Lennox MS8 SERIES Manual

Page 1 2015 Lennox Industries Inc.
Corp. 1244-L9
Revised January 12, 2015
MS8 SERIES
INSTALLATION AND SERVICE
PROCEDURES
MS8 SERIES UNITS — MINI-SPLIT SINGLE-ZONE SYSTEMS (208-230V)
MS8-CO Air Conditioner Outdoor Unit
MS8-HO Heat Pump Outdoor Unit
MS8-CI Air Conditioner Indoor Unit
MS8-HI Heat Pump Indoor Unit
Wireless
Remote Control
(furnished)
CAUTION
Physical contact with metal edges and corners while
applying excessive force or rapid motion can result in
personal injury. Be aware of, and use caution when
working near these areas during installation or while
servicing this equipment.
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.
Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
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.
IMPORTANT
These units must be installed as a matched system as
specified in the Lennox Engineering Handbook.
TABLE OF CONTENTS
I. OVERVIEW
Shipping and Packing List 2......................
Required Tools and Supplies 3....................
Specifications 4.................................
Model Number Identification 6....................
Unit Dimensions and Weights 6...................
Typical System Component Setup 6...............
II. INSTALLATION
General 8......................................
Clearances 8...................................
Torque Requirements for Caps and Fasteners 8....
Setting Outdoor Unit 8...........................
Repositioning Indoor Air Temperature Sensor 10.....
Indoor Unit Placement and Preparation 10..........
Indoor Unit Cable Connections 14..................
Securing Indoor Unit to Wall Mounting Bracket 15....
Outdoor Unit Cable Connections 16................
Operating Service Valves 19.......................
Line Set Requirements 20.........................
Leak Test and Evacuation 22......................
Unit Start-Up 23.................................
Adding Refrigerant for Longer Line Sets 23..........
Checking Large Line Operating Pressures 23........
Wrapping Bundle 25..............................
Maintenance 26....................................
III. OPERATING THE WIRELESS REMOTE
IV. SYSTEM OPERATION AND SERVICE
System Operational Modes 35.......................
System Functions 43...............................
System Protection Features 44......................
Other Functions 46.................................
Temperature Sensors (location, function and
troubleshooting 47.................................
Indoor and Outdoor Control Parts Identifications 53.....
Indoor and Outdoor Error Codes 57..................
Refrigerant System Flow Diagrams 66................
Typical Unit Wiring Diagrams 67...................
Troubleshooting 72.................................
Major System Components 81.......................
Optional Condensate Pump Wiring Connection 88...........
Disassembly Procedures 88.........................

Page 2
MS8C / MS8H (208-230V)
I. OVERVIEW
Shipping and Packing List
Check the unit components for shipping damage. If you find any damage, immediately contact the last carrier.
1 — ASSEMBLED INDOOR UNIT
The assembled indoor unit will include the following items:
Part Picture Part Name Name Name
Part Picture
Remote control (1 each)
Batteries (AAA)
(2 each)
Wall mounting bracket
screws (5 each)
Foam tube insulation
(for condensate line at
tached to indoor unit)
Wall mounting bracket
(1 each)
1/4” flare nut (45º-degree
SAE style) for small line
(1 each)
Cable routing guide with
mounting hardware (in
cluded with 18, 24 and
30kBtu. The -09 and 12
kBtu sizes include factory
installed cable routing
guide.
1 — ASSEMBLED OUTDOOR UNIT
The assembled outdoor unit will include the following items which are located with the unit:
Parts Figure Quantity Parts Figure Quantity
Auxiliary drain
hole plugs (heat
pump only)
1 - 3 Drain plug
(heat pump only) 1

Page 3 Corp. 1244-L9
Required Tools and Supplies
INSTALLATION TOOLS
Tool Picture Tool Name Tool Name
Tool Picture
A 5/16” female flare to
1/4” male flare adapter
(order Lennox catalog
number Y0576)
Adjustable wrench
Hole core drill
Measuring tape and
knife
Electric drill
Screw driver Multimeter
Allen wrench set
(metric)
Flaring tool and pipe
cutter
Refrigerant leak detector
or a bottle of soapy water
Level
500
Micron gauge
SUPPLIES
The following field-provided supplies may be required for installation
* Line set (see table 9 for requirements)
* Foam insulation (line set and condensate line)
* UV rated protective tape (used to maintain positioning of bundle). Bundle consists of line set, condensate line and wiring
between indoor and outdoor units.
* UV rated cable ties
* Outdoor unit pad
* Outdoor disconnect switch (indoor unit disconnect switch may be required by local code)
* Cable (4-conductor). All need to be rated either 208-240V and sized per NEC).
NOTE — Stranded wire must be used to connect the outdoor unit to the indoor unit. The stranded wire is necessary to ensure
proper system communication and operation.
* Plastic wall screw anchors
* Exterior wall channel (optional)
* Wall sleeve or PVC tubing material to field fabricate a wall sleeve for line set, condensate line and wiring (utility bundle).

