚C)

75˚F (24˚C) 59˚F (15˚C) 46˚F (8˚C )

Figure 29. MCFB018S4-*P Unit Wiring Diagram

M

FAN

C o m m .B u s

3

C N 3

DC MOTOR

DRIVER MODULE

To L V M

• • • • •
COMPONENT IN DASH
LINE IS OPTIONAL
OR FIELD WIRING.

Note: The
programmable
wired controller
and regular
wired controller
use the same
wiring connector

X Y E

INDOOR UNIT MAINBOARD

5

C N 13

WHITE

BLUE

BLACK

CN2 3

ON/O FF

Remote
Control

Figure 30. MCFA024S4-*P Unit Wiring Diagram

CN1 5

C N 19

Ceiling-Floor Type

CN3 3

ALA R M

Alarm
Output

CN8

CN18

CN21

CN24

CN40

CN10A

CN3

C N 1

C N 2

C N 41

R ED

B L A C K

FILTER-BOARD

17

RED

RED

5

5

M

VSWING(INACTIVE)

2

10

DISPLA Y

BOARD

CN6

4

BLACK

Y/G

YELLOW

BLACK

WHITE

WA TE R L EV EL SW IT C H

RED

CN5

In d uc to r

5

5

SWING

4

PROGRAMMABLE

2

CONTROLLER

5

TO WI RED

CONTRO LLER

INDO OR C OIL T EMP. SENS OR

ROOM TEMP. SENSOR

2 3

1

M

M

TO

WIRED

Y/G

T2

T1

CN5

In d uc to r

CN8

CN18

CN7

T2B

OUTER PIPE TEMP. SENSOR

T2

T1

CN6

4

BLACK

WHITE

RED

RED

VSWING(INACTIVE)

CN21

CN24

M

M

M

5

5

5

5

SWING

INDOOR UNIT MAINBOARD

DC MOTOR

DRIVER MODULE

CN1 3

CN3

M

3

C N 15

5

FAN1

Ceiling-Floor Type

CN2 3

ON/O FF

CN3 3

ALA RM

Alarm
Output

Remote
Control

CN19 CN16

BL U E

BL A C K

YE L L OW

G RA Y

To LVM
Comm.Bus

To outdoor
Comm.Bus

W H IT E

S1

S2

X Y

(

E

)

Y/G

C N 3

C N 2

C N 1

BLACK

RED

Ferr it e b ea d

FILTER-BOARD

L1

L 2

R ED

BL A C K

Y/G

Y/G

Y/G

• • • • •
COMPONENT IN DASH
LINE IS OPTIONAL
OR FIELD WIRING.

INDO OR C OIL T EMP. SENS OR

ROOM TEMP. SENSOR

FAN

WA TE R L EV EL SW IT CH

DISPLA Y

BOARD

10

CN10A

TO WI RED

CONTRO LLER

5

TO PROGRAMMABLE
WIRED CONTROLLER

2

CN40

4

2

Note: The
programmable
wired controller
and regular
wired controller
use the same
wiring connector

Figure 31. MCFA036S4-*P Unit Wiring Diagram

CN5

In d uc to r

CN8

CN18

CN7

T2B

OUTER PIPE TEMP. SENSOR

T2

T1

CN6

4

BLACK

WHITE

RED

RED

VSWING(INACTIVE)

CN21

CN24

M

M

M

5

5

5

5

SWING

INDOOR UNIT MAINBOARD

DC MOTOR

DRIVER MODULE

CN1 3

CN3

M

3

C N 15

5

FAN1

Ceiling-Floor Type

CN2 3

ON/O FF

CN3 3

ALA R M

Alarm
Output

Remote
Control

CN19 CN16

BL U E

BL A C K

YE L L OW

G RA Y

To LVM
Comm.Bus

To outdoor
Comm.Bus

W H IT E

S1

S2

X Y

(

E

)

Y/G

C N 3

C N 2

C N 1

BLACK

RED

Ferr ite b ea d

FILTER-BOARD

L1

L 2

R ED

BL A C K

Y/G

Y/G

Y/G

• • • • •
COMPONENT IN DASH
LINE IS OPTIONAL
OR FIELD WIRING.

