LENNOX V33B 360º Cassette VRF Indoor Unit Instruction Manual
- June 4, 2024
- Lennox
Table of Contents
V33B 360º Cassette VRF Indoor Unit
VRF
©2018 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 factory-
specified parts. Do not use this system if any part has been under water. A
flood-damaged appliance is extremely dangerous. 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.
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 filters can damage the units. Failure
to follow these guidelines will result in the warranty being voided.
INSTALLATION
INSTRUCTION
V33B 360º Cassette Units
VRF SYSTEMS — Indoor Units 507890-04 05/2022
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
specified in the Product Specifications (EHB) bulletin.
General
The V33B 360º cassette indoor units are matched with an outdoor heat recovery
or heat pump unit to create a VRF (variable refrigerant flow) system that uses
HFC-410A refrigerant. V33B indoor units are designed for indoor installation
only. Refer to the Product Specification bulletin (EHB) for the proper use of
these indoor units with specific 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.
Shipping and Packing List
Check the components for shipping damage. If you find any damage, immediately
contact the last carrier.
Package 1 of 1 contains the following:
1 – Assembled indoor cassette unit base
8 – Nuts
8 – Washers
4 – Cover panel screws
5 – Wire ties 1 – Condensate drain flexible pipe 1 – Condensate drain
insulation sleeve
1 – Clasp
1 – Cable
2 – Refrigerant pipe insulation 2 – Brass flare nuts 1 – Template
1 – Installation manual
NOTE – Assembled indoor unit cover panel is required for complete installation
and must be ordered separately.
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 Identification
V 33 B 012 H 4 – 3 P
Brand/Family V = Variable Refrigerant Flow (VRF)
Unit Type 33 = High Efficiency 360° Cassette Indoor Models
Major Design Sequence B = 2nd Generation
Nominal Cooling Capacity – Btuh 009 = 8,500 Btuh
012 = 12,000 Btuh 015 = 15,000 Btuh 018 = 18,000 Btuh 024 = 24,000 Btuh 030 =
30,000 Btuh 036 = 36,000 Btuh 048 = 48,000 Btuh
Voltage P = 208/230V-1 phase-60hz
Controls Protocol 3 = Phase 3
Refrigerant Type 4 = R-410A
Cooling Efficiency H = High Efficiency
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 confirm compatibility. Model numbers for Lennox VRF units start
with a “V” and model numbers for Lennox Mini-Splits start with a “M”.
System Piping
Caution
VRF system piping is customized for each installation. The Lennox VRF
Selection Software (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 figures 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 confirm 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 insufficient capacity, equipment failure, warranty being made void
and the refusal to commission the system.
Accessories Accessories designed to be used with this unit include:
Cat # 18F54 18F53
Model # V8V33B002-3P V8V33B001-3P
Description Blank-off Kit High Efficiency Filter Kit
2
Unit Dimensions – inches (mm)
37-3/8 (949) 30-3/4 (781)
GAS
4-1/8
LIQUID PIPE
A
(105)
DRAIN PIPE
CONNECTION 1-1/4 (32)
2-3/4 (70)
4 (102) dia. SECONDARY
SUPPLY DUCT
CONNECTION
37-3/8 (949) 26-3/4 (679) 33- 1/8 (841)
DRAIN PIPE
TOP VIEW 6 (152) dia.
SECONDARY SUPPLY DUCT
CONNECTION
INSTALLATION HANGERS (4)
LEVELING ADJUSTMENT
NUT(4)
CEILING
DIFFUSER PANEL
AIR OUTLET
AIR INLET 34-5/8 (879) (Ceiling Opening)
SIDE VIEW
AIR OUTLET
2-3/4 (70) dia. FRESH AIR
INTAKE
LIQUID PIPE
3/4 (19)
GAS PIPE
5-3/4 (146)
1-3/4 (44)
33-1/8 (841) BOTTOM VIEW
RECEIVER
OCCUPANCY SENSOR
GAS PIPE
LIQUID PIPE
BOTTOM (PANEL) VIEW
DRAIN CONNECTION
4 (102) dia. SECONDARY
SUPPLY DUCT
CONNECTION
SIDE VIEW
Size
009, 012 015, 018, 024, 030, 036, 048
A
in.
mm
9
229
11-7/8 302
NOTE – Horizontal installation only.
