Lennox VOSA036S4, VOSA048S4, VOSA054S4, VOSA072S4 Installation Instruction

©2017 Lennox Industries Inc.

Dallas, Texas, USA

THIS MANUAL MUST BE LEFT WITH THE OWNER
FOR FUTURE REFERENCE

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.

WARNING

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

Installation and service must be performed by a li­censed professional HVAC installer, service agency
or the gas supplier.

Failure to follow safety warnings and these instruc­tions exactly could result in property damage, dan­gerous operation, serious injury, or death.

Any additions, changes, or conversions required in
order for the appliance to satisfactorily meet the ap­plication needs must be made by a licensed profes­sional HVAC installer (or equivalent) using factory­specifi ed parts.

Do not use this system if any part has been under
water. A fl ood-damaged appliance is extremely dan-
gerous. Immediately call a licensed professional
HVAC service technician (or equivalent) to inspect
the system and to replace all controls and electrical
parts that have been wet, or to replace the system, if
deemed necessary.

The State of California has determined that this
product may contain or produce a chemical or
chemicals, in very low doses, which may cause
serious illness or death. It may also cause cancer,
birth defects, or 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.

NOTE - VOSA054 and VOSA072 units have special
wiring and piping considerations, see page 17.

INSTALLATION
INSTRUCTION

VOSA Outdoor Air Units

VRF SYSTEMS -- Indoor Units
507447-01
03/2017

IMPORTANT

The Clean Air Act of 1990 bans the intentional venting
of refrigerant (CFC’s and HCFC’s) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for non-compliance.

General

The VOSA dedicated outdoor air concealed ducted
indoor units are matched with an outdoor heat pump
unit (excluding Mini-VRF) to create a VRF (variable
refrigerant fl ow) system that uses HFC-410A refrigerant.

Refer to the Product Specifi cation bulletin (EHB) for
the proper use of these indoor units with specifi c heat
pumps, heat recovery units, mode switching devices,
branch pipes, line sets and controls.

Shipping and Packing List

Check the components for shipping damage. If you fi nd
any damage, immediately contact the last carrier.

Package 1 of 1 contains the following:

1 - Assembled dedicated outdoor air concealed ducted
unit

Refrigerant piping insulation sleeves

2 - VOSA036 and VOSA048

4 - VOSA054 and VOSA072

1 - Flexible condensate connector (VOSA036-048)

1 - Hose clamp (VOSA036-048)

1 - Condensate connection pipe (VOSA054-072)

1 - Roll tape for condensate pipe (VOSA054-072)

1 - Branch pipe kit (VOSA054-096)

Flare Nuts

1 - VOSA036-048

2 - VOSA054-096

2 - Connector for electronic expansion valves and liquid
lines (VOSA054-072)

1 - Resistor

1 - Installation manual

1

Safety Requirements

!

WARNING

ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.
Do not touch the unit or the controller if your hands are wet.
DO NOT spray water on the indoor unit for any reason.
Do not replace a fuse with a fuse of a different rating. Do not use a jumper wire to replace a fuse. Do not insert
your hands, tools or any other item into the air intake or air outlet at either the indoor or outdoor unit.
Do not allow children to operate the system.

Model Number Identifi cation

V OS A 036 S 4 - 1 P

Brand/Family

V = Variable Refrigerant Flow (VRF)

Unit Type

OS = Dedicated Outdoor Air Concealed Ducted Indoor Models

Major Design Sequence

A = 1st Generation

Nominal Cooling Capacity - Btuh

036 = 36,000 Btuh
048 = 48,000 Btuh
054 = 54,000 Btuh
072 = 72,000 Btuh

System Piping

CAUTION

VRF system piping is customized for each installation.
The LVSS piping report is an engineered design that
must be followed. The piping diagram or diagrams
included within the LVSS report have been prepared
based on the information provided to the Lennox VRF
applications department.

When the indicated lengths change from the fi gures
stated within the report, it is imperative that prior to the
commencement of the refrigerant pipe work installation,
Lennox VRF applications department are informed of
these proposed changes.

Upon receipt of this new information the Lennox VRF
applications department will confi rm any changes that
may be applicable to this installation. If changes are
required, a new piping diagram will be produced and will
supersede all other previously provided documents.

Failure to provide this information regarding changes
to the original design may lead to insuffi cient capacity,
equipment failure, warranty being made void and the
refusal to commission the system.