INDO OR C OIL T EMP. SENS OR

ROOM TEMP. SENSOR

FAN

WA TE R L EV EL SW IT CH

DISPLA Y

BOARD

10

CN10A

TO WI RED

CONTRO LLER

5

TO PROGRAMMA BLE

WIRED CONTROLLER

2

CN40

4

2

Note: The
programmable
wired controller
and regular
wired controller
use the same
wiring connector

Figure 32. MCFA048S4-*P Unit Wiring Diagram

18

Compressor
Control Board

L-OUT

COMPRESSOR DISCHARGE
TEMP.SENSOR

2

S

CN10

BLACK

RED

CODE PART NAME

COMP

EXV

FM1

HEAT1

HEAT2

H-PRO

L

L-PRO

SV

T3

T4

COMPRESSOR

ELECTRIC EXPANSION
VALVE

OUTDOOR DC FAN

CRANKCASE HEATER

PAN HEATER

HIGH PRESSURE SWITCH

PFC INDUCTOR

LOW PRESSURE SWITCH

4 WAY VALVE

OUTDOOR COIL TEMP.
SENSOR

OUTDOOR TEMP. SENSOR

Y/G

RED

PAN HEATER

Y/G

CRANK CASE HEATER

Figure 33. 208/230V MPA024S4S-*P Outdoor Unit Wiring Diagram

BLACK

W

RED

COMP

V

Y/G

U

DRIVER BOARD

YELLOW

BLUE

COMPRESSOR
DISCHARGE
TEMP. SENSOR

CN55

CN19

7

BLACK

RED

BLUE

BLUE

BLUE

YELLOW

CN54

CN51

CN53

CN52

W

V

U

RED

BLACK

SV

T3

T4

4 WAY
VALVE

HEAT1

HEAT2

H-PRO

L-PRO

CN3

ORANGE

CN4

CN10

CN22

ORANGE

ORANGE

CN40

CN44

CN8

CN9

BLACK

CN7

ORANGE

7

L

EXV

5

CN20

CN33

MAIN BOARD

CN5

CN6

RED

M

YELLOW

BLACK

CN34

FM1

CN12 CN11

BLACK

CN2

RED

CN1

P-1

Y/G

Figure 34. 208/230V MPA036S4S-*P Outdoor Unit Wiring Diagram

19

YELLOW

GRAY

S2

S1

XT2

TO INDOOR COMM. BUS

NOTEP lease use 2-core

shielded wire.

( )

TO INDOOR UNIT
POWER SUPPLY

RED

BLACK

2)(1

L1

L2

RED

BLACK

XT1

L1

L2

MAIN

PO W ER S UP PLY

CODE

COMP

CT1

D

DCFAN1,DCFAN2

HEAT_Y

HEAT_D

H-PRO

L

L-PRO

SV

T5

T3

T4

TH

PART NAME

COMPRESSOR

AC CURRENT DETECTOR

DIODE MODULE

OUTDOOR DC FAN

CRANKCASE HEATER

PAN HEATER

HIGH PRESSURE SWITCH

PFC INDUCTOR

LOW PRESSURE SWITCH

4-WAY VALVE

DISCHARGE
TEMP. SENSOR

OUTDOOR COIL
TEMP. SENSOR

OUTDOOR TEMP. SENSOR

HEATSINK TEMP. SENSOR

Compressor and Outdoor
Fan Control Board

W

BLACK

BLUE

V

U

COMP

U

CN55

V

W

RED

Y/G

YELLOW

Y/G

BLAC K

RED

LLEY OW

S1

XT2

Please use 2-core

H-PRO

L-PRO

XT1

L2

L1

MAIN

POWER SUPPLY

L2

L2

)

)
2

2

(

(

L1

1

1

( )