Page 4
MS8C / MS8H (208-230V)
Specifications - AIR CONDITIONER SYSTEMS
OUTDOOR UNIT
Nominal Tonnage 0.75 1 1.5 2
Outdoor Unit Model No. MS8CO09P MS8CO12P MS8CO18P MS8CO24P
Connections (in.) Small line o.d.  flare 1/4 1/4 1/4 1/4
Large line o.d.  flare 3/8 3/8 1/2 5/8
Ambient Temperature Operating Range  °F 0  109 0  109 5  109 5  109
1Refrigerant (R410A) furnished 2 lbs. 14 oz. 2 lbs. 14 oz. 3 lbs. 1 oz. 3 lbs. 9 oz.
Outdoor Coil
Net face area  sq. ft. 4.08 4.49 5.96 7.66
Tube diameter  in. 1/4 3/8 1/4 1/4
Number of rows 2 2 2 2
Fins per inch 20 20 20 20
Outdoor Fan
Motor
Diameter  in. 153/4 153/4 201/2 213/4
No. of blades 3 3 3 3
Cfm 940 940 1885 2355
Rpm 680/900 680/900 800 800
Shipping Data  lbs. Outdoor Unit 91 97 110 132
ELECTRICAL DATA
Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V
2Maximum overcurrent protection (amps) 15 15 20 25
3Minimum circuit ampacity 10 10 13 16
Compressor Rated load amps 27.2 6.5 9.7 11
4Compressor Power Input (W) 1075 860 1200 1420
Outdoor Fan
Motor
Rated load amps 0.13 0.13 0.28 1.1
Output (W) 40 30 60 90
MATCHING INDOOR UNIT
Indoor Unit Model No. MS8CI09P MS8CI12P MS8CI18P MS8CI24P
Connections (in.) Small line o.d.  flare 1/4 1/4 1/4 1/4
Large line o.d.  flare 3/8 3/8 1/2 5/8
Indoor Blower Air Volume (cfm)
Turbo 305 335 500 590
High 275 275 460 470
Medium 255 255 385 410
Low 220 220 325 355
Indoor Blower RPM
Turbo 1260 1330 1500 1500
High 1100 1100 1200 1200
Medium 950 950 1050 1050
Low 750 750 900 900
Indoor Coil
Net face area  sq. ft. 1.65 1.65 2.33 3.23
Tube diameter  in. 1/4 1/4 1/4 1/4
Number of rows 2 2 2 2
Fins per inch 20 20 20 18
Indoor Blower Diameter x Length  in. 3.6 x 25.4 3.6 x 25.4 3.9 x 28 3.9 x 30
Type Crossflow Crossflow Crossflow Crossflow
Shipping Data  lbs. Indoor Unit 31 29 38 47
ELECTRICAL DATA
Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V
Rated Load Amps 0.20 0.20 0.32 0.24
Output (W) 20 20 20 60
NOTE  Extremes of operating range are plus 10% and minus 5% of line voltage.
1Refrigerant charge sufficient for 15 ft. of line set.
2HACR type circuit breaker or fuse.
3Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.
4Rated Input

Page 5 Corp. 1244-L9
Specifications - HEAT PUMP SYSTEMS
OUTDOOR UNIT
Nominal Tonnage 0.75 1 1.5 2 2.5
Outdoor Unit Model No. MS8HO09P MS8HO12P MS8HO18P MS8HO24P MS8HO30P
Connections
(in.)
Small line o.d.  flare 1/4 1/4 1/4 1/4 1/4
Large line o.d.  flare 3/8 3/8 1/2 5/8 5/8
Ambient Temperature Operating
Range  °F
Cooling 0  109 0  109 14  109 14  109 5  109
Heating –5  75 –5  75 19  75 19  75 17  75
1Refrigerant (R410A) furnished 2 lbs. 14 oz. 2 lbs. 14 oz. 3 lbs. 1 oz. 3 lbs. 9 oz. 5 lbs. 5 oz.
Outdoor Coil
Net face area  sq. ft. 4.08 4.49 5.96 7.66 7.66
Tube diameter  in. 1/4 3/8 1/4 1/4 5/16
Number of rows 2 2 2 2 2
Fins per inch 20 20 20 20 18
Outdoor Fan
Motor
Diameter  in. 153/4 153/4 201/2 213/4 213/4
No. of blades 3 3 3 3 3
Cfm 940 940 1885 2355 2355
Rpm 680/900 680/900 800 800 830
Shipping Data  lbs. Outdoor Unit 110 119 110 135 164
ELECTRICAL DATA
Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V 208/230V
2Max. overcurrent protection (amps) 15 15 20 25 30
3Minimum circuit ampacity 10 10 13 16 20
Compressor Rated load amps 7.2 6.5 9.7 11 13.5
4Compressor Power Input (W) 860 860 1200 1420 2450
Outdoor Fan
Motor
Rated load amps 0.13 0.13 0.28 1.1 0.45
Output (W) 30 30 60 90 90
MATCHING INDOOR UNIT
Indoor Unit Model No. MS8HI09P MS8HI12P MS8HI18P MS8HI24P MS8HI30P
Connections
(in.)
Small line o.d.  flare 1/4 1/4 1/4 1/4 1/4
Large line o.d.  flare 3/8 3/8 1/2 5/8 5/8
Indoor Blower Air Volume
(cfm)
Turbo 306 335 500 590   
High 277 277 459 470 705
Medium 253 253 383 410 675
Low 218 218 324 355 645
Indoor Blower RPM (Cooling/
Heating)
Turbo 1260/1320 1330/1350 1500/1500 1500/1450   
High 1100/1200 1100/1170 1200/1250 1200/1150 1410/1410
Medium 950/1100 950/1050 1050/1150 1050/1020 1280/1280
Low 750/950 750/950 900/1050 900/950 1200/1200
Indoor Coil
Net face area  sq. ft. 1.65 1.65 2.33 3.23 14.8
Tube diameter  in. 1/4 1/4 1/4 1/4 1/4
Number of rows 2 2 2 2 2
Fins per inch 20 20 20 18 18
Indoor Blower Diameter x Length  in. 3.6 x 25.4 3.6 x 25.4 3.9 x 28 3.9 x 30 4.25 x 20.5
Type Crossflow Crossflow Crossflow Crossflow Crossflow
Shipping Data  lbs. Indoor Unit 37 37 38 47 60
ELECTRICAL DATA
Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V 208/230V
Rated Load Amps 0.20 0.20 0.32 0.24 0.40
Output (W) 20 20 20 60 40
NOTE  Extremes of operating range are plus 10% and minus 5% of line voltage.
1Refrigerant charge sufficient for 15 ft. of line set.
2HACR type circuit breaker or fuse.
3Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.
4Rated Input

