MITSUBISHI ELECTRIC MSZ-EX18NLW (01) PDF DOCUMENT

The symbols on your MITSUBISHI ELECTRIC MSZ-EX18NLW unit provide important safety information:

A2L WARNING (Risk of fire): This symbol indicates that the unit uses a flammable refrigerant (R454B). If the refrigerant leaks and comes into contact with fire or a heating part, it will create harmful gas and there is a risk of fire.

Read Instructions Symbol: This symbol indicates that you should read the OPERATING INSTRUCTIONS carefully before operation.

Service Personnel Symbol: This symbol indicates that service personnel are required to carefully read the OPERATING INSTRUCTIONS and INSTALLATION MANUAL before operation.

Further Information Symbol (i): This symbol indicates that further information is available in the OPERATING INSTRUCTIONS, INSTALLATION MANUAL, and the like.

Always observe the following safety precautions when installing the MITSUBISHI ELECTRIC MSZ-EX18NLW to prevent death, serious injury, or property damage.

Installation and Handling:

• 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, or injury.

• 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.

• Use only the provided or specified parts for installation work to avoid defects that could lead to fire, shock, or the unit falling.

Electrical Safety:

• Perform electrical work according to the installation manual and use an exclusive circuit. Do not connect other appliances to the circuit to avoid fire or electric shock from an overloaded 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, as this could cause a fire.

• Always shut off the main power when setting up the indoor P.C. board or wiring to prevent electric shock.

• Use the specified wires to securely connect the indoor and outdoor units. Attach wires firmly to the terminal block to avoid applying stress, which could cause a fire.

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

• When plugging in the power supply plug, ensure there is no dust, blockage, or loose parts in the outlet or on the plug. A poor connection can cause electric shock or fire.

• Securely attach the electrical cover to the indoor unit and the service panel to the outdoor unit to prevent dust and water from entering, which could cause a fire or electric shock.

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

Refrigerant (R454B) Safety:

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

• When installing, relocating, or servicing, ensure no substance other than the specified refrigerant (R454B) enters the refrigerant circuit. 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, ventilate the room. Contact with fire can generate harmful gas.

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

• When pumping down, stop the compressor before disconnecting refrigerant pipes to prevent an abnormal pressure rise from air being drawn in.

• Securely connect 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.

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

• 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 any part of the refrigerant circuit.

• Pipe-work shall be protected from physical damage and installed in compliance with national and local codes. The installation of pipe-work should be kept to a minimum.

You will need the following tools for the installation of the MITSUBISHI ELECTRIC MSZ-EX18NLW:

• 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

Select a suitable installation location for the MITSUBISHI ELECTRIC MSZ-EX18NLW indoor unit by following these guidelines:

General Location Requirements:

• The mounting height shall 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) determined by the total refrigerant amount (M) in the system. Refer to the table below.

• 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 to prevent interference.

• As far away as possible from fluorescent and incandescent lights so the remote control can operate normally.

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

• Away from other heat or steam sources.

Minimum Room Area for MITSUBISHI ELECTRIC MSZ-EX18NLW (System without Branch Box)

Total Refrigerant Amount (M) [kg]	Minimum Room Area (Amin) [m²]	Minimum Room Area (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

Locations to Avoid:

• Where flammable gas could leak.

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

• Salty places such as the seaside.

• Where sulfide gas is generated (e.g., hot springs, sewage).

• Where there is high-frequency or wireless equipment.

• Where there is emission of high levels of VOCs, which may cause chemical cracking.

Install the remote controller for your MITSUBISHI ELECTRIC MSZ-EX18NLW in a location that is:

• Convenient to operate and easily visible.

• Where children cannot easily touch it.

Select a position about 4 feet (1.2 m) above the floor and check that signals from the remote controller are received by the indoor unit (a ‘beep’ or ‘beep beep’ receiving tone will sound). If a holder is supplied, install it where the indoor unit can receive signals.

The MITSUBISHI ELECTRIC MSZ-EX18NLW has the following specifications:

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 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)

Wiring Requirements:

• 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.

• A disconnect switch needs to be installed to the power supply circuit when the indoor unit is powered from the outdoor unit, depending on local codes.

Piping Requirements:

• Insulate both refrigerant pipes to prevent condensation. Use the specified insulation thickness.

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

Ensure you have all the necessary parts before starting the installation of your MITSUBISHI ELECTRIC MSZ-EX18NLW.

Accessories included with the indoor unit:

• (1) Installation plate (1)
• (2) Attachment screws for the installation plate 4 x 25 mm (5)
• (3) Wireless remote controller (1)
• (4) Felt tape (For left or left-rear piping) (1)
• (5) Remote controller holder (1)
• (6) Screws for the remote controller holder 3.5 x 16 mm (Black) (2)
• (7) Battery (AAA) for (3) (2)
• (8) Air cleaning filter (2)
• (9) Soft dry cloth (NAB type only) (1)

Field-Supplied Parts (to be provided by the installer):

• (A) Indoor/outdoor unit connecting wire (1)
• (B) Extension pipe (1)
• (C) Wall hole sleeve (1)
• (D) Wall hole cover (1)
• (E) Pipe attachment strap (2 to 5)
• (F) Screw for (E) 4 x 20 mm (2 to 5)
• (G) Piping tape (1)
• (H) Putty (1)
• (I) Drain hose (or soft PVC hose, 19/32 inches [15 mm] inner diameter or hard PVC pipe VP16) (2 to 5)
• (J) Refrigerant oil (1)
• (K) Power supply cord (1)

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. For added support, you can install screws in other holes.

