CITY MULTI Air-Conditioners For Building Application INDOOR UNIT
Models: CMB-P-V-G1, CMB-P-V-GA1 (MAIN BC CONTROLLER), CMB-P-V-GB1 (SUBBC CONTROLLER), CMB-P-V-HA1 (MAIN BC CONTROLLER), CMB-P-V-HB1 (SUBBC CONTROLLER)
1. Safety Precautions
Before installing the unit, carefully read and follow all safety precautions provided in this manual. These precautions are crucial for preventing injury, death, or damage to the unit.
Symbols Used
- Warning: Indicates precautions to prevent danger of injury or death. ⚠️
- Caution: Indicates precautions to prevent damage to the unit. ⚠️
- Illustrations: ? (action to avoid), ✔️ (important instruction), ⏚ (grounding required).
- High Voltage Warning: Control box contains high-voltage parts. Turn off power and wait 10 minutes before inspection. ⚡️
General Installation Warnings
- Installation must be performed by a qualified technician to avoid water leakage, electric shock, or fire.
- Ensure the installation location can support the unit's weight.
- Use specified cables and ensure secure connections to prevent heat generation and fire.
- Prepare for earthquakes and install securely to prevent falling.
- Always use Mitsubishi Electric specified accessories and have them installed by authorized technicians.
- Never attempt to repair the unit yourself; consult the dealer.
- If refrigerant gas leaks, ventilate the room immediately, as it can produce poisonous gases when exposed to flame.
- Ensure proper electrical work by a licensed electrician, using a dedicated power supply.
- Securely install control box covers to prevent dust/water ingress.
- Do not charge the unit with a refrigerant other than the specified R410A.
- If installed in a small room, take measures to prevent refrigerant concentration from exceeding safety limits in case of leaks.
- Dispose of the product responsibly; consult your dealer.
- Ensure safety against leakage according to local regulations.
- Pay attention to installation locations where refrigerant gas can accumulate (e.g., basements).
1.2. Precautions for R410A Refrigerant
- Do not use existing refrigerant piping; it may contain contaminants that degrade R410A refrigerant oil. R410A operates at higher pressure and can burst old piping.
- Use only specified phosphorus deoxidized copper and copper alloy seamless pipes and tubes, ensuring they are clean and free from contaminants.
- Store piping indoors, sealed until use, to prevent dust, dirt, or water ingress.
- Apply a small amount of ester oil, ether oil, or alkyl benzene to flares. Avoid mineral oil.
- Do not vent R410A into the atmosphere; it is a greenhouse gas.
2. Selecting an Installation Site
This unit uses R410A refrigerant, requiring specific installation considerations.
2.1. About the Product
The unit uses R410A refrigerant, which has higher design pressure than conventional refrigerants. Ensure compatibility of tools and piping. Do not reuse existing piping due to potential contamination and pressure differences.
2.2. Installation Site Requirements
- Install indoors, away from rain.
- Ensure adequate space for servicing.
- Avoid locations that exceed piping length restrictions.
- Do not install in direct sunlight or near other heat sources.
- Avoid oily, steamy places or areas with high-frequency generating machinery.
- Consider noise impact on occupants; maintain distance between indoor and BC controllers in quiet environments (e.g., hotel rooms).
- Ensure easy access for utility connections (water, refrigerant, electrical).
- Avoid areas with flammable or sulfuric gas generation, inflow, accumulation, or leakage.
- Ensure a downward pitch of at least 1/100 for drain piping.
- Install the unit on a stable, load-bearing surface.
2.3. Securing Installation and Service Space
For ceiling-hung installations, provide a 450 mm square inspection hole. Install the unit away from regularly occupied areas. Ensure hanging bolts have a pull-out strength of at least 60 kg per bolt. The BC controller must be installed horizontally.
2.4. Checking Installation Site Parameters
Verify that elevation differences and refrigerant piping lengths comply with specifications. The following tables and diagrams detail these limitations:
Piping Length and Elevation Specifications (Example for CMB-P104-G1 to CMB-P1016-G1 models)
| Item | Piping Portion | Allowable Value (Unit: m) |
|---|---|---|
| Total piping length | A+B+a+b+c+d+e | Not to exceed the maximum refrigerant piping length *1 (165 m or less, equivalent length of 190 m or less) |
| Longest piping length | A+e | (Equivalent length of 190 m or less) |
| Between outdoor unit and BC controller | A | Below 110 |
| Between indoor units and BC controller | e | Below 40 *2 |
| Between indoor and outdoor units | Above outdoor unit (H) | Below 50 |
| Below outdoor unit (H1) | Below 40 | |
| Between indoor units and BC controller | h1 | Below 15 (Below 10)*3 |
| Between indoor units | h2 | Below 15 (Below 10)*3 |
*1 Refer to "Restrictions on piping length" on P. 4. *2 Refer to "Distance between BC controller and farthest Indoor unit" figure. *3 Values in parentheses apply when indoor unit capacity is 200 or more.
