Lennox MS8, MS8C, MS8H Installation And Service Procedures

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Page 1

INSTALLATION AND SERVICE

MS8 SERIES

Corp. 1244-L9 Revised January 12, 2015

PROCEDURES

MS8 SERIES UNITS — MINI-SPLIT SINGLE-ZONE SYSTEMS (208-230V)

TABLE OF CONTENTS

I. OVERVIEW

Shipping and Packing List 2......................

MS8-CI Air Conditioner Indoor Unit MS8-HI Heat Pump Indoor Unit

MS8-CO Air Conditioner Outdoor Unit MS8-HO Heat Pump Outdoor 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.

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.........................

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2015 Lennox Industries Inc.

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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

Remote control (1 each)

Batteries (AAA) (2 each)

Wall mounting bracket screws (5 each)

Wall mounting bracket (1 each)

Part Picture

Name Name

1/4” flare nut (45º-degree SAE style) for small line (1 each)

Foam tube insulation (for condensate line at tached to indoor unit)

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

Auxiliary drain hole plugs (heat pump only)

MS8C / MS8H (208-230V)

Figure Quantity Parts Figure Quantity

1 - 3

Drain plug (heat pump only)

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Required Tools and Supplies

INSTALLATION TOOLS

Tool Picture

Tool Name

Screw driver

Electric drill

Measuring tape and knife

Hole core drill

Tool Picture

Tool Name

Multimeter

Allen wrench set (metric)

Flaring tool and pipe cutter

Refrigerant leak detector or a bottle of soapy water

Adjustable wrench

500

Level

A 5/16” female flare to 1/4” male flare adapter (order Lennox catalog

Micron gauge

number Y0576)

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).

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Corp. 1244-L9

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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.)

Ambient Temperature Operating Range  °F 0  109 0  109 5  109 5  109

Refrigerant (R410A) furnished 2 lbs. 14 oz. 2 lbs. 14 oz. 3 lbs. 1 oz. 3 lbs. 9 oz.

Outdoor Coil

Outdoor Fan Motor

Shipping Data  lbs. Outdoor Unit 91 97 110 132

ELECTRICAL DATA

Maximum overcurrent protection (amps) 15 15 20 25

Compressor Rated load amps 27.2 6.5 9.7 11

Compressor Power Input (W)

Outdoor Fan Motor

Connections (in.)

Indoor Blower Air Volume (cfm)

Indoor Blower RPM

Indoor Coil

Indoor Blower

Shipping Data  lbs. Indoor Unit 31 29 38 47

Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V

ELECTRICAL DATA

Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V

NOTE  Extremes of operating range are plus 10% and minus 5% of line voltage.

Refrigerant charge sufficient for 15 ft. of line set.

HACR type circuit breaker or fuse.

Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.

Rated Input

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

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 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

Minimum circuit ampacity 10 10 13 16

1075 860 1200 1420

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

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

Turbo 305 335 500 590

High 275 275 460 470

Medium 255 255 385 410

Low 220 220 325 355

Turbo 1260 1330 1500 1500

High 1100 1100 1200 1200

Medium 950 950 1050 1050

Low 750 750 900 900

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

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

Rated Load Amps 0.20 0.20 0.32 0.24

Output (W) 20 20 20 60

MS8C / MS8H (208-230V)

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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.)

Ambient Temperature Operating Range  °F

Refrigerant (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

Outdoor Fan Motor

Shipping Data  lbs. Outdoor Unit 11 0 119 110 135 164

ELECTRICAL DATA

Line voltage data  60 hz  1ph 208/230V 208/230V 208/230V 208/230V 208/230V

Max. overcurrent protection (amps) 15 15 20 25 30

Compressor Rated load amps 7.2 6.5 9.7 11 13.5

Compressor Power Input (W)

Outdoor Fan Motor

Connections (in.)

Indoor Blower Air Volume (cfm)

Indoor Blower RPM (Cooling/

Heating)

Indoor Coil

Indoor Blower

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

NOTE  Extremes of operating range are plus 10% and minus 5% of line voltage.

Refrigerant charge sufficient for 15 ft. of line set.

HACR type circuit breaker or fuse.

Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.

Rated Input

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

Cooling 0  109 0  109 14  109 14  109 5  109

Heating –5  75 –5  75 19  75 19  75 17  75

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

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

Minimum circuit ampacity 10 10 13 16 20

860 860 1200 1420 2450

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

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

Turbo 306 335 500 590   

High 277 277 459 470 705

Medium 253 253 383 410 675

Low 218 218 324 355 645

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

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

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

Rated Load Amps 0.20 0.20 0.32 0.24 0.40

Output (W) 20 20 20 60 40

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Corp. 1244-L9

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Model Number Identification

−

Series Type

MS = Mini-Split

Series

Unit Type

CI = Air Conditioner Indoor Unit

HI = Heat Pump Indoor Unit

CO = Air Conditioner Outdoor Unit

HO = Heat Pump Outdoor Unit

CIMS

Unit Dimensions - inches (mm) and Weights

INDOOR UNIT

TABLE 1. INDOOR UNIT DIMENSIONS — INCHES

Model Size A B C

-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

−09

1 A

Minor Revision

Number of Zones

1 = single zone

Voltage

L = 115V-1phase-60hz

Capacity - BTUH 09 = 9,000

12 = 12,000

LINE SET, CONDENSATE DRAIN AND ELECTRICAL CONNECTIONS

Model Size A B C

-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

MS8C / MS8H (208-230V)

ELECTRICAL CONNECTIONS (UNDER COVER)

LINE SET CONNECTIONS (COVER REMOVED)

TABLE 2. OUTDOOR UNIT DIMENSIONS — INCHES

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LINE SET COVER

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TABLE 3. OUTDOOR UNIT DIMENSIONS — INCHES (MILLIMETERS)

Typical System Component Setup

TYPICAL COMPONENT SETUP

RETURN AIR

INDOOR UNIT

DISPLAY

INDICATORS

COOL

DRY

FAN

HEAT

RUN

TEMPERATURE SETTING, INDOOR AMBIENT TEMPERATURE OR ERROR CODE

NOTE — temperature can be displayed in either Fahrenheit or Celsius.

SUPPLY AIR

AIR IN

WIRELESS REMOTE

CONTROL

OUTDOOR UNIT (AIR

CONDITIONER OR HEAT

PUMP)

TAPE

REFRIGERANT LINE SET, CONDENSATE LINE

AND INDOOR / OUTDOOR CABLE

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.

OUTDOOR UNIT

TERMINAL BLOCK

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)

AIR OUT

FIGURE 1

2-WAY SHUT-OFF VALVE

3-WAY SERVICE VALVE (FLARE CONNECTION)

TO INDOOR

UNIT

TO POWER

SUPPLY

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Corp. 1244-L9

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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.

MINIMUM INSTALLATION CLEARANCES

TABLE 4

MINIMUM SYSTEM CLEARANCES

ID Location

A Clearance between unit and ceiling. 6 in. (152 mm)

B Clearance between unit and floor. 6 ft.(1829 mm)

C / D Clearance to the right and left of unit. 6 in. (152 mm)

E Clearance above unit. 2 ft. (610 mm)

Clearance between air inlet and

structure.

Clearance between unit and

H 4 ft. (1219 mm)

structures

I 12 in. (305 mm)

Clearance Required

12 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.

INSTALL UNIT AWAY FROM WINDOWS

FIGURE 2

MS8C / MS8H (208-230V)

TABLE 5

TORQUE REQUIREMENTS

Recommended Torque

Parts

Service valve cap 8 ft.- lb. 11

Sheet metal screws 16 in.- lb. 2

Machine screws #10 27 in.- lb. 3

Compressor bolts 7 ft.- lb. 10

Gauge port seal cap 8 ft.- lb. 11

*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.

United States

Customary

System*

Metric

(Newton Meter)

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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).

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).

SLOPE TOLERANCE

BUILDING STRUCTURE

GROUND

LEVEL

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.

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).

CONDENSATE DRAINAGE (HEAT PUMPS

ONLY -- UNIT INSTALLED ON FIELD-PROVIDED

WALL-MOUNTING FRAME)

DRAIN

CONNECTOR

DRAIN

CONNECTOR

DRAIN PLUGS

CHASSIS

FIGURE 3

Page 9

SECURING OUTDOOR UNIT TO SLAB

FOUR FIELD-PROVIDED ANCHOR BOLTS

FIGURE 5

Corp. 1244-L9

Page 10

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.

PREVAILING WIND BARRIER

PREVAILING WINTER WINDS

WIND BARRIER

INLET AIR

12” (305 MM) MINIMUM DISTANCE

DISCHARGE AIR

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.

SHIPPING LOCATION

SENSOR

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.

WALL MOUNTING BRACKET REMOVAL

FROM 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.

FIGURE 7

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:

MS8C / MS8H (208-230V)

Page 10

REAR OF UNIT

FIGURE 9

2. Determine the optimal exit location for bundle (line set, condensate line and wiring.

DETERMINING EXIT LOCATION

CONDENSATE/ REFRIGERANT

LINE EXIT LEFT

CONDENSATE/

REFRIGERANT LINE

EXIT LEFT REAR

CONDENSATE/ REFRIGERANT LINE EXIT RIGHT REAR (RECOMMENDED)

CONDENSATE/ REFRIGERANT LINE EXIT RIGHT

FIGURE 10

Page 11

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

CONDENSATE / REFRIGERANT PIPING REAR EXIT LOCATIONS

2-3/16”

(55)

09 − 12 kBtu

determine the exit point for the line set, condensate line and indoor / outdoor cable (figure 11).

21-5/16” (542)

2-3/16”

(55)

10-7/8”

(275)

18 kBtu

11-3/4”

(298)

3-1/4”

4”

(100)

2-3/16”

(55)

5/8” (16)

(82)

2-1/8”

(55)

2” (50)

22-3/16”

(563)

FIGURE 11

27-5/16”

(694)

5/8” (16)

33-1/4”

(945)

6-1/4”

(160)

5” (124)

7-3/4”

256

2-3/16”

(55)

(197)

2” (50)

1-3/4” (45)

4-7/8”

(124)

5-5/16”

(136)

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Corp. 1244-L9

Page 12

7-7/16”

(189)

40-1/8” (1018)

27 (685)

24 kBtu

30 kBtu

2-9/16”

(65)

2-9/16”

(65)

1” (25)

3-1/2”

(90)

4”

(102)

1-7/16” (36)

22-5/8”

(575)

2-1/2”

(65)

2-9/16”

(65)

4”

(102)

1-3/4”

(45)

2-9/16”

(65)

1“ (25)

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.

MS8C / MS8H (208-230V)

FIGURE 12

BORING HOLE FOR WALL SLEEVE

INSIDE

OUTSIDE

FIGURE 13

3. Measure the thickness of the wall from the inside edge to the outside edge and cut a field-provided PVC pipe

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Page 13

at a slight angle 1/4” (6 mm) shorter than the thickness of the wall.

CUTTING PVC FOR WALL SLEEVE

CUT PVC FOR WALL SLEEVE AT SLIGHT ANGLE

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.

PVC WALL SLEEVE INSTALLATION

PVC PIPE

SLIGHT

PLASTIC COVER

(FIELD PROVIDED)

INSIDE

WALL

ANGLE

OUTSIDE

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.

SECURING WALL MOUNTING BRACKET TO WALL

WALL MOUNTING

BRACKET

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.

MASONRY APPLICATIONS

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.

DRILL PILOT HOLES

USE ANCHORS

INSTALL ANCHORS

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 13

Corp. 1244-L9

Page 14

CHANGING CONDENSATE DRAIN LOCATION

(IF NECESSARY)

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.

REAR VIEW OF UNIT

DRAIN CAP

CLAMP

CONDENSATE LINE

4. Re-install the drain cap on the opposite side drain outlet.

REAR VIEW OF UNIT

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 (A or B).

2. Right-Rear or Left-Rear Utility Bundle Exit — The corner of the plastic cabinet does not need to be modified.

DRAIN CAP

5. Slide the condensate line over the opposite drain outlet and use the clamp to secure the line.

REAR VIEW OF UNIT

DRAIN PAN

OUTLET

CLAMP HOOK

LATCH

CLAMP

CLAMP HOOK

CONDENSATE LINE

IMPORTANT — Keep horizontal runs of condensate line external to unit as short as possible. Condensate line should be properly sloped to ensure proper drainage.

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.

LEFT- OR RIGHT-SIDE UTILITY EXIT

PLASTIC

CABINET

LEFT-SIDE

TUBING OUTLET

PLASTIC CABINET

RIGHT-SIDE TUBING OUTLET

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.

MS8C / MS8H (208-230V)

Page 14

Page 15

FEED CABLE THROUGH WALL

INDOOR UNIT WALL MOUNTING BRACKET

WALL

WIRING

FIELD-PROVIDED

PVC WALL SLEEVE

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 INDOOR UNIT) —

SECURING CABLE / WIRES

CONDUIT ROUTING

GUIDE

REAR VIEW OF INDOOR UNIT

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.

TYPICAL INDOOR UNIT TERMINAL BLOCK

AND STRAIN RELIEF

ACCESSING THE INDOOR UNIT TERMINAL BLOCK

TYPICAL

INDOOR UNIT

CONTROL

BOX COVER

TERMINAL

BLOCK

TYPICAL WIRING

STRAIN RELIEF

FIGURE 21

4. Feed cable / wiring through conduit routing guide.

NOTE — A cable routing guide has been factory-installed.

TERMINAL

BLOCK

WIRING 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

3. Feed the bundle through the wall sleeve and slide indoor unit onto upper mounting hooks.

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Corp. 1244-L9

Page 16

FEED BUNDLE THROUGH WALL SLEEVE

UPPER MOUNTING HOOKS

PASS BUNDLE THROUGH WALL

FIGURE 24

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.

1. Secure the indoor unit to the wall bracket using the lower mounting hooks.

SECURE INDOOR UNIT TO WALL MOUNTING

BRACKET

LOWER MOUNTING HOOKS

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.

INSTALLED INDOOR UNIT

INDOOR UNIT

SLOPE

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.

BUNDLE THROUGH WALL SLEEVE

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.

MS8C / MS8H (208-230V)

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 16

Page 17

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.

COMMUNICATION

N(1)

23L1

OUTDOOR UNIT

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.

OUTDOOR UNIT ELECTRICAL CONNECTIONS

ROUTE WIRES

THROUGH

ROUTING

PLATE

ACCESS PLATE

FIGURE 29

POWER

GROUND

N(1)

(L1)

(L2)

(COMMUNICATION)

INDOOR UNIT

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).

TYPICAL UNIT STRAIN RELIEF

OUTDOOR UNIT

TERMINAL BLOCK

TO INDOOR UNIT

TO POWER SUPPLY

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 17

Corp. 1244-L9

Page 18

TABLE 6

WIRE COLOR CODES

CODE CODE COLOR

WH WHITE BN BROWN

YE YELLOW BU BLUE

RD RED BK BLACK

YEGN

YELLOW

GREEN

COLOR CODE

OR SYMBOL

Table 8. Valve Caps Torque Recommendations

COLOR

TABLE 7

SYMBOLS

SYMBOL PARTS NAME

L1 REACTOR (CHOKE)

PCB1-PCB2 PRINTED CIRCUIT BOARD

S10/S11S40/S70/S80/S90 CONNECTOR

SAT OVERLOAD

COMP COMPRESSOR

Outside Diameter Recommended Torque

Inches

1/4” 6.35 11 - 14-3/4 ft.- lb. 15 ~ 20 N*m

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

Action

mm U.S. Metric

2-Way

Shut-Off Valve

No torque wrench available?

Finger tighten and use an appropriately sized wrench to turn an additional:

1/4 turn

3-Way

Service Valve

HOSE WITH

SCHRADER VALVE

CLOSED

Evacuating with a vacuum pump

REQUIRES FIELD-PROVIDED 5/16” FEMALE FLARE TO 1/4” MALE FLARE ADAPTER.

FULLY OPEN

FLARE CAP

Outdoor unit running

TO LINE

SET

PUSH

VALVE CAP

3-WAY SERVICE

VALV E

OPEN POSITION

CLOSED POSITION

1/4 TURN

SERVICE PORT

FULLY OPEN

SERVICE

PORT CAP

TO OUTDOOR UNIT

Checking pressure and adding refrigerant

TO LINE

SET

FLARE CAP

TO OUTDOOR UNIT

ALLEN WRENCH (5 MM)

OPEN POSITION

CLOSED POSITION

FIGURE 32

IMPORTANT !

To prevent stripping of the various caps, use an appropriately sized wrench and fit the wrench snugly over the cap before tightening.

MS8C / MS8H (208-230V)

Page 18

Page 19

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.

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Corp. 1244-L9

Page 20

TIGHTENING SERVICE VALVE CAPS

To Access Service Port:

1/6

TURN

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

* Without torque wrench: Finger tighten and use an appropri

ately sized wrench to turn an additional 1/6 turn clockwise.

