Safety Precautions and General Guidelines

Before beginning any installation work on a ductless ceiling cassette mini split system, it is imperative to read all safety instructions and manuals thoroughly. The following precautions are essential to prevent personal injury and equipment damage. Always wear appropriate personal protective equipment (PPE), including safety glasses and gloves.

The handling of refrigerant requires certified personnel. Ensure that all local and national regulations regarding refrigerant handling and recovery are strictly followed. Never release refrigerant into the atmosphere.

Electrical work demands meticulous attention to detail. All supply circuits must be disconnected before accessing terminals. Compliance with all local and national wiring standards is mandatory, and an independent circuit with a single outlet should be used for the unit. Inadequate electrical capacity or faulty wiring poses significant risks of electrical shock or fire. Specified cables must be used, and connections should be tightly clamped to prevent external force on terminals, as loose connections can lead to overheating and fire. Proper routing of wiring is essential to ensure the control board cover is securely fixed; an improperly secured cover can result in overheating, fire, or electrical shock at the connection point. Damaged supply cords must be replaced by the manufacturer, a service agent, or similarly qualified personnel to mitigate hazards. An all-pole disconnection switch, featuring a contact separation of at least 3mm in all poles, must be integrated into the fixed wiring [1].

Proper grounding of the air conditioner is non-negotiable. The ground wire must not be connected to gas pipes, water pipes, lightning rods, or telephone ground wires, as improper grounding can result in electric shocks. The installation of an earth leakage breaker is also mandatory to prevent electrical shocks. When connecting units, the outdoor unit's wires should be connected before the indoor unit's wires. Effective drainage and insulation of drain piping are critical to prevent condensation; improper drain pipe configuration can lead to water leakage and property damage. To prevent electromagnetic interference, power supply and connecting wires should be kept at least 1 meter away from televisions and radios [1].

Finally, the unit should not be installed in environments containing petrolatum, high-salinity air, caustic gases (e.g., sulfide), areas with voltage fluctuations, in buses or cabinets, kitchens with high concentrations of oily gases, areas with strong electromagnetic waves, or where inflammable materials, gases, acid, or alkaline liquids are present. The appliance must be installed in strict compliance with national wiring regulations and should not be operated in wet rooms such as bathrooms or laundry rooms. An all-pole disconnection device with at least 3mm clearances and a residual current device (RCD) not exceeding 30mA must be incorporated into the fixed wiring [1].

Tools Required

Installation Order

The installation of a ductless ceiling cassette mini split system should follow a specific sequence to ensure a smooth and efficient process. The recommended order of installation is as follows:

1. Indoor unit installation
2. Outdoor unit installation
3. Refrigerant pipe installation
4. Drain pipe connection
5. Electrical wiring work
6. Decoration panel installation
7. Test operation (commissioning)

Indoor Unit Installation

1.1 Selecting the Installation Site

Careful selection of the indoor unit's installation site is paramount for optimal air distribution, efficient operation, and ease of maintenance. The chosen location must meet several critical conditions, and customer approval should always be obtained [1]:

• The site must allow for optimum air distribution without any obstructions to the air passage.
• Proper condensate water drainage must be achievable.
• The false ceiling should not have a significant incline.
• Sufficient clearance for future maintenance and service must be ensured.
• There should be no risk of flammable gas leakage or exposure to potentially explosive atmospheres.
• Piping between the indoor and outdoor units must be feasible within the allowable limits, as specified in the outdoor unit's installation guide.
• To prevent electromagnetic interference, the indoor unit, outdoor unit, inter-unit wiring, and remote controller wiring should be kept at least 1 meter away from televisions and radios.
• If a wireless remote controller kit is used, the indoor unit should be installed as far as possible from fluorescent lights, which can shorten the effective distance of the remote controller.

Regarding Ceiling Height, the bottom panel of the indoor unit must be installed at a height greater than 2.5 meters (8.2 feet) above ground level to prevent accidental contact by users. For Ceiling Strength, installation hooks are to be used, and the ceiling's ability to support the indoor unit's weight must be verified. If there is any structural integrity risk, the ceiling must be reinforced before proceeding with the unit's installation [1].

1.2 Preparations

Before the physical installation of the indoor unit, several preparatory steps are essential to ensure a smooth and secure mounting process [1]:

1. Ceiling Opening: Create a square opening in the false ceiling, ensuring it is slightly larger than the indoor unit's dimensions. A paper pattern is typically provided with the unit to assist with this step. The opening must be precisely cut to ensure a snug fit for the decoration panel.
2. Installation Hooks: Install the installation hooks, typically using M8 or M10 size bolts. Utilize expansible hooks, sunken anchors, or other field-supplied parts to reinforce the ceiling, ensuring it can bear the unit's weight. Adjust the clearance from the ceiling as needed.
3. Position Adjustment: Precisely adjust the unit's position to ensure even gaps between the indoor unit and all four sides of the false ceiling. The lower part of the indoor unit should sink into the false ceiling by 24mm (0.9 inches).

1.3 Installing the Indoor Unit

The indoor unit's installation involves securely mounting it within the prepared ceiling opening [1]:

1. Temporary Installation: Attach the hanger bracket to the suspension bolt. Securely fix it using a nut and washer on both the upper and lower sides of the hanger bracket.
2. Check Level: Verify that the unit is perfectly level after temporary installation.

