Lennox VRF VMDB Series User manual

1
INSTALLATION
INSTRUCTION
VRF SYSTEMS -- Indoor Units
507893-03
09/2019
Shipping and Packing List
General
The VMDB medium-static ducted indoor units are matched
with an outdoor heat recovery or heat pump unit to create
a VRF (variable refrigerant ow) system that uses R-410A
refrigerant. VMDB indoor units are designed for indoor
installation only.
Refer to the Product Specication bulletin (EHB) for the
proper use of these indoor units with specic heat pumps,
heat recovery units, mode switching devices, branch
pipes, line sets and controls.
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.
VMDB Medium-Static Units
Check the components for shipping damage. If you nd
any damage, immediately contact the last carrier.
Package 1 of 1 contains the following:
1 - Assembled medium static, ducted unit
2 - Condensate drain insulation sleeves
1 - Flexible condensate connector
1 - Hose clamp
2 - Pipe reducers (VMD007, 009, 012 & 015)
1 - Resistor
1 - Cable
1 - Installation manual
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, ser vice 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, dan gerous
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 profes sional HVAC
installer (or equivalent) using factory-specied parts.
Do not use this system if any part has been under water.
A 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.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting
of refrigerant (CFCs, HCFCs and HFCs) as of July 1,
1992. Approved methods of recovery, recycling or
reclaiming must be followed. Fines and/or incarceration
may be levied for noncompliance. These units must be
installed as a part of a matched system as specied in
the Product Specications (EHB) bulletin.
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.
To ensure proper system performance and reliability,
Lennox does not recommend operation of VRF systems
during any phase of construction. Construction debris,
low temperatures, harmful vapors, and operation of the
unit with misplaced lters can damage the units. Failure
to follow these guidelines will result in the warranty
being voided.
VRF
©2019 Lennox Industries Inc. Dallas, Texas, USA

2
Model Number Identication
System Piping
V MD B 015 H 4 - 3 P
Brand/Family
V = Variable Refrigerant Flow (VRF)
Unit Type
MD = Concealed Medium Static Ducted Indoor Models
Major Design Sequence
B = 2nd Generation
Cooling E󰀩ciency
H = High E󰀩ciency
Refrigerant Type
4 = R-410A
Controls Protocol
3 = Phase 3
Voltage
P = 208/230V-1 phase-60hz
Nominal Cooling Capacity - Btuh
024 = 24,000 Btuh
030 = 30,000 Btuh
036 = 36,000 Btuh
048 = 48,000 Btuh
007 = 7,000 Btuh
009 = 8,500 Btuh
012 = 12,000 Btuh
015 = 15,000 Btuh
018 = 18,000 Btuh
NOTE - Only Lennox VRF indoor units will work with Lennox VRF outdoor units and associated mechanical
equipment. Lennox Mini Split indoor units are similar in appearance but must not be connected to a Lennox VRF
refrigerant circuit. Please refer to model numbers to conrm compatibility. Model numbers for Lennox VRF units
start with a “V” and model numbers for Lennox Mini-Splits start with a “M”.
Safety Requirements
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 di󰀨erent 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.
WARNING
CAUTION
VRF system piping is customized for each installation.
The LVSS (Lennox VRF Selection Software) 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 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 con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 insu󰀩cient capacity,
equipment failure, warranty being made void and the
refusal to commission the system.

3
VMDB007-009 Unit Dimensions
17-3/4 (451)
20-3/4 (527)
SUSPENSION BRACKETS(4)
SUSPENSION
BRACKETS (4)
FRESH AIR
INTAKE 3-5/8 (92)
Diameter
ELECTRICAL
CONTROL BOX
AIR FILTER
TOP VIEW
REAR VIEW
BOTTOM VIEW*
LEFT SIDE VIEW RIGHT SIDE VIEW
3-1/2
(89)
4
(102)
5-1/2
(140)
4-1/8
(105)
1 (25)
2 (51)
6-5/8
(168)
19-1/8 (486)
19-7/8 (505)
1
(25)
1/2 (13) 2-3/4
(70)
3/4
(19)
1-3/4
(44)
SUPPLY AIR SIDE
RETURN AIR SIDE
FRONT OF UNIT
REAR OF UNIT
SECTION A-A
SECTION D-D
SECTION B-B
SECTION C-C
SECTION B-BSECTION C-C
SECTION A-A
SECTION D-D
TOP OF UNIT
*NOTE - Unit
orientation reversed to
show alternative
filter location and
return air path on
bottom of unit.
AIR FLOW AIR FLOW
CONDENSATE LIFT PUMP
39-3/8 (1000)
36-1/4 (921)
28-7/8 (733)
1-3/4
(45)
5-3/4
(146) 8-1/4
(210)
5/8 (16)
SUPPLY AIR OPENING
FRONT VIEW
TOP OF UNIT
13-3/4 (349) 13-3/4
(359)
37-3/4 (959)
1-3/8 (35)
3/4(19) 3/4(19)
1-3/8 (35)
AIR FLOW
OPENING
RETURN AIR
32-1/4 (819)
LIQUID
PIPE
GAS
PIPE
DRAIN
CONNECTION AIR FILTER
OPTIONAL BOTTOM
RETURN AIR
OPENING
AIR FLOW