Reinstall Stem Cap:

1/12

TURN

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.

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.

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.

DE-BURRING LINE SET

BEFORE

AFTER

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

MS8C / MS8H (208-230V)

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.

Page 20

Page 21

TABLE 9

REFRIGERANT LINE SET REQUIREMENTS, LENGTH AND HEIGHT LIMITATIONS AND OUTDOOR UNIT

REFRIGERANT METERING DEVICE TYPE (AIR CONDITIONER AND HEAT PUMP SYSTEMS)

System

Size

(kBtu)

Small Line Large Line

-09 1/4 in. (6 mm) 3/8 in. (9.5 mm) 33 feet (10 m) 66 Feet (20 m)

-12

-18 1/4 in. (6 mm) 1/2 in. (12 mm)

-24 1/4 in. (6 mm) 5/8 in. (16 mm)

-30 1/4 in. (6 mm) 5/8 in. 16 mm) 33 feet (10 m) 98 Feet (30 m)

Line Set Diameters

Maximum Line Set

Elevation

49 feet (15 m) 98 Feet (30 m)

Maximum Line Set

Length

Electronic Expansion

Note - Minimum line set length for all sizes is 10 feet (3 meters).

LINE SET LENGTH AND ELEVATION

Refrigerant

Metering Device

Type

Valve

INDOOR UNIT

Maximum Line

Set Elevation

Maximum Line Set Length

OUTDOOR UNIT

Maximum Line Set

Length

INDOOR UNIT

FIGURE 35

TABLE 10

TORQUE SPECIFICATIONS

Outside Diameter Recommended Torque

Inches

1/4” 6.35 15 ft.- lb. 20

3/8” 9.52 26 ft.- lb. 35 1/2 turn

1/2” 12.70 41 ft.- lb. 55 7/8 turn

5/8” 15.88 48 ft.- Ib. 65 1 full turn

mm U.S.

Metric (Newton Meter)

No torque wrench available

Finger tighten and use an appropriately sized wrench to turn an additional:

1/4 turn

OUTDOOR UNIT

Maximum Line Set Elevation

1/4 TURN

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Corp. 1244-L9

Page 22

FLARING TOOLS

MAKING CONNECTIONS AT INDOOR UNIT

(MALE TO FEMALE CONNECTION)

APPLY REFRIGERANT

LUBRICANT HERE

CLUTCH TYPE

WING NUT TYPE

FIGURE 36

TYPICAL LINE SET CONNECTION TO

OUTDOOR UNIT

2-WAY LARGE LINE

SERVICE PORT

APPLY REFRIGERANT LUBRICANT HERE

FIGURE 37

CONNECTING LINE SET TO OUTDOOR UNIT

1. Apply a sealing cap or water-proof tape to prevent dust or water from getting into the refrigerant piping before it is connected.

2. Apply refrigerant lubricant to the matching surfaces of the flared line set and union before connecting them together (figure 37 -- A). This will reduce refrigerant leaks.

3. Align the flared refrigerant line with valve connection, then tighten the flare nut lightly at first to obtain a smooth match (figure 37 - B).

4. Tighten flare nuts. Do not over-tighten a flared joint. Once snug, continue another half turn on each nut. That should provide a gas-tight joint. You may also use a torque wrench to tighten nuts using table 10 recommendations.

CONNECTING LINE SET BETWEEN INDOOR AND OUTDOOR UNITS

1. Apply a sealing cap or water-proof tape to prevent dust or water from getting into the refrigerant piping before it is connected.

2. Apply refrigerant lubricant to the matching surfaces of the flared line set and union before connecting them together (figure 38 -- A).

3. Align the union tube and flared refrigerant line with each other, then tighten the flare nut lightly at first to obtain a smooth match (figure 38 -- B).

MALE FLARE CONNECTION

FIGURE 38

4. Tighten flare nuts. Do not over-tighten a flared joint. Once snug, continue another half turn on each nut. That should be a leak-free joint. You may also use a torque wrench to tighten nuts using table 10 recommendations.

TIGHTEN FLARE NUT

TORQUE

WRENCH

TO INDOOR

UNIT

TO OUTDOOR UNIT

BACKUP

WRENCH

FIGURE 39

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

Leak Test and Evacuation

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

* Pressure in the system rises * Operating current rises * Cooling or heating efficiency drops * Moisture in the refrigerant circuit may freeze and block

capillary tubing (-30 size only)

* Water may lead to corrosion of parts in the refrigeration

system

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

LEAK TEST

1. Connect the manifold gauge set and dry nitrogen gas cylinder to the large line service port as illustrated in figure 40.

2. Pressurize the system to no more than 150 PSIG with dry nitrogen. Check for leaks using soapy water.

3. After the system is found to be free of leaks, relieve the nitrogen pressure by loosening the charge hose

MS8C / MS8H (208-230V)

Page 22

Page 23

connector at the nitrogen cylinder. When the system pressure is reduced to normal, disconnect the hose from the cylinder.

EVACUATION

1. Connect the gauge set, micron gauge and vacuum pump as shown in figure 40.

2. The operation time for evacuation varies with the line set length and capacity of the pump. Allow the pump to operate until the system has been evacuated down to 300 microns. Allow the pump to continue running for an additional 15 minutes.

3. Turn off the pump and leave the connections secured to the 3-way service valve. After five minutes, if the system fails to hold 500 microns or less, check all connections for tight fit and repeat the evacuation procedure.

4. When the desired vacuum is reached, close the low knob of the manifold valve and stop the vacuum pump.

Unit Start-Up

IMPORTANT

If unit is equipped with a crankcase heater, it should be energized 24 hours before unit start-up to prevent compressor damage as a result of slugging.

UNIT START-UP

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

2. Verify that the manifold gauge set is connected as illustrated in figure 40.

3. Open the 3-way service and two-way shut off valves to release the refrigerant charge contained in outdoor unit into the system.

4. Replace the stem caps and tighten to the value listed in table 5.

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

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

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

Adding Refrigerant for Longer Line Set

IMPORTANT

FV50S PVE is the ONLY acceptable oil for Lennox MS7 and MS8 mini-split systems.

Polyvinylether (PVE) is an innovative refrigerant oil specially formulated for hydrofluorocarbon (HFC) refrigeration systems. In addition to providing lubricating properties, it also has a number of other applied advantages that help to increase the reliability of the refrigeration systems where it is applied.

1. Open the low side manifold gauge valve and weigh in liquid refrigerant. Use table 12 to calculate the correct weigh-in charge.

2. Close manifold gauge valves.

Table 11. Line Set Length and Adding Refrigerant

System

Size

(kBtu)

-09

-12

-18

-24

-30

Base Charge (outdoor unit is sufficient for up to listed length below)

26 feet (8 m)

Add Refrigerant

1 ounces per 40 inches (30 grams per meter)

0.71 ounces per 40 inches (20 grams per meter)

1 ounces per 40 inches (30 grams per meter)

2 ounces per 40 inches (50 grams per meter)

Checking Large Line Operating Pressures

Connect gauge set to service port as illustrated in figure 40.

1. Indoor temperatures should be between 70F and 86F (21C and 30C). Outdoor temperatures should be between 23F to 118F (-5C to 48C).

2. Turn the remote control I FEEL function ON.

3. Set all indoor zone remote controls to lowest setting 61F {16C} in the Cool mode.

4. Turn ON the TURBO function. (Note: Allow 3 minutes for compressor delay to time out).

5. Allow the system to operate for a minimum of 10 minutes before doing system checks: Indoor air coil temperature drop (Range of 18 to 24F (10 to 13C). Refrigerant pressure on big line. (Use pressure

ranges noted in table 12 for general guides. Minor variations in these pressures may be expected due to differences in installations).

HEATING

1. Indoor temperatures should be between 61F and 70F (16C and 21C). Outdoor temperatures should be between 5F to 80F (-15C to 27C)

2. Set all indoor zone remote controls to highest setting 86F {30C} in the Heat mode.

3. Turn the remote control I FEEL function ON.

4. Turn ON the TURBO function. (Note: Allow 3 minutes for compressor delay to time out).

5. Allow the system to operate for a minimum of 10 minutes before doing system before checking: Refrigerant pressure on big line. (Use pressure

ranges noted in table 12 for general guides. Minor variations in these pressures may be expected due to differences in installations).

IMPORTANT

If the operating pressures do not fall within the ranges given in the pressure table:

A. Check the indoor or outdoor unit displays for error

code(s).

B. Refer to troubleshooting procedure diagrams in

Service and Installation manual to verify component operation.

If no issues are found, follow the weigh-in charging procedure below to charge the system.

Page 23

Corp. 1244-L9

Page 24

MANIFOLD GAUGE SET CONNECTIONS FOR LEAK TESTING, EVACUATION AND CHARGING

MICRON GAUGE (REQUIRED FOR

EVACUATION

PROCEDURE ONLY)

VACUUM PUMP

Temperature Condition ºF (ºC)

Indoor Outdoor

67 to 80

(19.4 to 26.7)

67 to 80

(19.4 to 26.7)

75 to 95

(23.9 to 35)

43 to 47

(6.1 to 8.3)

500

A34000 1/4 SAE TEE WITH

SWIVEL COUPLER

LOW

NITROGEN

HFC-410A

FIGURE 40

TABLE 12

LINE SET LENGTH AND ADDING REFRIGERANT

System

Size

(kBtu)

09K Turbo High 152 PSIG (1.05 MPa) 12K Turbo High 135 PSIG (0.93 MPa) 18K Turbo High 131 to 160 PSIG (0.9 to 1.1 MPa) 24K Turbo High 116 to 145 PSIG (0.8 to 1.0 MPa) 30k Turbo High 116 PSIG (0.8 MPa)

09K Turbo High 380 PSIG (2.62 MPa) 12K Turbo High 402 PSIG (2.77 MPa) 18K Turbo High 319 to 348 PSIG (2.2 to 2.4 MPa) 24K Turbo High 363 to 392 PSIG (2.5 to 2.7 MPa) 30K Turbo High 535 PSIG (3.69 MPa)

Indoor

Fan Mode

Cooling Mode

Heating Mode

Outdoor

Fan Mode

Standard Suction / Vapor Operating

HIGH

MANIFOLD GAUGE SET

Pressure Ranges

Line Set

Length

25 feet

(7.62 m)

25 feet

(7.62 m)

Note - Minimum line set length for all sizes is 10 feet (3 meters).

USING HFC-410A WEIGH-IN METHOD

Amount specified on

nameplate

Adjust amount. for variation in line set

length listed in table 12.

NOTE — The above nameplate is for illustration purposes only. Go to actual nameplate on outdoor unit for charge information.

MS8C / MS8H (208-230V)

Total Charge

FIGURE 41

Page 24

Page 25

Wrapping Bundle

CONTROL WIRING BUNDLING

After system has been tested for leaks and proper operation has been verified, use tape to bundle the control wiring, line set and condensate line.

1. Wrap insulation material around the line set connection between the indoor and outdoor units.

2. Insulate remaining sections of line set and condensate line.

INSULATE AND TAPE LINE SET CONNECTION

PLASTIC WIRE TIES

TO INDOOR UNIT

INSULATION MATERIAL

TO OUTDOOR UNIT

FIGURE 42

INSULATE LINE SET

INSULATION MATERIAL

INSULATE AND TAPE LINE SET

CONTROL WIRING

BETWEEN INDOOR AND

OUTDOOR UNITS

WRAP WITH VINYL TAPE (NARROW)

FIGURE 45

4. Tape the control wiring to the line set bundle (figure 45).

5. Start from the bottom of the bundle at the outdoor unit and use tape to bundle the condensate line with the control wiring and line set (figure 46).

UTILITY BUNDLE (CABLE, LINE SET AND

CONDENSATE DRAIN LINE)

CONDENSATE LINE

BETWEEN INDOOR

CABLE

AND OUTDOOR

UNITS

INSULATED LINE SET

WRAP WITH VINYL TAPE (NARROW) (CABLE)

WRAP WITH VINYL TAPE (WIDE)

MINIMUM

5/16” (8 MM)

LINE SET

MINIMUM 5/16” (8 MM)

FIGURE 43

3. Start from the bottom at the outdoor unit and use tape to bundle the insulated line set together with tape (figure 44).

TAPE LINE SET

LINE SET

WIDE VINYL

TAPE

WRAP WITH VINYL TAPE

FIGURE 44

FIGURE 46

1. Clamp bundle to wall. Use one clamp approximately every 47” (1194 mm).

2. Apply sealant around the utility bundle on the outside of the wall sleeve to prevent rain and outdoor air from entering the room.

SEAL WALL SLEEVE AROUND BUNDLE

APPLY SEALANT HERE

BUNDLE

FIGURE 47

Page 25

Corp. 1244-L9

Page 26

3. An optional field-provided exterior wall channel may be used in lieu of taping the utility bundle (see figure 48) to protect the bundle from UV rays, weather, etc.

OPTIONAL EXTERIOR WALL CHANNEL

FIELD-PROVIDED PROTECTIVE

CHANNEL (UTILITY BUNDLE

INSIDE)

FIGURE 48

Maintenance

OUTDOOR UNIT

1. Ensure power is off before cleaning.

2. It may be necessary to wash the outdoor coil more frequently if it is exposed to substances which are corrosive or which block airflow across the coil (e.g., pet urine, cottonwood seeds, fertilizers, fluids that may contain high levels of corrosive chemicals such as salts).

3. Outdoor Coil (Sea Coast) — Moist air in ocean locations can carry salt, which is corrosive to most metal. Units that are located near the ocean require frequent inspections and maintenance. These inspections will determine the need to wash the unit including the outdoor coil. Consult your installing contractor for proper intervals/procedures for your geographic area or service contract.

4. Outdoor unit fan motor is pre-lubricated and sealed. No further lubrication is needed.

5. Visually inspect all connecting lines, joints and coils for evidence of oil leaks.

6. Check all wiring for loose connections.

7. Check for correct voltage at unit (unit operating).

INDOOR UNIT

1. Clean or change filters.

2. Check all wiring for loose connections

3. Check for correct voltage at unit (blower operating).

4. Clean coil, if necessary.

5. Check connecting lines and coils for signs of oil leaks.

6. Check condensate line and clean, if necessary.

NOTE

— The filter must be in place and the front panel must

be closed any time the unit is in operation.

MS8C / MS8H (208-230V)

Page 26

Page 27

III. OPERATING THE WIRELESS REMOTE

Wireless Remote Functions

The wireless remote control provides system control to the homeowner at the touch of a button. The indoor unit and remote control send information back and forth continuously. The remote control must be placed on a table or other surface in direct line of sight with the indoor unit infrared receiver. The remote control should not be placed in a drawer. Make sure that there are no obstructions between the indoor unit receiver and the remote control. Do not drop the control or spill liquid on the remote control.

POWER button

Press this button once to turn system on. Press again to turn the system off. When the POWER button is used to turn the system OFF, it overrides the Sleep Timer function (when it is in use).

+/- buttons

Use plus (+) and minus (-) but tons to adjust the temperature setting up and down.

NOTE - The temperature cannot be adjusted when the system is in AUTO mode.

FAN button

Press this button to select fan speed. AUTO fan is the default setting. In AUTO fan mode, the indoor fan speed is determined by the indoor ambient tempera ture. Press FAN button to step through FAN setting selections: AUTO, low speed, medium speed and high speed. Selected fan speed is shown at the top of the remote control dis play.

AUTO

Low Medium High

NOTE - The fan speed is not adjustable during DEHUMIDIFI CATION mode operation. The

low fan speed is necessary to ensure optimal humidity control.

MODE button

Press this button to select system operating modes. AUTO mode is the default setting. Press MODE button again to select COOL mode, again for DEHUMIDIFICATION mode, again for FAN mode and again for HEAT mode (heat pumps only).

Selected mode is displayed on both remote and indoor unit cover panel.

AUTO

COOL

DEHUMIDIFICATION

FAN

HEAT

I FEEL button

Press the I FEEL button to acti vate the I FEEL feature. When the I FEEL icon appears, tem perature sensor in remote control is used to initiate heating or cool ing demands. Press

I FEEL button again to cancel I FEEL feature and transfer room

temperature sensing back to sensor in indoor unit.

UNUSED buttons

These buttons are not functional in the MS8 system.

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Corp. 1244-L9

Page 28

Wireless Remote Functions (Continued)

SWITCH FROM °C TO °F

With system OFF, press MODE and - buttons simultaneously to switch from Centigrade to Fahrenheit. Current selection is displayed to the right of the temperature display.

CLOCK button

Use the CLOCK button to adjust the time displayed on the remote control. Press the CLOCK button once. The clock icon will flash. Within 2 seconds, use the and + buttons to adjust the time down or up in one-minute incre ments. Press the button continu ously to adjust the time in 10-minute increments. Press the CLOCK button again when cor rect time is displayed.

BLOW button

Use the BLOW button to extend low speed blower operation for 10 minutes at the end of a cooling demand.

The extended fan (BLOW) operation ensures that excess moisture is removed from the indoor coil before the blower shuts off.