3
19 (483) FILTER SIZE
19 (483)
Clearances
36 (914)
36 (914)
36 (914)
36 (914)
Minimum Vertical Clearances: Minimum Clearance from Structural Ceiling to Drop
Ceiling: 10-1/4 inches (260 mm) – 007, 009, 012, 015 models 13 inches (330 mm)
– 015, 018, 024, 030, 036, 048 models Minimum Clearance to Floor: 90 inches
(2286 mm) Maximum Clearance to Floor: 160 inches (4064 mm)
Minimum Service Clearance for refrigerant and drain lines – 24 inches (610 mm)
Typical cassette body shown, actual unit may vary.
4
Indoor Unit Placement
WARNING
Do not install the unit in an area where flammable materials are present due
to risk of explosion resulting in serious injury or death. Check suitability
of structure to which the unit support mechanism will be fixed to. If
structure is not capable of carrying the weight of the unit, unit may fall
causing personal injury or equipment damage. Use the provided and specified
components when installing equipment. Failure to do so may result in unit
falling, water leaking or electrical shocks, causing personal injury or
equipment or property 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 unit. The
unit should be installed between 90 in. (2286 mm) and 156 in. (3962 mm) above
the floor to ensure maximum performance.
AVOID
Do not install the unit in the following locations:
· Areas exposed to salt or other corrosive materials or caustic gases
· Areas exposed to extreme voltage variations (such as factories)
· Tightly enclosed areas that may impede service of the unit.
· Areas exposed to strong electromagnetic forces
· Areas exposed to acids or alkaline detergents (laundry rooms)
DO:
· Locate the unit so that it is central to the area being conditioned.
· Locate the unit so that it is not exposed to direct sunlight.
· Locate the indoor unit so that the room can be uniformly cooled. Install
unit at least 90 inches (2286 mm) above the floor, if possible, for best
performance.
· Select a structural location that can support the suspended weight of the
unit’s chassis.
· Select a location where condensate line will have the shortest run to a
suitable drain per local codes.
· Allow sufficient space around unit for proper operation and maintenance
(filter must able to be removed from the bottom of the unit).
· Install the indoor 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.
5
Cassette Base Installation
It is important to locate the cassette unit in the center of the area that is
being conditioned. This will provide the best air distribution.
1. If the unit is to be installed in an application that includes a drop-down
tile ceiling, remove the ceiling tiles necessary to accommodate installation
of the four-way cassette. Before removing the drop ceiling support grid, use a
plumb line or laser device to identify the center point of the structural
ceiling. Make sure that the ceiling is supported before removing any of the
support grid. It may be necessary to add extra support to maintain the
structural integrity of the drop ceiling.
2. If the unit is to be installed in an application that includes a sheet
rock (plasterboard) ceiling, the installation site must be carefully measured
and the sheet rock must be cut to accommodate the cassette unit. First,
identify the center point of the installed cassette. Use a plumb line to
transfer the center mark to the floor for future use. Use the provided
template to mark the area of the required opening. Carefully cut the required
opening. Make sure that the removal of the required ceiling support does not
affect the structural integrity of the ceiling. It may be necessary to add
extra support.
3. Use the unit as a template or use the provided paper template to mark the
location of the hanging brackets on the floor. Use a plumb line or a laser to
transfer the bracket positions to the main structural ceiling.
4. Make sure that structure within ceiling void such as a sub-floor or crawl
space is able to support the weight of the cassette unit. It may be necessary
to add extra support. If the structural support is constructed of concrete,
install anchors to accept four ” threaded rods to suspend the cassette base.
If the structural support includes wooden joists, use angle iron or a Unistrut
channel fixed securely in place to accept the ” 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 1.
5. 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 cassette base 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.
CONCRETE CEILING USING ANCHORS
ANCHOR
” THREADED ROD
ANGLE IRON BOLTED IN PLACE ACROSS WOODEN JOISTS
” THREADED ROD
ANGLE IRON ACROSS
WOODEN JOISTS
WOODEN JOIST
Figure 1. Suspending Methods
STRUCTURAL SUPPORT
” THREADED ROD
UNIT CHASSIS
L ” to ½”
LEVELING NUT
DROP CEILING
SUSPENSION BRACKET
Figure 2. Suspension Hardware
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).