Voltage

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

Minor Design Sequence

1 = 1st Revision
2 = 2nd Revision
3 = 3rd Revision

Refrigerant Type

4 = R-410A

Cooling Effi ciency

S = Standard Effi ciency

2

Unit Dimensions - Inches (mm)

VOSA036S4, VOSA048S4

13-3/8 (339)

(Duct Opening)

3-1/4

(83)

2-1/2

(65)

HOLES FOR SUSPENDING (4)

25-1/8

(638)

23-5/8

(600)

2 (51)

1-1/4

(38)

42-1/4 (1073)

(Duct Opening)

RETURN AIR VIEW

AIRRETURN

45-1/4 (1149)

RETURN AIR

DUCT FLANGE

1-3/8

(35)

3-1/2

(89)

2-3/4

(70)

3-1/4

(83)

LIQUID

PIPE

5-3/8 (137)

5/8 (16)

10 (253)

GAS
PIPE

DRAIN

CONNECTION

(Either Side)

SUPPLY AIR

DUCT FLANGE

5-3/8
(109)

3-1/4

(83)

AIRSUPPLY

TOP VIEW

51-1/4 (1302)

36-5/8 (930)

1-1/8 (29)

9-7/8 (251)

(Duct Opening)

SUPPL Y AIR VIEW

3

3-1/2

(89)

3/4 (19)

2-1/4 (57)

10-5/8

(270)

16-1/2

(419)

ELECTRICAL

CONTROL

BOX

VOSA036S4, VOSA048S4

13-3/8

(339)

(Return

Air Duct

Opening)

2

(51)

1-5/8 (41)

7-3/8 (187)

GAS
PIPE

BOX

4-7/8 (124)

4-7/8
(124)

27-1/4

(692)

1/2

(11)

9-7/8

(251)
(Supply
Air Duct

Opening)

1-3/8

(35)

AUXILIARY

DRAIN

CONNECTION

(Either Side)

ELECTRICAL

CONTROL

1/2 (11)

LEFT SIDE VIEW RIGHT SIDE VIEW

ELECTRONIC

EXPANSION

VALVE

1-5/8

(41)

7-3/8 (187)

LIQUID

PIPE

16-1/2

(419)

DRAIN

CONNECTION

(Either Side)

4

Unit Dimensions - Inches (mm)

VOSA054S4, VOSA072S4

13-1/2 (343)

(Duct Opening)

3-7/8 (98)

HOLES FOR

SUSPENDING (4)

32

(813)

3

(76)

SUPPLY AIR

DUCT FLANGE

2-3/8 (60)

44-1/8 (1121)

(Duct Opening)

RETURN AIR VIEW

AIRRETURN

50-1/4 (1276)

56-3/4 (1141)

AIRSUPPLY

RETURN AIR

DUCT FLANGE

GAS

PIPES (2)

2-1/4 (57)

2-5/8 (67)

LIQUID

PIPES (2)

TOP VIEW

2 (51)

15 (381)

(Duct Opening)

8 (203)

37 (940)

(Duct Opening)

SUPPL Y AIR VIEW

ELECTRONIC

EXPANSION

VALVES

18-1/2

(470)

ELECTRICAL

CONTROL

BOX

DRAIN

CONNECTION

RIGHT SIDE VIEW

LIQUID

PIPES (2)

GAS

PIPES (2)

4

(102)

5 (127)

1-3/4 (44)

2-3/4

(70)

5

Clearances

Refer to fi gure 1 for minimum clearance requirements.

Wall

Wall

Air

Flow

20” (508 mm) Minimum Service Clearance

24” (610 mm)

24” (610 mm)

Minimum

Service

Clearance

Minimum
Service
Clearance

TOP VIEW

Ceiling

1” (25 mm) Minimum Clearance

1” (25 mm) Minimum Clearance

CeilingSuspended

FRONT VIEW

NOTE - No part of the suspended ceiling, or other supports not directly associated with the indoor unit installation, can
be fi xed to, or touch the indoor unit, in any form. Minimum clearances must be observed at all times.

Figure 1. Minimum Installation Clearances

6

Unit Placement

WARNING

Use the provided and specifi ed components when
installing equipment. Failure to do so may result
in unit falling, water leaking or electrical shocks,
caus ing personal injury or equipment or property
dam age.