Page 6
MS8C / MS8H (208-230V)
Model Number Identification
CIMS −09
Minor Revision
Series Type
Voltage
L = 115V-1phase-60hz
P
−
81 A
Capacity - BTUH
09 = 9,000
12 = 12,000
Number of Zones
Series
Unit Type
CI = Air Conditioner Indoor Unit
HI = Heat Pump Indoor Unit
CO = Air Conditioner Outdoor Unit
HO = Heat Pump Outdoor Unit
MS = Mini-Split
1 = single zone
Unit Dimensions - inches (mm) and Weights
A
B
C
C
INDOOR UNIT
LINE SET, CONDENSATE
DRAIN AND ELECTRICAL
CONNECTIONS
TABLE 1. INDOOR UNIT DIMENSIONS — INCHES
Model Size ABC
-09 and -12 33-3/8 10-7/8 7
-18 37 11-3/4 8
-24 39-3/4 12-3/8 8-5/8
-30 53-1/8 12-7/8 10
LINE SET CONNECTIONS
(COVER REMOVED)
B
A
C
ELECTRICAL CONNECTIONS (UNDER COVER)
LINE SET COVER
TABLE 2. OUTDOOR UNIT DIMENSIONS — INCHES
Model Size ABC
-09 21-1/4 30 12-5/8
-12 23-1/4 30 12-5/8
-18 27-5/8 35 15-5/8
-24 and -30 31-1/8 36 16-7/8

Page 7 Corp. 1244-L9
TABLE 3. OUTDOOR UNIT DIMENSIONS — INCHES (MILLIMETERS)
Typical System Component Setup
INDOOR UNIT
RETURN AIR
SUPPLY AIR
WIRELESS REMOTE
CONTROL
DISPLAY
INDICATORS
COOL
DRY
FAN
HEAT
RUN
TEMPERATURE SETTING,
INDOOR AMBIENT TEMPERATURE
OR ERROR CODE
AIR IN
AIR OUT
A
B
C
D
E
F
H
I
A. Remote control
B. Front panel
C. Filters
D. Guide louver with display
E. Line set (wrapped in foam insulation)
F. UV-rated tape (field-provided)
G. Wiring (field-provided)
H. Condensate drain line (field-provided)
(wrapped in foam insulation). Recommend
installation of a vent when making long
horizontal runs on condensate line.
I. 3-way service valve
J. Access cover for power and control wiring
connections
K. Indoor unit wiring connections (under
access plate)
OUTDOOR UNIT
TERMINAL BLOCK
TO INDOOR
UNIT
TO POWER
SUPPLY
3-WAY SERVICE VALVE
(FLARE CONNECTION)
2-WAY SHUT-OFF VALVE
J
OUTDOOR UNIT (AIR
CONDITIONER OR HEAT
PUMP)
K
REFRIGERANT LINE SET, CONDENSATE LINE
AND INDOOR / OUTDOOR CABLE
G
H
D
L
TAPE
IMPORTANT - The refrigerant
metering device for this system is
located in the outdoor unit. This
makes it necessary to insulate
the refrigerant lines individually to
prevent sweating.
NOTE — temperature can be
displayed in either Fahrenheit or
Celsius.
TYPICAL COMPONENT SETUP
FIGURE 1

