Hitachi RAM-20MQ - User Manual

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INVERTER-DRIVEN

MULTI-SPLIT SYSTEM

AIR CONDITIONERS

Outdoor Units

Installation＆Maintenance Manual

Models：

8HP

10HP

12HP

14HP

16HP

18HP

20HP

22HP

24HP

RAM-8MQ(D)

RAM-10MQ(D)

RAM-12MQ(D)

RAM-14MQ(D)

RAM-16MQ(D)

RAM-18MQ(D)

RAM-20MQ(D)

RAM-22MQ(D)

RAM-24MQ(D)

◼ Be sure to hand over this manual to constructor of next step and finally let the customer keep it.

(Transportation and Handling) → (Refrigerant Piping) → (Electrical Wiring) → (Test Run) → (Customer)

Important Notice

⚫ This air conditioner has been designed for common air conditioning for people. Do not apply to other purposes such as for food, animals,

plants, high precision machines or work of art.

⚫ Do not install the unit in the following places. It may cause fire, deformation, corrosion or failure.

○ Places where is filled with mineral oil mist or oil spray (including machinery oil) or vapor is produced.

○ Places where is filled with sulfurous gas such as hot spring area.

⚫ Do not install the unit in the following places, it may cause corrosion.

○ Places where strong salty wind blows such as coast regions.

○ An acid or alkaline environment.

⚫ Pay attention to the following situations when the unit is installed in a hospital or other facilities where electromagnetic wave is radiated from

medical equipment.

○ Do not install the unit where the electromagnetic wave is directly radiated to the electrical box, remote control cable or remote control

switch.

○ To avoid the influence of electromagnetic waves via air, wave generating machines such as radio, medical equipment must be kept at

least 3 meters from air conditioner.

⚫ Do not install the unit in the place where wind directly blows on animals or plants. It could adversely affect the animals or plants.

⚫ Using wireless remote controller, the receiver may fail to receive signals due to effect of the lighting equipment. Therefore keep the receiver

away from the lighting equipment more than 1 meter as possible.

Safety Summary

⚫ Before installation, read this section carefully in order to install correctly.

⚫ This manual contains " Danger" symbol. This symbol indicates a hazardous situation which, if installed incorrectly, it may result in death or

serious injury. Therefore, make sure to observe important messages of safety.

⚫ While checking any abnormality during the test run after installation, explain to customer the correct methods of usage and maintenance

according to the instructions of user’s manual. Then hand over the installation manual and user’s manual to customers.

◼ 【Meaning of symbols】

DANGER：Indicates a hazardous situation which, If not avoided,

may result in death or serious injury.

：Mandatory Symbol: indicate instructing behavior of

general users.

：Mandatory Symbol: indicate grounding must be performed for

machine with grounding terminal.

：Indicate prohibited item.

About Electrical Works

DANGER

⚫ Assign an authorized dealer to perform the electrical work. Please note that if improperly performed by yourself, it may result in

electric shock.

⚫ Perform electrical work according to relevant national regulations and the installation manual. Make sure to use the exclusive

circuit to avoid electric shock or fire due to insufficient capacity of power or improper work.

⚫ Use only specified wires for wirings between units. Incorrect selection of wires also causes fire or electric shock.

⚫ Properly fasten the terminals of wirings. Improper fastening the joint of terminals may result in fire, electric shock or the

overheated terminals.

⚫ Fix the cables securely. External forces on the terminals could lead to a fire.

⚫ Installation of an earth leakage breaker (ELB) is necessary. If an ELB is not installed, current leakage may occur.

⚫ When opening the service cover due to need of wiring work or inspection, make sure to completely cut off power before work

to avoid electric shock.

⚫ Perform grounding according to the grounding work instructions. Incident of electric shock may occur if indoor and outdoor units

are not grounded. The ground wire must not be connected to gas pipe, water pipe, lighting rod and ground wire of telephone line.

If the ground wire is not properly connected, it may result in electric shock.

About installation

DANGER

⚫ Installation must be done in accordance with this installation manual. Improper installation may result in water leakage, electric

shock or fire.

⚫ Install the air conditioner on a foundation strong enough that it can withstand the weight of the unit. A foundation of insufficient

strength may result in the unit falling and injury.

⚫ Do not perform installation at locations subject to existence or entry of flammable gas.

⚫ Do not climb or put any object on the air conditioner to prevent injury caused by the unit falling.

⚫ In the event of refrigerant leakage, immediately turn off the fire source (e.g. stoves), wipe the refrigerant off the floor, open the

door and windows for ventilation and then contact the service personnel or the dealer.

66MP1565

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This document describes the Hitachi Inverter-Driven Multi-Split System Air Conditioners (Outdoor Units), covering installation, operation, and maintenance.

Function Description

The Hitachi Inverter-Driven Multi-Split System Air Conditioners are designed for common air conditioning applications in residential and commercial settings. These systems utilize R410A refrigerant and are capable of connecting multiple indoor units to a single outdoor unit, offering flexibility in system design and installation. The inverter technology allows for variable compressor speed, leading to improved energy efficiency and precise temperature control. The system supports various combinations of indoor and outdoor units, with specific guidelines for piping, electrical connections, and installation locations to ensure optimal performance and safety.