3. If you remove the knockout, apply vinyl tape to the edges to prevent damaging the wires.

Drilling the Wall Hole:

1. Determine the hole location on the wall based on the installation plate.

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

3. Insert the wall hole sleeve (C).

Follow these steps to safely connect the wiring for your MITSUBISHI ELECTRIC MSZ-EX18NLW indoor unit. Note that depending on local code, a disconnect switch may need to be installed if the unit is powered from the outdoor unit.

1. Remove the panel assembly.

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

3. Remove the 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 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. Connect it to the ground terminal of the electrical parts box. Make the ground wire slightly longer than the other wires.

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. Attach the wire securely so its core is not visible and no external force affects the connection.

8. Firmly tighten the terminal screws and verify that the wires are securely 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 R as needed. Reinstall the electrical cover, corner box, and front panel.

For future servicing, leave some slack in the connecting wires.

Proper pipe forming and drain piping are crucial for the correct operation of your MITSUBISHI ELECTRIC MSZ-EX18NLW.

Pipe Forming (General):

• 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.

• If 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 from 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 indoor unit.

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

6. Insert the drain hose into the wall hole sleeve (C) and attach the unit to the installation plate, shifting it left to make piping easier.

7. Connect the refrigerant piping and then attach the lower part of the unit to the installation plate.

Drain Piping Setup:

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

• The drain hose should always point downward to ensure 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.

• Do not create any of the following incorrect drain piping setups:

– Do not raise the pipe, as this will cause water to accumulate.

– Do not allow the end of the drain hose to be dipped in water.

– Ensure there is at least a 1-31/32 inches (50 mm) gap between the end of the hose and the ground/ditch.

– Avoid creating a wavy or trapped section in the hose.

• Do not put the drain pipe directly in a drainage ditch where Ammonia or Sulphuric gas may be generated, as this can cause odor and corrosion.

Follow these steps to create a proper flare connection for the MITSUBISHI ELECTRIC MSZ-EX18NLW:

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

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

3. Remove the flare nuts from the indoor and outdoor units and place them on the pipe.

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

5. Check the flare. It should have a smooth, shiny interior without any scratches and be of even length all around. If it is defective, cut off the section and repeat the process.

Flaring Dimensions and Tightening Torque

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)
ø 5/8 (15.88)	1-5/32 (29)		36 to 42 (500 to 575)	49.0 to 56.4
54 to 58 (750 to 800)	73.5 to 78.4

Pipe Connection:

1. Fasten the flare nut with a torque wrench to the specified torque listed in the manual. Overtightening can break the nut, and undertightening can cause leaks.

2. 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 the joint to the specified torque.

3. For the outdoor unit, connect pipes to the stop valve pipe joint using the same procedure.

4. Be sure to wrap insulation around the piping. Direct contact with bare piping may result in burns or frostbite.

Refrigerant Pipe Airtight Test:

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

2. Add pressure to the refrigerant lines through the service port of the GAS stop valve.

3. Pressurize the system to 601 psig (4.15 MPa). Do this gradually, not all at once.

4. If the pressure holds for about one day without decreasing (after correcting for temperature changes), the pipes have passed the test.

5. If the pressure decreases, there is a gas leak. Find and repair the source of the leak.

Insulation and Taping:

1. Cover piping joints with a pipe cover.

2. On the outdoor unit side, insulate all piping, including the 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 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 the operation, press the E.O. SW several times until all LED lamps turn off.

You can also check the remote (infrared) signal reception by pressing the OFF/ON button on the remote controller and listening for an audible indicator from the indoor unit. Press the button again to turn the air conditioner off.

The MITSUBISHI ELECTRIC MSZ-EX18NLW is equipped with an auto restart function. If the power supply is cut off during operation (e.g., during a blackout), this function automatically restarts the unit in its 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. Adhere to the following procedure:

Removal and Evacuation:

1. Remove refrigerant.

2. Purge the circuit with inert gas.

3. Evacuate.

4. Purge again with inert gas.

5. Open the circuit by cutting or brazing.

The refrigerant charge must be recovered into the correct recovery cylinders. The system shall be “flushed” with OFN (Oxygen-Free Nitrogen) to render the unit safe. This may need to be repeated several times. Do not use compressed air or oxygen for purging.

Recovery:

• When removing refrigerant, it is recommended good practice that all refrigerants are removed safely.

• Use only appropriate, designated, and labeled refrigerant recovery cylinders.

• Ensure recovery equipment is in good working order and suitable for the recovery of flammable refrigerants.

• A set of calibrated weighing scales must be available and in good working order.

• Hoses must be complete with leak-free disconnect couplings and in good condition.

• The recovered refrigerant shall be returned to the refrigerant supplier in the correct recovery cylinder with the relevant waste transfer note. Do not mix refrigerants in recovery units, especially not in cylinders.

• If compressors or compressor oils are to be removed, ensure they have been evacuated to an acceptable level to make certain that flammable refrigerant does not remain within the lubricant.

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 by 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 indoor unit of the MITSUBISHI ELECTRIC MSZ-EX18NLW from the installation plate, release the bottom of the unit. Release both the left and right bottom corner parts of the indoor unit and pull it downward and forward as shown in the installation manual diagrams.

The procedure for pumping down the refrigerant is indicated in the installation manual of the outdoor unit. However, observe the following critical warnings:

• If 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 gets into it.

To connect an interface (such as a Wi-Fi adapter) to your MITSUBISHI ELECTRIC MSZ-EX18NLW, 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 the CN105 connector 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.

Important Notes:

• Do not cut or extend the connecting cable, as this can result in connection defects.

• Do not bundle the connecting cable with the power supply cord, indoor/outdoor connecting wire, or ground wire. Keep as much distance as possible between them.

• The thin part of the connecting cable should be stored where customers cannot touch it.

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