Page 8
MS8C / MS8H (208-230V)
II. INSTALLATION
IMPORTANT INSTALLER INFORMATION
* Confirm proper slope and routing of condensate lines to ensure moisture is drained away from the indoor unit (see
procedure starting on page 12)
* Confirm proper insulating, taping and bundling of refrigeration lines, main power lines and drain line (see procedure
starting on pages 25).
General
The MS8 air conditioners and heat pumps are matched with
an indoor evaporator unit to create a ductless system that
uses HFC-410A refrigerant.
Clearances
CAUTION
In order to avoid injury, take proper precaution when lifting
heavy objects.
SYSTEM CLEARANCES
Refer to figure 2 for mandatory installation clearance
requirements.
A
B
C
D
EF
G
H
I
INSTALL UNIT AWAY
FROM WINDOWS
MINIMUM INSTALLATION CLEARANCES
FIGURE 2
TABLE 4
MINIMUM SYSTEM CLEARANCES
ID Location Clearance
Required
AClearance between unit and ceiling. 6 in. (152 mm)
BClearance between unit and floor. 6 ft.(1829 mm)
C / D Clearance to the right and left of unit. 6 in. (152 mm)
EClearance above unit. 2 ft. (610 mm)
FClearance between air inlet and
structure. 12 in. (305 mm)
GClearance between unit and
structures
12 in. (305 mm)
H4 ft. (1219 mm)
I12 in. (305 mm)
Torque Requirements for Caps and Fasteners
When servicing or repairing HVAC components, ensure the
fasteners are appropriately tightened. Table 5 provides
torque values for fasteners.
IMPORTANT
Only use Allen wrenches of sufficient hardness (50Rc -
Rockwell Harness Scale minimum). Fully insert the
wrench into the valve stem recess.
Service valve stems are factory-torqued (from 9 ft-lbs for
small valves, to 25 ft-lbs for large valves) to prevent
refrigerant loss during shipping and handling. Using an
Allen wrench rated at less than 50Rc risks rounding or
breaking off the wrench, or stripping the valve stem
recess.
See the Lennox Service and Application Notes #C-08-1
for further details and information.
TABLE 5
TORQUE REQUIREMENTS
Parts
Recommended Torque
United States
Customary
System*
Metric
(Newton Meter)
Service valve cap 8 ft.- lb. 11
Sheet metal screws 16 in.- lb. 2
Machine screws #10 27 in.- lb. 3
Compressor bolts 7 ft.- lb. 10
Gauge port seal cap 8 ft.- lb. 11
*The United States customary system (also called American system) is a
system of measurement commonly used in the United States. This system
is based on the British Imperial System.

Page 9 Corp. 1244-L9
Setting Outdoor Unit
OUTDOOR UNIT POSITIONING CONSIDERATIONS
(AIR CONDITIONER OR HEAT PUMP)
Consider the following when positioning the unit:
* Some localities are adopting sound ordinances based
on the unit's sound level registered from the adjacent
property, not from the property where the unit is
installed. Install the unit as far as possible from the
property line.
* When possible, do not install the unit directly outside a
window. Glass has a very high level of sound
transmission. For proper placement of unit in relation
to a window see the provided illustration in figure 2.
* Install unit level or, if on a slope, maintain slope
tolerance of 2 degrees [or 2 inches per 5 feet (50 mm
per 1.5 m)] away from building structure.
* Install the unit high enough above the ground or roof to
allow adequate drainage of defrost water and prevent
ice or snow build-up (required for heat pumps).
* In heavy snow areas, do not locate the unit where
drifting will occur. The unit base should be elevated
above the depth of average snows.
* When installed in areas where low ambient
temperatures exist, locate unit so winter prevailing
winds do not blow directly onto outdoor unit.
* Locate unit away from overhanging roof lines which
would allow water or ice to drop on, or in front of, coil
or into unit.
CONDENSATE DRAINAGE REQUIREMENT
(HEAT PUMP ONLY)
Condensate formed during the heating and defrost
processes must be drained from heat pump units. Drain
holes are provided in the base of the units to ensure proper
drainage. Heat pumps must be raised when installed on a
concrete pad or the ground to allow drainage to occur. If the
heat pump unit is installed on a wall mounting bracket,
insert the provided drain connector into one of the 1 inch
(25mm) drain holes and attached a field-provided insulated
drain hose to the connector. Use the provided rubber plugs
to cover any unused drain holes (figure 3).
DRAIN
CONNECTOR
DRAIN PLUGS
CHASSIS
DRAIN
CONNECTOR
CONDENSATE DRAINAGE (HEAT PUMPS
ONLY -- UNIT INSTALLED ON FIELD-PROVIDED
WALL-MOUNTING FRAME)
FIGURE 3
NOTICE
Roof Damage!
This system contains both refrigerant and oil. Some
rubber roofing material may absorb oil. This will cause
the rubber to swell when it comes into contact with oil.
The rubber will then bubble and could cause leaks.
Protect the roof surface to avoid exposure to refrigerant
and oil during service and installation. Failure to follow
this notice could result in damage to roof surface.
SLAB OR ROOF MOUNTING
Install the unit a minimum of 4 inches (102 mm) above the
roof or ground surface to avoid ice build-up around the unit.
Locate the unit above a load bearing wall or area of the roof
that can adequately support the unit. Consult local codes
for rooftop applications (figure 4).
GROUND
LEVEL
BUILDING STRUCTURE
Install unit level or maintain slope tolerance of 2
degrees (or 2 inches per 5 feet [50 mm per 1.5 m])
away from building structure.
SLOPE TOLERANCE
FIGURE 4
SECURING OUTDOOR UNIT TO SLAB OR FRAME
If the outdoor unit is installed on a field-provided slab or
frame, use lag bolts or equivalent to secure the outdoor unit
to the slab or frame (figure 5).
FOUR
FIELD-PROVIDED
ANCHOR BOLTS
SECURING OUTDOOR UNIT TO SLAB
FIGURE 5