Press the BLOW button once to initiate extended blower opera tion. Fan operation ends after 10 minutes. The extended fan (BLOW) operation icon is displayed when the feature is turned on.

Extended fan (BLOW) operation is available in cooling or dehu midification modes; extended fan (BLOW) operation is not avail able in AUTO, heating or fan mode.

LOUVER SETTING button

See page for complete details on louver operation.

SLEEP button

Use the SLEEP button to initiate or cancel the sleep function. Press SLEEP button. When sleep icon appears, press TIMER OFF button and use and + buttons to set time for sys tem shutdown. When desired time is displayed, press TIMER OFF button again. Press SLEEP button to cancel sleep function. In cooling mode, SLEEP function increases temperature (+1.8°F per hour) over a two-hour period after the selected sleep time. In heating mode, SLEEP function decreases temperature (-1.8°F per hour) over a two-hour period after the selected sleep time.

NOTE - The sleep function is not available in AUTO or FAN modes.

TURBO button

Use the TURBO button to initiate or cancel high-speed fan operation to accelerate cooling or heating of the ambient room temperature. The turbo icon is displayed when the function is turned on.

MS8C / MS8H (208-230V)

Page 28

Page 29

Wireless Remote Functions (Continued)

LOUVER SETTING button

Use the LOUVER SETTING button to choose a preferred setting for the indoor unit directional louver.

NOTE - Actual louver position is different than what is shown on remote icon. See comparison to the right.

Press the LOUVER SETTING button once to activate the full-range oscillation mode from top to bottom, then back again. The louver icon will appear in the lower section of the screen.

Press the LOUVER SETTING button again to turn the feature OFF. The louver will return to the default setting.

Press the LOUVER SETTING button twice and continue to press the button to scroll through the five available fixed positions

AND three other oscillating positions.

To return the louver to the default position, press the LOUVER SETTING button until the icon disappears.

Default Louver Positions

When the louver setting icon is not displayed, the louver is in the DEFAULT position.

When the remote control is powered OFF, the default position is fully closed.

When the remote control is set so that the unit is in COOLING, AUTO COOLING, or DEHUMIDIFICATION mode, the louver is in a fixed upward position .

When the remote control is set so that the unit is in HEAT or AUTO HEATING mode and the outdoor unit is OFF, the louver is fixed in the second position pointed upward. If the outdoor unit is ON, the louver is fixed in a downward position .

When the remote is set for continuous indoor fan to be ON, the louver is fixed in an upward position .

REMOTE

CONTROL ICON

POSITION

LOUVER

SETTING

ACTUAL LOUVER

POSITION

o r a b o v e

ICON

Page 29

Corp. 1244-L9

Page 30

Wireless Remote Functions (Continued)

TIMER ON button

Use the TIMER ON button to ini tiate or cancel a single timed-on event. Use this feature to bring the system on just before you re turn home or just before you wake in the morning.

Press the TIMER ON button once. The clock icon disappears and a time setting ap pears with the word ON flashing at the right. Use the - and + keys to adjust the time setting to the desired time for the system to begin operation. Press the TIM ER ON button again to accept the setting. When suc cessfully set, the word ON will appear to the right of the current time display. Press the TIMER ON button again if you want to cancel the timed-on event.

TIMER OFF button

Use the TIMER OFF button to initiate or cancel a single timedoff event. Use this feature to turn the system off just after you leave the house or just after you go to bed at night.

Use the same method described above to set the de sired time for the system to stop operation. When successfully set, the word OFF will appear to the right of the current time dis play. Press the TIMER OFF but ton again if you want to cancel the timed-off event.

REMOTE LOCK

Press - and + buttons simulta neously to either lock or unlock the remote control buttons. When locked, the icon is displayed.

TEMP button

Use the TEMP button to change the temperature display shown on the remote control. When ini tially powered on, the current temperature setting is displayed, along with the icon.

Press the TEMP button once to alter the display to show the current indoor ambient tempera ture, along with the icon. The indoor temperature sensor is in the indoor unit.

Press the TEMP button again to display the outdoor ambient tem perature icon. The outdoor ambient temperature display is not available on this system.

On occasion, the remote control will display the temperature that was not selected (indoor ambient temperature or setting tempera ture). The selected temperature will return to the display screen after 5 seconds.

NOTE - The TEMP button can also be used to temporarily dis play the indoor ambient tempera ture on the indoor unit display panel.

LIGHT button

Use the LIGHT button to turn the indoor unit display light on and off. When the light is on, the icon appears on the remote con trol.

MS8C / MS8H (208-230V)

Page 30

Page 31

System Start Up Using Wireless Remote

General Operation 1 - Press POWER button once to turn system on. 2 - Press MODE button until desired operating

mode icon is displayed.

NOTE - When AUTO mode is selected, the temperature setting is not displayed on the remote control. The - and + buttons cannot be used to make temperature setting selections.

3 - Press - or + buttons until desired temperature

setting is displayed.

NOTE - Skip this step in AUTO mode.

4 - Press FAN button until desired fan speed icon

is displayed.

NOTE - Fan speed will be set to low if

DEHUMIDIFICATION mode has been selected.

5 - Press OSCILLATE button. Indoor unit

directional louver will open and begin to oscillate. If a single setting is preferred, press button again when louver is in the desired position. Louver will remain in desired position until system is powered off.

Special Functions 6 - Press SLEEP button to initiate sleep function.

Then press TIMER OFF button to set timed off.

7 - Use TIMER ON and TIMER OFF buttons to

schedule desired timed on and off settings.

8 - Use LIGHT button to set display light on or off. 9 - Use BLOW button to turn on and off extended

fan operation feature.

10-Use TURBO button to turn accelerated fan

speed on or off.

11- Use I FEEL button to use temperature sensor

in remote control to initiate cooling and heat ing demands.

Page 31

Corp. 1244-L9

Page 32

Remote Control Batteries

The wireless remote control requires two AAA, 1.5V batteries. DO NOT attempt to use any other type of battery.

Follow the steps below and in the illustrations to replace the batteries when necessary.

1 - Remove screw that secures the battery access panel to

the remote. Place thumb on at the top of the battery access panel on the back of the remote control. Slide the panel in the direction of the arrow.

2 - Remove the existing AAA, 1.5V batteries. 3 - Replace batteries with fully charged AAA, 1.5V batteries.

NOTE - Pay attention to proper polarity of batteries. Remote control will not operate if batteries are improperly installed.

4 - Reposition battery access panel and slide forward until

panel snaps into locked position. Reinsert screw.

SCREW

IMPORTANT !

D If wireless remote will not be used for a long period of

time, remove batteries to avoid damage to the control.

D To verify that the remote control is transmitting com

mands to the indoor unit, press any command key and a wireless icon will appear in the upper right-hand corner of the remote control display.

D When being used in the I FEEL mode, t

he remote con trol must be placed on a table or other surface in direct line of sight with the indoor unit infrared receiver. The control should not be placed in a drawer. Make sure that there are no obstructions between the indoor unit receiv er and the remote control.

D Remote should remain within its receiving range to ensure proper system control.

Control should be kept at least 3 feet (914mm) away from other electrical appliances (televisions, stereos, etc.) to prevent signal interference.

D If remote control operation becomes erratic, remove batteries. Wait 30 seconds and

reinsert batteries. If proper remote operation is not restored, replace batteries.

MS8C / MS8H (208-230V)

Page 32

Page 33

Auto ON Switch

If the remote control is lost or damaged, or if charged AAA, 1.5V batteries are not available, the Auto ON switch can be used to turn the system on or off.

The Auto ON switch is located behind the cov er panel on the indoor unit. Lift the front panel and press the ON button once briefly to start the system. To stop emergency operation, push the ON button again.

IMPORTANT !

The Auto ON button initiates operation in the AUTO mode. The temperature and fan speed are not adjustable in the AUTO mode.

AUTO Switch

(Recessed)

AUTO

PENCIL OR OTHER

NON-METALLIC OBJECT

AUTO Switch

(Not Recessed)

PRESS

WITH

FINGER

AUTO BUTTON

Page 33

Corp. 1244-L9

Page 34

Homeowner Maintenance

WARNING!

Turn off all power to unit at system disconnect switch (at the outdoor unit) or circuit breaker before performing any main tenance procedures! Failure to follow this warning could lead to personal injury or death.

Coil fins are very sharp! Take care not to touch the fins in or der to avoid injury.

Indoor Unit Filters

The indoor unit filter should be cleaned every three months, or more frequently, if necessary.

Follow the steps below and in the illustrations to clean the filters.

1 - Pivot indoor unit front panel out and up to access filters.

2 - Gently pull each filter outward, then down to remove the filters

from the unit

3 - Use a vacuum cleaner to remove dust and dirt from each filter

or wash the filters with warm water and a mild detergent. Rinse filters thoroughly with clean water and set aside to air dry.

CAUTION!

Do not use hot water to clean the filters. Exposure to wa ter temperatures above 113°F (45°C) will damage filter media and frame.

4 - Reinsert clean, dry filters and close unit front panel. Restore

power to unit.

Indoor Unit

Check to make sure that there are no objects on top of unit or around unit that may be obstructing air flow. Check to make sure that indoor unit and wall bracket are secure and have not been damaged. Use a clean, dry cloth to gently remove dust from the outer surface of the indoor unit. The cloth may be slightly dampened with warm water, if necessary. Do not use soap or other cleaners.

CAUTION!

Hot water, soaps or other cleaning agents may damage indoor unit cabinet or display panel. Do not use hot water (above 113°F [45°C]). Cloth must be damp only (NEVER WET) to avoid damage to display. Do not use soap or other cleaning agents (window cleaner, abrasive cleansers, etc.) to clean the indoor unit cabinet.

Outdoor Unit

Check to make sure that there are no objects on top of unit or around unit that may be obstructing air flow. If the outdoor unit is installed on a wall bracket, make sure that bracket is secure and has not been damaged. Use a clean, slightly dampened cloth to gently remove dust from the outer surface of the outdoor unit. Do not use soap or other cleaners and DO NOT spray water into unit.

WARNING!

SHOCK HAZARD! DO NOT SPRAY water into outdoor unit. Failure to follow this warning could lead to electrical shock, resulting in personal injury or death.

Lennox recommends annual inspection by a licensed professional service technician, or equiva lent.

MS8C / MS8H (208-230V)

Page 34

Page 35

IV. SYSTEM OPERATION AND SERVICE

SYSTEM OPERATIONAL MODES

Air conditioner systems have four modes of operation. Heat pumps have five operational modes. These modes are:

* Auto * Cooling * Dehumidification * Fan * Heat (HP model only)

AUTO MODE

Auto Mode - Non-adjustable indoor temperature set points are 68F°and 77°F (20°C and 25°C)

NOTE — Reversing valve is de-energized in cooling mode and energized in heating mode.

AUTO MODE

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

If room ambient temperature is equal to or greater than 77°F (25°C), the unit cycles cooling ON. When the room ambient temperature is equal to or less than 77°F (25°C) minus 3.6°F (2°C), the compressor will cycle OFF, the outdoor fan will cycle OFF 60 seconds later. The indoor fan will run continuously at a preset speed until system has a heating demand or Auto Mode is switched OFF.

If room temperature is equal to or less than 64°F (18°C) plus 3.6°F (2 C), the heating will cycle ON when room temperature is equal to or greater than 64°F (18°C) plus 9.0°F (5°C), the compressor will cycle OFF. The outdoor fan will cycle OFF 60 seconds later. The indoor fan will cycle OFF after 60 seconds on low speed.

FIGURE 49

Protective Functions

Auto — Cool

Auto — Heat

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Corp. 1244-L9

Page 36

COOLING MODE (I FEEL MODE OFF)

Cool Mode - Indoor temperature set point range is 61°F and 86°F (16°C and 30°C)

NOTE — Reversing valve is de-energized in cooling mode.

COOLING MODE

FIGURE 50

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

Cool ON

If room ambient temperature is equal to or greater than the remote control set point, the unit cycles cooling ON.

Cool OFF

If room temperature is equal to or less than remote control set point minus 3.6ºF (2ºC), the compressor will cycle OFF. The outdoor fan will cycle OFF 30 seconds later. The indoor fan will continue to operate.

Indoor Fan Operation - Cooling

1. The indoor fan runs continuously.

2. The fan speed is determined by the difference between the room ambient temperature and the remote set point temperature.

INDOOR FAN OPERATION - COOLING

MS8C / MS8H (208-230V)

FIGURE 51

Page 36

Page 37

COOLING MODE (I FEEL MODE ON)

Cool Mode - Indoor temperature set point range is 61°F and 86°F (16°C and 30°C)

NOTE — Reversing valve is de-energized in cooling mode.

COOLING MODE

FIGURE 52

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

I FEEL Mode

The indoor unit will cycle the system to maintain the remote control temperature setting. The remote control will send its temperature setting to the indoor unit every 10 minutes. If the indoor unit does not receive the remote control signal after 11 minutes, the system will revert back to maintaining the setting of the return air sensor. If main power is interrupted to system, I FEEL mode will need to be reset by turning the I FEEL mode OFF and ON.

NOTE - For I FEEL mode to work, infrared eye on remote must be aimed at indoor front panel.

Cool ON

If room ambient temperature is equal to or greater 1.8°F (1°C) than the remote control setpoint, the unit cycles cooling ON.

Cool OFF

If room temperature is equal to or less than remote control setpoint minus 1.8°F (1°C), the compressor will cycle OFF. The outdoor fan will cycle OFF 30 seconds later. The indoor fan will continue to operate.

Indoor Fan Operation - Cooling

1. The indoor fan runs continuously.

2. The fan speed is determined by the difference between the room ambient temperature and the remote set point temperature.

INDOOR FAN OPERATION - COOLING

FIGURE 53

Page 37

Corp. 1244-L9

Page 38

DEHUMIDIFICATION MODE (I FEEL MODE OFF)

Dehumidification Mode - Indoor temperature set point range is 61°and 86°F (16°C and 30°C)

DEHUMIDIFICATION MODE

FIGURE 54

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

Cool ON

If room ambient temperature is equal to or greater than the remote control set point, the unit cycles cooling ON.

Cool OFF

Indoor Fan Operation - Dehumidification

The indoor fan runs continuously at low speed.

FAN MODE

The indoor fan will run at a preset speed and the compressor, outdoor fan and reversing valve (heat pump only) will be off.

MS8C / MS8H (208-230V)

Page 38

Page 39

DEHUMIDIFICATION MODE (I FEEL MODE ON)

Dehumidification Mode - Indoor temperature set point range is 61°F and 86°F (16°C and 30°C)

DEHUMIDIFICATION MODE

FIGURE 55

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

Cool ON

If room ambient temperature is equal to or greater than the remote control set point, the unit cycles cooling ON.

Cool OFF

Indoor Fan Operation - Dehumidification

The indoor fan runs continuously at low speed.

FAN MODE

The indoor fan will run at a preset speed and the compressor, outdoor fan and reversing valve (heat pump only) will be off.

Page 39

Corp. 1244-L9

Page 40

HEAT MODE (I FEEL MODE OFF)

Heat Mode - Indoor temperature set point range is 61°F and 86°F (16°C and 30°C)

NOTE — Reversing valve is energized in heating mode.

HEATING MODE

FIGURE 56

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

Heat ON

If room ambient temperature is equal to or less than the remote control set point plus 3.6ºF (2ºC), the unit cycles heat ON. If it has been three (3) minutes since the last heat demand, the compressor and outdoor fan will cycle ON. The indoor fan will operate according to the cold blow prevention function.

Heat OFF

If room temperature is equal to or greater than remote control set point plus 9ºF (5ºC), the compressor will cycle OFF. The outdoor fan will cycle OFF 30 seconds later. The indoor fan will operate for 60 seconds after heat cycles OFF.

Indoor Fan Operation - Heating

The fan speed is determined by the difference between the room ambient temperature and the remote set point temperature.

Cold Blow Prevention

The system prevents cold air from blowing into space during heating operation. After three (3) minute time delay, one of the following indoor fan cycles will occur:

* If the indoor ambient temperature is greater than 75ºF (24ºC): If the coil temperature is equal to or greater than 104ºF

(40ºC) the indoor fan will run at low speed for 1 to 2 minutes. If during that time the coil temperature rises above 106ºF (42ºC), the indoor fan will ramp to a preprogrammed heat speed for those conditions.

* If the indoor ambient temperature is less than 75ºF (24ºC): If the coil temperature is equal to or greater than 106ºF (42ºC)

the indoor fan will run at low speed and within one minute, the indoor fan will ramp to preprogrammed heat speed for those conditions.

Reversing Valve Operation

The reversing valve is energized in heating and will stay energized for two minutes after the compressor is de-energized. The reversing valve is energized 2 seconds before the compressor is energized.

MS8C / MS8H (208-230V)

Page 40

Page 41

HEAT MODE (I FEEL MODE ON)

Heat Mode - Indoor temperature set point range is 61°F and 86°F (16°C and 30°C)

NOTE — Reversing valve is energized in heating mode.

