MITSUBISHI ELECTRIC MSZ-EX18NLB (01) PDF DOCUMENT

WARNING: Failure to observe these precautions could lead to death or serious injury.

Installation:

• Do not install the unit by yourself (user). Improper installation can cause fire, electric shock, injury from the unit falling, or water leakage. Consult a qualified installer.

• Follow the instructions in the installation manual. Incomplete installation can lead to fire, electric shock, injury, or water leakage.

• Use appropriate protective equipment and tools for safety during installation.

• Install the unit securely in a location that can bear its weight. If the location is not strong enough, the unit could fall and cause injury.

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

• Perform electrical work according to the manual and use an exclusive circuit. Do not connect other 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.

• Use the specified wires to securely connect the indoor and outdoor units. Attach wires firmly to the terminal block to prevent stress.

• Do not install the unit where flammable gas may leak, as this could cause an explosion.

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

• Securely attach the electrical cover to the indoor unit and the service panel to the outdoor unit to prevent dust or water from causing a fire or electric shock.

• Fasten flare nuts with a torque wrench as specified. Over-tightening can cause the nut to break and lead to refrigerant leakage.

• Install the unit according to national wiring regulations.

Refrigerant Handling (R454B):

• This unit uses a flammable refrigerant (R454B). If refrigerant leaks and contacts fire or a heating part, it will create harmful gas and there is a risk of fire.

• Ensure no substance other than the specified refrigerant (R454B) enters the refrigerant circuit. The presence of foreign substances like air can cause abnormal pressure rise, leading to explosion or injury.

• Do not discharge refrigerant into the atmosphere. After installation, check for leaks. If refrigerant leaks during installation, ventilate the room immediately.

• Use appropriate tools and piping materials for R454B installation, as its pressure is 1.6 times higher than R22.

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

• When installing the unit, securely connect the refrigerant pipes before starting the compressor.

• 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.

• The appliance should 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 unit.

Operation & Maintenance:

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

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

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

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

CAUTION: Could lead to serious injury when operated incorrectly.

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

• Perform the drainage/piping work securely as per the manual to prevent water damage.

• 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 to prevent damage to electrical parts, which could cause malfunction, smoke, or fire.

The following tools are required for the installation of the MITSUBISHI ELECTRIC MSZ-EX18NLB air conditioner:

• 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 should be 5.9 feet (1.8 m) or more from the floor, with a recommended height of up to 7.5 feet (2.3 m).

The unit must be installed in a room that exceeds the minimum room area (Amin) determined by the total refrigerant amount (M). Refer to the table below for a system without a branch box.

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

Choose an installation location with the following characteristics:

• Where airflow is not blocked.

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

• On a rigid wall to reduce the possibility of vibration.

• Where it is not exposed to direct sunlight.

• Where it can be easily drained.

• At a distance of 3 feet (1 m) or more away from a TV and radio.

• In a place as far away as possible from fluorescent and incandescent lights.

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

• Where it is away from the other heat or steam source.

Avoid the following places for installation:

• Where flammable gas could leak.

• Where there is an excessive amount of machine oil in the air.

• Where oil is splashed or where the area is filled with oily smoke (such as cooking areas and factories).

• Salty places such as the seaside.

• Where sulfide gas is generated such as a hot spring, sewage, or waste water.

• Where there is high-frequency or wireless equipment.

• Where there is emission of high levels of VOCs, including phthalate compounds, formaldehyde, etc., which may cause chemical cracking.

Power Supply and Wiring:

• Power should be from an exclusive branched circuit.

• Use solid conductor Minches AWG14 or stranded conductor Minches AWG14.

• Use double insulated copper wire with 600 V insulation.

• Use copper conductors only and follow local electrical codes.

Electrical specifications

MODEL		MSZ-EX09NL MSZ-EX12NL MSZ-EX15NL MSZ-EX18NL
INDOOR UNIT
Power supply (V, PHASE, Hz)		208/230, 1, 60
Minches Circuit Ampacity (A)		1.0
Fan motor (F.L.A.) (A)		0.67

Refrigerant Pipes (R454B):

• To prevent condensation, insulate both refrigerant pipes.

• Use insulation of the specified thickness. Excessive insulation may cause incorrect installation, and too little insulation may cause condensation.

• Refrigerant pipe bending radius must be 4 inches (100 mm) or more.

Refrigerant Pipe Specifications

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)

1. Attaching the Installation Plate:

1. Find a stud in the wall to attach the installation plate (1) horizontally by tightening the fixing screws (2) firmly.

2. To prevent the plate from vibrating, install attachment screws in the holes indicated in the illustration. Additional screws can be used for extra support.

3. If the knockout is removed, apply vinyl tape to the edges to prevent damaging wires.

2. Drilling the Wall Hole:

1. Determine the hole location on the wall.

2. Drill a ø 3 inches (75 mm) hole. The outdoor side should be 6/32 to 9/32 inch (5 to 7 mm) lower than the indoor side.

3. Insert the wall hole sleeve (C).

3. Connecting Wires for the Indoor Unit:

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 straight joint (for rear piping) or elbow joint (for right, left, or 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 (A) and attach it to the terminal block securely.

