MITSUBISHI ELECTRIC MSZ-EX09NLS (01) PDF DOCUMENT

The “A2L” warning symbol indicates that the MITSUBISHI ELECTRIC MSZ-EX09NLS unit uses a flammable refrigerant. If the refrigerant leaks and comes into contact with a fire or heating part, it will create harmful gas and there is a risk of fire. You should read the operating instructions carefully before operation, and service personnel are required to carefully read both the Operating Instructions and Installation Manual before operation.

The following safety precautions should always be observed:

• Do not install the unit by yourself (user). Improper installation could cause fire, electric shock, injury, or water leakage.

• Follow the instructions in the installation manual. Incomplete installation could cause fire, electric shock, injury, or water leakage.

• When installing the unit, use appropriate protective equipment and tools for safety.

• Install the unit securely in a place that can bear its weight. If the location cannot bear the weight, the unit could fall and cause injury.

• Do not alter the unit, as it may cause fire, electric shock, injury, or water leakage.

• Do not install the unit where flammable gas may leak. Gas accumulation around the unit could cause an explosion.

• Use only the provided or specified parts for installation work to prevent injury, water leakage, fire, or electric shock.

• Do not touch the air inlet or the aluminum fins of the outdoor unit to avoid injury.

• Do not install the outdoor unit where small animals may live. If they enter and damage electrical parts, it could cause a malfunction, smoke, or fire.

Observe the following electrical safety warnings:

• Perform electrical work according to the installation manual and use an exclusive circuit. Do not connect other electrical appliances to the circuit to prevent fire or electric shock.

• Ground the unit correctly. Do not connect the ground wire to a gas pipe, water pipe, lightning rod, or telephone ground.

• Do not damage the wires. Damaged wires could cause a fire.

• Shut off the main power when setting up the indoor P.C. board or wiring.

• Use the specified wires to securely connect the indoor and outdoor units and attach them firmly to the terminal block to avoid stress.

• Do not use an intermediate connection of the power cord or an extension cord. Do not connect many devices to one AC outlet.

• When plugging in the power supply, ensure there is no dust, blockage, or loose parts on the plug or in the outlet. Ensure the plug is completely inserted.

• Securely attach the electrical cover to the indoor unit and the service panel to the outdoor unit.

• Depending on the installation area, install a Ground Fault Interrupt (GFI) circuit breaker to prevent electric shock.

The MITSUBISHI ELECTRIC MSZ-EX09NLS uses flammable refrigerant R454B. The following safety precautions are critical:

• When installing, relocating, or servicing, ensure no substance other than the specified refrigerant (R454B) enters the refrigerant circuit. Foreign substances like air can cause an abnormal pressure rise, leading to explosion or injury.

• Do not discharge refrigerant into the atmosphere. After installation, check for refrigerant gas leaks. If a leak occurs during installation, ventilate the room.

• Use appropriate tools and piping materials for installation. The pressure of R454B is 1.6 times higher than R22. Using inappropriate tools can cause pipes to burst.

• When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes to prevent an abnormal pressure rise.

• Securely connect the refrigerant pipes before starting the compressor.

• Fasten a flare nut with a torque wrench as specified. Over-tightening can break the nut and cause a leak.

• When using a gas burner or other flame-producing equipment, completely remove all refrigerant from the air conditioner and ensure the area is well-ventilated.

• Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manufacturer.

• The appliance shall be stored in a room without continuously operating ignition sources (e.g., open flames, an operating gas appliance, or an operating electric heater).

• Do not pierce or burn the appliance.

• Be aware that refrigerants may not contain an odor.

• Pipe-work shall be protected from physical damage and the installation of pipe-work shall be kept to a minimum.

• Do not remove the RED MARKING near the pipe connection part.

The following tools are required for installation:

• Phillips head screwdriver

• Level

• Scale

• Utility knife or scissors

• 3 inches (75 mm) hole saw

• Torque wrench

• Wrench (or spanner)

• 5/32 inch (4 mm) hexagonal wrench

• Flare tool for R410A/R454B

• Gauge manifold for R410A/R454B

• Vacuum pump for R410A/R454B

• Charge hose for R410A/R454B

• Pipe cutter with reamer

The mounting height of the indoor unit must be 5.9 feet (1.8 m) or more from the floor, with up to 7.5 feet (2.3 m) being recommended. The unit must be installed in a room that exceeds the minimum room area (Amin) determined by the total refrigerant amount (M).