Page 10
MS8C / MS8H (208-230V)
PREVAILING WINDS (HEAT PUMP ONLY)
If unit coil cannot be installed away from prevailing winter
winds, a wind barrier should be constructed. Size barrier at
least the same height and width as outdoor unit. Install
barrier 12 inches minimum (305 mm) from the sides of the
unit in the direction of prevailing winds as illustrated.
WIND BARRIER
INLET AIR
DISCHARGE AIR
PREVAILING WINTER WINDS
12” (305 MM) MINIMUM DISTANCE
PREVAILING WIND BARRIER
FIGURE 6
Repositioning Indoor Air Temperature
Sensor
The indoor temperature sensor may be installed in an
alternate location to facilitate shipping (figure 7). It is
recommend that the sensor is relocated to the proper
position shown in figure 8. Refer to the procedure on page
for removal of the front cover.
SENSOR
FIGURE 7
SHIPPING LOCATION
CORRECT
LOCATION
FIGURE 8
Indoor Unit Placement and Preparation
INDOOR UNIT LOCATION
Minimum clearances must be maintained as specified in
figure 2. In addition, the following items should be
considered:
AVOID
1. Direct sunlight if possible.
2. Locating unit less than 3-1/4” (1 meter) away from
combustible materials and vapors.
3. Locating unit near heat sources which could affect
system performance.
DO:
1. Locate the indoor unit where the room can be uniformly
cooled. Install unit as high as possible on the wall for
best performance.
2. Select a wall location that can support the weight of the
unit.
3. Select a location where line set and condensate line will
have the shortest run to the outside of the structure.
4. Allow sufficient space around unit for proper operation
and maintenance.
5. Consider vertical rise between the indoor unit and
outdoor unit. Do not exceed the maximum vertical line
rise of the line set between the indoor unit and outdoor
unit (table 12).
6. Install the indoor unit a minimum of 36 inches (914 mm)
away from any antenna, power cords (lines), radio,
telephone, security system, or intercom. Electrical
noise and radio frequencies from any of these sources
may affect operation.
DETERMINING WALL MOUNTING BRACKET
LOCATION
1. Remove the wall mounting bracket from the indoor unit.
A. Remove the shipping screw that secures the
wall mounting bracket to the rear of the unit.
B. Remove bracket from rear panel of indoor unit.
REAR OF UNIT
WALL MOUNTING BRACKET REMOVAL
FROM INDOOR UNIT
FIGURE 9
2. Determine the optimal exit location for bundle (line set,
condensate line and wiring.
CONDENSATE/
REFRIGERANT
LINE EXIT LEFT
CONDENSATE/
REFRIGERANT LINE
EXIT LEFT REAR
CONDENSATE/
REFRIGERANT
LINE EXIT RIGHT
CONDENSATE/
REFRIGERANT LINE
EXIT RIGHT REAR
(RECOMMENDED)
DETERMINING EXIT LOCATION
FIGURE 10

Page 11 Corp. 1244-L9
NOTE — If opposite-side exit is preferred, see figure 18 to
switch condensate line and drain cap.
3. Use the wall mounting bracket as a template to
determine the exit point for the line set, condensate line
and indoor / outdoor cable (figure 11).
09 −12 kBtu
21-5/16” (542)
10-7/8”
(275)
2” (50)
5” (124)
4”
(100)
2” (50)
2-3/16”
(55)
2-3/16”
(55)
18 kBtu
5/8” (16)
256
27-5/16”
(694) 7-3/4”
(197)
2-1/8”
(55)
33-1/4”
(945)
22-3/16”
(563)
5-5/16”
(136)
11-3/4”
(298)
5/8” (16)
6-1/4”
(160)
4-7/8”
(124)
3-1/4”
(82)
2-3/16”
(55)
2-3/16”
(55)
1-3/4” (45)
CONDENSATE / REFRIGERANT PIPING REAR EXIT LOCATIONS
FIGURE 11

Page 12
MS8C / MS8H (208-230V)
40-1/8” (1018)
27 (685)
7-7/16”
(189)
1-7/16” (36)
3-1/2”
(90)
2-1/2”
(65)
1-3/4”
(45)
2-9/16”
(65)
2-9/16”
(65)
24 kBtu
22-5/8”
(575)
4”
(102) 4”
(102)
2-9/16”
(65)
1“ (25)
2-9/16”
(65)
1” (25)
30 kBtu
FIGURE 12
INSTALLING WALL SLEEVE
1. Prior to making the hole, check to ensure that neither
studs nor plumbing are directly located behind the hole
location.
CAUTION
Electric Shock Hazard. Can cause injury or death. Avoid
location where electric wiring or conduits may be present
inside the wall.
2. Use either a sabre saw, key hole saw or hole-cutting
drill attachment to cut a 2-3/16-inch (55 mm) diameter
hole in the wall. Hole should be at a slight downward
slant - 3/16” to 3/8” (5 to 10 mm) to the outdoor side.
INSIDE
OUTSIDE
BORING HOLE FOR WALL SLEEVE
FIGURE 13
3. Measure the thickness of the wall from the inside edge
to the outside edge and cut a field-provided PVC pipe

