MITSUBISHI ELECTRIC MSZ-EX12NLW (01) PDF DOCUMENT

The following tools are required for the installation of the MITSUBISHI ELECTRIC MSZ-EX12NLW:

• 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 MITSUBISHI ELECTRIC MSZ-EX12NLW uses a flammable refrigerant (R454B). If refrigerant leaks and comes in contact with fire or a heating part, it will create harmful gas and there is a risk of fire. Always observe the following safety precautions:

General Installation:

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

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

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

• Install the unit securely in a place that can bear the weight of the unit.

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

• Use only the parts provided or specified for the installation work.

Electrical Safety:

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

• 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 fire.

• Be sure to 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. Attach wires firmly to the terminal block.

• 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 in the outlet or on the plug.

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

Refrigerant and Piping Safety:

• When installing, relocating, or servicing, ensure no substance other than the specified refrigerant (R454B) enters the refrigerant circuit.

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

• Use appropriate tools and piping materials. The pressure of R454B is 1.6 times higher than R22. Using improper tools could cause pipes to burst.

• When pumping down, stop the compressor before disconnecting the refrigerant pipes.

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

• Fasten a flare nut with a torque wrench as specified. Overtightening can 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.

When installing the MITSUBISHI ELECTRIC MSZ-EX12NLW, observe the following cautions:

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

• Perform the drainage/piping work securely according to the installation manual to prevent water from dripping from the unit and damaging household items.

• Do not touch the air inlet or the aluminum fins of the outdoor unit, as this could cause injury.

• Wear protective equipment when touching the base of the outdoor unit to prevent injury.

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

The mounting height of the indoor unit must be 5.9 feet (1.8 m) or more from the floor; up to 7.5 feet (2.3 m) is recommended. The unit must be installed in a room that exceeds the minimum room area (Amin) based on the total refrigerant amount (M), as shown in the table below.

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

• As far away as possible from fluorescent and incandescent lights.

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

• Away from other heat or steam sources.

Avoid the following places for installation where air conditioner trouble is liable to occur:

• 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.

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

Power Supply and Wire Connection:

• Power should be taken from an exclusive branched circuit.

• Use solid or stranded conductor Minches AWG14.

• Use double insulated copper wire with 600 V insulation.

• Use copper conductors only.

• Follow local electrical codes.

Refrigerant Pipes:

Insulate the two refrigerant pipes to prevent condensation. Use insulation of the specified thickness. 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)

Attaching the Installation Plate:

1. Find a stud in the wall to attach the installation plate (1) horizontally.

2. Tighten the fixing screws (2) firmly into the holes indicated in the illustration to prevent vibration.

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

Drilling:

1. Determine where the hole will be located on the wall.

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

3. Insert the wall hole sleeve (C).

Follow these steps to connect the wires to 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. The thread of the joint appearing inside should be less than 3/8 inch (10 mm).

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. Ensure there is no mis-wiring and that the wire is attached securely so its core cannot be seen.

8. Firmly tighten the terminal screws. After tightening, verify that the wires are tightly 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 corner box L or corner box R. Reinstall the electrical cover, corner box, and front panel.

Pipe Forming:

• Place the drain hose below the refrigerant piping.

• Ensure 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, you must reattach the drain hose and drain cap. Failure to do so may cause water to drip from the unit.

1. Place the refrigerant piping and drain hose together, then firmly apply felt tape (4) 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. Put the drain cap into the section where the drain hose was originally attached at the rear of the unit.

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

6. Continue with the installation as described in the manual.

For Rear, Bottom, or Right piping, put the refrigerant piping and drain hose together, apply piping tape, insert them into the wall hole sleeve, and hook the unit onto the installation plate.

Drain Piping:

• 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.

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

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

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

• Avoid incorrect drain piping configurations such as raising the hose, creating a dip that traps water, or immersing the end of the hose in water.

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. Firmly hold the copper pipe in the flaring tool according to the dimensions in the table below. Select dimension A based on the tool you use.

5. Check the flared work. If it is defective (tilted, uneven, burred), cut off the section and repeat the procedure. The inside should be shining without any scratches and smooth all around.

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

Pipe Connection:

• Fasten the flare nut with a torque wrench as specified in the table. Overtightening may cause the nut to break and leak refrigerant.

• Be sure to wrap insulation around the piping. Direct contact with bare piping may result in 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.

• Connect pipes to the outdoor unit following the same procedure.

Refrigerant Pipe Airtight Test:

1. Connect testing tools. Ensure stop valves are closed.

2. Add pressure to the refrigerant lines through the service port, pressurizing to 601 psig (4.15 MPa).

3. If the pressure holds for about one day and does not decrease, the pipes have passed the test.

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 valves.

3. Apply piping tape (G) starting from the connection on the outdoor unit.

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 for mis-wiring.

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

To check the 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 MITSUBISHI ELECTRIC MSZ-EX12NLW is equipped with an auto restart function. When the power supply is cut off during operation (e.g., during a blackout), the function automatically starts operation in the previous setting once the power supply is resumed. After installation, the installer should explain this function to the user. If the auto restart function is unnecessary, it can be deactivated by a service representative.

Removal Procedure:

1. Unlock the upper and lower vanes 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 in order to attach the assembly completely to the unit.

3. Install the horizontal vanes.

Refer to the procedures indicated in the installation manual of the outdoor unit for pumping down. It is critical to observe the following warning:

When the refrigeration circuit has a leak, do not execute pump down with the compressor. When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes. The compressor may burst if air etc. get into it.

To connect an interface (e.g., for Wi-Fi) to the air conditioner, follow these steps:

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.

Fix the connecting cable at the prescribed position securely. Incorrect installation may cause electric shock, fire, and/or malfunction.