4
VMDB012-048 Unit Dimensions
PP
N3/4 (19)
3/4 (19)
1 (25) 1 (25)
E
A
G
F
B
K
L
J
H
D
C
M
SUSPENSION
BRACKETS (4)
ELECTRICAL
CONTROL
BOX
AIR FILTER
TOP VIEW
Q
R
SU
1-7/8
(29)
V
W
X
Y
SUPPLY AIR OPENING
FRONT VIEW
REAR VIEW
BOTTOM VIEW*
LEFT SIDE VIEW RIGHT SIDE VIEW
SUPPLY AIR SIDE
RETURN AIR SIDE
FRONT OF UNIT
REAR OF UNIT
*NOTE - Unit
orientation reversed to
show alternative
filter location and
return air path on
bottom of unit.
SECTION A-A
SECTION D-D
SECTION B-B
SECTION C-C
SECTION B-B
SECTION C-C
SECTION A-A
SECTION D-D
TOP OF UNIT
ELECTRICAL
CONTROL BOX
AIR FILTER
OPTIONAL BOTTOM
RETURN AIR
OPENING
TOP OF UNIT
SUSPENSION
BRACKETS (4)
FRESH AIR INTAKE
VMDB012 - 3-5/8 (92) Diameter
VMDB015-048 - 5 (127) Diameter
LIQUID PIPE
GAS PIPE
DRAIN
CONNECTION
RETURN AIR
OPENING
AIR FLOW
AIR FLOW AIR FLOW
AIR FLOW
1/2 (13)
1
(25)
1-3/4 (44)
1-7/8
(48)
CONDENSATE LIFT PUMP
Size A B C D E F G H J
in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm
012 36-1/4 921 10-5/8 270 25-3/8 645 22-1/2 572 39-3/4 1010 2-5/8 67 28 711 1-3/8 35 7 178
015/018/024 44-7/8 1140 10-5/8 270 30-1/2 775 28 711 48-1/2 1232 2-5/8 67 36-3/4 933 1-3/8 35 7 178
030/036/048 47-1/4 1200 11-7/8 302 34-1/8 867 31-1/2 800 50-3/4 1289 3-1/8 79 38-1/8 968 1-1/2 38 8 203
Size K L M N P Q R S T U
in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm
012 32 813 10-1/4 260 - - - - - - 37-3/4 961 13-3/4 349 3-7/8 99 4-5/8 117 6 152 5-5/8 143 8-1/8 206
015/018/024 40-3/4 1035 10-1/4 260 3/4 18 46-3/4 1188 19-1/4 490 3-7/8 99 4-5/8 117 6 152 5-1/2 140 11-3/8 289
030/036/048 43 1092 11-3/8 289 2 48 49 1246 19-3/4 502 6-3/8 162 6-7/8 175 8-3/8 213 7-5/8 194 9-3/4 248
Size V W X Y
in. mm in. mm in. mm in. mm
012 1-7/8 48 6-3/4 171 24-1/8 613 25-1/8 638
015/018/024 4-1/4 108 6-3/4 171 29-3/8 746 30-1/4 768
030/036/048 7-1/4 184 6-3/4 171 33-1/8 841 34 864

5
Clearances
Refer to Figure 1 for minimum clearance requirements.
Figure 1. Minimum Installation Clearances
NOTE - No part of the suspended ceiling, or other supports not directly associated with the indoor unit installation,
can be xed to, or touch the indoor unit, in any form. Minimum clearances must be observed at all times.
NOTE - Horizontal installation only.
20” (508 mm) Minimum Service Clearance
24” (610 mm)
Air
Flow
24” (610 mm)
Minimum
Service
Clearance
TOP VIEW
DUCTED
UNIT
FRONT VIEW
24” (610 mm) Minimum Clearance
Ceiling
Wall
Wall
1” (25 mm) Minimum Clearance
CeilingSuspended
Minimum
Service
Clearance
To ensure full fan deck removal a minimum
distance of 24” (610 mm) should be
between the unit and ceiling or closest
obstruction.