HEATING MODE

FIGURE 57

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. Minimum three (3) minute compressor time delay between operating cycles.

2. Minimum six (6) minute compressor run time between operating cycles.

Heat ON

If room ambient temperature is equal to or less than the remote control setpoint - 1.8°F (1°C) the unit cycles heating ON. If it has been 3 minutes since the last heating demand, the compressor and outdoor fan motor will cycle ON. The indoor fan will operate according to the Cold Blow Prevention function.

Heat OFF

If room temperature is equal to or greater than remote control setpoint + 1.8°F (1 °C ), the compressor will cycle OFF. The outdoor fan will cycle OFF 30 seconds later. The indoor fan will operate for 60 seconds after heating cycles OFF.

Indoor Fan Operation - Heating

The fan speed is determined by the difference between the room ambient temperature and the remote set point temperature.

Cold Blow Prevention

The system prevents cold air from blowing into space during heating operation. After three (3) minute time delay, one of the following indoor fan cycles will occur:

* If the indoor ambient temperature is greater than 75ºF (24ºC): If the coil temperature is equal to or greater than 104ºF

* If the indoor ambient temperature is less than 75ºF (24ºC): If the coil temperature is equal to or greater than 106ºF (42ºC)

the indoor fan will run at low speed and within one minute, the indoor fan will ramp to preprogrammed heat speed for those conditions.

Reversing Valve Operation

The reversing valve is energized in heating and will stay energized for 2 minutes after the compressor is de-energized. The reversing valve is energized 2 seconds before the compressor is energized.

Page 41

Corp. 1244-L9

Page 42

DEFROST MODE (HEAT PUMP ONLY)

The front panel indicator will display an H1 code when the system is in defrost. The system will perform as indicated in the figure 58.

DEFROST MODE

FIGURE 58

Protective Functions

Delays that normally protect the compressor are disabled during defrost cycles:

1. There is no three (3) minute minimum compressor time off delay between operating cycles.

2. There is no six (6) minute minimum compressor operating cycles.

Defrost Initiation

Defrost is controlled by the microprocessor and will be initiated when:

* System is in heating mode, * System has been running for at least six (6) minutes, or * Successive heating operations of more than 45 minutes or accumulated heating time more than 90 minutes. * One of the conditions listed under defrost termination that last longer than three (3) minutes.

Defrost Termination

Defrost is controlled by the microprocessor and will be terminated when:

* Outdoor coil temperature goes above 55ºF (13ºC) +

5ºF (+ 3ºC)

* Defrost time is a maximum of ten (10) minutes.

Cold Blow Prevention

The system prevents cold air from blowing into space during heating operation. After three (3) minute time delay, one of the following indoor fan cycles will occur:

* If the indoor ambient temperature is greater than 75ºF (24ºC): If the coil temperature is equal to or greater than 104ºF

* If the indoor ambient temperature is less than 75ºF (24ºC): If the coil temperature is equal to or greater than 106ºF (42ºC)

the indoor fan will run at low speed and within one minute, the indoor fan will ramp to preprogrammed heat speed for those conditions.

Defrost Test Function

When the unit is in Heat mode and set temperature is 61 F (16 C), press ”+, -, +, -, +, -” successively for 5 seconds. The indoor and outdoor unit will enter defrost test function.

MS8C / MS8H (208-230V)

Page 42

Page 43

SYSTEM FUNCTIONS

These systems have several functions which are addressed in this section. These functions are:

* Sleep * Turbo * Cold Blow Prevention (Heat Pumps Only)

SLEEP

Cooling or Dehumidification — Sleep Function

When sleep function has been set properly , the setpoint will be increased by 1.8°F (1°C) after the sleep function has run for 1 hour, will be increased by another 1.8°F (1°C) after 2 hours and increased by another 1.8°F (1°C) after 3 hours. The setpoint will be increased by 5.4°F (3°C) total in three hours. No further temperature adjustments will be made for the remainder of the sleep function.

Heating — Sleep Function

When sleep function has been set properly , the setpoint will be decreased by 1.8°F (1°C) after the sleep function has run for 1 hour, will be increased by another 1.8°F (1°C) after 2 hours and increased by another 1.8°F (1°C) after 3 hours. The setpoint will be decreased by 5.4°F (3°C) total in three hours. No further temperature adjustments will be made for the remainder of the sleep function.

SLEEP FUNCTION

TURBO

When turbo function is activated, the indoor fan speed and compressor frequency (speed) is increased to maximize the delivery of cooled or heated air to the space.

Operational Mode Maximum Fan Speed Compressor Speed

Cool Maximum Speed Operating frequency + 10HZ

Dehumidification No Change No Change

Heat Maximum Speed Operating frequency + 10HZ

Fan No Change No Change

Auto No Change No Change

FIGURE 59

TABLE 13

TURBO FUNCTION

Page 43

Corp. 1244-L9

Page 44

COLD BLOW PREVENTION

This function prevents cold air from blowing into space in heating mode. After a three (3) minute time delay, one of the following two indoor fan cycles occurs:

1. When the following conditions are met: A. Indoor ambient temperature is greater than 75°F (24°C). B. Coil temperature is equal to or greater than 104°F (40°C). The indoor fan will run at low-speed for one to two minutes. If during that time the coil temperature rises above 106°F (42°C) the indoor fan will ramp to a pre-programmed heat speed for those conditions.

2. When the following conditions are met: A. Indoor ambient temperature is equal to or less than 75°F (24°C) B. Coil temperature is equal to or greater than 106°F (42°C) The indoor fan will run at low-speed, and within one minute, the indoor fan will ramp to a preprogrammed heat speed for those conditions.

SYSTEM PROTECTION FEATURES

COMPRESSOR PROTECTION

In order to protect the compressor, there is a 3-minute delay after the unit shuts off. The delay occurs even during a call for heating or cooling.

INDOOR COIL FREEZE PROTECTION

When the unit is running in the COOL or DEHUMIDIFICATION mode, the indoor coil can freeze due to any of the following:

* Low system charge * Reduced indoor airflow (restricted filter) * Restricted refrigerant flow * Low ambient temperature (outdoor) * Low indoor system load

The indoor coil sensor monitors the coil temperature continuously. If the coil temperature drops below 30.2°F (-1°C), the compressor and the outdoor fan (30 seconds later) will be turned OFF. When the coil temperature rises above 42.8°F (6°C) and the compressor has been off for 3 minutes, the compressor and outdoor fan will cycle ON.

INDOOR COIL FREEZE PROTECTION

FIGURE 60

Indoor Fan Operation

When compressor is cycled ”OFF”, the indoor fan will continue to run at a preset speed.

MS8C / MS8H (208-230V)

Page 44

Page 45

INTELLIGENT POWER MODULE (IPM) PROTECTION (H5)

The IPM module, which is an integrated part of the outdoor control, protects the system from the following conditions:

* High ambient temperatures * Loss of cooling to the heat sink * Low voltage * Loose heat sink to control board

An inverter drive (VFD) works by taking AC mains (single or three phase) and first rectifying it into DC. The DC is usually smoothed with capacitors and often a DC choke before it is connected to a network of power transistors to turn it into three phases for the motor.

The network of power transistors of a small Inverter drive is actually one intelligent power module or inverter power module (IPM) and includes its own basic control circuits and protection from overheating and low voltage conditions.

The IPM inverts the DC into AC, hence the term inverter. The control method is known as for pulse width modulation (PWM). This means the DC is switched on and off very quickly (chopped) by the transistor switches.

POWER FACTOR CORRECTION (PFC) PROTECTION (HC)

The PFC module which is an integrated part of the outdoor control will monitor the DC bus for high, low and abnormal voltage conditions. If any of these conditions are detected the PFC function and compressor will stopped. The appropriate error code will be displayed on the indoor or outdoor units or both. Once the detected condition is corrected, the system will resume normal operations after the minimum 3-minute compressor delay is met. In the case of either an abnormal condition or a high / low voltage condition that has occurred three consecutive times, the system will need to be manually powered off (outdoor unit disconnect or main breaker panel) and back on to continue operation.

NOTE — HC for example is an error code for a PFC module failure. Codes that are generated by the PFC module when monitor voltage conditions are for example H4, U3, PL, etc.

COMPRESSOR OVER-CURRENT PROTECTION (P5)

The compressor current is continuously monitored. Based on the current draw (amps) the microprocessor will signal the compressor to increase, maintain drop or cycle OFF the compressor. Over current condition can result from any of the following:

* High outdoor ambient temperatures * Locked rotor on the compressor * Outdoor air restriction or blockage * Restriction or blockage in refrigeration system

COMPRESSOR OVER-LOAD PROTECTION (OVC-COM) (H3)

If temperature detected by the overload sensor exceeds 239ºF (115ºC), the compressor will stop. The outdoor fan will stop after a delay of 30 seconds. Once the compressor temperature drops below 204ºF (95ºC), the compressor overload protection feature will reset and the system will resume normal operations.

OUTDOOR COIL HIGH TEMPERATURE PROTECTION (FA)

Outdoor coil for air conditioning operation and indoor coil for heating operation (Heat pump only). When the coil

temperature (outdoor coil for air conditioning and indoor coil for heating) drops below 124°F ( 51°C) and the compressor has been OFF for more than 3 minutes, the system will resume normal operation. The coil sensor (outdoor coil sensor for air conditioning and indoor coil sensor for heating) is continuously monitoring the coil temperature and communicates this to the microprocessor. The microprocessor takes these measurements and changes the frequency of the compressor to meet the system load. If the coil temperature increases into the ranges noted in the above chart, the microprocessor will adjust the frequency or cycle the compressor OFF.

Indoor Fan Operation

When compressor is cycled OFF, the indoor fan will continue to run at a preset speed in air conditioning or in heating it will cycle OFF 60 seconds after compressor.

Page 45

Corp. 1244-L9

Page 46

OUTDOOR COIL HIGH TEMPERATURE PROTECTION

FIGURE 61

COMMUNICATION FAULT (E6)

If either the indoor or outdoor controls are unable to communicate with each other for a minimum of three minutes, the system will stop and an error code is displayed on the indoor unit.

OUTDOOR UNIT CONTROL PROTECTION

When excessive temperature is sensed at the outdoor unit control, the compressor will stop. The compressor anti-short cycle routine will be implemented and the compressor will not resume operation until the 3-minute time period has ended.

OTHER FUNCTIONS

SYSTEM REFRIGERANT RECOVERY FUNCTION (PUMP DOWN SYSTEM REFRIGERANT INTO OUTDOOR UNIT)

Enter Refrigerant Recovery Mode

1. Set all zone remote controls at 61ºF (16ºC) in the cooling mode.

2. Within five (5) minutes of system cooling operation, press remote control LIGHT button three (3) times consecutively within three (3) seconds.

3. The system will enter refrigerant recover mode. Indoor display will indicate Fo, indoor fan will run on high speed and the louver position will be adjusted.

Exit Refrigerant Recovery Mode

1. If remote control cooling mode setting is changed or refrigerant recovery mode has lasted longer than 25 minutes the system will exit this mode.

2. The indoor fan will run at the last setting before the system was placed in refrigerant recovery mode.

INDOOR MODE CONFLICT PROTECTION (E7)

When different modes of operation are being called by various indoor units:

1. Basic Mode: The first indoor unit to make a call for cooling or heating will established what is considered basic mode for the outdoor unit operation. Cooling mode is a conflict with heating mode. Indoor units in conflict with first zone call will display E7 on the front panel.

2. When the outdoor unit's basic mode is set to heating, then any request for fan mode at a indoor unit is made will be ignored. Even when the first unit to operate is in fan mode, if any other indoor unit makes a call for heating, the basic mode will be for heating. Fan mode is a conflict with heating mode.

MS8C / MS8H (208-230V)

Page 46

Page 47

TEMPERATURE SENSORS (LOCATION, FUNCTION AND TROUBLESHOOTING)

Refer to tables 15, 16 and 17 for sensor resistance valves and figure 63 for location of sensors.

INDOOR UNIT

1. Indoor Air Temperature Sensor (RT1): This sensor measures the return air temperature coming into the indoor coil

and sends this information to the indoor and outdoor controls.

2. Indoor Coil Temperature Sensor (RT2): This sensor is located on one of the copper tubes of the indoor coil. This sensor

is used to:

S Control the electronic expansion valve (EEV) in cooling mode; S Prevent freezing. During cooling operation, if the temperature drops abnormally, the compressor speed is

decreased. If the temperature continues to fall, the compressor will be cycled OFF;

S Terminate defrost cycle.

OUTDOOR UNIT

1. Outdoor Coil Temperature Sensor (RT3): This sensor is located on one of the copper tubes of the outdoor coil. This

sensor is used to:

S Control the electronic expansion valve (EEV) in heating mode; S Protect the system from high temperatures during cooling mode; S Terminate defrost cycle.

2. Outdoor Air Temperature Sensor (RT4): This sensor measures the outdoor air temperature coming into the outdoor

coil and sends this information to the outdoor controls.

3. Discharge Line Temperature Sensor (RT5): This sensor is used to monitor the discharge line temperature. If the

temperature of the discharge pipe rises abnormally, the compressor speed is decreased. If the temperature continues to rise, the compressor will be cycled OFF.

Page 47

Corp. 1244-L9

Page 48

DISCHARGE LINE TEMPERATURE SENSOR (RT5)

High compressor discharge temperature can result from either of the following conditions:

* Low refrigerant charge * Restricted refrigerant flow

When the discharge line temperature drops below 194°F (90°C) and the compressor has been OFF for more than 3 minutes, the system will resume normal operation.The discharge line sensor continuously monitors the discharge temperature and communicates this to the microprocessor. The microprocessor takes these measurements and changes the frequency of the compressor to meet the system load. If the discharge temperature increases to the ranges noted in the above chart, the microprocessor will adjust the frequency or cycle the compressor OFF (table 14).

DISCHARGE LINE TEMPERATURE PROTECTION SEQUENCE (RT5)

FIGURE 62

TABLE 14

MONITORING OF OUTDOOR DISCHARGE (RT5) LINE TEMPERATURE

Condition Action

If outdoor discharge line temperature is greater than 208.ºF (98ºC) Change in compressor speed is not allowed.

If outdoor discharge line temperature is greater than 217ºF (103ºC) Compressor will run at reduced speed.

If outdoor discharge line temperature is greater than 230ºF (110ºC) Compressor will stop.

If outdoor discharge line temperature is less than 194ºF (90ºC)

After anti-short cycle (3 minutes) delay, the compressor and outdoor fan will resume operation.

Indoor Fan Operation

When compressor is cycled ”OFF”, the indoor fan will continue to run at a preset speed in air conditioning or in heating it will cycle ”OFF” 60 seconds after compressor.

TEMPERATURE SENSOR FAULTS

Refer to the error code tables for details concerning fault conditions and equipment behavior.

TESTING TEMPERATURE SENSOR RESISTANCES

Sensors are connected to the indoor and outdoor controls through field-replaceable harnesses. These sensors provide indoor ambient air (RT1), outdoor ambient air (RT4), indoor coil (RT2), outdoor coil (RT3) and outdoor discharge line (RT5) temperatures to the indoor and outdoor controls to identify fault conditions. As the temperature changes, the resistance across these sensor changes. Tables 15 through 17 indicates how the resistance varies as the temperature changes for all reference temperature sensors.