8. Firmly tighten the terminal screws.

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 corner box L or R. Reinstall the electrical cover, corner box, and front panel.

Pipe Forming General Instructions:

• Place the drain hose below the refrigerant piping.

• Make sure the drain hose is not crowded or bent.

• Do not pull the hose when applying tape.

• When the drain hose passes through the room, wrap it with insulation material (field-supplied).

For Left or Left-Rear Piping:

1. Place refrigerant piping and drain hose together, then firmly apply felt tape (4).

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. Put the drain cap into the section where the drain hose was originally attached.

5. Insert the drain hose fully into the drain pan at the back right of the indoor unit.

6. Insert the drain hose into the wall hole sleeve (C) and attach the upper part of the indoor unit to the installation plate (1). Shift the unit left for easier piping.

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

8. Connect the refrigerant piping with the extension pipe (B).

9. Attach the lower part of the indoor unit into the installation plate (1).

Drain Piping Instructions:

• 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 (I).

• When connecting to a hard vinyl chloride pipe, insert it securely.

• Ensure no stress is applied to the connecting portion of the drain hose after installation.

• Do not apply any agent on the drain port.

• Do not make drain piping as shown in the incorrect examples (raised, dipped in water without a gap, or with a wave).

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

2. Remove all burrs from the cut section of the pipe, ensuring no metal shavings get into the piping.

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

4. Perform the flaring work. Firmly hold the copper pipe in the dimension shown in the table. Select dimension A from the table according to the tool you use.

5. Check the flared work. If it is defective (tilted, uneven, burred), cut off the section and repeat.

Pipe diameter inch (mm)	B inch (mm)	A inches (mm)			Tightening torque
		Clutch type tool for R410A/R454B	Clutch type tool for R22	Wing nut type tool for R22	ft-lb (kgf.cm)	N•m
ø 1/4 (6.35)	21/32 (17)	0 to 0.02 (0 to 0.5)	0.04 to 0.06 (1.0 to 1.5)	0.06 to 0.08 (1.5 to 2.0)	10 to 13 (140 to 180)	13.7 to 17.7
ø 3/8 (9.52)	7/8 (22)			0.08 to 0.10 (2.0 to 2.5)	25 to 30 (350 to 420)	34.3 to 41.2
ø 1/2 (12.7)	1-1/32 (26)				36 to 42 (500 to 575)	49.0 to 56.4
ø 5/8 (15.88)	1-5/32 (29)				54 to 58 (750 to 800)	73.5 to 78.4

1. Pipe Connection:

• Fasten the flare nut with a torque wrench as specified in the torque table.

• Be sure to wrap insulation around the piping to prevent burns or frostbite.

• For the indoor unit, connect both liquid and gas piping. First align the center, then tighten the first 3 to 4 turns of the flare nut by hand. Use two wrenches to tighten to the specified torque.

• For the outdoor unit, connect pipes to the stop valve pipe joint following the same procedure.

2. 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 GAS stop valve.

2. Pressurize to 601 psig (4.15 MPa). Add pressure gradually, not all at once.

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

4. If the pressure decreases, there is a gas leak. Find and fix the source of the leak.

3. 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 (G) starting from the connection on the outdoor unit. Use additional field-supplied insulation if piping is installed through a ceiling, closet, or high-humidity area to prevent condensation.

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

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

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

Checking remote (infrared) signal reception:

Press the OFF/ON button on the remote controller and listen for an audible indicator from the indoor unit. Press the OFF/ON button again to turn the air conditioner off. The compressor will not operate for 3 minutes after stopping to protect the unit.

The MITSUBISHI ELECTRIC MSZ-EX18NLB is equipped with an auto restart function. When the power supply is cut off during operation, such as during a blackout, the function automatically starts operation in the previous setting once the power supply is resumed. If this function is not needed, it can be deactivated by a service representative.

When breaking into the refrigerant circuit for repairs or other purposes, it is important that best practice is followed since flammability is a consideration. The following procedure must be adhered to:

• Remove refrigerant.

• Purge the circuit with inert gas.

• Evacuate.

• Purge again with inert gas.

• Open the circuit by cutting or brazing.

The refrigerant charge must be recovered into the correct recovery cylinders. For appliances containing flammable refrigerants, the system shall be “flushed” with OFN to render the unit safe. This process may need to be repeated several times. Compressed air or oxygen must not be used for purging refrigerant systems.

Removal Procedure:

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

2. Remove the 2 screws that 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 indicated by the arrows to attach the assembly completely to the unit.

3. Install the horizontal vanes.

To remove the bottom of the indoor unit from the installation plate, release both the left and right bottom corner parts of the indoor unit and pull it downward and forward as shown in the figure in the manual.

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 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 4×16 as shown in the figure.

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

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

Note: Do not cut or extend the connecting cable of the interface. Do not bundle it with the power supply cord, connecting wire, or ground wire. Keep as much distance as possible between the connecting cable and those wires. The thin part of the connecting cable should be stored where customers cannot touch it.