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5. Installation information
YKB/YLM 2nd
S.D. R2
MEE15K022
5. Installation information
5-1. General precautions
5-1-1. Usage
The air-conditioning system described in this Data Book is designed for human comfort.
This product is not designed for preservation of food, animals, plants, precision equipment, or art objects. To prevent
quality loss, do not use the product for purposes other than what it is designed for.
To reduce the risk of water leakage and electric shock, do not use the product for air-conditioning vehicles or vessels.
5-1-2. Installation environment
Do not install any unit other than the dedicated unit in a place where the voltage changes a lot, large amounts of mineral  
oil (e.g., cutting oil) are present, cooking oil may splash, or a large quantity of steam can be generated such as a kitchen.
Do not install the unit in acidic or alkaline environment.
Installation should not be performed in the locations exposed to chlorine or other corrosive gases. Avoid near a sewer.
To reduce the risk of fire, do not install the unit in a place where flammable gas may be leaked or inflammable material
is present.
This air conditioning unit has a built-in microcomputer. Take the noise effects into consideration when deciding the in-
stallation position. Especially in a place where antenna or electronic device are installed, it is recommended that the air
conditioning unit be installed away from them.
Install the unit on a solid foundation according to the local safety measures against typhoons, wind gusts, and earth-
quakes to prevent the unit from being damaged, toppling over, and falling.
5-1-3. Backup system
In a place where air conditioner's malfunctions may exert crucial influence, it is recommended to have two or more sys-
tems of single outdoor units with multiple indoor units.
5-1-4. Unit characteristics
Heat pump efficiency depends on outdoor temperature. In the heating mode, performance drops as the outside air tem-
perature drops. In cold climates, performance can be poor. Warm air would continue to be trapped near the ceiling and
the floor level would continue to stay cold. In this case, heat pumps require a supplemental heating system or air circu-
lator. Before purchasing them, consult your local distributor for selecting the unit and system.
When the outdoor temperature is low and the humidity is high, the heat exchanger on the outdoor unit side tends to
collect frost, which reduces its heating performance. To remove the frost, Auto-defrost function will be activated and the
heating mode will temporarily stop for 3-10 minutes. Heating mode will automatically resume upon completion of defrost
process.
Air conditioner with a heat pump requires time to warm up the whole room after the heating operation begins, because
the system circulates warm air in order to warm up the whole room.
The sound levels were obtained in an anechoic room. The sound levels during actual operation are usually higher than
the simulated values due to ambient noise and echoes. Refer to the section on "SOUND LEVELS" for the measurement
location.
Depending on the operation conditions, the unit generates noise caused by valve actuation, refrigerant flow, and pres-
sure changes even when operating normally. Please consider to avoid location where quietness is required.
For BC controller, it is recommended to unit to be installed in places such as ceilings of corridor, restrooms and plant
rooms.
The total capacity of the connected indoor units can be greater than the capacity of the outdoor unit. However, when the
connected indoor units operate simultaneously, each unit's capacity may become smaller than the rated capacity.
When the unit is started up for the first time within 12 hours after power on or after power failure, it performs initial startup
operation (capacity control operation) to prevent damage to the compressor. The initial startup operation requires 90
minutes maximum to complete, depending on the operation load.
5-1-5. Relevant equipment
Use an earth leakage breaker (ELB) with medium sensitivity, and an activation speed of 0.1 second or less.
Consult your local distributor or a qualified technician when installing an earth leakage breaker.
If the unit is inverter type, select an earth leakage breaker for handling high harmonic waves and surges.
Leakage current is generated not only through the air conditioning unit but also through the power wires. Therefore, the
leakage current of the main power supply is greater than the total leakage current of each unit. Take into consideration
the capacity of the earth leakage breaker or leakage alarm when installing one at the main power supply. To measure
the leakage current simply on site, use a measurement tool equipped with a filter, and clamp all the four power wires
together. The leakage current measured on the ground wire may not accurate because the leakage current from other
systems may be included to the measurement value.
Do not install a phase advancing capacitor on the unit connected to the same power system with an inverter type unit
and its equipment.
If a large current flows due to the product malfunctions or faulty wiring, both the earth leakage breaker on the product
side and the upstream overcurrent breaker may trip almost at the same time. Separate the power system or coordinate
all the breakers depending on the system's priority level.