7. Access is required during the commissioning process to test the condensate
disposal system (See Figure 9), to check the electronic expansion valve and
associated flare nuts (See Figure 3), and to check the local disconnect.
Ceiling framing should not restrict access.
6
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.
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 flare 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. Slowly loosen one of the flare nuts to release the factory nitrogen
charge.
3. Remove the flare nuts from the connections on the unit and discard the
seal from each of the piping connections.
4. Slide the flare nuts onto the ends of the field-provided refrigerant
piping before using a suitable flaring tool to flare the end of the copper
pipe.
5. Apply recommended HFC-410A refrigerant lubricant to the outside of the
flared refrigerant lines (Figure 3-A).
6. Align the threaded connections with the flared refrigerant lines. Tighten
the flare nuts lightly at first to obtain a smooth match (Figure 3-B).
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 flare nuts using Table
2 recommendations. See Figure 4. Do not over-tighten a flared joint. Flared
connections should always be accessible and must be insulated to prevent
condensation.
8. After refrigerant piping has been installed and checked for leaks, apply
insulation over all flared joints ensuring an air tight seal has been made
between unit connections and field supplied insulated piping. All field piping
connections shall be insulated and air tight to prevent unwanted condensation
build-up. Figure 5.
IMPORTANT!
The compressor in this unit contains PVE oil (Polyvinylether). PVE oil is
formulated for hydrofluorocarbon (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.
Table 1. Refrigerant Piping Connections
Nominal Capacity
(Btuh) 9000 12000 15000 18000 24000 30000 36000 48000
Liquid Line in.
Vapor Line in.
1/4
1/2
3/8
5/8
A
APPLY REFRIGERANT LUBRICANT ON THE OUTSIDE OF THE FLARE
MALE FLARE CONNECTION
B
Figure 3. Making Connections (Male to Female Connection)
7
IMPORTANT!
Always use two wrenches when tightening flare nuts to avoid twisting
refrigerant piping. DO NOT over-tighten flare nuts.
IMPORTANT
Flared connections should always be accessible and must be insulated to
prevent condensation. See Figure 5.
Torque Wrench To Indoor Unit
Backup Wrench
UNIT BASE
INSULATE ALL FLARED CONNECTIONS TO PREVENT CONDENSATION
To Outdoor Unit Figure 4. Tighten Flare Nut
Table 2. Flare Nut Torque Recommendations
Outside Diameter
Inches 1/4″ 3/8″ 1/2″ 5/8″
Recommended Torque
U.S. 15 ft.-lb. 26 ft.-lb. 41 ft.-lb. 48 ft.-lb.
No torque wrench available
Finger tighten and use an appropriately sized wrench to turn an
additional:
1/4 turn
1/2 turn
7/8 turn
1 full turn
Figure 5. Insulate Flared Connections
IMPORTANT
Support ALL piping within 12 in. (305 mm) of any mechanical fitting such as a
flared connection.
8
Condensate Piping Connections
CAUTION
Make sure that drain piping is properly routed and insulated in order to
prevent both leaks and condensation.
1. Use the provided hose clamp to secure the provided flexible condensate
drain connector to the drain line stub on the side of the cassette base. Wrap
the flexible connector with the provided insulation. NOTE – Take care not to
over-tighten the hose clamp as this may damage the drain line stub.
2. Make a water-tight connection between the fieldprovided condensate drain
line and the flexible condensate connector. Use 1-1/4″ OD PVC pipe for the
drain line.
6. 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. Pour water into
the evaporator drain pan to ensure proper condensate drainage. See Figure 8.
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.
Cap (Remove for test)
Cassette Base Drain Pan
Pour water here for test
3. See Figure 6 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.
4. See Figure 7 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) and that each individual drain is connected to the main drain exactly as
shown.
5. Drain should be as short as possible and should not have any droops or
kinks that would restrict condensate flow and shall be approved resistant
pipe.
Drain Plug
Figure 8. Test Condensate Drain
IMPORTANT!
