Mitsubishi Electric PAC-LV11M-J M-Controller Installation Manual

1. Safety Precautions

Before installation and electrical work, carefully read the safety precautions. These precautions contain important safety information and must be followed.

1.1. Before Installation and Electrical Work

• Warning: Safety measures to prevent risk of death or serious injury to the user.
• Caution: Safety measures to prevent damage to the unit.

Symbols Used in Text

• Warning: Indicates safety measures to avoid risk of death or serious injury.
• Caution: Indicates safety measures to avoid damage to the unit.

Symbols Used on Unit Labels

• !: Indicates actions to avoid.
• ?: Indicates instructions that must be followed.
• ⏚: Indicates parts that must be grounded.
• ⚠: Indicates caution when working with rotating parts. (Yellow color)
• ⚡: Indicates caution for electric shock. (Yellow color)

Important Warnings

• Request installation of the M-controller from a dealer. Improper installation may lead to water leakage, electric shock, or fire.
• Install the unit in a location that can support its weight. Insufficient strength may cause the unit to fall, resulting in injury.
• Use the specified cable for electrical connections. Ensure connections are secure without straining wires on terminals. Loose connections can cause overheating and fire.
• Consider earthquake or strong wind resistance when selecting an installation location. Improper installation may cause the unit to fall, resulting in injury.
• Use air fresheners, humidifiers, electric heaters, and other accessories specified by Mitsubishi Electric. Request installation of accessories from authorized specialists. Improper installation may lead to water leakage, electric shock, or fire.
• Never attempt to repair the unit yourself. Consult a dealer if repairs are needed. Improper repairs may lead to water leakage, electric shock, or fire.
• Always wear protective clothing, such as gloves and safety goggles, when working with the unit. Improper handling may cause injury.
• In case of refrigerant gas leakage during installation, ventilate the room. Refrigerant gas can form poisonous gases when exposed to flame.
• Install the air conditioner according to the installation manual. Improper installation may lead to water leakage, electric shock, or fire.
• All electrical work must be performed by a licensed electrician in accordance with local regulations and this manual. Incorrect power supply or electrical work may cause electric shock or fire.
• Keep electrical parts away from water. This may cause electric shock or fire.
• When installing or moving the unit, do not use a refrigerant other than that specified on the unit (R410A). Mixing with other refrigerants or air may damage the hydraulic circuit.
• If the unit is installed in a small room, measures must be taken to prevent refrigerant gas concentration from exceeding safe limits in case of leakage. Consult a dealer for appropriate measures. Refrigerant leakage and exceeding safe concentration limits can lead to oxygen deficiency.
• Contact a dealer or authorized representative for moving and reinstallation. Improper installation may lead to water leakage, electric shock, or fire.
• After installation, check for refrigerant leaks. Refrigerant gas in contact with a heat exchanger, stove, oven, or other heat source can produce poisonous gases.
• Do not reconstruct or change the settings of protective devices. Short circuits or forced operation of pressure relays, thermal relays, or other protective equipment may cause fire or explosion.
• Contact a dealer for unit disposal.
• Do not use leak detection additives.

1.2. Safety Precautions for Units with R410A Refrigerant

• Caution:
• Do not use existing refrigerant lines. Old refrigerants and oils may cause premature aging of the new refrigerant oil.
• Use refrigerant lines made of C1220 (Cu-DHP) phosphorus-deoxidized copper according to JIS H3300. Ensure pipes are clean and free from sulfur, oxides, dirt, chips, oil, moisture, or other contaminants. Contaminants can cause premature aging of the refrigerant oil.
• Store refrigerant lines indoors, sealed at both ends, until installation. (Store fittings and adapters in plastic bags.) Dust, dirt, or water entering the refrigerant circuit can degrade oil and cause compressor failure.
• Use liquid refrigerant for system charging. Charging with gaseous refrigerant may result in an uneven refrigerant composition and reduced performance.
• Do not use refrigerants other than R410A. Refrigerants like R22 contain chlorine, which can cause premature aging of the refrigerant oil.
• Use a vacuum pump with a check valve. Vacuum pump oil may enter the hydraulic circuit and degrade the refrigerant oil.
• Do not use tools previously used with conventional refrigerants (manifold gauge set, charging hose, leak detector, back-check valve, vacuum gauge, recovery machine). Mixing conventional refrigerants and R410A refrigerant oil can degrade refrigerant properties. Mixing water with R410A degrades refrigerant oil. Leak detectors for conventional refrigerants will not respond to R410A as it does not contain chlorine.
• Do not use charging cylinders. Using charging cylinders can degrade refrigerant properties.
• Handle tools with care. Dust, dirt, or water entering the hydraulic circuit can degrade refrigerant properties.