( )

TO INDOOR UNIT

XT3

ARG Y

S2

L

A

CN15

6

ELECTRONIC
EXPANSION
VALVE A

Y/G

P-6

CN22

CN12

D

RED

BLUE

CN9

DCFAN2

CN8

BLACK

CN6

CN3

7

CN7

5

CN11

5

DCFAN1

HEAT_Y

HEAT_D

CN15

CN14

RED

CN39

BLACK

12

4

RED

3

5

5

4-WAY

SV

BLACK

BLUE

BLUE

CN4

CN39

CN18

CN25

CN20

CT1

CN2

CH5

CN17

CN24

CN19

YELLOW

CN5

CN6

MAIN BOARD

CN3

CN1

9NC

YELLOW

01NC

RED

CN8

T5

Y/G

BLACK

WHITE

2

TO INDOOR COMM. BUS

NOTE：

shielded wire.

T4
T3

TH

Figure 35. 208/230V MPA048S4S-*P Outdoor Unit Wiring Diagram

Figure 36. 208/230V MPB018S4S-*P and MPB024S4S-*P Outdoor Unit Wiring Diagram

20

CO MP

MAIN B OA RD

R ED

BLACK

U

V

W

Y/G

Y/G

L

L-PRO

T3

T4

CODE PART NAME

COMPRESSOR

HEAT 1

4-WAY VALVE

COMP

EXV

ELECTRIC EXPANSIO N
VALVE

H-PRO

L-PRO

LOW PRESSURE SWIT CH

HIGH PRE SSURE SWIT CH

T3

T4

OUTDOOR COIL
TEMPERATU RE SENSOR

OUTDOOR
TEMPERAT URE SENSOR

CRANKCAS E HEAT ER

POWER SUPPLY

H-PRO

SV

L

PFC INDUCTOR

T5

T5

COMP RESS OR DISCH ARGE
TEMP ERA TURE SENS OR

RED

BLA CK

V

U

CN19

CN51

CN55

W

EXV

BLACK

DRIVER BOARD

RED

7

7

YELLOW

BLUE

P-1

FM1

OUTDOOR DC FAN

CN53

CN20

CN34

CN3

CN4

CN10

CN40

CN22

CN44

C N8

C N9

CN7

CN2

C N1

CN5

CN54

CN52

CN33

5

CN6

SV

4-WAY
VALVE

BLUE

BLUE

HEAT2

HEAT1

BLACK

RED

BLUE

BLUE

BLUE

YELLOW

RED

BLACK

RED

BLACK

TO INDOOR COMM. BUS

XT 2

YE LLO W

GR AY

S1

S2

XT 1

L1

L2

L1

L2

2)(1

()