Outdoor Unit Installation

2.1 Precautions for Location Selection

Selecting an appropriate location for the outdoor unit is crucial for its operational efficiency, longevity, and to minimize disturbance to occupants and neighbors. Several factors must be carefully considered [1]:

• Sturdiness: The chosen site must be robust enough to withstand the unit's weight and vibrations without amplifying operational noise.
• Noise/Discharge: The location should prevent hot air discharge or operational noise from causing a nuisance to neighbors. Installation near bedrooms or other quiet areas should be avoided.
• Space: Sufficient space is required for transporting the unit to and from the site, as well as for unobstructed air passage around the air inlet and outlet.
• Flammable Gas: The site must be free from any potential flammable gas leakage.
• Interference: To prevent interference with televisions and radios, units, power cords, and inter-unit wiring should be positioned at least 3 meters away.
• Corrosion: In coastal areas or environments with salty atmospheres or sulfate gases, corrosion can significantly shorten the air conditioner's lifespan. Such locations should be avoided or protective measures taken.
• Drainage: As condensate drains from the outdoor unit, no moisture-sensitive items should be placed directly underneath it.
• Low Ambient Temperature: When operating in low outdoor ambient temperatures, the outdoor unit's suction side should face a wall to prevent exposure to wind. Direct wind exposure to the suction side must be avoided. Consideration should also be given to installing a baffle plate on the air discharge side.
• Snowfall: In regions prone to heavy snowfall, the installation site must be chosen such that accumulated snow will not impede the unit's operation.

2.4 Outdoor Unit Installation

Once the location is selected, the outdoor unit can be installed [1]:

1. Installation: Securely fix the unit using foundation bolts. Typically, four sets of M8 or M10 foundation bolts, nuts, and washers are required.
2. Drain Work: If drain work is necessary, a drain plug should be used. If the drain port is obstructed by a mounting base or floor surface, additional foot bases, at least 30mm (1.2 inches) in height, must be placed under the outdoor unit's feet. In cold climates, using a drain hose with the outdoor unit is not recommended, as the drain water may freeze and impair heating performance.

Installing the Refrigerant Pipe

3.1 Flaring the Pipe Ends

Proper flaring of the refrigerant pipe ends is critical to prevent leaks. This process requires precision and the use of the correct tools.

Precautions:

• Complete heat insulation on both gas and liquid piping is essential to prevent water leakage. For heat pump systems, gas piping temperatures can reach up to 120°C (248°F), necessitating insulation with sufficient resistance.
• Use manufacturer-specified accessories and parts.
• Do not use mineral oil on the flared part. Prevent mineral oil from entering the system, as this can reduce the service life of the units.
• Only annealed material should be used for flare connections.
• Do not reuse flare nuts.
• Ensure there are no cracks or scratches on the flared part.
• When connecting the flare nuts, apply refrigerant oil to the flared surfaces and tighten them with a torque wrench until the wrench clicks.

Procedure:

1. Cut the pipe end squarely with a pipe cutter.
2. Remove burrs from the cut surface, ensuring the surface faces downward to prevent chips from entering the pipe.
3. Place the flare nut onto the pipe.
4. Flare the pipe according to the specified dimensions. For example, Ø6.35 (1/4in) requires a flare dimension of 1.3mm-0.7mm, Ø9.52 (3/8in) requires 1.6mm-1.0mm, Ø12.7 (1/2in) requires 1.8mm-1.0mm, and Ø15.9 (5/8in) requires 2.0mm-1.2mm.

3.2 Connecting the Pipes

Align the centers of the pipes and tighten the flare nuts by hand. Then, use a torque wrench to tighten them to the specified torque values [1]:

Commissioning (Test Operation)

After completing the installation, a thorough test operation is required to ensure the system is functioning correctly and safely. This process, also known as commissioning, involves several checks and procedures.

7.1 Pre-Commissioning Checks

Before starting the test operation, verify the following [1]:

• The indoor and outdoor units are installed correctly on solid bases.
• The refrigerant piping and drain piping are connected correctly.
• All wiring is connected correctly.
• The system has been checked for gas leakage.
• The system has been properly evacuated.
• The insulation work is complete.
• The grounding is connected correctly.
• The length of the piping and the added refrigerant stowage volume have been recorded.
• The power voltage conforms to the rated voltage of the air conditioner.
• There are no obstacles at the air inlet and outlet of the indoor and outdoor units.
• The gas-side and liquid-side stop valves are both fully open.

7.2 Test Operation Procedure

Follow these steps to perform the test operation [1]:

1. Turn on the power supply.
2. Press the ON/OFF button on the remote controller to start the unit.
3. Set the operating mode to COOL and check the following:
• The indoor unit's louver operates correctly.
• The indoor unit's fan speed can be adjusted.
• The drain system is functioning correctly.
4. Set the operating mode to HEAT and check the following:
• The indoor unit's louver operates correctly.
• The indoor unit's fan speed can be adjusted.
5. If any malfunctions are detected, refer to the “Troubleshooting” chapter in the Owner’s Manual.