1.3. Before Starting Installation

• Caution:
• Do not install the unit in locations where flammable gas may leak. Gas leaks near the unit can cause an explosion.
• Do not use the M-controller in areas where food products, pets, plants, or works of art are stored. Quality of these items may deteriorate.
• Do not use the unit under special conditions. Oil, steam, sulfurous fumes, etc., can significantly reduce performance or damage unit components.
• If installing the unit in a hospital or similar facility, ensure adequate protection against interference. Inverters, generators, high-frequency medical equipment, or wireless communication equipment can cause air conditioner malfunctions. Conversely, the air conditioner may interfere with such equipment, disrupting medical procedures and radio communication.
• Do not install the unit on structures that may cause leaks. If the humidity exceeds 80% or the drain pipe is clogged, condensate may drip from the indoor unit. Install a shared drain system with the outdoor unit when necessary.
• The unit should be installed on the ceiling at a height of 2.5 m or more from the floor.

1.4. Electrical Work Before Installation (Relocation)

• Caution:
• Ground the unit. Do not connect the ground wire to gas pipes, water pipes, lightning rods, or telephone ground lines. Improper grounding may cause electric shock.
• Route the power cable without excessive tension. Excessive tension can lead to cable breakage, overheating, and fire.
• Install a ground-leakage circuit breaker if necessary. Failure to do so may result in electric shock.
• Use power cables of sufficient capacity and current rating. Cables with insufficient capacity may burn out, overheat, and cause fire.
• Use circuit breakers and fuses of the specified capacity only. Fuses or circuit breakers with higher capacity, or steel or copper wires, may cause unit failure or fire.
• Do not wash the unit. Washing may cause electric shock.
• Check the condition of the unit's installation base during prolonged use. If damage is not repaired, the unit may fall, causing injury or damage.
• Install the drain piping according to the Installation Manual to ensure drainage. Insulate pipes to prevent condensation. Improper installation of drain piping may cause water leakage and damage to furniture or other property.
• Handle the unit with care during transportation. Do not use plastic packing straps for moving the unit; it is dangerous.
• Dispose of packaging materials safely. Nails and other metal or wooden parts of the packaging can cause cuts and other injuries. Tear plastic packaging into pieces and dispose of it where children cannot play with it, to prevent suffocation.

1.5. Before Test Run

• Caution:
• Turn on the power at least 12 hours before operation. Starting the unit immediately after turning on the main power switch may seriously damage internal components. The main power switch should remain on throughout the operating period.
• Do not touch switches with wet hands. Touching with wet hands may cause electric shock.
• Do not touch refrigerant lines during or immediately after unit operation. Refrigerant lines may be hot or cold depending on the refrigerant state. Touching them may cause burns or frostbite.
• Do not operate the air conditioner with panels and covers removed. Rotating, hot, or live parts can cause injury.
• Do not turn off the power immediately after operation stops. Wait at least five minutes before turning off the power. Otherwise, water leakage or unit failure may occur.
• If the power cord is damaged, it must be replaced by the manufacturer, a service company, or similarly qualified personnel to avoid hazards.
• This device is not intended for use by persons (including children) with reduced physical, sensory, or mental capabilities, or lack of experience and knowledge, unless supervised or instructed on the use of the device by persons responsible for their safety.
• Children should be supervised to ensure they do not play with the device.

2. Unit Overview

2.1. System Description

2.1.1. Example System

The M-controller connects to indoor units and the outdoor unit, managing the air conditioning system.

• Outdoor Unit
• M-controller
• Indoor Unit
• M-controller
• M-controller
• M-controller

2.2. Unit Construction

Refrigerant Pipe

M-controller

Wall Mounting

• Refer to dealer for connectable indoor unit models.