RED

BLAC K

MAIN

TO INDOOR UNIT
POWER SUPPLY

FM1

Y/G

BLACK

BLACK

RED

RED

HEAT 2

PAN HEAT ER

NOTE: PLEASE USE 2-CORE
SHIELDED WIRE

Figure 37. 208/230V MPB036S4S-*P Outdoor Unit Wiring Diagram

DR IV ER B OA RD

CODE

PART NAME

COMPRESSOR

D

HEAT 1

CT1

AC CURRENT DETECTOR

4-WAY VALVE

COMP

EXV

ELECTRIC EXPANSIO N
VALVE

H-PRO

L-PRO

LOW PRESSURE SWITCH

HIGH PRESSURE SWITCH

T3

T4

OUTDOOR COIL
TEMPERATU RE SENSOR

OUTDOOR
TEMPERAT URE SENSOR

CRANKCASE HE ATER

DIODE MODULE

SV

L

PFC INDUCTOR

TH

HEATSINK
TEMPERAT URE SENSOR

T5

COM PRES SOR DISC HARG E
TEMP ERA TURE SENSOR

MAIN BOARD

FM1,FM2

OUTDOOR DC FAN

EX V

O
UTD

O
OR T

E
M

P . SE

NS
OR

O
UTDO OR C O

LI T EM

P .
SE NS OR

D

12

3

4

5

P5

CN19

CN20

CN24

CN25

CN17

FAN1

CN18

HEAT1

HEAT2

SV

4-WAY
VALVE

BLUE

RED

BLUE

CN4

CN2

CN3

CN1

CO MP

U

V

W

Y/G

CN6

CN9

10

3

CN1

CN2

L

YELLOW

YELLOW

U

V

W

BLUE

BLACK

RED

RED/WIHTE

BLACK

RED

BLACK

CH1

CT1

FM2

FM1

Y/G

Y/G

DC MOT OR
DR IV ER B OA RD

CON1

FAN1

CN1

FAN2

3

3

P6

2

CN6

CN3

Y/G

BLACK

TO INDOOR COMM. BUS

XT 2

YEL LO W

GR AY

S1

S2

NOTE: PLEASE USE 2-CORE
SHIELDED WIRE

L2

L1

MAIN

POWE R SUPPLY

XT1

TO INDOOR UNIT

L1

Y/G

XT2

1L21

L2

1

NL

N

L

P9

P7

P8

CN22

RED

BLUE/BLACK

ORAN GE

ORA NGE

RED

BLACK

CH2

CH2

CH2

~

~

~

C
OMPR E S S

OR D SI CHA R GE

T

E
MP
.

S
ENS O R

HEAT 2

PAN HEATER

Figure 38. 208/230V MPB048S4S-*P Outdoor Unit Wiring Diagram

21

COMP

YELLOW

CODE

COMP

CAP1

EEV

FM1

H-PRO

L-PRO

SV

TS

BLACK

W

RED

V

BLUE

U

DRIVER BOARD

BLACK

RED

BLUE

BLUE

BLUE

YELLOW

L

FAN MOTOR CAPACITOR

ELECTRIC EXPANSION
VALVE

OUTDOOR DC FAN

HIGH PRESSURE SWITCH

L

PFC INDUCTOR
LOW PRESSURE SWITCH

4-WAY VALVE

DISCHARGE
TEMPERATURE SENSOR
CONDENSER

T3

TEMPERATURE SENSOR

T4

OUTDOOR AMBIENT
TEMPERATURE SENSOR

FM1

3

3

CN5 5

CN1 9

W

V
U

RED

CN54

CN51

BLACK

CN53

CN52

PART NAME

COMPRESSOR

Y/G

4-WAY1

SV

HEAT1

Crankcase H eater

HEAT2

Bas e Pan Hea ter

36K ODU

BLUE

BLUE

T3
T4

ONLY FOR

H-PRO

CN3

CN4

CN10

L-PRO

CN22
CN40
CN44

CN8

CN9

BLACK

CN7

RED

EEV

5(6 )

CN33

CN20

MAIN BOARD

CN5

CN6

RED

BLACK

1

2

TO INDOO R UNIT

Y/G

YELLOW

RED

L1

3

S

CN2

CN1

P-1

BLACK

L2

L1

L2

POWER SU PPLY

YELLOW
BLACK

RED

Y/G

Y/G

Figure 39. 208/230V MLA024S4S-*P Outdoor Unit Wiring Diagram

22

Unit Start-Up

Troubleshooting

IMPORTANT

Units should be energized 24 hours before unit start-up
to prevent compressor damage as a result of slugging.

1. Inspect all factory- and eld-installed wiring for loose
connections.

2. Verify that the manifold gauge set is connected.

3. Add additional refrigerant charge if required before
opening valves and while system is still under a
vacuum.

4. Open the liquid and gas line service valves to release
the refrigerant charge contained in outdoor unit into
the system.

5. Replace the stem caps and tighten to the value listed
in “Table 3. Flare Nut Torque Recommendations” on
page 13.

6. Check voltage supply at the outdoor unit terminal strip.
The voltage must be within the range listed on the
unit’s nameplate. If not, do not start the equipment
until you have consulted with the power company and
the voltage condition has been corrected.