Drain should have a slope of at least ¼ inch per foot and should be approved
corrosion-resistant pipe. You must confirm operation of every drain and pump
in the system as part of the commissioning procedure.
Supports
1 ft. (305 mm)
max
3 ft. (1 m)
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.
Drop Ceiling
Drain Line
Figure 6. Sloped Condensate Drain — Single Unit
8 in. 2~3-15/16 in.
8 in. 2~3-15/16 in.
8 in. 2~3-15/16 in.
Cassette Unit
Cassette Unit
Cassette Unit
Max. 28 in. Max. 28 in. Max. 28 in.
INDIVIDUAL DRAIN OUTLET FROM EACH INDOOR UNIT (Must be connected to internal
pump and must be routed to
main drain as shown.)
MAIN DRAIN (slope of at least ¼ inch per foot)
Figure 7. Using a Main Drain to Serve Multiple Indoor Units
9
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 fire.
Use specified 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 fire.
Wiring must be installed so that all cover plates can be securely closed.
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.
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). Refer to unit nameplate for rated
voltage. Power wiring must be protected in a field-supplied conduit. See
Figure 9.
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.
3. Connect the communications cable (per Figures 11, 12 and 13. Communication
cable is polarity sensitive.
Figure 9. Field-Supplied Electrical Conduit Example
Code
Title
FM Indoor fan motor
T1 Room temp. sensor
T2 Midlet pipe temp. sensor
T2A Inlet pipe temp. sensor
T2B Outlet pipe temp. sensor
XP1-7 Connectors
XS1-7 Connectors
XT1 Terminal
PUMP Pump motor
GM Swing motor
CS Water level switch
ALARM Warning lamp
EEV Electronic expansion valve
Error code E0 E1 E2 E3 E4 E5 E6 E7
Error Content Mode conflict Comm. error with outdoor unit Temp. sensor (T1) error Temp. sensor (T2) error Temp. sensor (T2B) error Temp. sensor (T2A) error DC fan error EEPROM error
To outdoor/
P
indoor/MS units comm. bus
Q
Attention:
For the convenience of
To wired
COM
wiring, the communication
controller
terminals can be pulled out from the main board.
power
12V
HA
NOTE:
To wired
1. Refer to manual for com-
controller
HB
munication wiring
comm. bus
2. Please use the 2-conductor
shielded cable
Error code U4 F8 Eb Ed EE FE A0 D8
Error Content MS error in auto system-check mode MS error EEV error Outdoor unit error Water level alarm No address when first time power on Emergency stop Remote OFF
P (COM) Q HA (12V) HB
CN11
CN12 CN2
CN3 CN18
CN24 Y/G
BLUE RED
L1 L2
XT1
FM
POWER IN
ALARM
Main board
” +5V GND +12V ” ONLY USED FOR TESTING
CN54
CN26
CN9
XS7 Display board
XP7
CN15
CN14 CN52 CN21 CN22 CN8
CN5
XP5 XS5 XP6 XS6
RED WHITE BLACK BLUE
XP1-XP4 XS1-XS4
HHE interface
CN50
ON/OFF PUMP SWITCH
Occupancy sensor
T2A T2 T1 T2B
CN51 GM
FAN CTON HTON AUXH
( Current range: 0-1A) ( Voltage range: 0-24V AC/DC)
GM EEV CS
Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.
Figure 10. Typical V33B Wiring Diagram
10
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.