6
Unit Placement
In addition to clearances, the following items should be
considered:
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 su󰀩cient space around unit for proper operation
and maintenance
• Install unit a minimum of 3 feet (1 meter) away from
any antenna, power cord (line) radio, telephone,
security system, or intercom. Electrical interference
and radio frequencies from any of these sources may
a󰀨ect 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 equipment.
Unit Installation
Unit Installation Guidelines
• Install a eld-provided isolation grommet as shown in
Figure 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.
• It is recommended that you use 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.
• For Ducted return systems, a minimum surface area
of 200 sq. in. per ton is recommended.
Example: 3 Ton IDU.
3 tons x 200 sq. in. per ton = 600 sq. in.
Remove tape
from Receiver
(rear of electrical
control box) prior to
commissioning
WARNING
Use the provided and speci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 suitability of structure to which the unit support
mechanism will be xed to. If structure is not capable
of carrying the 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 su󰀨ocation.
CAUTION
Do not place items which may be damaged by water
under or around the unit.
The unit should be installed at least 8 feet above the
oor (if possible) to ensure maximum performance and
comfort.

7
Unit Installation Instructions
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 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 Figure 2.
3. Slide one nut and one washer onto each threaded rod.
Use electrical tape to keep the washer from failing o󰀨.
Position the nuts slightly above the nal resting place
of the four suspension brackets. See Figure 3.
Figure 2. Suspending Methods
ANGLE IRON
BOLTED IN
PLACE ACROSS
WOODEN JOISTS
WOODEN JOIST
⅜” THREADED
ROD
ANGLE IRON
ACROSS
WOODEN JOISTS
ANCHOR
CONCRETE CEILING
USING ANCHORS
⅜” THREADED
ROD
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. It is recommended to install a eld-provided isolation
grommet as shown in Figure 4 to prevent transmission
of vibration from unit to structural ceiling.
INDOOR UNIT
LEVELING
NUT
⅜”THREADED
ROD
SUSPENSION
BRACKET
SUPPLY AIR
OPENING
FRONT VIEW
When unit is
level, tighten
nut to secure
position of
suspension
bracket on
rod.
Figure 3. Suspension Hardware
Figure 4. Isolation Grommet
LEVELING
NUT
⅜”THREADED
ROD
SUSPENSION
BRACKET
FIELD-PROVIDED
ISOLATION GROMMET
WASHER
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 Figure
20) and to check the local disconnect.
7. The unit is factory-congured for the supply air to be
delivered from the front and the return air lter at the
rear of the unit. The return air lter location can be
relocated in the eld for bottom return air lter access,
if more convenient. See Figure 10.

8
Return Air Filter
Foldable Return Air Filter
The factory-supplied return air lter is hinged to allow it
to be folded if needed to remove it from the unit in tight
spaces. See Table 1 for lter dimensions.
Figure 5. Foldable Factory-Supplied Return Air Filter
Remove Return Air Filter Instructions
1. If removing the lter from the left side (facing the rear
of the unit), remove the factory-installed receiver
from the electrical control box panel by sliding the re-
ceiver up until the two plastic mounting brackets on
the back of the receiver slide out of the slots on the
back of the control box. This step is not necessary if
removing the lter from the right side (facing the rear
of the unit).
2. Loosen the screw that secures the lter retaining
bracket and slide the bracket away from the unit.
3. Grasp the lter removal tab and slide the lter out.
Figure 7. Loosen Filter Retaining Bracket
Filter
removal
tab
Figure 8. Slide Out Filter
Filter removal tab
4. Reverse these steps to reinstall the lter. Be sure
to reinstall the receiver if it was detached during the
lter removal.
Figure 9. Filter Partially Removed
Hinges
Figure 6. Remove Receiver
Receiver Lift up to
remove
receiver.
Indoor Unit Model Filter Dimensions Each Section of Filter Dimensions
VMDB007,009 32 x 7-1/2 x 3/8 in.
813 x 192 x 10 mm
8-1/2 x 7-1/2 x 3/8 in.
217 x 192 x 10 mm
VMDB012 32 x 10 x 3/8 in.
813 x 252 x 10 mm
8-1/2 x 7-1/2 x 3/8 in.
217 x 252 x 10 mm
VMDB015,018,024 40-3/4 x 10 x 3/8 in.
1035 x 252 x 10 mm
13-1/2 x 7-1/2 x 3/8 in.
345 x 252 x 10 mm
VMDB030,036,048 43-1/8 x 11 x 3/8 in.
1095 x 278 x 10 mm
14-3/8 x 11 x 3/8 in.
365 x 278 x 10 mm
Table 1. Filter Dimensions