Check stability of wall, fl oor, or ceiling and unit
support. If sup port is not capable of carrying
weight of the unit, unit may fall causing personal
injury or equipment damage.

Consider the possibility of earthquakes in your
area when installing the equipment. If the unit is
not correctly secured, it may fall, causing personal
injury or equipment damage.

Safely dispose of packing materials, which include
nails, wood and other sharp objects, as well as
plastic wrapping. Children playing with plastic
wrap or bags risk the danger of suffocation.

CAUTION

Do not place items which may be damaged by water
under or around the indoor unit.

The unit should be installed at least 8 feet above the
fl oor (if possible) to ensure maximum performance
and comfort, when installed in the horizontal
position only.

AVOID

Do not install the unit in the following locations:

• Areas exposed to petrochemicals or petrochemical
products

• Areas exposed to salt or other corrosive materials or
caustic gasses

• 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 (laundry
rooms)

DO:

• Locate 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 suffi cient space around unit for proper operation
and maintenance

• Install unit a minimum of 3 feet 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

7

Installation

It is important to locate the unit where it can be accessed
for service in the future. Refer to unit dimensions on Page
3 for exact locations of suspension brackets, return air
and supply air openings.

1. Make sure that the structural ceiling or slab is able
to support the weight of the indoor unit. It may be
necessary to add extra support.

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 ⅜” threaded rods to
suspend the indoor unit. If the structural ceiling
includes wooden joists, use angle iron or Unistrut
channel fi xed securely in place to accept the ⅜”

threaded rods. NOTE - Threaded rod (requirement

of Lennox warranty program) is the ONLY acceptable
method of suspending the unit; do not use chains or
straps. See fi gure 2.

Ǫ´7+5($'(D

CONCRETE CEILING

USING ANCHORS

$1&+25

ANGLE IRON

BOLTED IN

PLACE ACROSS

WOODEN JOISTS

Ǫ´7+5($'(D

ROD

ANGLE IRON

WOODEN JOISTS

WOODEN JOIST

Figure 2. Suspending Methods

3. Slide one nut and one washer onto each threaded rod.
Use electrical tape to keep the washer from failing off.
Position the nuts slightly above the fi nal resting place
of the four suspension brackets. See fi gure 3.

Ǫ” THREADED

ROD

INDOOR UNIT

SUPPLY AIR

OPENING

LEVELING

FRONT VIEW

NUT

Figure 3. Suspension Hardware

ROD

ACROSS

When unit is
level, tighten

nut to secure

position of

suspension

bracket on

SUSPENSION

BRACKET

rod.

Ǫ” THREADED

ROD

FIELD-PROVIDED

ISOLATION GROMMET

WASHER

LEVELING

NUT

SUSPENSION

BRACKET

Figure 4. Isolation Grommet

4. Use either a mechanical lifting device or a minimum
of two people to raise the unit and insert the threaded
rods into the suspension brackets on the cassette
base. Slide a washer and then a nut onto each rod
below each suspension bracket. Use the leveling nut
(beneath suspension bracket) 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.

5. If necessary, install a fi eld-provided isolation grommet
as shown in fi gure 4 to prevent transmission of
vibration from unit to structural ceiling.

6. If the unit is being installed in an application that includes
a sheet rock (plasterboard) ceiling, it is required that
an access panel be installed in a suitable location.
This will also allow access for future maintenance
(requirement of Lennox warranty program).
Access is required during the commissioning process
to test the condensate disposal system (See fi gures
10, 11 and 12), to check the electronic expansion
valve and associated fl are nuts (See fi gure 5), and to
check the local disconnect.

7. The unit is factory-confi gured for the supply air to be
delivered from the front and the return air fi lter at the
rear of the unit.

INSTALLATION GUIDELINES

• Install a fi eld-provided isolation grommet as shown in
fi gure 4 to prevent transmission of vibration from unit

to structural ceiling.

• Provide separate support for the weight of the duct
system. Duct system must not be supported by the
indoor unit.

• Use fl exible joints (canvas) at the point where the duct
connects to the unit on both ends. Material must meet
all local and national code requirements.

• When unit is being installed in a location where even
the slightest noise would be a problem (meeting room
or other very quiet space), design duct system to
avoid transmission of vibration to the structure to the
extent possible.

8

Refrigerant Piping Connections

WARNING

Refrigerant leaks are unlikely; however, if a
refrigerant leak occurs, open a door or windows to
dilute the refrigerant in the room. Turn off the unit
and all other appliances that may cause a spark.
Call a licensed professional HVAC technician (or
equivalent) to repair the leak.