Page 13 Corp. 1244-L9
at a slight angle 1/4” (6 mm) shorter than the thickness
of the wall.
CUT PVC FOR WALL SLEEVE AT SLIGHT ANGLE
CUTTING PVC FOR WALL SLEEVE
FIGURE 14
4. Place a field-provided plastic cover over the end of the
pipe that will be visible from the inside wall and insert
the pipe in the wall.
PLASTIC COVER
(FIELD PROVIDED)
INSIDE OUTSIDE
SLIGHT
ANGLE
WALL
PVC PIPE
PVC WALL SLEEVE INSTALLATION
FIGURE 15
SECURE WALL MOUNTING BRACKET TO WALL
Determine that wall will support the weight of the indoor
unit. See table 1 for indoor unit weight. Install the wall
mounting bracket so that is is correctly positioned
horizontally and vertically. The indoor unit must be installed
level on the wall to allow proper condensate drainage.
1. Use a carpenter's level or tape measure to verify the
wall mounting bracket is horizontally level.
2. Secure the wall mounting bracket to the wall using the
provided screws. If possible, align the rear panel screw
holes with wall stud locations marked on the wall.
HINT — Use the wall mounting bracket as a template to
mark locations where screws will be used.
3. Secure the wall mounting bracket to the wall using as
many screws into studs as possible. All other screws
must be secured using plastic wall anchors.
NOTE —It is important to use all screws provided to secure
the wall mounting bracket to the wall. Additional holes may
be drilled through the metal wall mounting bracket to better
secure wall bracket to wall studs.
WALL MOUNTING
BRACKET
SECURING WALL MOUNTING BRACKET TO WALL
FIGURE 16
4. The wall mounting bracket must be installed flush
against the wall so that the indoor unit will be flush after
installation. Any space between the wall and unit will
cause noise and vibration.
5. The wall mounting bracket must be installed
horizontally level on the wall.
6. If the wall is made of brick, concrete or other similar
material, then drill pilot holes in the wall. Insert
field-provided plastic anchors for mounting screws.
DRILL PILOT HOLES
USE ANCHORS
INSTALL ANCHORS
MASONRY APPLICATIONS
FIGURE 17
CONDENSATE DRAIN CONFIGURATION
If the condensate line needs to be moved, use the following
procedure to change the drain line exit location.
NOTICE
Care must be taken when moving the condensate line to
the opposite position to prevent damaging the
condensate line or connector.

Page 14
MS8C / MS8H (208-230V)
CONDENSATE LINE
DRAIN CAP
CONDENSATE LINE
DRAIN PAN
OUTLET
CLAMP
1. Locate the condensate line and the drain cap
located on unit.
2. Remove the clamp which secures the condensate
line to the drain outlet and pull the line to remove it.
3. Apply moderate force to pull off the drain cap from
the unit.
CLAMP HOOK
CLAMP HOOK
LATCH
IMPORTANT — Keep horizontal runs of condensate line external
to unit as short as possible. Condensate line should be properly
sloped to ensure proper drainage.
4. Re-install the drain cap on the opposite side
drain outlet.
5. Slide the condensate line over the opposite
drain outlet and use the clamp to secure the
line.
CLAMP
DRAIN CAP
REAR VIEW OF UNIT
REAR VIEW OF UNIT
REAR VIEW OF UNIT
CHANGING CONDENSATE DRAIN LOCATION
(IF NECESSARY)
FIGURE 18
CONDENSATE DRAIN LINE INSTALLATION
IMPORTANT !
Drain should have a slope of not less than ¼ inch per
foot and be approved corrosion resistance pipe.
1. Confirm proper slope (not less than 1/4 inch per foot)
and routing of condensate lines to ensure moisture is
drained away from the indoor unit (see page 12).
2. Drain should not have any droops or kinks that would
restrict condensate flow and shall be approved
resistant pipe.
3. Condensate drains should be ran as short as possible.
4. Once installation of drain is complete, pour water into
the evaporator drain pan to ensure proper condensate
drainage. If condensate will not properly drain from
evaporator pan, a condensate pump should be added
to system.
5. Confirm proper insulating, taping and bundling of
refrigeration lines, main power lines and drain line (see
page 16).
PREPARING INDOOR UNIT FRAME FOR LEFT- OR
RIGHT-SIDE EXIT OF UTILITY BUNDLE
1. Right- or Left-Side Utility Bundle Exit — Cut out the
corner of the right/left plastic cabinet with a hacksaw or
similar tool (Aor B).
2. Right-Rear or Left-Rear Utility Bundle Exit — The
corner of the plastic cabinet does not need to be
modified.
B
A
RIGHT-SIDE
TUBING OUTLET
PLASTIC
CABINET
LEFT-SIDE
TUBING OUTLET
PLASTIC
CABINET
LEFT- OR RIGHT-SIDE UTILITY EXIT
FIGURE 19
Indoor Unit Cable Connections
NOTE — Stranded wire must be used to connect the
outdoor unit to the indoor unit. The stranded wire is
necessary to ensure proper system communication and
operation.
1. Route the cable (4-conductor, stranded wire, line
voltage, sized per National Electric Code) through the
wall sleeve. Refer to unit nameplate for rated voltage.