9
Figure 10. Remove Filter, Filter Frame and Return Air
Cover Plate from Existing Location
Relocate Return Air Filter Instructions
1. Remove the return air lter from its existing location
at the rear of the unit.
2. Remove the screws that secure the lter frame to the
rear of the unit and set the frame aside. See Figure
10.
3. Remove the screws that secure the return air cover
plate to the bottom of the unit. Set the cover plate
aside. See Figure 10.
Return Air Cover Plate
Return Air Filter Frame
4. Apply eld-supplied foam insulating tape to the return
air opening on the bottom of the unit. See Figure 11.
Figure 11. Apply Foam Insulating Tape
Field-supplied
foam insulating
tape
5. Use the existing screws to re-install the return air
lter frame on the bottom of the unit. See Figure 12.
6. Use the existing screws to re-install the return air
cover plate on the rear of the unit. See Figure 14.
7. Re-install the return air lter in the repositioned lter
frame in the bottom of the unit. Use the provided
clips to secure the lter within the lter frame as
shown in Figure 13.
Figure 12. Re-install Filter Frame and Return Air Cover
Plate
Figure 13. Re-install Filter using Clips
Figure 14. Relocate Return Air Filter Complete

10
Refrigerant Piping Connections
IMPORTANT
The compressor in the unit this air handler is matched
with contains PVE oil (Polyvinyl ether). PVE oil is
formulated for hydrouorocarbon (HFC) refrigerants,
such as R410A, 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.
Refrigerant leaks are unlikely; however, if a refrigerant
leak occurs, open a door or windows to dilute the
refrigerant in the room. Turn o󰀨 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.
WARNING
IMPORTANT
Support ALL piping within 12 in. (305 mm) of any
mechanical tting such as a ared connection.
WARNING
Danger of re. Bleeding the refrigerant
charge from only the high side may result
in pressurization of the low side shell and
suction tubing. Application of a brazing torch
to a pressurized system may result in ignition
of the refrigerant and oil mixture. Check the
high and low pressures before applying heat.
CAUTION
Brazing alloys and ux contain materials which are
hazardous to your health.
Avoid breathing vapors or fumes from brazing operations.
Perform operations only in well-ventilated areas.
Wear gloves and protective goggles or face shield to
protect against burns.
Wash hands with soap and water after handling brazing
alloys and ux.
IMPORTANT
Refrigerant lines must be clean, dry, refrigerant-grade
copper lines. Air handler coils should be installed
only with specied line sizes for approved system
combinations.
Handle refrigerant lines gently during the installation
process. Sharp bends or kinks in teh lines will cause
restrictions.
IMPORTANT
Only use brazing rods/sticks which are suitable/
recommended for air conditioning pipework installations
- Do Not Use Soft Solder.
CAUTION
Purge low pressure nitrogen [1 to 2 psig (6.0 to 12.8
kPA)] through the refrigerant piping during brazing. This
will help to prevent oxidation and the introduction of
moisture into a system.
To prevent the build-up of high levels of nitrogen when
purging be sure it is done in a well ventilated area.