208/230V 1Ph 60Hz Power supply
L1 L2
208/230V 3Ph 60Hz or 460V 3Ph 60Hz
Power supply
L1 L2 L3
L1 L2
Dedicated breaker
L1 L2 L3
Outdoor Unit (Main Unit)
L1 L2 L3
Outdoor Unit (Sub1 unit)
L1 L2 L3
Outdoor Unit(Sub2 Unit)
L1 L2 L3
Service Disconnect
L1 L2 L3
L1 L2 L3
Service Disconnect
L1 L2 L3
Mode Selection Box
Indoor unit
Indoor unit
L1 L2 L3
Service Disconnect
L1 L2 L3
Indoor unit
L1 L2
Service
Fuse
Disconnect
L1 L2 Service
Fuse
Disconnect
L1 L2 Service
Fuse
Disconnect
L1 L2
Service
Fuse
Disconnect
Figure 11. Typical Power Wiring Diagram (VRF Heat Recovery System Shown)
11
Outdoor unit Outdoor unit Outdoor unit (main unit) (sub1 unit) (sub2 unit)
K1 K2
(H1 H2 ) (H1 H2 ) (H1 H2 ) (PQ)
OA
XY
PQ
H1 H2
Outdoor Unit Communication Terminal Block
(PQ) (PQ)
MS Box
(PQ)
(PQ)
MS Box
(PQ)
PQ MS Box Communication
Terminal Block
HA HB 12V COM P Q Indoor Unit Communication Terminal Block
Ground drain wire or cable shield to MS Box and Outdoor Unit chassis
P Q Install a terminating resistor (120) on terminals P&Q on the indoor unit
which is furthest from the outdoor unit. 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. NOTE – Each
communication wire from the MS box should follow the refrigerant piping for
that port.
Figure 12. Typical Communication Wiring Diagram (VRF Heat Recovery System)
12
Outdoor unit (main unit)
Outdoor unit Outdoor unit (sub1unit) (sub2 unit)
(H1 H2 )
(H1 H2 )
(H1 H2 )
K1 K2
OA
XY
PQ
H1 H2
Outdoor Unit Communication Terminal Block
(PQ) (PQ)
HA HB 12V COM P Q Indoor Unit Communication Terminal Block
Ground cable shield to Indoor Unit chassis
P Q Install a terminating resistor (120) at the last indoor unit terminals P
and Q of the daisy chain.
All shields of shielded cable connect to chassis GROUND terminal at Indoor
Units. 18 GA., stranded, 2-conductor, shielded control wire (polarity
sensitive). Typical Wiring Diagram, NEC/CEC and Local Codes apply.
Figure 13. Typical Communication Wiring Diagram (VRF Heat Pump System)
Tightening torque for the terminal screws
· Use the correct screwdriver for fighting 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, confirm all connections are correct; Then turn on power supply
to the unit.
Table 3. Terminal Screw Tightening Torque
Terminal base of remote controller/Signal transmission wire (X2M)
Terminal base of power supply (X1M)
Grounding terminal (M4)
Tightening torque (lb-ft)
0.58-0.72
0.87-1.06
1.06-1.43
13
Outside Air Connection A limited amount of filtered outside air can be brought
into the cassette unit [through the 3 inch (76 mm)] outside air knockout to be
conditioned and mixed into the supply air.
Duct Screw Holes (4)
Outside Air Knockout
Supply Air Configurations
Supply air is typically provided from all four sides of the cassette unit. See
Figure 16.
If needed for the application, one or two sides of the cassette supply air can
be blanked off to prevent air flow from that side. See Figures 17 and 18 for
possible air flow configurations.
Use field-provided blocking and sealing materials. Materials must be listed
ANSI/UL and ASTM E 84 approved. NOTE – A maximum of two sides can be blanked
off.
Figure 14. Typical Outside Air Knockout 1. Knock out the outside air supply
opening. See Figure
14. 2. Remove any insulation. 3. Make sure the outside air supply channel is
clear of
Styrofoam and debris. See Figure 15. 4. Connect the outside air duct to
cassette body using
the four screw holes shown in Figure 14.
Outside Air Supply Channel
Typical cassette body shown, actual unit may vary in size and location of
supply air channel.
Figure 15. Typical Outside Air Supply Channel 5. Relocate the indoor unit’s
return air sensor to either
the controller (electronically) or physically by using the remote sensor
accessory. 6. The outside air supply duct length must be 10 feet or less. 7.
Use a field-supplied booster fan to increase static pressure.
Typical cassette body shown, actual unit may vary in size and location of
supply air openings.
Figure 16. Typical Supply Air Configuration
1. Remove the decorative cover panel if installed. 2. Identify and measure
the supply air opening that will
be blanked off. See Figure 16. 3. Prepare the blocking material. Cut a piece
of
Styrofoam or other non-conductive material to fit the supply air opening. 4.