2.3. Installation

2.3.1. M-controller Installation

Parts to be Procured Locally

• Suspension bolts or anchor bolts: M10
• Nut: M10
• Washer: M10

Ceiling Installation

1. Install suspension bolts.
2. Install the M-controller.

Wooden Structures

• Use ceiling joists (single-story homes) or second-floor joists (two-story homes) as support structures.
• Wooden beams for suspending air conditioners must be strong, with a cross-section of at least 6x6 cm and a spacing of no more than 90 cm.
• Suspension bolts must be M10. (Bolts are not included with the unit.)

Reinforced Concrete Structures

• Secure suspension bolts using the method shown or steel or wooden brackets for suspension bolt installation.
• Inserts rated for 100-150 kg each (Procured locally)
• Suspension bolts M10 (Procured locally)
• Reinforcing steel bars
• Suspension bolt M10 (Procured locally)
• Nut (Procured locally)
• Washer (Procured locally)
• Washer (Procured locally)
• Nut (Procured locally)

Wall Mounting

1. Install anchor nuts.
2. Install the M-controller.

Do not install refrigerant lines above the unit when mounting it on the wall. Condensate may drip onto electrical components, causing electric shock or fire.

2.3.2. Refrigerant Pipe Installation

Check M-controller Accessories and Parts

1. Pipe insulation x 2
2. Thermistor holder - Ø9.52 x 1
3. Thermistor holder - ø12.7 x 1

Connecting the M-controller to the Refrigerant Pipe

When brazing refrigerant pipes, cover the pipe insulation with a wet cloth to prevent it from igniting or shrinking due to heat.

• To indoor unit
• To outdoor unit
• M-controller
• Refrigerant pipe (Procured locally)

Slide the pipe insulation 1 onto the liquid refrigerant pipe towards the M-controller and secure it. Use the supplied 20 mm clamps to secure the pipe insulation 1.

• Clamp (Procured locally)
• M-controller
• Pipe insulation
• Refrigerant pipe (Procured locally)
• Tape (Procured locally)

Wrap the pipe insulation 1 with tape.

2.3.3. Thermistor Installation

Ensure thermistors (gas) supplied with the unit are installed as shown in the figure.

• The unit will not operate if thermistors are not installed. Improper thermistor installation will cause incorrect operation.

Take measures to prevent condensate from contacting thermistor wiring or entering electrical devices. Before installing heat insulation on the refrigerant pipes connecting to the indoor unit, install the thermistors as described on this page.

• Refer to section 8.4. "Electrical Wiring" for CN44 placement.

M-controller

Gas: CN44

Solder point

Outdoor Unit

Control board

Max. 15000

Max. 2000

Thermistor-G (gas)

Outdoor Unit

Refrigerant pipe (gas)

Refrigerant pipe (liquid)

Thermistor Installation Order

1. Securely attach the thermistor (gas) supplied with the unit using the thermistor holders (2, 3) at the refrigerant pipe connection points of the indoor unit.
2. Install the Thermistor-G (gas) in the thermistor holders 2 and 3, then secure the refrigerant pipes.

Thermistor

Refrigerant pipe

Applicable pipe diameters are indicated here.

Thermistor holder

Thermistor holder

Thermistor

Max. 1500 mm

• Caution
• Secure the thermistor wire with a clamp so it does not detach even when pulled.
• Cut the end of the clamp after securing.

Gas

Ø9.52 indicated

Ø12.7 indicated

• Select thermistor holders corresponding to the refrigerant pipe diameter.