Use only R410A refrigerant to charge this system.
Use of other refrigerant or gas will damage the
equipment.

Do not allow air or other contaminants to enter
system during installation of refrigerant piping.
Contaminants will result in lower system capacity
and abnormally high operating pressures and may
result in system failure or explosion.

Insulate all refrigerant piping.
Refrigerant pipes may be very hot during unit

operation. Do not allow contact between wiring and
bare copper pipes.

After refrigerant piping connections have been
completed, check the system for leaks per
commissioning instructions.

NOTE - See page 21 for additional piping instructions for
VOSA054 and 072 units.

Field piping consists of two copper lines connected to the
indoor unit. Table 1 lists the connection sizes at the indoor
unit. The connections are made using the provided brass
fl are nuts at the end of the refrigerant piping connections.

Both lines must be individually insulated.

NOTE - Always slide a fl are nut onto the fi eld-provided

refrigerant piping before fl aring the lines.

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. Slowly loosen one of the fl are nuts to release the
factory nitrogen charge.

3. Remove the fl are nuts and discard the seal from each
of the piping connections.

4. Slide the fl are nuts onto the ends of the fi eld-provided
refrigerant piping before using a suitable fl aring tool to
fl are the end of the copper pipe.

IMPORTANT

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

5. Apply recommended HFC-410A refrigerant lubricant
to the outside of the fi eld-provided fl ared line sets
(fi gure 5 -- A).

6. Align the union tube and fl ared refrigerant lines with
each other, then tighten the fl are nuts lightly at fi rst to
obtain a smooth match (fi gure 5 -- B).

Table 1. Refrigerant Piping Connections

System Size

(Btuh)

36000

48000

54000

72000

A

Liquid Line Vapor Line

3/8” 5/8”

3/8” (2) 5/8” (2)

CANT ON THE OUTSIDE OF

THE FLARE

MALE FLARE

CONNECTION

B

Figure 5. Making Connections at Indoor Unit

(Male to Female Connection)

7. Once snug, continue another half-turn on each nut
which should create a leak-free joint. A torque wrench
may be used to tighten fl are nuts using Table 2
recommendations. See fi gure 6. Do not over-tighten
a fl ared joint.

IMPORTANT

Always use two wrenches when tightening fl are
nuts to avoid twisting refrigerant piping. DO
NOT over-tighten fl are nuts.

TORQUE WRENCH

TO INDOOR

UNIT

TO OUTDOOR UNIT

Figure 6. Tighten Flare Nut

BACKUP

WRENCH

9

8. Flared connections should always be accessible and
must be insulated to prevent condensation. See fi gure

7.

Table 2. Flare Nut Torque Recommendations

Outside

Diameter

Inches U.S.

3/8” 26 ft.-lb. 1/2 turn

5/8” 48 ft.-lb. 1 full turn

UNIT
BASE

Recommended

Torque

INSULATE ALL FLARED CONNECTIONS

TO PREVENT CONDENSATION

No torque wrench

available

Finger tighten and

use an appropriately

sized wrench to turn an

additional:

Incoming
liquid line
connection

Incoming
suction line
connection

Connect
these two
pipes

Connect
these two
pipes

Figure 7. Insulate Flared Connections

9. Locate the pre-formed copper connector pipes
provided in the bag assembly (VOSA054-072 only).
These pipes are used to connect the unit piping to the
electronic expansion valves. Remove the plastic seal
from each end of the pipe. See fi gure 8.

10. Apply a small amount of recommended HFC-410A
refrigerant lubricant to the outside of the fl ared ends
of the connector.

11. Immediately align the connector pipe with the identifi ed
piping in fi gures 8 & 9. Hand-tighten the fl are nuts at
fi rst. Then, use two wrenches to continue to tighten
the nuts without twisting the pipes. See fi gure 6.

Torque requirements are given in table 2. Again, do

not over-tighten the fl ared joints.

12. After refrigerant piping has been installed and
checked for leaks, apply insulation over the connector
pipes and all fl ared connections.

Incoming
suction line
connection

Incoming
liquid line
connection

Figure 8. VOSA054/072 Refrigerant Connections

Incoming
suction line
connection

Incoming
liquid line
connection

Figure 9. VOSA036/048 Refrigerant Connections

10

Condensate Piping Connections

CAUTION

Make sure that drain piping is properly routed and
insulated in order to prevent both leaks and condensation.
Follow these instructions exactly to ensure proper
drainage and unit operation.