MS8C / MS8H (208-230V)

Page 48

Page 49

TABLE 15

INDOOR AND OUTDOOR AMBIENT SENSOR RESISTANCE VALUES (15K) — ºF (ºC)

Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ)

-2.2 138.1 68 18.75 138.2 3.848 208.4 1.071

-0.4 128.6 69.8 17.93 140 3.711 210.2 1.039

1.4 121.6 71.6 17.14 141.8 3.579 212 1.009

3.2 11 5 73.4 16.39 143.6 3.454 213.8 0.98 5 108.7 75.2 15.68 145.4 3.333 215.6 0.952

6.8 102.9 77 15 147.2 3.217 217.4 0.925

8.6 97.4 78.8 14.36 149 3.105 219.2 0.898

10.4 92.22 80.6 13.74 150.8 2.998 221 0.873

12.2 87.35 82.4 13.16 152.6 2.896 222.8 0.848 14 82.75 84.2 12.6 154.4 2.797 224.6 0.825

15.8 78.43 86 12.07 156.2 2.702 226.4 0.802

17.6 74.35 87.8 11.57 158 2.611 228.2 0.779

19.4 70.5 89.6 11.09 159.8 2.523 230 0.758

21.2 66.88 91.4 10.63 161.6 2.439 231.8 0.737 23 63.46 93.2 10.2 163.4 2.358 233.6 0.717

24.8 60.23 95 9.779 165.2 2.28 235.4 0.697

26.6 57.18 96.8 9.382 167 2.206 237.2 0.678

28.4 54.31 98.6 9.003 168.8 2.133 239 0.66

30.2 51.59 100.4 8.642 170.6 2.064 240.8 0.642 32 49.02 102.2 8.297 172.4 1.997 242.6 0.625

33.8 46.6 104 7.967 174.2 1.933 244.4 0.608

35.6 44.31 105.8 7.653 176 1.871 246.2 0.592

37.4 42.14 107.6 7.352 177.8 1.811 248 0.577

39.2 40.09 109.4 7.065 179.6 1.754 249.8 0.561 41 38.15 111.2 6.791 181.4 1.699 251.6 0.547

42.8 36.32 11 3 6.529 183.2 1.645 253.4 0.532

44.6 34.58 114.8 6.278 185 1.594 255.2 0.519

46.4 32.94 116.6 6.038 186.8 1.544 257 0.505

48.2 31.38 118.4 5.809 188.6 1.497 258.8 0.492 50 29.9 120.2 5.589 190.4 1.451 260.6 0.48

51.8 28.51 122 5.379 192.2 1.408 262.4 0.467

53.6 27.18 123.8 5.197 194 1.363 264.2 0.456

55.4 25.92 125.6 4.986 195.8 1.322 266 0.444

57.2 24.73 127.4 4.802 197.6 1.282 267.8 0.433 59 23.6 129.2 4.625 199.4 1.244 269.6 0.422

60.8 22.53 131 4.456 201.2 1.207 271.4 0.412

62.6 21.51 132.8 4.294 203 1.171 273.2 0.401

64.4 20.54 134.6 4.139 204.8 1.136 275 0.391

66.2 19.63 136.4 3.99 206.6 1.103 276.8 0.382

Page 49

Corp. 1244-L9

Page 50

TABLE 16

INDOOR AND OUTDOOR COIL SENSOR RESISTANCE VALUES (20K) — ºF (ºC)

Appendix 2: Resistance Table of Outdoor and Indoor Tube Temperature Sensors(20K)

Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ)

-2.2 181.4 68 25.01 138.2 5.13 208.4 1.427

-0.4 171.4 69.8 23.9 140 4.948 210.2 1.386

1.4 162.1 71.6 22.85 141.8 4.773 212 1.346

3.2 153.3 73.4 21.85 143.6 4.605 213.8 1.307 5 145 75.2 20.9 145.4 4.443 215.6 1.269

6.8 137.2 77 20 147.2 4.289 217.4 1.233

8.6 129.9 78.8 19.14 149 4.14 219.2 1.198

10.4 123 80.6 18.13 150.8 3.998 221 1.164

12.2 116.5 82.4 17.55 152.6 3.861 222.8 1.131 14 110.3 84.2 16.8 154.4 3.729 224.6 1.099

15.8 104.6 86 16.1 156.2 3.603 226.4 1.069

17.6 99.13 87.8 15.43 158 3.481 228.2 1.039

19.4 94 89.6 14.79 159.8 3.364 230 1.01

21.2 89.17 91.4 14.18 161.6 3.252 231.8 0.983 23 84.61 93.2 13.59 163.4 3.144 233.6 0.956

24.8 80.31 95 13.04 165.2 3.04 235.4 0.93

26.6 76.24 96.8 12.51 167 2.94 237.2 0.904

28.4 72.41 98.6 12 168.8 2.844 239 0.88

30.2 68.79 100.4 11.52 170.6 2.752 240.8 0.856 32 65.37 102.2 11.06 172.4 2.663 242.6 0.833

33.8 62.13 104 10.62 174.2 2.577 244.4 0.811

35.6 59.08 105.8 10.2 176 2.495 246.2 0.77

37.4 56.19 107.6 9.803 177.8 2.415 248 0.769

39.2 53.46 109.4 9.42 179.6 2.339 249.8 0.746 41 50.87 111.2 9.054 181.4 2.265 251.6 0.729

42.8 48.42 11 3 8.705 183.2 2.194 253.4 0.71

44.6 46.11 114.8 8.37 185 2.125 255.2 0.692

46.4 43.92 116.6 8.051 186.8 2.059 257 0.674

48.2 41.84 118.4 7.745 188.6 1.996 258.8 0.658 50 39.87 120.2 7.453 190.4 1.934 260.6 0.64

51.8 38.01 122 7.173 192.2 1.875 262.4 0.623

53.6 36.24 123.8 6.905 194 1.818 264.2 0.607

55.4 34.57 125.6 6.648 195.8 1.736 266 0.592

57.2 32.98 127.4 6.403 197.6 1.71 267.8 0.577 59 31.47 129.2 6.167 199.4 1.658 269.6 0.563

60.8 30.04 131 5.942 201.2 1.609 271.4 0.549

62.6 28.68 132.8 5.726 203 1.561 273.2 0.535

64.4 27.39 134.6 5.519 204.8 1.515 275 0.521

66.2 26.17 136.4 5.32 206.6 1.47 276.8 0.509

MS8C / MS8H (208-230V)

Page 50

Page 51

TABLE 17

OUTDOOR DISCHARGE LINE SENSOR RESISTANCE VALUES

Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ) Temp.(°F) Resistance(kΩ)

-20.2 853.5 50 98 120.2 18.34 190.4 4.754

-18.4 799.8 51.8 93.42 122 17.65 192.2 4.609

-16.6 750 53.6 89.07 123.8 16.99 194 4.469

-14.8 703.8 55.4 84.95 125.6 16.36 195.8 4.334

-13 660.8 57.2 81.05 127.4 15.75 197.6 4.204

-11.2 620.8 59 77.35 129.2 15.17 199.4 4.079

-9.4 580.6 60.8 73.83 131 14.62 201.2 3.958

-7.6 548.9 62.6 70.5 132.8 14.09 203 3.841

-5.8 516.6 64.4 67.34 134.6 13.58 204.8 3.728

-4 486.5 66.2 64.33 136.4 13.09 206.6 3.619

-2.2 458.3 68 61.48 138.2 12.62 208.4 3.514

-0.4 432 69.8 58.77 140 12.17 210.2 3.413

1.4 407.4 71.6 56.19 141.8 11.74 212 3.315

3.2 384.5 73.4 53.74 143.6 11.32 213.8 3.22 5 362.9 75.2 51.41 145.4 10.93 215.6 3.129

6.8 342.8 77 49.19 147.2 10.54 217.4 3.04

8.6 323.9 78.8 47.08 149 10.18 219.2 2.955

10.4 306.2 80.6 45.07 150.8 9.827 221 2.872

12.2 289.6 82.4 43.16 152.6 9.489 222.8 2.792 14 274 84.2 41.34 154.4 9.165 224.6 2.715

15.8 259.3 86 39.61 156.2 8.854 226.4 2.64

17.6 245.6 87.8 37.96 158 8.555 228.2 2.568

19.4 232.6 89.6 36.38 159.8 8.268 230 2.498

21.2 220.5 91.4 34.88 161.6 7.991 231.8 2.431 23 209 93.2 33.45 163.4 7.726 233.6 2.365

24.8 198.3 95 32.09 165.2 7.47 235.4 2.302

26.6 199.1 96.8 30.79 167 7.224 237.2 2.241

28.4 178.5 98.6 29.54 168.8 6.998 239 2.182

30.2 169.5 100.4 28.36 170.6 6.761 240.8 2.124 32 161 102.2 27.23 172.4 6.542 242.6 2.069

33.8 153 104 26.15 174.2 6.331 244.4 2.015

35.6 145.4 105.8 25.11 176 6.129 246.2 1.963

37.4 138.3 107.6 24.13 177.8 5.933 248 1.912

39.2 131.5 109.4 23.19 179.6 5.746 249.8 1.863 41 125.1 111.2 22.29 181.4 5.565 251.6 1.816

42.8 119.1 113 21.43 183.2 5.39 253.4 1.77

44.6 113.4 114.8 20.6 185 5.222 255.2 1.725

46.4 108 116.6 19.81 186.8 5.06 257 1.682

48.2 102.8 118.4 19.06 188.6 4.904 258.8 1.64

(50K) — ºF (ºC)

Page 51

Corp. 1244-L9

Page 52

FAN

OUTDOOR

FILTER

BI-FLOW

OUTDOOR

SENSOR (RT5)

TEMPERATURE

DISCHARGE LINE

COIL

OUTDOOR

SWITCH

KBTU

NOTE: NOT

HIGH PRESSURE

AVAILABLE ON 18

MUFFLER

SENSOR

DISCHARGE

TEMPERATURE

SENSOR (RT4)

OUTDOOR AIR

TEMPERATURE

INVERTER

NOTE: NOT

COMPRESSOR

AVAILABLE

ON 18 KBTU

TEMPERATURE

OUTDOOR COIL

SYSTEM TEMPERATURE SENSORS

SENSOR (RT3)

OUTDOOR UNIT

BI-FLOW

INDOOR UN IT

A. INDOOR COIL

SEPARATOR

GAS-LIQUID

FILTER

BI-FLOW

D. INDOOR COIL

FILTER

BI-FLOW

B. INDOOR COIL

C. INDOOR COIL

BI-FLOW

FILTER

MS8C / MS8H (208-230V)

INDOOR COIL

SENSOR (RT2)

TEMPERATURE

FIGURE 63

Page 52

INDOOR AIR

SENSOR (RT1)

TEMPERATURE

Page 53

Indoor and Outdoor Control Parts Identifications

INDOOR CONTROLS

TYPICAL INDOOR UNIT CONTROL (9 - 12 KBTU)

Jumper Cap Terminal

FIGURE 64

TYPICAL INDOOR UNIT CONTROL (18 KBTU)

FIGURE 65

Page 53

Corp. 1244-L9

Page 54

TYPICAL 24 KBTU INDOOR UNIT CONTROL (208-230V)

234

1. Ground terminal.

2. DC fan motor terminal

3. Louver Up/Down motion terminal.

4. Not used.

5. Display terminals

6. Indoor temperature sensor input

7. Indoor coil temperature sensor input

8. Indoor/outdoor communication terminal

9. Live wire

10. Fuse T3.15AH, 250VAC

11. Neutral terminal.

56789

FIGURE 66

TYPICAL 30 KBTU INDOOR UNIT CONTROL (208-230V)

1 2 3

1. Neutral wire terminal.

2. Auto button.

3. Louver terminal for horizontal operation.

4. Louver terminal for vertical operation.

5. Communication terminal.

6. Jumper cap.

7. Indoor ambient temperature sensor in

put terminal.

8. Indoor coil temperature sensor input ter minal.

9. Display terminals.

10. Transformer output terminal.

11. Live wire terminal.

12. Fuse

13. Transformer input terminal.

MS8C / MS8H (208-230V)

FIGURE 67

Page 54

Page 55

OUTDOOR CONTROLS

TYPICAL 9-12 KBTU OUTDOOR CONTROLS (208-230V)

10 7

89 11

216131214

1. Neutral

2. Power line input

3. Communications interface

4. Reactor interface 1

5. Reactor interface 2

6. Fan interface

7. Chassis electric heat

8. Compressor electric heat

9. Reversing valve interface

10. Reversing valve power

11. Heat tape wiring

12. Overload input

13. Heat packs

14. Compressor connections (U, V, and W)

15. Ground

16. Pressure switch input.

FIGURE 68

TYPICAL 18 - 24 KBTU OUTDOOR CONTROLS (208-230V)

1234567

1. Compressor interface

2. Outdoor coil temperature sensor in put

3. Compressor overload protection ter minal.

4. Outdoor temperature sensor

5. Electronic expansion valve terminal

6. Outdoor fan terminal

7. Reversing valve terminal

8. Chassis electric heat terminal

9. Communication input

10. Power line input

11. Ground wire

12. Neutral line

13. PFC inductor line

FIGURE 69

Page 55

Corp. 1244-L9

Page 56

TYPICAL 30 KBTU OUTDOOR CONTROLS (208-230V)

123456

1. T1 transformer.

2. Overload protection terminal (OVC-COMP)

3. Thermal package terminals

(CN2)

4. High voltage protection ter minals (HPP)

5. Expansion valve terminal (EV)

6. High voltage protection ter minal (HPP1)

7. Reversing valve terminal

8. Chassis heater terminal (HEAT2-L)

9. Compressor heater terminal (HEAT1-L)

10. Live terminal

11. Neutral

12. Fuse (FU101)

13. Ground

14. Choke (L101 and L102)

15. Outdoor fan terminal (OFANDC)

FIGURE 70

MS8C / MS8H (208-230V)

Page 56

Page 57

Indoor and Outdoor Error Codes

This section identifies error codes that appear on the front panel of the indoor unit or outdoor unit control. Many of the error codes will automatically clear themselves when the error no longer exist. However some error codes may required disconnecting power to the system at the unit disconnect switch or circuit breaker in order to clear them and resuming system operations.

INDOOR UNIT FRONT PANEL INDICATORS

RUN

MODE

HEAT INDICATOR

COOL INDICATOR

TEMPERATURE*

DEHUMIDIFY

SIGNAL

INFRARED

RECEIVER

* The temperature readout (either temperature setpoint or indoor ambient) will be replaced by an error code if there is a malfunction. If multiple errors are detected, the display will alternate between each error code. On the 30kBtu

system, the indoor ambient temperature will only display in centigrade.

NOTE - No history is kept on past error codes.

FIGURE 71

Page 57

Corp. 1244-L9

Page 58

Table 18. 09 through 12 and 30 kBtu System Status and Error Codes — Indoor Character Display and Outdoor

LEDs

Indoor

Character

Display

NONE BLINKING

NONE

NONE 8

Indoor

Character

Display

NONE 1 OFF OFF

NONE OFF 11 OFF

NONE OFF 13 OFF Power issue

C5 OFF OFF OFF

EE 11 OFF OFF EEPROM failure S Replace outdoor control.

E2 3 OFF OFF

E3 OFF 9 OFF

E4 7 OFF OFF

Outdoor LED Displays

(number of blinks)

Yellow Red Green

BLINK

ING

Outdoor LED Displays

(number of blinks)

Yellow Red Green

Description System Status

SYSTEM STATUS LEDs

Indoor and outdoor units are communicating

Compressor is running

System has a heating or cooling demand

SYSTEM ERROR DISPLAY AND LEDs

Error Description System Status

Compressor has an open circuit.

Frequency limiting module temperature

Indoor control jumper is missing (labeled JUMP)

Indoor coil freeze protection

Outdoor coil blockage or low refrigerant due to leak.

Discharge line temperature protection

System is operating normally. The blinking interval is 1 second on, 1 second off.

System is operating normally. The blinking interval is 1 second on, 1 second off and up to three second pause between repeating blinks.

Troubleshooting for Possible

All system functions are terminated except indoor fan.

Compressor speed automatically adjusted to match conditions.

All system functions are terminated.

All system functions are terminated except indoor fan. The indoor coil sensor (RT2) monitors the coil temperature continuously. If coil temperature drops below

30.2ºF (-1ºC), the compressor and the outdoor fan (30 seconds later) are switched off. Condition is cleared when indoor coil temperature rises above 42.8ºF (6ºC) and the compressor has been off for a minimum of three minutes.

All system functions are terminated except indoor fan.

Sensor RT5 monitors compressor discharge line temperature and communicates with outdoor unit microprocessor. Depending on the temperature measured, the compressor speed will be increased to meet the load or will continue to run at the existing speed. If the temperature becomes excessively high, the compressor will be de-energized. When the compressor discharge temperature drops below 194ºF (90ºC), the unit will resume normal operation. See unit information manual for further information.

S Check connections between com

pressor and outdoor control (con trol terminals are marked U, V and W).

S Verify proper attachment of heat

sink.

S Clean heat sink, if necessary.

System power issue.

S Check indoor control jumper con

nections and replace jumper, if missing.

S Check for restricted indoor airflow

and change filter, if necessary.

S Check for restricted refrigerant

flow.

S Check for low outdoor ambient

temperature or low indoor system load.

S Check for proper clearances

around outdoor unit.

S Check outdoor coil for and clean,

if necessary.

S Check for low refrigerant charge. S Check for restricted refrigerant

flow due to blocked capillary.

Causes

MS8C / MS8H (208-230V)

Page 58

Page 59

Continued — 09 through 12 and 30 kBtu System Status and Error Codes — Indoor Character Display and Outdoor LEDs

Indoor

Character

Display

E5 5 OFF OFF

E6 OFF OFF OFF

FH OFF 4 OFF

F0 OFF OFF OFF

F1 OFF OFF OFF

F2 OFF OFF OFF

F3 OFF 6 OFF

F4 OFF 4 OFF

F5 OFF 7 OFF

F6 OFF 3 OFF

F8 OFF 1 OFF

F9 OFF 2 OFF

HC 14 OFF OFF

H1 2 OFF OFF

H3 8 OFF OFF

Outdoor LED Displays

(number of blinks)

Yellow Red Green

Error Description System Status

Compressor over-current protection

Communication failure between indoor unit and outdoor unit

Anti-freezing upper and lower limit range

Indoor coil is gathering refrigerant

Indoor ambient sensor (RT1) open or short circuited

Indoor coil sensor (RT2) open or short circuited

Outdoor ambient sensor (RT4) open or short circuit

Outdoor coil sensor (RT3) open or short circuit

Discharge line sensor (RT5) error

Compressor over load limit issue

High current limit issue

Discharge line temperature too high

Power factor correction protection

Defrosting (heat pump only)

Compressor overload protection sensor (CT1,2) malfunction.