Indoor Unit Capacity	Liquid Pipe Diameter (mm)	Gas Pipe Diameter (mm)
6.35	9.52	6.35	12.7
15-50	6.35	9.52	6.35	12.7

• Caution
• Wrap thermistor connections with heat insulation to prevent condensation.
• Install the thermistor on the top of the pipe (as shown in the figure above).
• Route the thermistor wire above the pipe.
• Install the thermistor indoors.
• Route the following wires, lines, and cable pairs so they do not contact each other:
• Thermistor wire and indoor unit/M-controller signal line
• Thermistor wire and power cable
• Signal line and power cable

2.3.4. Electrical Work

2.3.4.1. Important Notes

1. Comply with local technical regulations and standards related to electrical equipment, wiring, and the power company's specifications.
2. Control wiring (referred to as signal line) should be routed at least 5 cm away from power wiring to avoid electrical interference. (Do not route signal wiring and power wiring in the same cable channel.)
3. Always ground the outdoor unit.
4. Do not connect the main power supply to the signal line terminal block. This will cause electrical parts to burn out.
5. Use a 2-core shielded cable for connecting the signal line to the M-controller's TB5. Transmitting data from different systems over the same multi-core cable may degrade transmission and reception of data, leading to incorrect operation.
6. The system will not operate if connected incorrectly.
• TB2: Power terminal block
• TB: Signal line terminal block for indoor unit
• TB5: Signal line terminal block for outdoor unit

2.3.4.2. Connecting Signal Cables for M-controller, Indoor, and Outdoor Units

Outdoor Unit

M-controller

M-controller

TB3

M1M2 S

L1

TB5

TB

M1M2 S S1 S2 S3

L2

TB5

TB

M1M2 S S1 S2 S3

S1 S2 S3

TB

Indoor Unit

M-controller

TB5

S1 S2 S3

TB

Indoor Unit

M1 M2 S

TB

S1 S2 S3

TB

Indoor Unit

• Connect the outdoor unit (TB3) to the M-controller (TB5) using a 2-core wire, without observing polarity. The "S" terminal on the M-controller (TB5) is for connecting the shielded wire. Refer to the outdoor unit installation manual for connection cable specifications.
• Connect the indoor unit (TB) to the M-controller (TB). Refer to the indoor unit installation manual for connection cable specifications.

Allowable Length

1. Indoor Unit - M-controller: Maximum signal cable length: l1 and l2, l3 ≤ 10 m (2-core, 1.0 mm²)
2. Outdoor Unit - M-controller + M-controller - M-controller: Maximum signal cable length: (L1 + L2) or (L1 + L3) or (L2 + L3) ≤ 200 m

2.3.4.3. Main Power Wiring and Equipment Capacity

15 A Switch

15 A Overcurrent Protection

M-controller

Circuit Breaker

Wiring

Main Power Wiring Thickness and Capacity

Model	Minimum Cable Diameter (mm)	Junction Box	Main Cable	Branch Cable	Grounding	Circuit Breaker (NFB)	Leakage Circuit Breaker
	Outer Diameter	Outer Diameter
M-controller	1.5	1.5	1.5	15 A	15 A

2.3.4.4. Electrical Wiring

Check M-controller Accessories and Parts

1. Cable tie with retainer x 2
2. Thermistor

1) Remove the cover.

2) Install two cable ties with retainers 1

118

Control board

Cover

68

57

(1) Cable tie with retainer

Wiring entry

(Power, for indoor unit)

AT connector board

Clamps

Wiring entry

(for outdoor unit, from gas thermistor)

Terminal block

Cable tie with retainer

Screws

3) Insert wiring and thermistor 2 into the unit, then secure them with clamps inside the unit.

4) Connect each wire to the terminal block.

5) Connect the thermistor ② to CN44 of the control board.

6) Tighten the cable ties 1 firmly to prevent stress on the cable outside the unit.

Cable

Ground terminal

Indoor unit cable

① Cable tie with retainer

Clamps

① Cable tie with retainer

Outdoor unit cable

Terminal block: TB2

(Power)

Control board

-/N 220-240 V/220 V

50/60 Hz

Terminal block: TB

(for indoor unit)

CN44

+8

Z

S

Terminal block: TB5

(for indoor unit)

2 Thermistor wire

7) After installing the unit, attach the cover.

2.3.5. Refrigerant Pipe

Example of Indoor Unit Connection

• Connect one M-controller to each indoor unit.
• Connect the M-controller to the liquid refrigerant pipe.
• The Thermistor-G (gas) is installed close to the gas refrigerant pipe connection point for the indoor unit.