11
Indoor Unit Size
(Btuh) Liquid Line Vapor Line
7,000
9,000
12,000
15,000
1/4” 1/2”
18,000
24,000
30,000
36,000
48,000
3/8” 5/8”
Table 2. Refrigerant Piping Connections
• Field provided piping consists of two HVAC/R rated
copper lines connected to the indoor unit.
• Final equipment connections must be brazed
connections. Compression or other types of ttings
are not permitted for nal connections.
• Refrigerant lines must be connected by a qualied
technician in accordance with established
procedures.
• Copper-phosphorous brazing alloys are to be used to
join all pipework connections where applicable.
• Always ow/purge nitrogen to avoid oxidation while
brazing.
• Always use an appropriate heat absorption compound
to protect the unit and internal sensors from conductive
heat while brazing.
1. The seal on the unit refrigerant piping connections
should remain in place until the last possible moment.
This will prevent dust or moisture from getting into the
refrigerant piping before it is connected.
2. Prior to brazing remove rubber air grommets from
indoor unit refrigerant line ports.
3. Slowly loosen one of the rubber plugs to release the
factory nitrogen charge. Remove the rubber plug from
both liquid and gas lines or cut pipework tails to suit
eld installation conditions.
4. All refrigerant piping shall be free of defects, debris,
and oil.
5. Connect the liquid and gas lines to the evaporator coil.
6. Always use an appropriate heat absorption compound
to protect the unit and internal sensors from conductive
heat while brazing. Take care to protect the cabinet
and internal components.
7. Ensure nitrogen is owing at all times during the
brazing process.
8. Braze connections. Allow pipe to cool before removing
wet rag.
9. Reinstall the rubber grommets into the refrigerant
piping panel.
10. Insulate both pipes individually.
Sealing the Unit
Seal the unit so that warm air is not allowed into the
cabinet. Warm air introduces moisture, which results in
condensation problems.
This is especially important when the unit is installed in an
unconditioned area.
If installed in an unconditioned space, sealant should be
applied around the electrical wires, refrigerant tubing, and
condensate lines where they enter the cabinet.
WARNING
There must be an air-tight seal between the unit and the
return air plenum. Use berglass sealing strips, caulking,
or equivalent sealing method between the plenum and
the air handler cabinet to ensure a tight seal. Return
air must not be drawn from a room where this unit or
any gas-fueled appliance (i.e. water heater) or carbon
monoxide-producing device (i.e. wood replace) is
installed.
VMDB007-015
Use provided piping reducers.
Φ 1/4”
Φ 3/8”
3-1/8”
Φ 3/4”
Φ 5/8”
3-1/8”
1/2”
1/2”
Figure 15. VMDB007-015 Piping Reducers.

12
Condensate Piping Connections
1. Use the provided hose clamp to secure the provided
exible condensate drain connector and insulating
sleeve to the drain line stub on the side of the indoor
unit. See Figure 16. NOTE - Take care not to over-
tighten the hose clamps this may damage the drain
line stub.
2. Make a water-tight connection between the eld-
provided condensate drain line and the exible
condensate connector. Unit connection is 1 in. O.D.
Use 1” I.D. PVC pipe for the drain line. NOTE - copper
drains are suitable for use within plenum rated ceilings.
3. See Figure 17 for applications including a single unit
and a single gravity 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.
A gravity drain connection port is located on the
side of the unit with the refrigerant piping and on the
opposite side of the unit. Select one connection to
use and leave the unused connection port sealed.
Seal and plug the lift pump connection port
when using either gravity drain connection port.
Disconnect the factory-installed lift pump, CN 13.
INSULATION
INDOOR
UNIT
CONDENSATE
LINE STUB
HOSE CLAMP
FLEXIBLE DRAIN
CONNECTOR
PVC DRAIN
PIPE
GRAVITY
DRAIN
CONNECTION
LIFT PUMP
CONNECTION
Figure 16. Condensate Drain Connection
4. See Figure 18 for applications including a single unit
using the internal drain pump.
Suspension Rods
Drain line
Structural Ceiling
3 ft.
(1 m)
Support
straps
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.
Do not operate unit without condensate drain trap.
Clean Out
Do not glue
3”
3”
Anti-siphon vent must extend above the
height of the coil drain pan by 2” (51 mm).
1 ft.
(305 mm) max
Indoor Unit
Figure 17. Sloped Condensate Gravity Drain
Single Unit
SUSPENSION RODS
DRAIN LINE
STRUCTURAL CEILING
8 in.
(203 mm)
Max. 28 in.
SUPPORT
STRAPS
3 ft. (1 m)
Figure 18. Condensate Drain with Lift Pump
Single Unit
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.
5. See Figure 19 for applications including multiple units
using the internal pump to provide lift into a single,
correctly sized main drain. In this case, ensure that
the main drain line is properly sloped, no less than
1/4 inch per foot (6 mm per 305 mm), and that each
individual drain is connected to the main drain exactly
as shown.
6. In all cases, drain should be as short as possible and
should not have any droops or kinks that would restrict
condensate ow and shall be constructed using an
approved 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.
IMPORTANT
You must conrm operation of every drain and pump in
the system as part of the commissioning procedure.