All system functions are terminated except indoor fan.

All system functions are terminated after three-minute delay except indoor fan.

Compressor will run at reduced speed until temperature increases.

All system functions are terminated except indoor fan.

Cooling and dehumidification modes will continue to operate as well as indoor fan. Unit will not operate in heating mode.

All system functions are terminated except indoor fan.

All system functions will continue to run for 3 minutes, then terminate. Indoor fan will continue to run.

Normal operational state with compressor speed automatically adjust for operational conditions. System will continue to operation at reduced compressor speed until issue is corrected.

System will continue to operate at reduce compressor speed until issue is corrected.

Normal operation Normal defrost operation.

All system functions are terminated except indoor fan.

Troubleshooting for Possible

Causes

S Check for locked compressor rotor

due to excessively high ambient temperature.

S Check for restricted refrigerant flow

due to blocked capillary tubing.

S Check outdoor unit to make sure

that coil is not blocked.

S If error is displayed on outdoor unit,

check communications cable / wire at indoor and outdoor controls to verify proper connection. See unit information manual for further information.

S Wait for temperature to increase

above 42.8ºF (6ºC), then recheck operation status.

S Pump refrigerant into outdoor unit.

Check 2-way shut-off valve in small line to see if it is closed or if flow is restricted. Correct, if necessary.

S Check sensor to ensure that it is in

acceptable range.

S Check sensor for proper resistance. S Replace sensor if shorted, open or

out-of-calibration.

S Check sensor to ensure that it is in

acceptable range.

S Check sensor for proper resistance. S Replace sensor if shorted, open or

out-of-calibration.

S Check sensor for proper resistance.

Sensor should be in acceptable range. Replace sensor if shorted, open or out-of-calibration.

S Check outdoor ambient air

temperature. Could be too high.

S Check for locked compressor rotor. S Check for blocked refrigeration

circuit (capillary tubes for example).

S Check for blocked or restricted

outdoor air flow. Clear, if necessary.

S Check for low refrigerant charge.

S Check for low or high input voltage.

Correct if necessary. Could be too high.

S Check discharge line temperature.

Correct if to high.

See unit information manual for fur

ther information.

S Check for proper wiring connec

tions and loose wires at outdoor control (CT1, 2) input plug.

S Check for continuity across over

load protection sensor terminals mounted at top of compressor.

Page 59

Corp. 1244-L9

Page 60

Continued — 09 through 12 and 30 kBtu System Status and Error Codes — Indoor Character Display and Outdoor LEDs

Indoor

Character

Display

H4 6 OFF OFF

H5 4 OFF OFF

H6 OFF OFF OFF

Outdoor LED Displays

(number of blinks)

Yellow Red Green

Error Description System Status

Compressor high temperature protection

All system functions are terminated except indoor fan.

Intelligent Power Module (IPM) module protection

Indoor fan not communicating

Troubleshooting for Possible

Causes

S Check for proper wiring connec

tions and loose wires at outdoor control (CT1, 2) input plug.

S Check for continuity across over

load protection sensor terminals mounted at top of compressor.

This can be caused by any of the fol lowing:

S Loss of cooling to the heat sink S Low voltage. S High ambient temperature S Loose screws fastening the outdoor

control to the heat sink

See unit information manual for further information.

Possible Indoor control failure or in door motor failure.

S Check wiring between fan motor

and indoor control.

S Check wiring between fan motor

and terminal marked OFFAN.

S Replace one or both, if necessary.

LP 16 OFF OFF

L3 OFF 14 OFF

L9 9 OFF OFF

PH 13 OFF OFF

PL 12 OFF OFF

Indoor and outdoor unit mismatch

Outdoor DC fan motor malfunction

Power factor protection

High voltage protec tion

Low voltage protec tion

All system functions are terminated.

The two system components are mis-matched. Refer to engineering handbook for correct match-up. Also, verify that the red jumper is in place on the indoor control board.

S Check wiring between fan motor

and outdoor control terminal marked OFFAN.

S If wiring is correct, replace outdoor

DC fan motor.

Indoor unit is experiencing either a high or low input voltage condition.

S Verify proper input voltage at

terminal strip N(1) and 3.

S Check input voltage on outdoor unit

terminal strip (N and L terminals).

S If voltage is higher than 265VAC,

disconnect power to unit. Correct input voltage problem before reap plying power to system.

S If voltage is below 265VAC, then

check capacitor while unit is turned off.

S If voltage is between 200-208V, ca

pacitor is working properly

S If voltage is some other value, re

place capacitor.

S If input voltage and capacitor are

normal, replace outdoor control.

S Check input voltage on outdoor unit

terminal strip (N and L terminals).

S If voltage is lower than 150VAC,

restart system and check power again.

S 9 - 12 kBtu, 208-230VAC systems

only -- Check reactor (choke) line

connection on outdoor control terminal marked AC-L2.

MS8C / MS8H (208-230V)

Page 60

Page 61

Continued — 09 through 12 and 30 kBtu System Status and Error Codes — Indoor Character Display and Outdoor LEDs

Indoor

Character

Display

U7 OFF OFF OFF

NONE 1 OFF OFF

NONE OFF 8 OFF

NONE OFF 11 OFF

NONE OFF 13 OFF Power issue

Outdoor LED Displays

(number of blinks)

Yellow Red Green

Error Description System Status

Reversing valve malfunction

Compressor has an open circuit.

Outdoor ambient air temperature is not within the outdoor unit's start up range

Frequency limiting module temperature

All system functions are terminated except indoor fan.

Normal status indicator when unit is turned off.

All system functions are terminated except indoor fan.

Compressor speed automatically adjusted to match conditions.

Troubleshooting for Possible

Causes

S Check input voltage on outdoor unit

terminal strip (N and L terminals). If lower than 175 VAC, correct voltage problem.

S Check reversing valve wiring

connection for damage.

S If voltage and wiring connections

are correct, replace reversing valve.

S Check connections between com

pressor and outdoor control (control terminals are marked U, V and W).

Status indicator. System functioning properly. Outdoor unit will not oper ate if outdoor ambient temperature is out of range.

S Verify proper attachment of heat

sink.

S Clean heat sink, if necessary.

System power issue. See unit infor mation manual for further informa tion.

Page 61

Corp. 1244-L9

Page 62

Table 19. 18-24 kBtu System Status and Error Codes — Indoor Character Display and Outdoor LEDs

Outdoor Unit LED Status

Indoor

Unit

Display

NONE

EE o o o

E1 o

E5 o

E6 o o o

This unit has three display

status indicators

o OFF

n ON ® BLINKS

D5 D6 D16 D30

n n n n

® ® ®

n ®

n n

Error Description System Status

System is operating within normal parameters

Indoor control jumper is missing (labeled JUMP)

All system functions are

EEPROM failure Replace outdoor control.

System high pressure

Indoor coil freeze protection

Discharge line temperature protection

Compressor over-current protection

Communication failure between indoor unit and outdoor unit

Compressor high temperature protection

terminated.

The indoor coil sensor (RT2) moni tors the coil temperature continu ously. When the coil temperature drops below 30.2ºF (-1ºC), the compressor and out door fan (30 seconds later) are switched off until the coil tempera ture rises above 42.8ºF (6ºC) and the compressor has been off for a minimum of three minutes. All system functions are terminated except indoor fan.

The compressor discharge line sensor (RT5) monitors the temper ature continuously and communi cates with the outdoor unit micro processor. Depending on the tem perature measured, the compres sor speed will be increased to meet the load or will continue to run at the existing speed. If the discharge line temperature be comes excessively high, the com pressor will be de-energized. When the compressor discharge temperature drops below 194ºF (90ºC), the unit will resume normal operation. See figure 72.

All system functions are termi nated except indoor fan.

All system functions except indoor fan are terminated after a 3-minute delay.

All system functions are termi nated except indoor fan.

Troubleshooting for Possible

Causes

Indoor control jumper is missing or is not installed correctly. (Indoor control jumper location is labeled JUMP.)

Check for low refrigerant charge, blocked coil or excessively high outdoor ambient temperature.

Check for reduced indoor airflow (restricted filter), restricted refriger ant flow, low ambient temperature (outdoor) and low indoor system load. Correct, if necessary.

Check for low system refrigerant charge. Check capillary tubes for blockage. Correct, if necessary.

Over-current protection error can result due to any of the following:

S Ambient temperature is too high.

Check for locked rotor on the compressor.

S Check for blocked refrigeration

circuit (capillary tubes for exam ple). Correct, if necessary.

S Check for blocked or restricted

outdoor air. Correct, if necessary.

If error is displayed on outdoor unit, check communications cable / wire at indoor and outdoor controls to verify proper connection. See unit information manual for further information.

See unit information manual for further information.

MS8C / MS8H (208-230V)

Page 62

Page 63

Continued — 18 - 24 kBtu System Status or Error Codes — Indoor Character Display and Outdoor LEDs

Outdoor Unit LED Status

Indoor

Unit

Display

F3 o o

F4 o o

F5 o o

HC o

H1 Defrosting (heat pump only) Normal operation

H2 Electrostatic protection

This unit has three display

status indicators

o OFF

n ON ® BLINKS

D5 D6 D16 D30

n n n ®

n n n

® n

® ®

n n

® ®

o o Discharge temperature too high

n ® ®

® ®

Error Description System Status

Intelligent Power Module protection limit

Anti-freezing upper and lower limit range

Indoor ambient sensor (RT1) open or short-circuited

Indoor coil sensor (RT2) open or short-circuited

Outdoor ambient sensor (RT4) open or short-circuited

Outdoor coil sensor (RT3) open or short-circuited

Discharge line sensor (RT5) error

Compressor overload limit issue

High current limit issue

Power factor correction protec tion

Heating mode anti-high temperature protection

System will continue to run; how ever at reduced compressor speed until issue is corrected.

Cooling and dehumidify will contin ued to operate as well as indoor fan. Heating will not operate.

All system functions are termi nated except indoor fan.

All system functions except indoor fan will be terminated after 3-min ute delay.

Normal operational state with com pressor speed automatically adjust for operational conditions. System will continue to operate at reduced compressor speed until issue is corrected.

System will continue but will re duce compressor speed to correct issue

System will continue operation at a reduced compressor speed until issue is resolved.

System protection feature. All sys tem functions are terminated ex cept indoor fan.

Troubleshooting for Possible

Intelligent Power Module protection limit error can result from any of the following:

S Loss of cooling to the heat sink S Low voltage S High ambient temperature S Loose screws fastening the out

door control to the heat sink

Check all and correct, if necessary. See figure 92 for troubleshooting.

The indoor coil sensor (RT2) moni tors the coil temperature continu ously. Any time the coil tempera ture falls between 42.8ºF (6ºC) and 30.2ºF (-1ºC), the micropro cessor will initiate anti-freeze protection operation.

Sensor input is out of acceptable input range. Check sensor for proper resistance. Replace sensor if shorted, open or out-of-calibra tion.

S Check outdoor ambient air tem

perature. Could be too high.

S Check for locked compressor ro

tor

S Check for locked refrigeration cir

cuit (capillary tubes for example)

S Check for blocked or restricted

outdoor air flow. Clear, if neces sary.

S Check for low refrigerant charge.

See unit information manual for further information.

Check input voltage. It may be ei ther too low or too high.

Discharge line temperature is high. See figure 72.

See unit information manual for further information.

Normal operation to defrost out door coil.

Excessive electrostatic charge present. Correct, if possible.

Causes

Page 63

Corp. 1244-L9

Page 64

Continued — 18 - 24 kBtu System Status or Error Codes — Indoor Character Display and Outdoor LEDs

Outdoor Unit LED Status

Indoor

Unit

Display

H3 o

H5 o

Lc o

PH o

PL o

PU o

P5 o

P7 o o

U1 o

U3 o

This unit has three display

status indicators

o OFF

n ON ® BLINKS

D5 D6 D16 D30

Compressor overload

® ®

o o o Fan module protection

n n

® n

n n n

protection sensor malfunction

n n

o o

n ®

® n

System operating abnormally

Intelligent Power Module

protection

Unit start-up failure

High voltage protection

o Low voltage protection

Capacitor charge failure

Compressor overcurrent protection

Outdoor control failure Replace outdoor control.

Intelligent Power Module temperature is too high

Compressor current test circuit

malfunction

Unstable DC voltage protection Input voltage is not stable.

Error Description System Status

All system functions are termi nated except indoor fan.

All system functions are termi nated.

Outdoor unit operations are termi nated. Indoor fan will run.

All system functions are termi nated.

All system functions are termi nated except indoor fan.

Troubleshooting for Possible

Check for proper wiring and loose connections at outdoor control in put plug. Also, check for continuity across overload protection sensor terminals mounted at top of com pressor.

See unit information manual.

Intelligent Power Module protection error can result from any of the following:

S Loss of cooling to the heat sink S Low voltage S High ambient temperature S Loose screws fastening the

outdoor control to the heat sink

Check all and correct, if necessary.

See unit start-up troubleshooting charts.

Check wire connections to outdoor fan motor or fan motor module on main board is damaged. Replace main board.

S Check input voltage on outdoor

unit terminal strip (N and L terminals).

S If voltage is higher than 265VAC,

disconnect power to unit. Correct input voltage problem before reapplying power to system.

S If voltage is within normal range,

test capacitor output. If capacitor range is between 200-208VAC, replace outdoor control.

S Check input voltage on outdoor

unit terminal strip (N and L termi nals).

S If voltage is lower than 150VAC,

restart system and check power again.

S Check reactor (choke) line con

nection on outdoor control termi nal marked INDC1.

See unit information manual for further information.

Intelligent Power Module high temperature error can result from any of the following:

S Loss of cooling to the heat sink S Low voltage S High ambient temperature S Loose screws fastening the

outdoor control to the heat sink

Check all and correct, if necessary.

Replace outdoor control.

Causes

MS8C / MS8H (208-230V)

Page 64

Page 65

Continued — 18 - 24 kBtu System Status or Error Codes — Indoor Character Display and Outdoor LEDs

Outdoor Unit LED Status

Indoor

Unit

Display

U5 o

This unit has three display

status indicators

o OFF

n ON ® BLINKS

D5 D6 D16 D30

n ® n

n n ®

o Reversing valve malfunction

Error Description System Status

Entire unit current monitoring malfunction

Outdoor unit zero cross detection error

All system functions are terminat ed except indoor fan.

All system functions are termi nated except indoor fan.

Troubleshooting for Possible

• Outdoor control malfunction.

• Check refrigerant charge.

• Check for electric current error (low current amperage or overcurrent).

S Relocate the coil sensor from its

current position onto the large line leaving the indoor coil. Secure the sensor with a tie wrap.

S Check input voltage on outdoor

unit terminal strip (N and L termi nals). If lower than 175 VAC, cor rect voltage problem.

S Check reversing valve wiring

connection for damage.

S If voltage and wiring connections

are correct, replace reversing valve.

Replace outdoor control.

Causes

Page 65

Corp. 1244-L9

Page 66

Refrigerant System Flow Diagrams

The following two diagrams illustrate refrigerant flow in either cooling or heating (heat pump only) operations.

TYPICAL AIR CONDITIONER SYSTEM

INDOOR UNIT OUTDOOR UNIT

INDOOR COIL

3-WAY

SERVICE

VALV E

2-WAY

SHUT-OFF

VALV E

MUFFLER

Discharge

COMPRESSOR

STRAINER

Suction

ACCUMULATOR

OUTDOOR COIL

Capillary

ELECTRONIC

EXPANSION VALVE

FIGURE 72

TYPICAL HEAT PUMP SYSTEM

INDOOR UNIT OUTDOOR UNIT

STRAINER

COOLING

INDOOR COIL

3-WAY

SERVICE

VALV E

2-WAY

SHUT-OFF

VALV E

COMPRESSOR

FIGURE 73

MUFFLER

Discharge

Suction

STRAINER

REVERSING

VALV E

ACCUMULATOR

ELECTRONIC

EXPANSION VALVE

(EXCEPT 30K WHICH

USES CAPILLARY)

OUTDOOR COIL

STRAINER

COOLING

HEATING

MS8C / MS8H (208-230V)

Page 66

Page 67

Typical Unit Wiring Diagrams

The indoor wiring diagram location is on the inside of the cabinet at the terminal connection end. To access the diagram will required removal of the cabinet. The wiring diagram on the outdoor unit is located on the top of the control box.

WARNING

Electric Shock Hazard. Can cause injury or death. Unit must be grounded in accordance with national and local codes.

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

WARNING

Delayed Electric Shock Hazard Capacitors in this unit may hold charge. Do not remove this cover or service this area for 2 minutes after

the main power has been removed.