Page 15 Corp. 1244-L9
WIRING
FIELD-PROVIDED
PVC WALL SLEEVE
WALL
INDOOR UNIT WALL MOUNTING BRACKET
FEED CABLE THROUGH WALL
FIGURE 20
2. Make sure to provide a sufficient length of cable so that
connections are made to the unit before it is secured to
the wall mounting bracket.
3. Lift indoor unit front panel to access the control box
cover. Remove the screw(s) securing the cover plate.
Remove the plate.
TYPICAL
INDOOR UNIT
CONTROL
BOX COVER
TERMINAL
BLOCK
TYPICAL WIRING
STRAIN RELIEF
ACCESSING THE INDOOR UNIT TERMINAL BLOCK
FIGURE 21
4. Feed cable / wiring through conduit routing guide.
NOTE — A cable routing guide has been factory-installed.
CONDUIT
ROUTING
GUIDE
REAR VIEW OF INDOOR UNIT
TYPICAL INDOOR UNIT INDOOR UNIT) —
SECURING CABLE / WIRES
FIGURE 22
5. Strip the wire insulation to expose the stranded wire.
6. Tightly twist each wire end.
7. Terminal designations for the indoor unit terminal block
are illustrated in figure 30.
8. Use the provided strain relief plate to secure the
terminal block wiring.
TERMINAL
BLOCK
WIRING STRAIN RELIEF
TYPICAL INDOOR UNIT TERMINAL BLOCK
AND STRAIN RELIEF
FIGURE 23
Securing Indoor Unit to Wall Mounting Bracket
1. Shape the refrigerant line set so that it can be guided
either out the back of the indoor unit or through either
side of the indoor unit frame, then through the wall
sleeve to the outside unit.
2. Use field-provided tape to bundle the cable, refrigerant
line set and condensate line together as shown in figure
1.
3. Feed the bundle through the wall sleeve and slide
indoor unit onto upper mounting hooks.

Page 16
MS8C / MS8H (208-230V)
PASS BUNDLE
THROUGH WALL
UPPER MOUNTING
HOOKS
FEED BUNDLE THROUGH WALL SLEEVE
FIGURE 24
1. Secure the indoor unit to the wall bracket using the
lower mounting hooks.
LOWER MOUNTING
HOOKS
SECURE INDOOR UNIT TO WALL MOUNTING
BRACKET
FIGURE 25
2. Carefully bend the bundle (line set, condensate line
and cable) to run along the outside wall toward the
outdoor unit. Downward slope of wall sleeve will ensure
proper condensate drainage.
INDOOR UNIT
SLOPE
BUNDLE THROUGH
WALL SLEEVE
INSTALLED INDOOR UNIT
FIGURE 26
CONDENSATE LINE
1. Use the provided foam insulation to wrap the
factory-installed condensate line.
2. Connect indoor unit factory-installed condensate line
to field-provided condensate drain pipe.
CONNECTING CONDENSATE LINE
FIGURE 27
3. Use tape approved for waterproofing line
connections to secure the field-provided pipe to the
factory-installed condensate line.
TAPING CONDENSATE LINE CONNECTION
FIGURE 28
NOTE — Use a clean, dry cloth to wipe the indoor unit after
installation is complete to remove fingerprints. Do not use
wet cloth, cleansers or solutions.
Outdoor Unit 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.
MAIN SYSTEM CIRCUIT BREAKER AND OUTDOOR
UNIT DISCONNECT SWITCH
The main system circuit breaker and outdoor unit
disconnect switch should be sized per local codes and unit
requirements.
Local codes may require a disconnect between the indoor
and outdoor units.
INDOOR / OUTDOOR CABLE
Wiring must conform to local and national codes.

Page 17 Corp. 1244-L9
NOTE — Stranded wire must be used to connect the
outdoor unit to the indoor unit. The stranded wire is
necessary to ensure proper system communication and
operation.
SUPPLY POWER
Size per unit nameplate and local and national codes.
WIRING CONNECTIONS
1. Remove access panel.
2. Route all wiring to outdoor unit through the wire routing
plate.
3. Connect the control wiring and power supply wiring per
the figures that follow.
4. The unit must be grounded according to local codes.
5. Secure wiring using built-in wire strain relief.
ACCESS PLATE
ROUTE WIRES
THROUGH
ROUTING
PLATE
OUTDOOR UNIT ELECTRICAL CONNECTIONS
FIGURE 29
OUTDOOR UNIT
INDOOR UNIT
N(1) 23L1
L2
L2
L1
POWER
COMMUNICATION
N(1) 23
(L1) (L2)
GROUND
(COMMUNICATION)
TERMINAL LEGEND
N(1) = L1
2 = Communication line
3 = L2
= Ground
IMPORTANT
Check indoor to outdoor field wiring to confirm (N) 1
from indoor goes to (N) 1 outdoor, terminal 2 from indoor
goes to terminal 2 outdoors and terminal 3 indoors goes
to terminal 3 in outdoor.
FIGURE 30
6. Connect the green/yellow ground wire to the ground
terminal.
7. Use the strain relief to secure the cabling (figure 31).
OUTDOOR UNIT
TERMINAL BLOCK
TO POWER SUPPLY
TO INDOOR UNIT
TYPICAL UNIT STRAIN RELIEF
FIGURE 31
WIRING DIAGRAM SYMBOLS AND COLOR CODES
The following tables identify the wiring color codes
and ground symbol used in the following wiring
diagrams.