13
Indoor Unit
2~3-15/16 in.
8 in.
2~3-15/16 in.
2~3-15/16 in.
MAIN DRAIN
INDIVIDUAL DRAIN OUTLET FROM EACH INDOOR UNIT
(Must be connected to internal pump and must be routed to
main drain as shown.)
tinUroodnItinUroodnI
(Sloped at1/4” per foot (6 mm per 305 mm) AWAY
from unit and should be supported as needed to prevent sagging.)
8 in. 8 in.
Max. 28 in.
Max. 28 in.
Max. 28 in.
Figure 19. Condensate Drain with Lift Pump
Multiple Indoor Units
7. After system installation is complete, the
condensate drain line must be checked for leaks
and the condensate pumps must be checked to
ensure proper operation. This check is part of the
commissioning sequence. Turn the condensate
drain pan test cover latch counterclockwise to open
the cover and access the drain pan. See Figure 20.
Funnel enough water to engage the pump into the
drain pan through a exible tube.
8. Operate the system in the cooling mode. If the
internal pump is being used, ensure that the pump is
operating and the water in the pan is draining freely.
If the internal pump is not being used, pour the water
into the drain pan and conrm that it has owed freely
out of the pan and out of the drain termination. If a
leak is found, shut down power to the unit at once and
do not restore power to the unit until the problem has
been resolved.
DRAIN PAN
TEST COVER
FUNNEL WATER INTO
PAN THROUGH TUBE
FOR TEST
COVER LATCH
(Turn latch
counterclockwise
to unlock)
CL
OSE
D
O
PE
N
CLOS
E
D
O
PE
N
Figure 20. Condensate Drain Test
9. Return the test cover and turn the latch clockwise to
re-lock it.
IMPORTANT
When using a gravity drain instead of the factory-
installed lift pump.
Disconnect the factory-installed lift pump, CN 13. See
unit wiring diagrams for location of CN 13.
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.

14
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 (two-conductor,
shielded cable) per Figures 21. 22 and 23. Refer to
unit nameplate for rated voltage.
3. If the indoor unit is the 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 can be
repositioned, if necessary. Use optional extension
cable kit V0CTRL93P-1 (cat # 14R84).
Wiring Connections
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 - Two-conductor stranded shielded cable
must be used for the communication wiring. This is
necessary to ensure proper system communication
and operation.
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 re.
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
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 a󰀨ect remote control
operation.
CAUTION
A disconnection device having an air gap contact
separation in all active conductors should be
incorporated in the xed wiring according to the National
Wiring Regulation.
• 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.

15
Indoor units and mode selection boxes on the same
refrigeration circuit should have a common power
supply but must have an independent disconnect switch
installed adjacent to each item of equipment for servicing
and maintenance purposes. Indoor unit and mode
selection box power supply MUST not be taken from the
outdoor unit. Always follow NEC/CEC and Local Codes.
Figure 21. Typical Power Wiring Diagram (VRF Heat Recovery System Shown)
L2 L3L1
L2L1
208/230V 3Ph 60Hz
or 460V 3Ph 60Hz
Power supply
208/230V 1Ph 60Hz
Power supply
Mode Selection Box Indoor unit Indoor unit Indoor unit
Dedicated
breaker
Service
Disconnect
L1 L2
L1 L2
Fuse
Service
Disconnect
L1 L2
Fuse
Service
Disconnect
L1 L2
Fuse
Service
Disconnect
L1 L2
Fuse
Outdoor Unit (Main Unit)
L1 L2 L3
Outdoor Unit (Sub1 unit)
L1 L2 L3
Outdoor Unit(Sub2 Unit)
L1 L2 L3
L1 L2 L3
L1 L2 L3
L1 L2 L3
L1 L2 L3
L1 L2 L3
L1 L2 L3
Service
Disconnect
Service
Disconnect Service
Disconnect

16
P Q
All Drain Wires will connect from outdoor unit chassis to mode selection box chassis at the end of
the signal run.
18 GA., stranded, 2-conductor, shielded control wire (polarity sensitive).
Typical Wiring Diagram, NEC/CEC and Local Codes apply.
Outdoor unit Outdoor unit
(sub1 unit)
Outdoor unit
(sub2 unit)
(PQ)
(main unit)
(PQ)
MS
Box
(PQ)
(PQ)
MS
Box
(PQ)
(PQ)
(H1 H2 ) (H1 H2 ) (H1 H2 )
Outdoor Unit Communication Terminal Block
P Q H1 H2X YO AK1 K2
MS Box Communication
Terminal Block
P Q
Indoor Unit Communication Terminal Block
HA HB 12V COM P Q
Ground drain wire or
cable shield
to MS Box
and Outdoor Unit chassis
Install a terminating resistor (Ω120) on terminals P&Q on the indoor unit
which is furthest from the outdoor unit.
Figure 22. Typical Communication Wiring Diagram (VRF Heat Recovery System)
NOTE - Each communication wire from the MS box should follow the refrigerant piping for that port.