1. Use the provided hose clamp to secure the
provided fl exible condensate drain connector
and insulating sleeve to the drain line stub
on the side of the indoor unit. See fi gure 10.

NOTE - T ake care not to over -tighten the hose clamps
this may damage the drain line stub.

024 shown

CONTROL

BOX

3. See fi gure 11 for applications including a single unit
and a single drain. In this case, ensure that the drain
line is properly sloped (no less than 1/4 inch per foot)
and condensate lines are routed to ensure moisture is
drained away from the indoor unit.

Structural Ceiling

Suspension Rods

Indoor Unit

Do not operate unit without condensate drain trap.

NOTE - Drain line should be sloped 1/4 inch per foot (18 mm per m)
AWAY from unit and should be supported as needed to prevent sagging.

Do not overtighten drain fitting.

Anti-siphon vent must extend above the
height of the coil drain pan by 2” (51 mm).

1 ft.

(305 mm) max

Clean Out
Do not glue

3”

3”

3 ft.

(1 m)

Support

straps

Drain line

Figure 11. Sloped Condensate Drain -- Single Unit

AUXILIARY

DRAIN

CONNECTION

(Either Side)

INDOOR

CONDENSATE

LINE STUB

UNIT

(Bottom of Unit)

FLEXIBLE DRAIN

CONNECTOR

HOSE CLAMP

PRIMARY

DRAIN

CONNECTION

(Either Side)

PVC DRAIN

PIPE

INSULATION

Figure 10. Condensate Drain Connection

IMPORTANT

You must confi rm operation of every drain and pump in
the system as part of the commissioning procedure.

2. Make a water-tight connection between the fi eld-
provided condensate drain line and the fl exible
condensate connector (VOSA036-048 5/8” I.D.,
VOSA054-072 1” I.D.).

Install an anti-siphon vent for each trap - must extend above
the height of the coil drain pan by 2” (51 mm).

IMPORTANT

Drain should have a slope of at least 1/4 inch per foot
and should be approved corrosion-resistant pipe.

4. See fi gure 12 for applications including multiple units
and a single drain. In this case, ensure that the drain
line is properly sloped (no less than 1/4 inch per foot)
and condensate lines are routed to ensure moisture
is drained away from the indoor unit.

5. In all cases, drain should be as short as possible and
should not have any droops or kinks that would restrict
condensate fl ow and shall be constructed using an

approved pipe. All drains should contain traps. There

must be a 2-inch space between the end of the
condensate drain and the fi nal termination point
(ground, open drain, etc.) to ensure that the line
will drain freely.

6. After system installation is complete, the
condensate drain line must be checked for leaks
and if a condensate pump has been fi tted, it must
be checked to ensure proper operation. This
check is part of the commissioning procedure.

Suspension

Rods

Indoor Unit tinU roodnItinU roodnI

Install a trap for each indoor unit.

Do not operate unit without condensate drain trap.

Do not overtighten drain fitting.

Clean Out
Do not glue

3”

3”

Figure 12. Using a Main Drain to Serve Multiple Indoor Units with Gravity Drains

1 ft.

Clean Out
Do not glue

Vent

3”

3”

NOTE - Drain line should be sloped 1/4 inch per foot (18 mm per m)
AWAY from unit and should be supported as needed to prevent sagging.

(305 mm) max

Clean Out
Do not glue

Vent

3”

3”

11

3 ft.

(1 m)

Support

straps

Wiring Connections

WARNING

Isolate the power supply before accessing unit electrical
terminals.

Install unit so that unit disconnect is accessible.

Follow all local and national codes, as well as this
installation instruction, during installation. Do NOT
overload electrical circuit, as this may lead to failure and
possible fi re.

Use specifi 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 fi re.

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

CAUTION

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.

Install all wiring at least 3 feet away from televisions,
radios or other electronic devices in order to avoid the
possibility of interference with the unit operation.

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

CAUTION

A disconnection device having an air gap contact
separation in all active conductors should be
incorporated in the fi xed wiring according to the National
Wiring Regulation.

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).

Refer to unit nameplate for minimum circuit ampacity and
maximum overcurrent protection size.