TYPICAL INDOOR UNIT WIRING DIAGRAM — 09 THROUGH 18 KBTU SYSTEMS (208 / 230V)

TUBE

TEMP. SENSOR

ROOM

TEMP. SENSOR

FAN

MOTOR

RT2

TUBE

CAP

JUMP

DISP1

RECEIVER AND

DISPLAY BOARD

DISP2

AP1

RT1

ROOM

SWING−UD

SWING

MOTOR

AP2

FIGURE 74

PGF

COM−OUT

AC−L

EVAPORATOR

N(1)

OUTDOOR UNIT

YEGN(GN)

ELECTRIC BOX

Page 67

Corp. 1244-L9

Page 68

TYPICAL INDOOR UNIT WIRING DIAGRAM — 24 KBTU SYSTEMS (208 / 230V)

RECEIVER AND

ROOM

TEMP. SENSOR

RT1

ROOM

CAP

JUMP

SWING−UD2 DC−MOTOR

TUBE

TEMP. SENSOR

RT2

TUBE

AP2: MAIN BOARD

DISPLAY BOARD

AP1

DISP1

DISP2

COM−OUT

AC−L

MAGNETIC

RING

YEGN(GN)

TERMINAL

BLOCK

YEGN(GN)

N(1)

XT1

OUTDOOR UNIT

C0NNECTING

CABLE

STEPPING

MOTOR

FAN MOTOR

EVAPORATOR

ELECTRIC BOX

FIGURE 75

TYPICAL INDOOR UNIT WIRING DIAGRAM — 30 KBTU SYSTEMS (208 / 230V)

MS8C / MS8H (208-230V)

FIGURE 76

Page 68

Page 69

TYPICAL OUTDOOR UNIT WIRING DIAGRAM — 09 AND 12 KBTU SYSTEMS (208 / 230V) HEAT PUMP

U N I T

I N D O O R

XT1

N(1)

POWER

W4 YEGN

W14 YEGN

W2 BU

W3 BK

W1 BN

W6 YE

COMP

L2L2L2

W7 RD

W8 YEGN

W13 WH

HPP

W10 RD

OVC−COMP

CT1,2

SAT

TUBE

TEM.SENSOR

RT1

0 0 0

OUTROOM EXHAUST

TEM.SENSOR

RT2

TEM.SENSOR

RT3

CN2

W5 BU

COMP−U COMP−VCOMP−W

COMU

AP1

AC−L1

OFAN1

HEAT−LHEAT−N1

EH1

HEATER

(COMP)

HEAT−L

(CHASSIS)

HEAT−N2

EH2

HEATER

CN1

EKV

4YV

AC−L2

LX−1

W11 WH

LX−2

W12

W9 BU

FAN MOTOR

FIGURE 77

TYPICAL OUTDOOR UNIT WIRING DIAGRAM — 18 KBTU SYSTEMS (208 / 230V) AIR CONDITIONER

Please don’t touch any terminal when

WARNING

the voltage of terminal P(DC+) and

N(DC−) at AP1 is higher than 30V to

prevent the risk of electrical shock!

TERMINAL

YEGN

N(1)

INDOOR UNIT

POWER

BLOCK

N(1)

XT1

YEGN

MAGNETIC

RING

COM−INNER

AC−L

YEGN

RT4

MANUAL

.SENSOR

OUTTUBE2

TEMP

RT1

EKV

Electronic expansion valve

(OPTIONAL)

OUTTUBE

TEMP.SENSOR

RT2

T−SENSOR

OUTROOM

EXHAUST

TEMP.SENSOR

RT3

FAN MOTOR

TEMP.SENSOR

OVC−COMP

AP1

OFAN

OVERLOAD

INDC1

YEGN

MAGNETIC

RING

COMP−U

REACTOR

PROTECTOR

L2 L2

COMP

COMP−V

INDC2

SAT

COMP−W

COMP.

YEGN

FIGURE 78

Page 69

Corp. 1244-L9

Page 70

TYPICAL OUTDOOR UNIT WIRING DIAGRAM — 18 KBTU SYSTEMS (208 / 230V) HEAT PUMP

Please don’t touch any terminal when

WARNING

the voltage of terminal P(DC+) and

N(DC−) at AP1 is higher than 30V to

prevent the risk of electrical shock!

TERMINAL

YEGN

BLOCK

N(1)

INDOOR UNIT

N(1)

XT1

YEGN

MAGNETIC

RING

COM−INNER

AC−L

OUTTUBE2

RT4

MANUAL

.SENSOR

OUTTUBE

TEMP

RT1

OUTROOM

TEMP.SENSOR

RT3

RT2

T−SENSOR

EXHAUST

TEMP.SENSOR

AP1

TEMP.SENSOR

OVC−COMP

OVERLOAD

OFAN

MAGNETIC

RING

COMP−U

PROTECTOR

L2 L2

INDC1

COMP

COMP−V

SAT

COMP−W

INDC2

COMP

YEGN

POWER

YEGN

VTVT

EKV

Electronic

4YV

4−WAY

VALVE

expansion

valve

(OPTIONAL)

FAN MOTOR

REACTOR

YEGN

FIGURE 79

TYPICAL OUTDOOR UNIT WIRING DIAGRAM — 24 KBTU SYSTEMS (208 / 230V) AIR CONDITIONER

MAGNETIC

RING

YEGN

PROTECTOROVERLOAD

COMP−VCOMP−U

INDC1

SAT

COMP

COMP−W

REACTOR

YEGN

INDC2

COMP

Please don’t touch any terminal when

WARNING

the voltage of terminal P(DC+) and

N(DC−) at AP1 is higher than 30V to

prevent the risk of electrical shock!

YEGN

TERMINAL

BLOCK

N(1)

INDOOR UNIT

XT1

POWER

YEGN

MAGNETIC

RING

COM−INNER

AC−L

RT4

MANUAL

YEGN

.SENSOR

OUTTUBE2

TEMP

Electronic expansion valve

(OPTIONAL)

RT1

EKV

OUTTUBE

RT2

T−SENSOR

OUTROOM

TEMP.SENSOR

EXHAUST

TEMP.SENSOR

RT3

TEMP.SENSOR

OVC−COMP

AP1

CAP.

FAN MOTOR

OFAN

MS8C / MS8H (208-230V)

FIGURE 80

Page 70

Page 71

TYPICAL OUTDOOR UNIT WIRING DIAGRAM — 24 KBTU SYSTEMS (208 / 230V) HEAT PUMP

MAGNETIC

RING

PROTECTOROVERLOAD

SAT

COMP

L2L2

COMP−W

REACTOR

YEGN

INDC2

COMP−VCOMP−U

INDC1

YEGN

Please don’t touch any terminal when

WARNING

the voltage of terminal P(DC+) and

N(DC−) at AP1 is higher than 30V to

prevent the risk of electrical shock!

YEGN

TERMINAL

BLOCK

N(1)

INDOOR UNIT

XT1

POWER

YEGN

MAGNETIC

RING

COM−INNER

AC−L

YEGN

RT4

MANUAL

.SENSOR

OUTTUBE2

TEMP

RT1

4YV

4−WAY

VALVE

OUTTUBE

TEMP.SENSOR

RT2

T−SENSOR

EKV

Electronic expansion

valve

(OPTIONAL)

OUTROOM

EXHAUST

TEMP.SENSOR

RT3

TEMP.SENSOR

OVC−COMP

AP1

CAP.

FAN MOTOR

OFAN

FIGURE 81

TYPICAL OUTDOOR UNIT WIRING DIAGRAM — 30 KBTU SYSTEMS (208 / 230V) HEAT PUMP

FIGURE 82

Page 71

Corp. 1244-L9

Page 72

Troubleshooting

SYSTEM FAILED START UP (ALL SIZES)

APPLICABLE UNIT SIZE(S): All

System failed to start.

Breaker trip or blow fuse.

Non-responsive system after power up. No audible response and control input is unresponsive.

APPLICABLE ERROR CODE(S): NONE

Circuit breaker immediately trips when set to ON on remote control.

Circuit breaker trips after system has been running for a few minutes.

No power.

Power connections are incorrect.

Fuse on outdoor control has blown.

Transformer connection is loose, bad contact, or the transformer has malfunction.

Issue could be system circuit fault. Verify circuit breaker is installed correctly. If installation is correct, then replace circuit breaker.

Measure insulation resistance to ground and see if there is any leakage.

Check power supply circuit.

Check power connections and repair.

Replace fuse.

Repair wiring connection to the transformer; measure the output voltage of the transformer. If incorrect, replace transformer.

No response from remote control.

Outdoor control has malfunction.

Remote control batteries are dead

Remote control has malfunction.

Indoor unit infra-red receiver wire harness has a loose connection.

Infra-red receiver has malfunction.

System voltage is low

FIGURE 83

Replace remote control.

Replace batteries.

Press the AUTO (MANUAL) button to place the unit into AUTO mode. If system is unresponsive, check wiring between indoor and outdoor unit. If system is responsive and runs normally. Verify IR receiver connection to indoor control is good and that remote control is working.

Check voltage and if lower than 10% of the rated input voltage, then determine fault and repair.

MS8C / MS8H (208-230V)

Page 72

Page 73

Poor system performance.

POOR SYSTEM OPERATION (ALL SIZES)

Incorrect temperature setting.

Load demand is greater than system capacity.

Low refrigerant due to leak.

Internal compressor high or low pressure leak.

Refrigerant flow issue.

Possible heat loss due to poor line set insulation.

Reversing valve malfunction (heat pump only).

Possible refrigerant flow restriction.

Adjust temperature set point.

Check heating or cooling load calculations.

Repair leak, check refrigerant charge and adjust accordingly.

Replace compressor.

Replace reversing valve

Locate source of restriction and correct.

Verify line set is properly insulated. If insulation is missing then repair.

Block indoor or outdoor coil.

Air filter blocked.

Insufficient air flow

Outdoor air temperature is too high

Indoor fan speed set to low.

Fan speed is not constant. or running at lower speed that configured.

Improper outdoor unit installation.

Clean indoor or outdoor coil.

Clean or replace air filters

Set fan speed to middle or high speed.

Damage

capacitor

Fan motor

damaged

Proper ventilation around outdoor unit is required for correct unit operation. Reposition unit to required clearances.

Recommend installing a field-proved cover over the the outdoor unit. If cover does not resolve problem, then a higher capacity system may be required. Replace system.

Replace capacitor.

Replace fan motor.

FIGURE 84

Page 73

Corp. 1244-L9

Page 74

POOR SYSTEM OPERATION (ALL SIZES) (CONTINUED)

Indoor fan is not running.

In either cooling or

heating mode:

The compressor is running but the outdoor fan is off.

The compressor is not running, however the outdoor fan is on.

Indoor fan has malfunction or is damage.

Fan motor has a built-in thermal protection circuit that may be stopping the motor due to some type of abnormal operation.

Indoor fan motor may be installed incorrectly.

The indoor fan capacitor may have an open or damage circuit.

The outdoor fan motor has malfunction or is damage.

The outdoor fan motor capacitor is damage.

Compressor has malfunction or is damage.

Compressor capacitor has malfunction.

Voltage is either too high or low.

Replace indoor fan.

identify type of abnormal condition and correct.

Verify and correct wiring using the unit wiring diagram.

Replace indoor fan motor capacitor.

Verify and correct wiring using the unit wiring diagram. If malfunction continues, replace outdoor fan.

Replace outdoor fan motor capacitor.

Replace compressor.

Replace capacitor.

Check unit refrigerant operating pressure.

The compressor is running hot and the overload protection feature is cycling compressor off.

The louver motor is not running.

Compressor is installed incorrectly. Possible wiring connections.

The compressor's thermal protection circuits have malfunction.

The refrigerant is either low or high.

The capillary tubes are blocked which may cause a temperature rise.

Compressor is running errantly or has stopped.

The compressor's thermal protection circuits have malfunction.

The louver motor is installed incorrectly

The indoor control has malfunction and may result in the louver(s) not operating properly.

Verify and correct wiring using the unit wiring diagram.

Use a multimeter to check the compressor overload contacts. If the resistance is zero ohms, the thermal protection circuit is open. if the compressor is not hot to the touch, the thermal protection circuit should be replace.

Adjust refrigerant charge.

Replace capillary.

Replace compressor.

Check to see if louver motor was installed correctly using the unit wiring diagram. If wired correctly, then either the louver motor or indoor control has failed.

MS8C / MS8H (208-230V)

FIGURE 85

Page 74

Page 75

HEAT PUMP FAILED START UP (CONTINUED)

Either outdoor control has malfunction, current limiting circuit protector failed, or relay loop parallel capacitor leakage.

Compressor will not start in either heating or cooling modes.

Loose or incorrectly installed compressor harness.

Replace outdoor control.

Verify wiring using unit wiring diagram and correct.

Indoor unit leaking water.

Abnormal sound or vibration.

Incorrect temperature setting.

Condensate line is blocked.

Condensate line insulation is missing or loose.

Indoor fan motor assembly is loose or in contact with other components.

Foreign object located in unit.

Compressor vibrates.

Line set vibration.

Outdoor unit fan or coil grille(s) not secure.

Abnormal compressor noise.

FIGURE 85

Adjust air temperature setting.

Clear blockage.

Repair missing insulation.

Tighten fan motor assembly to unit or adjust position of assembly.

Locate foreign object and remove.

Adjust compressor mounting hardware.

Verify line set is secure and not in contact with external object.

Secure outdoor unit fan or coil grille(s).

Verify system charge and compressor input voltage. If okay, replace compressor.

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Corp. 1244-L9

Page 76

CAPACITOR CHARGE FAULT (OUTDOOR UNIT) (9-12K BTU SYSTEMS)

NOTE— Reactor (choke) line test procedure reference here is applicable for both the 115V and 208-230V systems.

APPLICABLE ERROR CODE(S): PU, PH

VERIFY VOLTAGE

Switch unit on and wait one minute.

Use DC voltmeter to measure the voltage on the two ends of the capacitor.

* 115VAC Systems: Use AC voltmeter to check voltage between L and

N on outdoor control.

Voltage higher than 103.5V (115V units) and 187V for 208-230V units.

Measure the AC voltage between terminals (L and N) or (L1 and L2) on outdoor unit terminal strip.

Voltage within 103.5V and

126.5V for 115V units and 187-253V for 208-230V units)

Switch off the power and wait 20 minutes; or use DC voltmeter to measure the voltage on the two ends of capacitor, until the voltage is lower than 20V.

Check the reactor (choke) line connection on the outdoor control to verify that it is connected using the unit wiring diagram.

There is a fault with the tested circuit on the outdoor (control)

Switch off the power and repair the supply power to restore the previously reference voltage ranges.

Replace outdoor control

Restore power and switch on the unit

Fault eliminated?

Is connection good?

Replace the outdoor control.

End

MS8C / MS8H (208-230V)

Reconnect to terminal.

Apply power to unit and turn on.

FIGURE 85

Page 76

Did this eliminate the fault?

Page 77

OUTDOOR UNIT HIGH TEMPERATURE AND OVERLOAD PROTECTION

High temperature and overload protection

APPLICABLE UNIT SIZE(S): All

APPLICABLE ERROR CODE(S): E1, E5, H4

Is the outdoor ambient temperature higher than 127ºF (53ºC)?

Power off system and restart after 20 minutes

Is heat dissipation of indoor and outdoor units abnormal?

Is outdoor unit fan operating correctly?

This is a normal protection

feature of the unit. once outdoor ambient air temperature drops below 53ºC (127ºF) system will operate.

Improve heat dissipation of environment around unit.

1. Check connection to OFAN terminal on outdoor control.

1. Check resistance between OFAN terminals, should be 1k ohm.

Replace outdoor control

End

Replace C1 fan capacitor

Replace outdoor fan

FIGURE 86

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Corp. 1244-L9

Page 78

OUTDOOR UNIT OVERLOAD AND DISCHARGE LINE SENSOR MALFUNCTION

APPLICABLE UNIT SIZE(S): All

APPLICABLE ERROR CODE(S): E4, H4

Is the electronic expansion valve terminal FA connected correctly.

Resistances between the blue wire terminal and all other wire terminals should be within +

Replace electronic expansion valve

5 of each other.

Is fault corrected?

Is wired correctly?

Check for refrigerant leak, correct leak and correct charge

Is fault corrected?

Replace Outdoor control

End

FIGURE 87

MS8C / MS8H (208-230V)

Page 78

Page 79

OUTDOOR POWER FACTOR CORRECTION FAULT

Start

Check the outdoor wiring connections for both the reactor (choke) line and power factor correction capacitor

APPLICABLE UNIT SIZE(S): All

APPLICABLE ERROR CODE(S): HC

Any damage or short circuit?

Remove power factor correction capacitor (CBB65) and check for open or shorted condition between terminals.

Is resistances near zero?

Disconnect the reactor (choke) terminals and measure resistances between both using ohm gauge.

Is component damage or short-circuited?