7. Refer to the included user guide to operate the system
using the provided remote control.

8. Visually check for binding of both indoor and outdoor
fans.

Table 7. Troubleshooting Codes

Code Description

E0 Indoor unit EEPROM error

E1 Communication error between indoor unit and outdoor unit

E3 Indoor fan speed error

E4 Indoor return air temperature sensor error

E5 Indoor coil temperature sensor error

EC Low refrigerant

EE High water level alarm

F0 Outdoor current overload sensed

F1 Outdoor ambient temperature sensor error

F2 Outdoor coil temperature sensor error

F3 Compressor discharge temperature sensor error

F4 Outdoor unit EEPROM error

F5 Outdoor unit fan speed error

P0 Inverter module IPM error

P1 High or low voltage protection

P3 Outdoor unit low temperature lockout

P4 Compressor drive error

-- Mode conict

P6 Compressor high-pressure or low-pressure switch open

Test Run

Adding Refrigerant for Longer Line Set

The outdoor unit is factory-charged with refrigerant.
Calculate the additional refrigerant required according to
the diameter and the length of the liquid pipe between the
outdoor unit and indoor unit connections.

Be sure to add the proper amount of additional refrigerant.

Failure to do so may result in reduced performance.

Table 6. Additional Refrigerant Charge

System Size

(KBtu)

18 >25 (7.5) 0.161 oz/ft (15g/m)

24 >25 (7.5) 0.322 oz/ft (30g/m)

36 >25 (7.5) 0.322 oz/ft (30g/m)

48 >25 (7.5) 0.322 oz/ft (30g/m)

Pipe Length

(feet / meters)

Amount of Refrigerant

to add

Pre-Checks

Only perform test run after you have completed the

following steps:

• Electrical Safety Checks – Conrm that the unit’s
electrical system is safe and operating properly

• Refrigerant Leak Checks – Check all are nut connec-

tions and conrm that the system is not leaking

• Conrm that liquid and gas valves are fully open

Procedure

You should perform the Test Run for at least 30 minutes.

1. Connect power to the unit.

2. Press the ON/OFF button on the remote controller to
turn it on.

3. Press the mode button to scroll through the following
functions, one at a time:

• COOL - Select lowest possible temperature

• HEAT - Select highest possible temperature

4. Let each function run for 5 minutes, and perform the
following checks:

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Table 8. Test Run Checklist

Checks Pass Fail

No electrical leakage

Unit is properly grounded

All electrical terminals
properly covered

Indoor and outdoor units are
solidly installed

All pipe connection points do
not leak

Water drains properly from
drain hose

All piping is properly
insulated

Unit performs COOL function

properly

Unit performs HEAT function

properly

Indoor unit louvers rotate
properly

Indoor unit responds to
remote controller

Outdoor

(2):

Indoor

(2):

Dry Mode Operation (Dehumidication)

Procedure

1. Use the provided wireless remote control and press
the MODE button and select DRY mode.

2. Press the UP/ DOWN button to select the desired
temperature. The temperature setting range is from
62°F (17°C) to 86°F (30°C) in one degree increments.

NOTE: The blower is preset at a low speed and cannot be

changed therefore it will get cold and most likely
will over shoot the temperature setting by 6-10°F
(3-5°C) depending on the room size or other
various factors. Also the Follow Me mode does
not operate in this mode.

NOTE: In addition, the indoor units do not have a humidistat

installed therefore they are unable to determine
humidity levels. This product is not recommend as

a main source for dehumidication.

Sequence of Operation

When in dry mode operation the unit is actually in cooling
mode with a low speed blower operation. Set remote temp
to a lower room temp to begin the dry mode operation.
The compressor will stop when the room temperature is

4°F (2°C) lower than the temperature setting.
However there is a temperature compensation for cooling

mode that is two degrees Celsius. So the unit will stop
when the temperature is 8°F (4°C) lower than the room

temperature settings.

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