NOTE - Three-conductor stranded shielded cable must be
used for the communication wiring. This is necessary to
ensure proper system communication and operation.

NOTE - See page 27 for wiring and piping instructions for
VOSA054 and 072 units.

• A circuit breaker capable of shutting down the power
supply to the entire system must be installed.

• A single switch can be used to supply power to units
on the same system. However, branch switches and
circuit breakers must be selected carefully.

• Fit the power supply wiring of each unit with a switch
and fuse as shown in the wiring diagram.

• Install a wiring interrupter or ground-fault circuit
interrupter for the power wiring.

• Make sure the ground resistance is no greater than
100Ω. This value can be as high as 500Ω when using
a grounding fault circuit interrupter since the protective
ground resistance can be applied.

1. Remove the screws that secure the control box cover.
Remove the cover and place it to the side where it will
not be damaged.

2. Locate the terminal strip in the control box. Connect
the power wiring (sized per NEC/CEC and local codes)
and communications cable (three-core, shielded
cable). Refer to unit nameplate for rated voltage.

3. If the indoor unit is the fi nal unit in a group that is wired
in series, install the provided resistor across terminals
P and Q.

4. The infra-red receiver / display panel is factory installed
and can be repositioned, if necessary. Use optional
extension cable kit V0CTRL93P-1 (cat # 14R84).

12

Tightening torque for the terminal screws

• Use the correct screwdriver for fi ghting the terminal
screws. If the screwdriver blade is too small, the head
of the screw might be damaged, and the screw will not
be properly tightened.

• If the terminal screws are over tightened, screws
might be damaged.

• Refer to the table below for the tightening torque of
the terminal screws.

IMPORTANT

DO NOT adjust DIP switch settings. Settings may only
be adjusted by a trained technician as part of the com­missioning procedures.

Table 3. Terminal Screw Tightening Torque

Tightening torque (lb-ft)

Terminal base of
remote controller/Signal
transmission wire (X2M)

Terminal base of power
supply (X1M)

Grounding terminal (M4) 1.06-1.43

• After wiring, confi rm all connections are correct; Then
turn on power supply to the unit.

0.58-0.72

0.87-1.06

Power DistribuƟon Box

Legend

PQE CommunicaƟon wiring

L1/L2 Single-Phase power wiring

Electrical disconnect switch

L1/L2

L1/L2

L1/L2

L1/L2

L1/L2

L1/L2

PQE

PQE

PQE

PQE

PQE

PQE

PQE

PQE

PQE

PQE

L1/L2

L1/L2

L1/L2

L1/L2

L1/L2

L1/L2

PQE

L1/L2

L1/L2

L1/L2

Figure 13. Typical Power Wiring Diagram (VRF Heat Pump System Shown)

13

PQE

L1/L2

PQE

L1/L2

PQE

L1/L2

PQE

Outdoor unit

(main unit)

Outdoor unit

(sub1 unit)

Outdoor unit

(sub2 unit)

(PQE)

(H1 H2 E) (H1 H2 E)

Ground cable shield

(H1 H2 E)

DO NOT connect to E

(PQE)

P Q

Install a terminating resistor at the last indoor unit terminals P and Q of the daisy
chain.

All shields of shielded cable connect to GROUND terminal,

not to terminal E.

18 GA., stranded, 3-conductor, shielded control wire (polarity sensitive).

Typical Wiring Diagram, NEC/CEC and Local Codes apply.

Figure 14. Typical Communication Wiring Diagram (VRF Heat Pump System Shown)

14

KEY

FM

EEV

TA
T0

T2B

T2
XP1-7
XS1-7

C

TR
PUMP

CS

XT1-2

GM

COMPONENT

INDOOR FAN
ELECTRONIC

EXPANSIONVALVE
OUTLETAIRTEMP.

INLETAIR TEMP.

EVAPOUTLETTEMP

IN COOLING MODE

COIL TEMP.

PLUG
JACK

FAN CAPACITOR

TRANSFORMER
PUMP MOTOR

WATER

LEVEL SWITCH

TERMINAL BLOCK

SWING MOTOR

;6

&1

;3

',63/$< %2$5'

;3

&1δ<(//2:ε

32:(5B6

21

-

6:

&1

(1&

&1

&1

&1

&1

&1

;6

:,5('
&21752//(5

&21752/ ,17(5)$&(
02'8/(

;6

;3

:((./< 7,0(5
:,5(' &21752//(5

ALARM

&1

TA

BLACK

&1

21

6:

21

6:

&1

&1δ:+,7(ε

21

6:

75



&1

&1

;6

5('

%/8(

&1

&1

0$,1 &21752/ %2$5'

5<

5<

5<

3

3

&1

<*

*5281'

5('

:+,7(

&

:+,7(*5$<

)0

<(//2:*5((1

*5281'

:+,7(

7

%/$&.