Insert the blocking material into the supply air opening. 5. Prepare the
sealing material. Cut a piece of tape or other non-conductive sealing material
to cover and secure the blocking material. 6. Seal the supply air opening
using the sealing material. 7. Install the decorative cover panel.
14
Figure 17. Three-way Outlet Possible Flow Patterns
Typical cassette body shown, actual unit may vary. Figure 18. Two-way Outlet
Possible Flow Patterns 15
Installation of Secondary Supply Duct A limited amount of conditioned air can
be diverted through a small duct to a location outside of the zone. For
example, a common application is for the cassette unit to serve an office that
has a small attached bathroom. Air can be supplied to the bathroom from the
cassette unit by following these instructions. NOTE – Secondary supply duct
knockouts are located on all four sides of the V33B cassette body. If the
knock out is used, the supply air opening of the same side should be blocked
and sealed.
Duct Knockouts
1. Decide which side of the cassette body will be ducted.
2. Seal the supply air outlet on the side to which the duct will be attached.
See the Supply Air Configurations section for detailed instructions.
3. Knockout the secondary supply duct opening. See Figure 19.
4. Remove any insulation.
5. Connect the secondary supply duct to the cassette body using the eight
screw holes shown in figure 19.
6. A field-supplied duct transition may be required. Be sure there is an air-
tight seal between the transition and the cassette body and between the
transition and the secondary supply duct.
7. The secondary supply duct must be 4 or 6 inches in diameter and 10 feet or
less in length (including transitions).
NOTE – A field-supplied volume control damper can be used to control the
amount of air supplied to the space, however, the area being conditioned by
the secondary supply duct will not have control over the temperature of the
air being supplied.
Typical cassette body shown, actual unit may vary in size and location of
secondary duct knockouts.
Figure 19. Typical Duct Knockout
Supports
Supply Duct
10 feet maximum
Drop Ceiling Seal supply air outlet on duct side
NOTE – The secondary supply duct must be 4 or 6 inches in diameter and 10 feet or less in length (including transitions).
Figure 20. Supply Duct Maximum Length
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Cassette Cover Panel Installation NOTE – Cover panel must be ordered as a
separate accessory.
1. Carefully remove the cassette cover panel from its protective packaging
and place the panel diffuserside-out on a clean, level surface.
CORNER ACCESS COVER
CAUTION
Do not place the cover panel with the diffusers face down on the floor or
other surface. Louvers will be damaged if pressure is applied to them.
Remove screws and loosen straps to remove corner covers from panel.
2. Press the two grille latch release buttons at the same time to release the
grille. See Figure 21. Tilt the return air grille outward at a 45º angle and
lift the grille away from the panel. Carefully place the return air grille off
to the side.
LATCH RELEASE BUTTONS
Press latch release buttons at the same time to release latch.
45º
Tilt return air grille outward, then, lift to remove grille from panel.
Figure 22. Remove Corner Covers
4. Position the ceiling panel so that the arrow on the panel is aligned with
the arrow sticker on the cassette base (both arrow stickers should be on the
same side of the cassette base). NOTE – If the panel and the base are not
properly aligned, the airflow will be blocked and the harness plugs from the
panel to the cassette base will not be long enough to plug together.
5. Locate the cover panel hangers on the two corners with the louver swing
motors. Place these two hangers on the corresponding hooks on the corners of
the cassette base. See detail A in Figure 23. Then, place the other hangers
from the other two corners over their corresponding hooks on the cassette base
as shown in detail B in Figure 23.
6. Connect the six-pin harness plugs from each of the two swing motors to the
matching six-pin plugs from the control box in the cassette base.
7. Connect the black harness from the display on the cover panel to the
corresponding black plug from the control box in the cassette base.
8. Connect the orange harness from the occupancy sensor to CN 26 on the
indoor unit main board. A wired local controller is required to use occupancy
sensor. See the wired controller manual for directions on setting up the
sensor.