Thermistor-G (gas)

Indoor Unit

M-controller

Max. 15 m

Refrigerant pipe connection point (Brazing)

Refrigerant Pipe Connection Size

Indoor Unit Capacity	Liquid Refrigerant Pipe Size (mm)
15-50	Ø6.35 x 0.8
* M-controller	Ø6.35 x 0.8

Additional Refrigerant Quantity

• If necessary, add the required amount of additional refrigerant following the calculation method provided in the outdoor unit manual.
• When calculating the additional refrigerant quantity, do not forget to include refrigerant for the length of the M-controller - indoor unit liquid refrigerant pipe.
• The system must be refilled with the amount of refrigerant required for the indoor units. Refer to the outdoor unit manual for details.

2.3.6. Error Codes

The table below lists the error codes for indoor and outdoor units connected to the M-controller. Refer to the respective service manuals for other error codes.

Error Code	Indoor Unit Error Code	Error Type
0404	Fb, FC	Internal EEPROM error of indoor unit
4124	PE	Electrical system failure due to damper malfunction
6840	E6, E8	Communication reception error
6841	E9	Communication synchronization failure
6842	E7, E9	Communication transmission/reception hardware error
6843	E6, E8	Initial communication bit detection error

2.4. DIP Switch Settings

1) SW2

Set the M-controller DIP switches as shown below to configure the connected indoor unit's capacity setting.

Note: SW2 timing setting is performed before powering on the unit.

2) SW4

Set the M-controller DIP switches as shown below.

SW4 Setting

ON

OFF

12345678910

3) Address Switch

The actual address setting for the indoor unit varies depending on the system. Refer to the outdoor unit installation manual for address setting details. Each address is set by a combination of tens and units digit settings. Example: To set address "3", set units to 3 and tens to 0. To set address "25", set units to 5 and tens to 2.

4) Branch Number Setting (PURY Only)

Setting Method

• Assign the lowest address to the main unit in the group.
• In a system with auxiliary BC controllers, perform settings for indoor units in the following order:
• a) Indoor unit connected to the main BC controller.
• b) Indoor unit connected to auxiliary BC controller 1.
• c) Indoor unit connected to auxiliary BC controller 2.
• Perform settings for indoor units satisfying the formula: "a) < b) < c)"

Note: Branch number setting is required when connecting with a BC controller.

5) Other

When the unit is used in an atmosphere of high temperature and humidity, change the outdoor unit DIP switch settings as follows.

3. Specifications

4. Diagram and Dimensions

4-10x5 oval holes

(For mounting on a flat surface)

15

20

2-ø12 holes

(For suspension bolts)

Power

Wiring to terminal block: TB2

1-phase, 220-240 V, 50/60 Hz

For indoor unit

Wiring to terminal block: TB

Screws (M5x10)

Note 3

For outdoor unit

Wiring to terminal block: TB5

For gas refrigerant pipe

Wiring from gas thermistor

4-10x5 oval holes

For wall mounting

Mounting plate

24

58

68

142

62

100

183

11

62

69

V

--

V

280

250

240

Notes:

1. Attach the gas thermistor to the gas refrigerant pipe.
2. When shipped from the factory, the mounting plate is not attached to the main body.
3. When mounting the unit on the wall, attach the mounting plate as shown in the figure on the left. (M5x10)
4. When using suspension bolts, attach the mounting plate in reverse.
5. Suspension bolt (ø10), washer (M10), and nut (M10) must be procured locally.

Accessories

• Mounting plate: 1 pc.
• Gas thermistor: 1 pc.
• Thermistor holder (Ø9.52): 1 pc.
• Thermistor holder (ø12.7): 1 pc.
• Screw (M5x10): 2 pcs.
• Pipe insulation: 2 pcs.
• Cable tie: 2 pcs.

Indoor unit connection pipe

Ø6.35 (Brazing)

Indoor unit connection pipe

Ø6.35

5 (Brazing)

110

+

V

34

65

4. Diagram and Dimensions

5. Electrical Connection Diagram

M-controller for CITY MULTI

P.B.

TAB1

SA

NR

U

280-340 V DC

Rectifier circuit

2 CN2S

A.B.

Circuit breaker

2

TB2

CN001 000

Fuse

F001

123

L

N

CNSK

(Red)

Power

220-240 V AC

50/60 Hz

To indoor unit

TB

S1

S2

S3

ZNR001

U

CN450

30

32.