7

φ

127(
&20321(17 ,1 '$6+
/,1( ,6 237,21$/
25 ),(/' :,5,1*

;7

/

,1'225 32:(5

L2

   

z

No addres s g ive n on
initial uni t start -u p

z Mode conflict

z Communication error

between indoor and
outdoor unit

Timer and R un LEDs
flashing simultaneously,
or "FE" displayed

Def rost LEDflas hing,

or "E0" d isplayed

Timer LE D flashin g
or "E1" displayed

z Temp se nsor (T1) erro r

z Temp sens or T2 error˄˅

z Temp sens or T2B error˄˅

Run LED flashingor 2"

displaye d

RunLEDflashingor 3"

displayed

RunLED flashing or "E4"

disp l ayed

"E

"E

Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.

Figure 15. VOSA036S4-1 and VOSA048S4-1 Typical Wiring Diagram

7%

z Eeprom error

z Outdoor unit error

z Water level alarm

((9

;7

&211(&7 72
:,5(' &21752//(5

127(  5()(5 72 0$18$/ )25

Defrost L ED flashing
slowly or "E7" displayed

AlarmLED flashing
slowlyor "Ed" displayed

Alarm LED flashing or

E" displayed"E

(E)

P Q (E)XY

&211(&7 72
287'225 81,7

&20081,&$7,21 :,5,1*

 3/($6( 86( 7+(

&21'8&725
6+,(/'(' &$%/(

15

75%

φ

127(
&20321(17 ,1 '$6+
/,1( ,6 237,21$/
25 ),(/' :,5,1*

KEY

COMPONENT

FM1(FM2)

TA(A),TA(B)
T0(A),T0(B)

T2B(A),T2B(B)

T2(A),T2(B)

XP0-9
XS0-9

TR(A),TR(B)

XT1-3

RL1-3

CAP1(CAP2)

290-0G2

EEV

INDOORFAN
ELECTRONIC

EXPANSIONVALVE
OUTLETAIR TEMP.

INLETAIRTEMP.

EVAPOUTLET TEMP

IN COOLING MODE

COIL TEMP.

PLUG
JACK

TRANSFORMER

TERMINAL BLOCK

RELAY

FAN CAPACITOR

NOISE FILTER

:+,7(

&1

7%

&1

%/$&.

7%

TA (B)

&1



&1

21

21

6:

6:

COMM.BUS

BLACK

&1

21

6:

0$,1 &21752/ %2$5'%

% 6<67(0

&1 &1

((9

7%%

;7

&211(&7 72
:,5(' &21752//(5

127(  5()(5 72 0$18$/ )25

TO CCM

&1

&1

32:(5B6

21

-

6:

(1&

&1

XY PQ

&20081,&$7,21 :,5,1*

 3/($6( 86( 7+(

&21'8&725
6+,(/'(' &$%/(

E

&211(&7 72
287'225 81,7

&1 

',63/$< %2$5'

;6

TA(A)

75$

&1

&1

&1



&1

&1

0$,1 &21752/ %2$5'$

BLACK

21

6: 6:

TO CCM

COMM. BUS

&1 &1

&1

21

21

6:

;3

&1 

-

&21752/ ,17(5)$&( 02'8/ (

32 :(5 B6

21

6:

(1&

$ 6<67(0

&1 

&1

&1

:+,7(

((9

7%$7$

XY PQ

&20081,&$7,21 :,5,1*

 3/($6( 86( 7+(

&21'8&725
6+,(/'(' &$%/(

;7

L2

/

72 ,1'225 32:(5

BLUE

&1

5/

5('

<*

GROUND

&20

5('
5('
5('

*

7 

5<5<5<

5/

5/

&20

&20

0(',80+,*+

/2:

<* <*< *

&1

BLACK

:+,7(

7$

;7

&211(&7 72
:,5(' &21752//(5

127(  5()(5 72 0$18$/ )25

&1

E

&211(&7 72
287'225 81,7

:,5(' &21752/ /(5

z

No addr ess gi v e n on
initial uni t sta rt -up

z Mode conflict

z Commun ication error

between indoorand
outdoor unit

Timer andRunLEDs
flashingsimultaneously,
or "FE" displayed

Defros t LED flas hing,

or "E0"displayed

Timer LED flashing
or "E1" displayed

z Temp sensor (T1 ) erro r

z Temp sensor T2 error˄˅

z Temp sensor T2B error˄˅

Run LED flashingor 2"

display ed

RunLEDflashingor 3"

displ a yed

RunLED flashing or "E4"

displayed

"E

"E

Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.