The unit should be installed in a location that meets the following criteria:

• Where airflow is not blocked.

• Where cool (or warm) air spreads over the entire room.

• On a rigid wall to reduce vibration.

• Where it is not exposed to direct sunlight.

• Where it can be easily drained.

• At least 3 feet (1 m) away from a TV and radio.

• As far as possible from fluorescent and incandescent lights.

• Where the air filter can be removed and replaced easily.

• Away from other heat or steam sources.

The following table shows the minimum room area required:

SYSTEM WITHOUT BRANCH BOX

M [kg]	Amin [m²]	Amin [ft²]
0.5	1.9	20
0.6	2.3	24
0.7	2.6	28
0.8	3.0	32
0.9	3.4	36
1.0	3.8	40
1.1	4.1	44
1.2	4.5	48
1.3	4.9	52
1.4	5.2	56
1.5	5.6	60
1.6	6.0	64
1.7	6.3	68
1.8	6.8	73
1.9	7.2	77
2.0	7.6	81
2.1	7.9	85
2.2	8.3	89
2.3	8.7	93
2.4	9.1	97
2.5	9.4	102
2.6	9.8	106
2.7	10.2	110
2.8	10.6	114

To prevent condensation, insulate both refrigerant pipes. Use insulation of the specified thickness from the table below. The refrigerant pipe bending radius must be 4 inches (100 mm) or more.

Pipe	Outside diameter inch (mm)	Minimum wall thickness inch (mm)	Insulation thickness inch (mm)	Insulation material
For liquid	1/4 (6.35)	0.0315 (0.8)	5/16 (8)	Heat resistant foam plastic 0.045 Specific gravity
For gas	3/8 (9.52)	0.0315 (0.8)	5/16 (8)
	1/2 (12.7)	0.0315 (0.8)	5/16 (8)

Follow these steps to connect the wiring:

1. Remove the panel assembly.

2. Place the upper part of the indoor unit on the installation plate.

3. Remove corner box R and the electrical cover.

4. Remove the display P.C. board holder, conduit cover, and conduit plate.

5. Attach the appropriate joint (straight for rear piping, elbow for right/left/downward piping) to the conduit plate with a lock nut.

6. Process the end of the ground wire and connect it to the ground terminal of the electrical parts box.

7. Process the end of the indoor/outdoor unit connecting wire. Attach it to the terminal block, ensuring no mis-wiring. Attach the wire securely so its core cannot be seen and no external force affects the connection.

8. Firmly tighten the terminal screws and verify the wires are fastened.

9. Reinstall the conduit plate, conduit cover, and display P.C. board holder.

10. According to the piping direction, remove the shaded part of the appropriate corner box (L or R). Reinstall the electrical cover, corner box, and front panel.

Pipe Forming (Left or Left-Rear Piping):

1. Place the refrigerant piping and drain hose together, then firmly apply felt tape from the end.

2. Pull out the drain cap at the back right of the indoor unit.

3. Pull out the drain hose at the back left of the indoor unit.

4. Insert the drain cap into the section where the drain hose was, at the rear of the unit.

5. Insert the drain hose fully into the drain pan at the back right of the unit, ensuring it is securely hooked.

6. Insert the drain hose into the wall hole sleeve and attach the upper part of the indoor unit to the installation plate.

7. Use cardboard spacers from the shipping box to lift the indoor unit for easier access.

8. Connect the refrigerant piping with the extension pipe.

9. Attach the lower part of the indoor unit to the installation plate.

Drain Piping (General):

• Do not cut the drain hose of the unit.

• If the extension drain hose passes through a room, wrap it with insulation.

• The drain hose should point downward for easy drainage.

• If the provided drain hose is too short, connect it with a field-supplied drain hose.

• Do not put the drain pipe directly in a drainage ditch where ammonia or sulfuric gas may be generated.

• Do not raise the drain pipe, create a dip where water can accumulate, or dip the end of the hose in water, as this can cause water leakage.