17
Figure 23. Typical Communication Wiring Diagram (VRF Heat Pump System)
Tightening torque for the terminal screws
• Use the correct screwdriver for 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.
• After wiring, conrm all connections are correct; Then
turn on power supply to the unit.
Table 3. Terminal Screw Tightening Torque
Tightening torque
(lb-ft)
Terminal base of
remote controller/Signal
transmission wire (X2M)
0.58-0.72
Terminal base of power
supply (X1M)
0.87-1.06
Grounding terminal (M4) 1.06-1.43
(PQ)
(PQ)
Outdoor unit
(mainunit)
Outdoor unit
(sub1unit)
Outdoor unit
(sub2 unit)
Install a terminating resistor (Ω120) at the last indoor unit terminals P and Q of the daisy chain.
P Q
All shields of shielded cable connect to chassis GROUND terminal at Indoor Units.
18 GA., stranded, 2-conductor,shielded control wire (polaritysensitive).
Typical Wiring Diagram, NEC/CEC and Local Codes apply.
(H1 H2 )
Outdoor Unit Communication Terminal Block
P Q H1 H2X YO AK1 K2
(H1 H2 )
(H1 H2 )
Indoor Unit Communication Terminal Block
HA HB 12V COM P Q
Ground cable shield
to Indoor Unit chassis
IMPORTANT
DO NOT adjust DIP switch settings. Settings may only
be adjusted by a trained technician as part of the com-
missioning procedures.

18
Figure 24. Wiring Diagram - VMDB007-048-P3 Wiring Diagram
EXV
FM
ALARM
PUMP
CN18CN3
CN24
CN2
EARTH
Y/G
CN15CN9
CN17
Y/G
L1 L2
CN51
CN50
CN1
HHE interface
( Current range:
0-1A)
(Voltage range:
0-24V AC/DC)
FAN
CTON HTON
AUXH
T2A
T2B
T2
T1
XS5
XP5
Display Board
RED BLUE
N=5
YELLOW
GRAY
WHITE
BLUE
ON/OFF
SWITCH Occupancy
sensor
Main Board
CS
POWER IN
XT1
XT2
CN21
CN26CN4
CN5
CN54 CN52 CN8
T2A
T2B
T2
EXV
Warning lamp
Electronic expansion valve
ALARM
Indoor fan motor
Room temperature sensor
T1
FM
Code Title
XS1-7
XP1-7
XT1-2
Connectors
Terminals
Pump motor
Water level switch
Swing motors
PUMP
GM1-2
CS
Error Code Error Content
E1
E0
E2
E3
E4
Mode conflict
Communication error between
indoor and main outdoor unit
E5
FE
D8
A0
Eb
U4
Ed
EE
F8
No address
Outdoor unit fault
Water level alarm
Emergency stop
Remote OFF
E6
DC fan motor error
E7
EEPROM failure error
“ +5V GND +12V ”
ONLY USED
FOR TESTING
CN30
RED
BLACK
HA HB 12V COM QP
Magnet
Ring
To wired
controller
comm. bus
To outdoor/
indoor/MS
units
comm.bus
To wired
controller
power
MS error
CN14
GM1 GM2
XP6
XP4
XP3
XP2
XP1
BLUE
BLACK
WHITE
RED
XS4
XS3
XS2
XS1
XS6
XP7 XS7
CN12
NOTE:
1. Refer to manual for communication
wiring
2. Please use the 2-conductor shielded
twisted cable for communication
NOTE:
Component in dash line is
optional or field wiring
Inlet of evaporator sensor
Outlet of evaporator sensor
Middle of evaporator sensor
T1(Room temperature sensor) malfunction
T2(Middle of evaporator sensor) malfunction
T2A(Inlet of evaporator sensor) malfunction
T2B(Outlet of evaporator sensor) malfunction
MS self-inspection error
EXV malfunction
Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.