Figure 16. VOSA054S4-1 and VOSA072S4-1 Typical Wiring Diagram

z Eepr om error

z Outdoor u ni t error

z Water level alarm

Defros t L ED flashing
slowly or "E7" displaye d

AlarmLED flashing
slowly or "Ed" displayed

Alarm LED flashingor

E"displayed"E

16

VOSA054 and 072 Piping and Wiring Connections

VOSA054 and 072 units have two control boards in the
control box and have two gas pipes, two liquid pipes, two
branch pipes and two electronic expansion valves (EXV).

The additional boards and piping connections require
special considerations when connecting the piping and
communication wiring.

LED Display

Control box

Refrigerant piping

(two sets)

Condensate pipe

EXV B

EXV A

Control board B

Control board A

Terminal block

Inside of Control Box

Figure 28. VOSA054 and 072 Unit Identifi cation

17

Communication (PQE) Wiring

NOTE - Control board A is the bottom control board and
Control board B is the top control board in the electronic
control box.

Control Board B - Top

Control Board A - Bottom

Terminal Block A

PQE

Terminal Block B

PQE

Figure 30. VOSA054 and 072 Terminal Block

Figure 29. VOSA054 and 072 Main Control Boards

18

Connect the incoming PQE wiring to the terminal block for
Control board A.

If this is the last indoor unit in the system, no additional
PQE wiring is needed.

Add a resistor between P and Q on Control board B.

IDU Control Box

Main Control Board

Connecting V0STAT51

Connect the V0STAT51 cable to the cable attached to
Control board A.

IDU Control Box

Main Control Board

B

B

Main Control Board

A

Terminal set A Terminal set B

X Y E P Q

Wiring in

Figure 31. VOSA054 and 072 Connect Communication

Wires to Single Indoor Unit

If there are additional indoor units, the outgoing wiring is
connected to the terminal block for Control board B.

X Y E P Q

IDU Control Box

Main Control Board

CN10

A

Terminal set A Terminal set B

X Y E P Q

Plug in

V0STAT51
Controller

Figure 33. VOSA054 and 072 Connect to Single Indoor

To control more than one VHIA072 or 096 unit from the
same controller,

1. Connect the V0STAT51-1P cable to Control board A.

2. Connect Control board B XYE to the next indoor unit
to be controlled by the controller

IDU Control Box

X Y E P Q

Unit

Main Control Board

B

Main Control Board

A

Terminal set A Terminal set B

X Y E P Q

Wiring in Wiring out

Figure 32. VOSA054 and 072 Connect Communication

Wires to Additional Indoor Units

X Y E P Q

Main Control Board

B

Main Control Board

CN10

A

Terminal set A Terminal set B

X Y E P Q

Plug in

V0STAT51

Controller

Figure 34. VOSA054 and 072 Connect to Additional

Indoor Units

X Y E P Q

Wiring out

19

Refrigerant Piping

• Use the provided branch pipe kit to connect both sets
of refrigerant line connections.

• Locate branch pipes no more than 32 feet from indoor
unit.

See piping report

for pipe sizes

Liquid branch pipe

(Provided with VOSA unit)

3/8”

• Piping between branch pipe and indoor unit: liquid line
= 3/8” and gas line = 5/8“.

• Consult LVSS piping report diagram for all other piping
sizes.

VOSA054/072

Liquid pipe Gas pipe

Gas branch pipe
(Provided with VOSA unit)

32’ maximum distance

between branch pipes and indoor unit

Figure 35. Piping for VOSA054 and 072

Incoming
liquid line
connection

Incoming
suction line
connection

Connect
these two
pipes

5/8”

Connect
these two
pipes

Figure 37. VOSA054 and 072 Refrigerant Connections

Incoming
suction line
connection

Incoming
liquid line
connection

20