Page 18
MS8C / MS8H (208-230V)
TABLE 6
WIRE COLOR CODES
CODE CODE COLOR COLOR CODE
OR SYMBOL COLOR
WH WHITE BN BROWN
YE YELLOW BU BLUE
RD RED BK BLACK
YEGN YELLOW
GREEN
TABLE 7
SYMBOLS
SYMBOL PARTS NAME
L1 REACTOR (CHOKE)
PCB1-PCB2 PRINTED CIRCUIT BOARD
S10/S11S40/S70/S80/S90 CONNECTOR
SAT OVERLOAD
COMP COMPRESSOR
Table 8. Valve Caps Torque Recommendations
Outside Diameter Recommended Torque No torque wrench available?
Finger tighten and use an
appropriately sized wrench to turn an
additional:
12
3
4
5
6
7
8
9
10
11 12
1/4 TURN
Inches mm U.S. Metric
1/4” 6.35 11 - 14-3/4 ft.- lb. 15 ~ 20 N*m 1/4 turn
3/8” 9.52 26 - 29-1/2 ft.- lb. 35 ~ 40 N*m 1/2 turn
1/2” 12.70 44-1/4 - 48 ft.- lb. 60 ~ 65 N*m 7/8 turn
5/8” 16 51-5/8 - 55-1/4 ft.- lb. 70 ~ 75 N*m 1 full turn
TO LINE
SET
FLARE CAP
VALVE CAP
OPEN POSITION
CLOSED POSITION
PIN
SERVICE
PORT
SERVICE
PORT CAP
TO OUTDOOR UNIT
Action
Evacuating with a
vacuum pump
Outdoor unit
running
Checking
pressure and
adding refrigerant
CLOSED
FULLY
OPEN
FULLY
OPEN
HOSE WITH
SCHRADER VALVE
3-WAY SERVICE
VALVE
ALLEN WRENCH
(5 MM)
OPEN POSITION
CLOSED POSITION
TO OUTDOOR UNIT
TO LINE
SET
FLARE CAP
REQUIRES FIELD-PROVIDED 5/16”
FEMALE FLARE TO 1/4” MALE FLARE
ADAPTER.
PUSH
FIGURE 32
2-Way
Shut-Off Valve
3-Way
Service Valve
IMPORTANT !
To prevent stripping of the various caps, use an appropriately sized wrench and fit the wrench snugly over the cap before
tightening.

Page 19 Corp. 1244-L9
Operating Service Valves
The large line service valve on the outdoor unit is used to
purge air, test for leaks, check operating pressures and add
refrigerant to system. The 3-way service valve is equipped
with a service port which has a factory-installed valve core.
Figure 32 provides information on how to access and
operate the 3-way service and 2-way shut-off valves.
IMPORTANT
To prevent stripping of the various caps, use an
appropriately sized wrench and fit the wrench snugly over
the cap before tightening.

Page 20
MS8C / MS8H (208-230V)
12
3
4
5
6
7
8
9
10
11 12
1/12
TURN
To Access Service Port:
A service port cap protects the service port core
from contamination and serves as the primary
leak seal.
1. Remove service port cap with an
appropriately sized wrench.
2. Connect gauge set to service port.
3. When testing is complete, replace service
port cap and tighten as follows:
* With torque wrench: Finger tighten and torque cap per table
5.
* Without torque wrench: Finger tighten and use an appropri
ately sized wrench to turn an additional 1/6 turn clockwise.
12
3
4
5
6
7
8
9
10
11 12
1/6
TURN
Reinstall Stem Cap:
Stem cap protects the valve stem from damage
and serves as the primary seal. Replace the
stem cap and tighten as follows:
* With Torque Wrench: Finger tighten, then
torque cap per table 5.
* Without Torque Wrench: Finger tighten,
then use an appropriately sized wrench
to turn an additional 1/12 turn clockwise.
TIGHTENING SERVICE VALVE CAPS
FIGURE 33
USING MANIFOLD GAUGE SET
When checking the system charge, only use a manifold
gauge set that features low-loss, anti-blow-back fittings.
Manifold gauge set used for HFC-410A refrigerant systems
must be capable of handling the higher system operating
pressures. The manifold gauges should be rated for:
* High side — Pressure range of 0 - 800 pound-force per
square inch gauge (psig)
* Low side — Use with 30” vacuum to 250 psig with
dampened speed to 500 psig
* Manifold gauge set hoses must be rated for use up to
800 psig of pressure with a 4000 psig burst rating.
Line Set Requirements
This section provides information on installation of the
field-provided line set.
LINE SET INSTALLATION
Field piping consists of two lines from the outdoor unit to the
indoor unit. Use field-fabricated line set with flare
connections and sizes as listed in table 12.
Seal and isolate the opening where the bundle (including
refrigerant lines) passes through so vibration is not
transmitted to the building. Pay close attention to line set
isolation during installation of any HVAC system. When
properly isolated from building structures (walls, ceilings.
floors), the refrigerant lines will not create unnecessary
vibration and subsequent sound. Line set must be
insulated.
LINE SET LENGTH AND ELEVATION
Capacity is based on standard line set length and maximum
allowable length and elevation (table 12).
Minimum line set length for all sizes is 10 feet (3 meters).
IMPORTANT
Mineral oils are not compatible with HFC-410A.
LINE SET CONNECTIONS
Line connections are made to the outdoor unit using
field-provided flare nuts.
Remove the service valve cover from the outdoor unit.
FLARING PROCEDURE
1. Use a tube cutter to cut the copper line set to the
required length. Cut the lines approximately 12” to 20”
(305 mm to 508 mm) longer than the estimated
required length.
2. Use a pipe reamer or file to remove burrs at the end of
the line set.
BEFORE AFTER
DE-BURRING LINE SET
FIGURE 34
3. Remove flare nut from outdoor unit and slide it onto the
copper tube.
4. Use a flaring tool to flare the end of the copper tube.