C.B.

02

50

01

40

30

CNXC2

20

4321

10

654321

ΣΙ

CN44

LEV

CNXB2

CN60

TB5

CN570

(Red)

5432

M1

To outdoor unit control panel

M2

S

CN351 20

10

(Blue)

CN2M

(Blue)

Symbol

Name

Symbol

Name

C.B.

Control board

SW1(C.B.)

Switch (for mode selection)

P.B.

Power board

SW2(C.B.)

Switch (for capacity code)

A.B.

AT connector board

SW3(C.B.)

Switch (for mode selection)

: Terminal

TB2

Power terminal block

SW4(C.B.)

Switch (for model selection)

TB

Signal line terminal block

SW5(C.B.)

Switch (for mode selection)

TB5

Signal line terminal block

SW11(C.B.)

Switch (address setting)

F001

Fuse 250 V AC, 6.3 A

SW12(C.B.)

Switch (address setting)

ZNR001

Varistor

SW14(C.B.)

Switch (branch number)

NR

Varistor

SWA(C.B.)

Switch (for static pressure selection)

SA

Arrester

SWC(C.B.)

Switch (for static pressure selection)

TH23

Thermistor (pipe temp./gas pipe temp. detection)

LEV

LED 1

Light emitting diode (Power)

Linear expansion valve

Notes:

Symbols used in the diagram above

------ (Dotted line): On-site wiring

5. Electrical Connection Diagram

6. Hydraulic Circuit Diagram

(G)

(B)

(A)

(F)

(E)

(E)

(A) Thermistor on gas refrigerant pipe TH23

(B) Gas refrigerant pipe

(C) Liquid refrigerant pipe

(D) Brazed connections

(E) Filter (with 100 mesh)

(F) Linear expansion valve

(G) Indoor unit

(H) M-controller

(H)

(C)

(D)

6. Hydraulic Circuit Diagram

7. Troubleshooting

7.1. Test Run

Important Notes:

Before operating the unit, ensure that the wiring, refrigerant pipes, and thermistors are installed, and switches are set correctly.

Refer to the "Test Run" section of the indoor unit and outdoor unit installation manuals.

After installing the indoor unit, M-controller, and outdoor unit, perform a test run to check for water leaks in the M-controller. Always perform a test run in cooling mode for each installed indoor unit. Ensure each indoor unit operates correctly according to the installation manual supplied with the unit.

If the test run is performed for all indoor units simultaneously, incorrect refrigerant pipe connections and wiring connections for the indoor and outdoor units cannot be detected.

Important Notes:

• Always use a control panel to operate the indoor unit.
• Operation from the outdoor unit is not possible when using the M-controller.
• The following symptoms are not malfunctions:

* Refer to the indoor unit user manual for details.

** This mode is activated for approximately 1 minute to prevent refrigerant shortage during heating mode when the indoor unit is stored or turned off due to temperature.

• A hissing sound may be heard immediately after the air conditioner starts or stops. This is the sound of refrigerant flowing inside the M-controller. The problem is insignificant.

7.2. Inspection Methods

1. Components and Check Points

1) Thermistor

• Thermistor for gas refrigerant pipe (TH23)

Disconnect the connector and measure the resistance between the terminals using a tester. (Ambient temperature 10°C - 30°C)

(See thermistor characteristic graph below.)

1) Thermistor Characteristic Graph

Low-temperature thermistor

• Thermistor for gas refrigerant pipe (TH23)
• Thermistor Ro = 15 kΩ ±3%
• Constant B = 3480 kΩ ±2%

Rt = 15 exp { 3480 ( 1/(273+t) - 1/273 ) }

0°C: 15 kΩ

10°C: 9.6 kΩ

20°C: 6.3 kΩ

25°C: 5.2 kΩ

30°C: 4.3 kΩ

40°C: 3.0 kΩ

(A) Temperature (°C)

(B) Resistance (kΩ)

50

40

30

20

10

0

-20 -10 0 10 20 30 40 50

(A)

2) Linear Expansion Valve

Disconnect the connector and measure the resistance between the terminals using a tester. Refer to the next page for details.