Important Technical Specifications

Models: RAM-8MQ(D), RAM-10MQ(D), RAM-12MQ(D), RAM-14MQ(D), RAM-16MQ(D), RAM-18MQ(D), RAM-20MQ(D), RAM-22MQ(D), RAM-24MQ(D).
Refrigerant: R410A.
Refrigerant Oil: Idemitsu Kosan Co., Ltd. (FVC68D).
Air-tight Test Pressure: 4.15 MPa.
Operating Temperature Range (Cooling): Outdoor Unit: -5°C DB ~ 43°C DB; Indoor Unit (Non-room Temperature): 21°C DB/15°C WB ~ 32°C DB/23°C WB.
Piping Sizes (Gas/Liquid): Vary by HP and equivalent length. For example, an 8HP unit with equivalent length < 100m uses 19.05mm gas pipe and 9.53mm liquid pipe, while an equivalent length ≥ 100m uses 22.2mm gas pipe and 12.7mm liquid pipe.
Pipe Thickness: Ranges from 0.8mm to 1.55mm depending on diameter.
Flare Nut Dimensions: Vary by diameter (e.g., Ø6.35 uses 17mm B-dimension, Ø19.05 uses 36mm B-dimension).
Maximum Connectable Indoor Unit Number: Varies by outdoor unit HP (e.g., 8HP: 13 units, 24HP: 40 units).
Range of Combination Capacity: Max. 130% of outdoor unit HP.
Maximum Piping Length: Total length (Lt) ≤ 1000m, Length between First Multi-kit and furthest indoor unit (L1) ≤ 190m, Length between each Multi-kit and each indoor unit (L2) ≤ 90m, Length between Piping Connection Kit 1 and furthest outdoor unit (L3) ≤ 40m.
Maximum Height Difference: Outdoor unit higher than indoor unit (H1) ≤ 50m, Indoor unit higher than outdoor unit (H1) ≤ 40m, Between each indoor unit (H2) ≤ 15m, Between each outdoor unit (H5) ≤ 0.1m.
Electrical Power Supply: 3Ø 230V 60Hz or 3Ø 380V 60Hz.
Earth Leakage Breaker (ELB): High-speed type (active time less than 0.1 sec). Rating sensitivity 30mA. Rating current and capacity vary by model (e.g., RAM-8MQ: 40A/30A/8A, RAM-24MQ: 150A/100A/50A for 230V; RAM-8MQD: 30A/30A/8A, RAM-24MQD: 100A/60A/22A for 380V).
Transmission Cable: 2-Core shielded twist pair cable, 0.75mm², total length below 1000m.
Foundation Height: Minimum 150mm higher than ground level.
Horizontal Tolerance: Within 10mm.
Anchor Bolt: M12 (4-38x15 round-end hole).
Drain Hole: Ø26 x 2.
Piping Fixation Interval: Max. 1.0m for Ø22.2, 1.5m for Ø25.4≤.

Usage Features

Installation Location Flexibility: The outdoor unit can be installed in various configurations (1, 2, 3, or 4 walls) with specific minimum clearances for air inlet and outlet to ensure proper ventilation and performance. It should be placed in a dry, well-ventilated, and shaded area, away from direct sunlight, high-temperature heat sources, strong winds, and areas with mineral oil mist, sulfurous gas, or strong salty air.
Electromagnetic Wave Protection: Special attention is required when installing near medical equipment or other sources of electromagnetic waves. The unit should not be directly exposed to such waves, and wave-generating machines should be kept at least 3 meters away.
Multi-Kit Piping: The system supports multi-kit piping for connecting multiple indoor units. Specific guidelines are provided for piping length, diameter, and the use of oil traps to prevent refrigerant oil accumulation.
Refrigerant Charging: The system uses R410A, which requires specific tools and procedures for charging to prevent contamination. Additional refrigerant must be calculated based on pipe length and indoor unit capacity.
Test Run Procedure: A detailed test run procedure is outlined to ensure correct installation and operation, including checking electrical connections, refrigerant piping, and system performance. The remote controller displays test run status and alarm codes for troubleshooting.
Dip Switch Settings: Various dip switches on the outdoor unit's PCB allow for configuration of refrigerant cycle number, capacity, function settings, emergency operation, power supply, outdoor unit number, high static pressure mode, and inverter settings. These settings are crucial for proper system operation and must be configured correctly.

Maintenance Features

Safety Precautions: Emphasizes reading the safety summary before installation, highlighting "Danger" symbols for hazardous situations. It mandates authorized dealers for electrical work and adherence to national regulations.
Electrical Safety: Requires the use of exclusive circuits, specified wires, proper fastening of terminals, secure cable fixation, and installation of an earth leakage breaker (ELB). Power must be cut off before opening service covers for wiring or inspection. Grounding is mandatory for both indoor and outdoor units, with specific prohibitions against connecting the ground wire to gas pipes, water pipes, lightning rods, or telephone lines.
Refrigerant Handling: Stresses the use of adequate non-flammable R410A refrigerant and FVC68D refrigerant oil. Prohibits charging other refrigerants, oxygen, or acetylene into the system to prevent explosion or fire. The unit contains high-pressure gas and must not be heated.
Leakage Detection: Requires checking for refrigerant leakage during installation and test runs. In case of leakage, immediate action (turning off fire sources, ventilating the area, contacting service personnel) is necessary. The document provides a formula to calculate maximum permissible refrigerant concentration in a room to prevent suffocation.
Piping Maintenance: Instructions for cutting copper pipes, blowing with nitrogen or dry air to remove dust, and securing caps on pipe ends to prevent contamination.
Foundation Integrity: Requires installing the air conditioner on a strong foundation to withstand the unit's weight and vibrations, preventing falling and injury. The concrete base must be set along the foot direction to prevent deformation.
Troubleshooting: Provides a comprehensive alarm code list with categories, content of abnormality, and leading causes to assist in diagnosing and resolving system issues. This includes problems related to indoor/outdoor units, transmission, power supply, voltage, cycle, sensors, fan motor, compressor, protection devices, and inverter.
Post-Maintenance Procedures: After maintenance, it is crucial to restore all dip switch settings to factory defaults. In case of refrigerant leakage, the entire system must be re-processed, not just recharged with new refrigerant, due to R410A being a non-azeotropic refrigerant.