Figure 21. Remove Return Air Grille
3. Remove access covers from each corner of the panel. See Figure 22.
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REFRIGERANT PIPING CONNECTIONS
CONDENSATE DRAIN
CONNECTION
HANGER
CASSETTE BASE HOOK
DETAIL A DETAIL B
LOUVER SWING MOTORS
COVER PANEL
DETAIL C
COVER PANEL SECURING SCREW
PHILLIPS SCREWDRIVER
Figure 23. Install Cover Panel
3/8″ THREADED
ROD
3/4(19)
LEVELING NUT
CEILING
COVERPANEL
Side View Cutaway
CASSETTE BASE CEILING
CASSETTE BASE
FOAM INSULATION
5/32-1/4 (4-6 mm)
5-3/4 (146)
1-3/4 (44)
FOAM INSULATION
COVER PANEL
air out
SUPPLY AIR LOUVER
Figure 24. Cover Panel in Place
9. Tighten the provided screws in the bracket in the cover panel immediately
below each panel hanger. See detail C in Figure 23. Adjust the cover panel by
turning slightly clockwise, if necessary, to make sure that the panel is
properly aligned with the cassette base.
LOOSEN UPPER NUT
CORNER PANEL
TIGHTEN LOWER NUT
Figure 25. Adjust Unit Height Through Corner Panel
10. Continue to tighten the cover panel securing screws until the insulation
between the cover panel and the cassette base has been compressed to
approximately ¼”. The cover panel must form a seal with the ceiling and the
cassette base around the entire perimeter of the unit. See Figure 24.
11. If it is necessary to adjust the cassette height after the cover panel
has been installed, access the leveling nut through the removable access cover
on each corner. See Figure 25.
12. The return air grille must be reinstalled on the cover panel. Align the
four tabs on the grille with the four slots in the cover panel. Tilt the panel
back into place. Press the opposite side of the cover gently until the latches
engage.
18
Network Address and Commissioning
After the system has been installed, each indoor unit must be assigned an
address as part of the commissioning procedure.
Spot Check Instructions
Use the Spot Check Performance tables below and the Manual button on the unit receiver to view diagnostic information the indoor unit.
Table 4. Spot Check Performance Identification Table
No. Content 0 Normal display 1 Communication address of indoor unit 2 Indoor unit capacity (horsepower) 3 Network address of indoor unit 4 The actual setpoint temperature 5 The actual indoor temperature T1 6 The middle coil temperature T2 7 The coil inlet temperature T2A
Recorded Value/Date
8 The coil outlet temperature T2B 9 The actual superheat temperature 10 The actual subcool temperature 11 Error Code 12 Indoor software version 13 End (–)
This Spot Check Performance table is located on the unit service panel. The diagnostic information can also be obtained using the wired remote controller.
Troubleshooting
Digital Display
The indoor unit is equipped with a receiver that has a digital display that
provides an error code. Refer to the table below to view the error codes. The
error code will replace the temperature setting displayed on the receiver. If
more than one error has occurred, the codes will alternate so that all codes
are shown.
Make note of the code (E1, EE, etc.), then reset the display by pressing the
ON/OFF button on the unit controller. Press the ON/OFF button a second time to
reapply power to unit. If the code is still displayed, disconnect and restore
power at the unit disconnect switch or circuit breaker. If the problem was
temporary, the code will not reappear. If the error code reappears after power
has been broken and restored at the disconnect switch or circuit breaker, call
VRF Technical Support 1-800-453-6669.
Receiver/Display
Figure 26. Cover Panel
19
Table 7. Fault Code Display on Indoor Unit Receiver
Error Code FE E0 E1 E2 E3 E4 E5 E6 E7 Eb Ed EE A0 D8 U4 F8
Description No address Mode conflict Communication error between indoor and main outdoor unit T1 (Room temperature sensor) malfunction T2 (Middle of evaporator sensor) malfunction T2B (Outlet of evaporator sensor) malfunction T2A (Inlet of evaporator sensor) malfunction DC fan motor error EEPROM failure EXV malfunction Outdoor unit Fault High Water Alarm Emergency stop Remote off MS self-inspection error MS error
Table 8. Fault Code Display on Controller
Error Code Description
F0
Communication/Address error between indoor units and wired controller
F1
Communication/Wiring error between indoor units and wired controller
E2
Controller temperature sensor error
Technical Support 1-800-4LENNOX
(1-800-453-6669)
technicalsupport@lennoxind.com LennoxCommercial.com
Download the app from the Apple App Store or the Google Play store.
20
References
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