If capacitor is

Y Y

short-circuited, then replace

Replace damage component

Replace reactor (choke)

Restart unit

Is fault corrected?

Replace outdoor control

End

FIGURE 88

Page 79

Corp. 1244-L9

Page 80

INTER-UNIT COMMUNICATION ERROR

APPLICABLE UNIT SIZE(S): All

APPLICABLE ERROR CODE(S): E6

Start

See page 87 for procedure for testing communication line.

Check inter-unit wiring

The control voltage detection circuit is at fault.

Is fault corrected?

Is cable (wires) damaged?

Check communication circuit of outdoor unit

Is there a communication circuit error?

Did the system operate normally before the failure occurred?

Verify inter-unit wiring using the unit wiring diagram

Is connection

correct?

Correct inter-unit using unit wiring

Replace outdoor control

diagram.

Is fault corrected?

Replace indoor or outdoor control

Is fault corrected?

End

FIGURE 89

MS8C / MS8H (208-230V)

Page 80

Page 81

Major System Components

This section describes the following system components.

1. COMPONENT: INDOOR FAN MOTOR

DESCRIPTION:

The indoor fan is driven by a single-phase (115V) AC motor. The motor adopts step-less speed regulation to operate at different speeds. The motor speeds are determined by the output voltage and frequency signal from the indoor control. A Hall effect sensor, that is located in the end of the motor, feeds back information to the indoor control to confirm that the indoor motor is operating at the requested RPM.

TROUBLESHOOTING:

Check wiring connections at indoor control.

Measure resistance between the plug-in pins (if reading show open or shorted, replace fan motor). Measure resistance between leads red to brown, red to white and brown to white. If resistance is 0 ohms or infinite, replace motor.

2. COMPONENT: INDOOR LOUVER MOTOR (SWING MOTOR)

PHOTO OF INDOOR FAN MOTOR NAME PLATE (18-24 KBTU

UNITS)

DESCRIPTION:

A stepper motor (or step motor) is a brush less, electric motor that can divide a full rotation into a large number of steps. The louver motor operates on a 12 VDC input to vary the indoor air discharge louver to a programmed setting. Stepper motors effectively have multiple toothed electromagnets arranged around a central gear-shaped piece of iron. The electromagnets are energized by an external control circuit, such as a microcontroller. To make the motor shaft turn, first one electromagnet is given power, which makes the gear's teeth magnetically attracted to the electromagnet's teeth. When the gear's teeth are thus aligned to the first electromagnet, they are slightly offset from the next electromagnet. So when the next electromagnet is turned on and the first is turned off, the gear rotates slightly to align with the next one and from there the process is repeated. Each of those slight rotations is called a step, with an integer number of steps making a full rotation. In that way, the motor can be turned a precise angle.

TROUBLESHOOTING:

* Check wiring connections at indoor control. * Measure resistance between the plug-in pins (if

readings show open or shorted, replace motor). Normal reading between red-pink, red-blue, red-orange and red-yellow should be approximately 135 ohms +

10%.

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Corp. 1244-L9

Page 82

3. COMPONENT: OUTDOOR FAN MOTOR

ELECTRICAL CHARACTERISTICS:

* Power supply: 100~120V * Frequency: 60Hz * Number of poles: 2 or 4 * Output power: 90W. * Description:

S Single-phase capacitor run asynchronous DC

motor with iron shell. This type of motor is reliable, highly efficient, well structure, low noise output with minimum vibration attributes.

S Run capacitor separate remotely mounted in the of

outdoor board

TROUBLESHOOTING:

Measure resistance between wire leads. If resistance is 0 ohms or infinite between any of the wire leads, replace motor.

4. COMPONENT: ROTARY COMPRESSOR WITH ACCUMULATOR

DESCRIPTION:

PHOTO OF OUTDOOR FAN MOTOR NAME PLATE

(18-24 KBTU UNITS)

The rotary compressor is a 3-phase, direct-current (DC) compressor. In a rotary compressor the refrigerant is compressed by the rotating action of a roller inside a cylinder. The roller rotates eccentrically (off-center) around a shaft so that part of the roller is always in contact with the

inside wall of the cylinder.

A spring-mounted blade is always

rubbing against the roller. The two points of contact create two sealed areas of continuously variable volume inside the cylinder. At a certain point in the rotation of the roller, the intake port is exposed and a quantity of refrigerant is sucked into the cylinder, filling one of the sealed areas. As the roller continues to rotate the volume of the area the refrigerant occupies is reduced and the refrigerant is compressed. When the exhaust valve is exposed, the high-pressure refrigerant forces the exhaust valve to open and the refrigerant is released. Rotary compressors are very efficient because the actions of taking in refrigerant and compressing refrigerant occur simultaneously.

TROUBLESHOOTING:

Check wiring connections at outdoor control board plug-in and terminals of compressor.

COMPRESSOR OVERLOAD

(SAT)

COMPRESSOR TERMINALS

(U, V, W)

MS8C / MS8H (208-230V)

Page 82

OUTDOOR CONTROL

COMPRESSOR HARNESS

WITH FERRITE (X1)

Page 83

5. COMPONENT: ROTARY COMPRESSOR WITH ACCUMULATOR (CONTINUED)

TROUBLESHOOTING (CONTINUED):

Check winding resistance of each terminal. If resistance value is 0 ohms or infinite, replace compressor.

6. COMPONENT: COMPRESSOR TEMPERATURE OVERLOAD PROTECTION

DESCRIPTION:

If temperature detected by the overload sensor exceeds 239ºF (115ºC), the compressor will stop and the outdoor fan will stop after a delay of 30 seconds. Once the compressor temperature drops below 204ºF (95ºC), the compressor overload protection feature will reset and the system will resume normal operations.

RESISTANCE BETWEEN EACH SET OF WINDINGS SHOULD BE EQUAL.

COMPRESSOR OVERLOAD AS

SEMBLY (SAT)

OUTDOOR CONTROL

CONNECTION

TROUBLESHOOTING:

* Check wiring connections at compressor terminals and

at the outdoor control.

* Check control SAT to determine if it is closed or open.

If resistance is infinite ohms, then the overload control is closed. If the resistance is 0 ohms, then the overload control is CLOSED. If the compressor is not hot to the touch, then the overload control assembly should be replaced.

OUTDOOR CONTROL

Page 83

Corp. 1244-L9

Page 84

8. COMPONENT: ELECTRONIC EXPANSION VALVE

DESCRIPTION:

Electronic expansion valve is used in Inverter air conditioning system to adjust flow of refrigerant automatically. Thus the air conditioner can always stay at the optimized working conditions with quick cooling, precise temperature control, low energy consumption, etc. This valve is reversible and can control the flow under either cooling or heating condition.

Electronic Expansion Valve (EXV) is mainly composed of valve body and 12 VDC, rectangular wave coil. The controller in the air conditioning system can control the step motor of EXV to synchronize the turning of gear train which converts the rotation of gears to a pull/push force and moves the valve pin axially which can change the flow area and flow of refrigerant accordingly.

The outdoor control sends pulse signal to the coil which controls the rotor synchronizing the turning of feed screw and nut, converting the rotation to movement of valve pin. Thus the flow area and flow of refrigerant will be changed accordingly.

The EXV is driven by permanent-magnet (PM) type step motor (claw pole field motor) which consists of two relative separate parts: 1) step motor coil; 2) multi-pole rotor valve body. The coil is fixed onto the body through a clipper.

Check resistance between blueblack, blue-yellow, blue-red and blue-orange. All resistance read ings should be within +

5 of each

other.

TROUBLESHOOTING:

Check opening and closing operation of valve. Check operation of valve by measuring temperature differences between the inlet and outlet pipes of the EXV.

MS8C / MS8H (208-230V)

Page 84

Page 85

10. COMPONENT: REVERSING VALVE (HEAT PUMP ONLY)

DESCRIPTION:

The 4-way reversing valve is a component that switches the system between cooling and heating modes. By switching the flow of refrigerant, the heat pump can incorporate the functions of cooling in summer and heating in winter together. The 4-way reversing valve consists of main and pilot valves, and a solenoid coil.

Any of the following starting conditions are required to actuate the reversing valve for a specific operating condition.

NOTE — The reversing valve is energized in heating mode.

STARTING CONDITIONS:

1. When entering heating mode on start up.

2. When changing from cooling to heating mode.

3. When entering defrost mode.

4. When entering heating mode after defrost.

TROUBLESHOOTING:

Using a multimeter set to ohms, insert the test lead probes into the plug end of the reversing valve coil. If resistance value is between 950 to 1500 ohms then the reversing valve is good. If not within the specified range, replace reversing valve.

REVERSING VALVE BODY

REVERSING VALVE 220-240

VOLT COIL

POWER CONNECTOR FOR REVERSING VALVE (TYPICALLY

PLUGGED INTO THE OUTDOOR CONTROL 4V JACK

Page 85

Corp. 1244-L9

Page 86

12. COMPONENT: STRAINERS

DESCRIPTION:

Mesh strainers are required on the inlet and outlet of the electronic expansion valve to prevent debris from entering the valve.

TROUBLESHOOTING:

Normally strainers should not have any temperature differences between the inlet and outlet as shown in item 1 below. However if a temperature differences is detected then the strainer may be clogged. If strainer is clogged, replace strainer.

ITEM 1

STRAINERS

13. COMPONENT: REACTOR (CHOKE)

DESCRIPTION:

Choke coils are inductances that isolate AC frequency current from certain areas of a radio circuit. The reactor (coke) depend upon the property of self-inductance for its operation. Chokes can be used to block alternating current while passing direct current.

TROUBLESHOOTING:

Inspect reactor (choke) for loose connections or burnt windings.

14. COMPONENT: FERRITES

DESCRIPTION:

Ferrites are chemical compounds consisting of ceramic material with iron oxide as their principle component. Some ferrites have magnetic properties and are used to make permanent magnets and ferrite cores for transformers which can be used in various applications.

Electronic cabling and wires, by virtue of their length-towidth ratios, are perfect natural antennas. In the presence of high-speed microprocessor signals, cable will conduct, radiate, and receive unwanted high-frequency interfering signals. Control of radio-frequency (RF) interference can be ensured by the proper placement of an insertion-loss device, such as a ferrite suppressor. They are consistently stable over time and and over wide temperature ranges, and provide RF suppression without high eddy-current losses.

FERRITE

CHOKE

FERRITE WITH UNIT WIRING

INSTALLED

MS8C / MS8H (208-230V)

Page 86

Page 87

15. COMPONENT: INDOOR TRANSFORMER

DESCRIPTION:

Indoor unit contains a transformer that will convert the 115 power to 12VAC or on some units there are two output voltages. The transformer in the pictured shows a transformer that will output 12VAC (yellow wires) and

8.5VAC (white wires). Output voltages will vary with input power into transformer.

16. COMPONENT: INDOOR / OUTDOOR COMMUNICATION LINE

DESCRIPTION:

These units can use the same wire insulation and gauge as the main power wire into the system. The wire is routed from the outdoor unit to the indoor unit.

TRANSFORMER

TRANSFORMER INSTALLED

IN INDOOR CONTROL

HOUSING

TROUBLESHOOTING:

Use a true RMS meter to read between terminals neutral. The communication signal can vary:

S 9 and 12kBtu indoor Units - 0 to 70VAC. S 18 and 24kBtu indoor units - 0 to 56VAC S 30Kbtu indoor unit - 0 to 15VAC

2 and

Page 87

Corp. 1244-L9

Page 88

Optional Condensate Pump Wiring Connection

In order to use one of the condensate pumps available from Lennox, the pump will need to be wired as illustrated in the following diagram.

Mini Orange

INCOMING 115V POWER WIRES

PERMANENTLY LIVE

TERMINAL

BLOCK IN

CONDENSER

WIRE

NUT

1 2 3 G

BLACK

1 AMP FUSE

ORANGE (N/O)

DO NOT USE (ISOLATE WITH WIRE NUT)

Figure 90. Installing Condensate Pump

Disassembly Units

BLACK LINE 1

COMMUNICATION

PURPLE (NC)

5 AMPS MAX

PUMP

GROUND

RED

GRAY (COM)

5 AMPS MAX

TERMINAL BLOCK IN CONDENSER

1 2 3 G

RED LINE 2

WIRE NUT

This section describes how to dismantle the indoor and outdoor units down to the replacement component level.

NOTE — Due to multiple size units, some of the dismantling procedures may vary from what is shown in this section.

INDOOR UNIT FRONT CASE REMOVAL

This section describes how to remove the indoor unit front case.

NOTE — This procedure may vary slightly on differently sized units.

REMOVING AIR FILTER AND FRONT PANEL

1. Lift front panel out and up to remove.

2. Remove the air filters.

MS8C / MS8H (208-230V)

Page 88

Page 89

3. Loosen the clasps that secure the louvers to the case cover. Bend the louver slightly to remove it.

5. Lift the screw cover to access the screws that secure the lower portion of the front cover to the unit.

4. Remove the screw(s) that secure the indoor terminal strip access cover.

Page 89

Corp. 1244-L9

Page 90

6. Remove the two screws that secure the display to the front panel.

7. Remove the screws that secure the upper portion of the front cover to the unit.

8. Remove the access cover.

MS8C / MS8H (208-230V)

Page 90

Page 91

OUTDOOR UNIT DIS-ASSEMBLY

Step Outdoor Unit Procedure

1. Remove the top cover and front-side plates.

A * Remove the screws that secure the top panel to

unit.

* Remove top panel.

TOP PANEL

B * Remove the screws that secure the valve cover to

the unit.

* Remove valve cover.

C * Remove the screws securing the front-side panel

to chassis.

* Remove the front-side panel.

2. Remove exhaust grille

* Removes screws securing the exhaust grille to the

unit.

* Remove grille.

FRONT-SIDE PLATE

EXHAUST GRILLE

VALV E

COVER

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Corp. 1244-L9

Page 92

3. Remove panel

* Remove the screws securing the coil guard to the

chassis.

* Remove coil guard.

4. Remove handle

* Remove the screws securing the handle to

chassis.

* Remove handle.

COIL GUARD

5. Remove right-side panel.

* Remove screws securing the right-side panel to

the chassis, valve support and condenser.

* Remove right-side panel.

HANDLE

handle

RIGHT-SIDE PLATE

MS8C / MS8H (208-230V)

Page 92

Page 93

6. Remove electric box

A * Remove screws securing electric box cover.

* Remove cover.

B * Remove screws securing the electric box.

* Pull out the wiring terminal by cutting the tie straps. * Pull electric box upwards to remove.

ELECTRIC BOX COVER

ELECTRIC BOX

C * Remove screws securing the electric box 2 to the

left-side plate.

* Pull box upwards to remove.

Page 93

ELECTRIC BOX 2

Corp. 1244-L9

Page 94

7. Remove left-side plate

* Remove screws securing the left-side plate with

the chassis.

* Remove left-side plate.

8. Remove axial flow blade

Remove the nut that secure the fan blade to the fan motor shaft. Remove fan blade.

LEFT-SIDE PLATE

CHASSIS

FAN BLADE

9. Remove motor and motor support

A * Disconnect fan motor wiring harness.

* Remove screws that secure the fan motor to the

fan motor support.

* Remove motor.

NUT

FAN MOTOR

SUPPORT

FAN

MOTOR

MS8C / MS8H (208-230V)

Page 94

Page 95

B * Remove screws that secure the fan motor support

to the chassis.

* To remove, pull assembly upwards.

10. Remove Reversing Valve

De-braze the piping between the following components:

* Compressor * Outdoor coil * Valves Remove reversing valve.

CHASSIS

REVERSING VALVE

OUTDOOR COIL

FAN MOTOR SUPPORT

Page 95

VALVES

Corp. 1244-L9

Page 96

11. Remove 2-Way Shutoff and 3-Way Service Valves

* Remove bolts securing the valve assembly. * De-braze joint between 3-way service valve and

air-return pipe and remove valve.

* De-braze solder joint between 2-way shut-off

valve and connection pipe of valve and remove valve.

IMPORTANT — Wrap both valves with water saturated cloths before de-brazing valves. Water saturated cloths must remain water saturated throughout the de-brazing and cool-down process.

12. Remove Compressor Assembly

* Remove the three bolts at the base of the

compressor assembly (compressor and accumulator).

* Remove compressor assembly.

3-WAY VALVE

COMPRESSOR ASSEMBLY

13. Remove Isolation Sheet

* Remove screws securing the isolation sheet and

end plate of the coil and chassis.

* Remove isolation sheet.

ISOLATION SHEET

compressor

MS8C / MS8H (208-230V)

Page 96

Page 97

14. Remove Coil Support Plate.

* Remove screws securing the support plate to the

coil.

* Remove support plate.

15. Remove Chassis and Coil

Pull coil upwards to separate from the chassis.

COIL SUPPORT PLATE

COIL

CHASSIS

Page 97

Corp. 1244-L9

Lennox MS8, MS8C, MS8H Installation And Service Procedures

Specifications and Main Features

Frequently Asked Questions

User Manual