1. Cut the copper pipe as straight as possible with a pipe cutter.

2. Remove all burrs from the cut section of the pipe, avoiding getting metal shavings into the piping.

3. Remove flare nuts attached to the indoor and outdoor units, then put them on the pipe.

4. Using a flaring tool, firmly hold the copper pipe and create the flare. The dimension ‘A’ (the amount the pipe extends from the die) should be set according to the tool type as shown in the table below.

5. Check the flared work. It should be smooth, shiny, and of even length all around. If defective, cut it off and repeat the procedure.

Pipe diameter inch (mm)	A inches (mm) Clutch type tool for R410A/R454B	Tightening torque ft-lb (kgf.cm)	Tightening torque N·m
ø 1/4 (6.35)	0.04 to 0.06 (1.0 to 1.5)	10 to 13 (140 to 180)	13.7 to 17.7
ø 3/8 (9.52)		25 to 30 (350 to 420)	34.3 to 41.2
ø 1/2 (12.7)	0.08 to 0.10 (2.0 to 2.5)	36 to 42 (500 to 575)	49.0 to 56.4
ø 5/8 (15.88)		54 to 58 (750 to 800)	73.5 to 78.4

Refrigerant Pipe Airtight Test:

1. Connect testing tools. Ensure stop valves are closed. Add pressure to the refrigerant lines through the service port of the stop valve for GAS.

2. Pressurize to 601 psig (4.15 MPa) slowly, not all at once. Measure the surrounding temperature and refrigerant pressure.

3. If the specified pressure holds for about one day without decreasing, the pipes have passed the test. If the surrounding temperature changes by 1°F (0.5°C), the pressure will change by about 1 psig (0.007 MPa); make necessary corrections.

4. If the pressure decreases, there is a gas leak. Look for the source of the leak.

Insulation and Taping:

1. Cover piping joints with a pipe cover.

2. For the outdoor unit side, insulate the piping, including the valves.

3. Apply piping tape starting from the connection on the outdoor unit. For high humidity areas, use additional field-supplied insulation to prevent condensation.

1. Insert the power supply plug into the outlet and/or turn on the breaker.

2. Press the Emergency Operation Switch (E.O. SW) once for COOL, and twice for HEAT operation. The test run will perform for 30 minutes. If the left lamp of the operation indicator blinks every 0.5 seconds, inspect the indoor/outdoor unit connecting wire for mis-wiring. After the test run, emergency mode (set temperature 75°F [24°C]) will start.

3. To stop operation, press the E.O. SW several times until all LED lamps turn off.

To check the remote signal reception, press the OFF/ON button on the remote controller and listen for an audible indicator from the indoor unit. Press it again to turn the air conditioner off.

The MITSUBISHI ELECTRIC MSZ-EX09NLS is equipped with an auto restart function. When the power supply is cut off during operation (e.g., a blackout), the function automatically starts operation in the previous setting once the power supply is resumed. If this function is unnecessary, it can be deactivated by a service representative.

Removal Procedure:

1. Unlock the upper and lower vanes as shown in the diagram using a thin instrument. Then, remove the horizontal vanes.

2. Remove the 2 screws which fix the panel assembly.

3. Remove the panel assembly. Be sure to remove its bottom right end first.

Installation Procedure:

1. Install the panel assembly following the removal procedure in reverse.

2. Be sure to press the positions as indicated by the arrows to attach the assembly completely to the unit.

3. Install the horizontal vanes.

To connect an interface (such as a Wi-Fi adapter) to the air conditioner:

1. Remove the panel and the lower right corner box.

2. Open the covers of the indoor control P.C. board.

3. Join the connecting cable to connector CN105 on the indoor control P.C. board.

4. Attach the cable clamp provided with the interface to the thick part of the connecting cable with a screw.

5. Hook the connecting cable into the ribs as shown in the figure.

6. Close the covers of the indoor control P.C. board, being careful not to catch the thin part of the connecting cable in the cover. Reinstall the panel and the lower right corner box.

Important: Do not cut or extend the connecting cable of the interface. Keep it as far as possible from power supply cords and other wires. The thin part of the cable should be stored where customers cannot touch it. Incorrect installation may cause electric shock, fire, and/or malfunction.