19
Relocate T1 Return Air Sensing
Figure 26. Identify T1 Sensor Connection on PCB
Relocate Physical T1 Sensor Instructions
This sensor can be extended with 18 AWG stranded
shielded cable.
1. Identify the T1 connection on the main board - CN4.
(white wires soldered to PCB)
Figure 27. Identify White Plug into Black Wire
Figure 28. Cut the Black Wire
2. Identify where the white wire is plugged into the black
wire.
3. Cut the black wire between the plug and the sensor
thermistor. Leave adequate room for making wiring
connections on each end.
4. Prepare the 18 AWG stranded shielded extension
cable.
5. Solder the extension cable to the black wire on each
end or use the VRF accessory V0SNSR00P to splice
in the extension cable.
6. Locate the return air thermistor to the conditioned
area of which the indoor unit serves.
Figure 29. Sensor Thermistor
Relocate the unit return air sensing from inside the unit
to a location within the conditioned zone whenever the
return is pulling air from above the ceiling or if fresh air is
being introduced and mixed into the return. The T1 sen-
sor cannot accurately read the space temperature under
these conditions if the sensing remains located inside of
the unit.
Two methods of relocating the return air sensing are:
1. Set return air sensing to the wired local controller. See
the specic controller’s installation and user manual
for instructions.
2. Relocate physical T1 sensor. Instructions below.
IMPORTANT
Avoid installing sensor in high load or heat loss areas
such as exterior walls or walls that are against uncondi-
tioned spaces, near entry doors and windows, or where
direct sunlight may be present.

20
EXV
FM
ALARM
PUMP
CN18CN3
CN24
CN2
EARTH
Y/G
CN15CN9
CN17
Y/G
L1 L2
CN51
CN50
CN1
HHE interface
( Current range:
0-1A)
(Voltage range:
0-24V AC/DC)
FAN
CTON HTON
AUXH
T2A
T2B
T2
T1
XS5
XP5
Display Board
RED BLUE
N=5
YELLOW
GRAY
WHITE
BLUE
ON/OFF
SWITCH Occupancy
sensor
Main Board
CS
POWER IN
XT1
XT2
CN21
CN26CN4
CN5
CN54 CN52 CN8
T2A
T2B
T2
EXV
Warning lamp
Electronic expansion valve
ALARM
Indoor fan motor
Room temperature sensor
T1
FM
Code Title
XS1-7
XP1-7
XT1-2
Connectors
Terminals
Pump motor
Water level switch
Swing motors
PUMP
GM1-2
CS
Error Code Error Content
E1
E0
E2
E3
E4
Mode conflict
Communication error between
indoor and main outdoor unit
E5
FE
D8
A0
Eb
U4
Ed
EE
F8
No address
Outdoor unit fault
Water level alarm
Emergency stop
Remote OFF
E6
DC fan motor error
E7
EEPROM failure error
“ +5V GND +12V ”
ONLY USED
FOR TESTING
CN30
RED
BLACK
HA HB 12V COM QP
Magnet
Ring
To wired
controller
comm. bus
To outdoor/
indoor/MS
units
comm.bus
To wired
controller
power
MS error
CN14
GM1 GM2
XP6
XP4
XP3
XP2
XP1
BLUE
BLACK
WHITE
RED
XS4
XS3
XS2
XS1
XS6
XP7 XS7
CN12
NOTE:
1. Refer to manual for communication
wiring
2. Please use the 2-conductor shielded
twisted cable for communication
NOTE:
Component in dash line is
optional or field wiring
Inlet of evaporator sensor
Outlet of evaporator sensor
Middle of evaporator sensor
T1(Room temperature sensor) malfunction
T2(Middle of evaporator sensor) malfunction
T2A(Inlet of evaporator sensor) malfunction
T2B(Outlet of evaporator sensor) malfunction
MS self-inspection error
EXV malfunction
Figure 31. Typical Wiring Connections
CN4
18 AWG stranded shielded cable
White plug
White wire
Black wire Black wire
Thermistor
Solder or connect with V0SNSR00P
Figure 30. Identify T1 Sensor on Wiring Diagram
Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.
Setting Blower Operation
Blower cycling can be congured to determine indoor
operation.
• Default operation is indoor unit blower OFF when the
indoor unit is in thermo OFF.
• Settings can be adjusted in the -3P controller and
cannot be congured at the indoor unit PCB.
• Consult the specic controller manual for detailed
blower setting information.
NOTE - Ensure the blower is set to the ON position when
using an electrical duct heater.