Diagrams (Fig. 2.4.1, 2.4.2) illustrate system layouts with components and piping connections, specifying lengths and height differences. Fig. 2.4.3 provides graphs for piping length restrictions based on model series.
Distance between BC controller and farthest indoor unit is graphically represented against height difference.
3. Installing BC Controller
Ensure the BC controller is installed horizontally using a level to prevent drain water leakage.
3.1. Checking Accessories
Supplied accessories for BC controllers include drain hose, tie band, hose band, and refrigerant connection pipes. Specific quantities vary by model.
3.2. Installing Hanging Bolts
Use locally procured hanging bolts (Ø10 threaded rod) and washers. Lift the unit using a machine and pass it through the hanging bolts. The suspension bracket has an oval hole.
4. Connecting Refrigerant Pipes and Drain Pipes
4.1. Connecting Refrigerant Pipes
Connect liquid and gas pipes to the correct end connection numbers on the BC controller. List indoor unit model names and BC controller end connection numbers for identification. Seal unused ports with cover caps. For specific models (e.g., CMY-Y102S-G2), connect horizontally. Ensure pipe expansion by cutting piping at the specified point based on indoor unit capacity. Remove burrs after cutting.
Use non-oxidative brazing. Braze indoor unit ports first, then outdoor unit ports, using nitrogen purge. Support pipes after connection to prevent stress on BC controller connections.
Warning: Do not mix refrigerants or air with R410A, as it can cause malfunction and damage. ⚠️
Caution: Use clean, specified refrigerant piping. Store piping sealed. Do not vent R410A. ⚠️
Piping Size Specifications
| Total Capacity of Indoor Units | Liquid Line | Gas Line |
|---|---|---|
| Below 140 | Ø9.52 | Ø15.88 |
| 141 to 200 | Ø9.52 | Ø19.05 |
| 201 to 250 | Ø9.52 | Ø22.2 |
For connecting 15 to 50 type indoor units, cut piping at specific points for pipe expansion. For units with capacity higher than 81, use piping kits (e.g., CMY-R160-J1). For multiple indoor units on one connection, total capacity should be less than 80 (or 250 with joint pipe), with a maximum of 3 units per port.
4.2. Refrigerant Piping Work
After connecting pipes with stop valves closed, evacuate vacuum from service ports. Then, open stop valves to complete the refrigerant circuit. Perform leak checks using a detector or soap-and-water solution. Wrap piping with damp cloths during brazing to prevent heat damage. Do not use leak-detection additives.
4.3. Insulating Refrigerant Pipes
Insulate high-pressure and low-pressure pipes separately with sufficient thickness of heat-resistant polyethylene, ensuring no gaps. Pay attention to insulation in ceiling plenums. Specified insulation thicknesses are provided for different pipe sizes and applications.
4.4. Drain Piping Work
Ensure drain piping has a downward pitch of more than 1/100. Use a drain-up mechanism if necessary. Support long drain piping to prevent bending. Connect the supplied drain hose to the discharge port and secure it. Install a collecting pipe with a downward pitch. Insulate drain pipes to prevent condensation.
Caution: Improper drain piping insulation can lead to water leakage and property damage. ⚠️
5. Electrical Work
All electrical work must be handled by qualified engineers according to regulations and manual instructions. Use a dedicated power supply. Connect wires securely. Never connect power cables to control wire terminals. Use appropriate wire sizes and fuses/breakers. Ensure proper grounding, avoiding connection to gas/water pipes or lightning rods. ⏚
| Switch (A) | Capacity | Fuse | Molded case circuit breaker | Earth leakage breaker | Wire size |
|---|---|---|---|---|---|
| 16 | 16 | 20 A | 20 A 30 mA | 1.5 mm² |
Refer to the outdoor unit installation manual for detailed information.
6. Setting Addresses and Operating Units
The BC controller address switch is factory-set to "000". Set the address to 1 + the outdoor unit's address. If this creates a conflict, set addresses between 51 and 100, ensuring they are unique.
7. Test Run
Before test run: check for refrigerant leaks and loose cables. Measure insulation resistance (min. 1.0 MΩ) between the power terminal block and ground. Perform a discharge test by adding a small amount of water to the BC controller and checking for leaks.
Product Compliance
This product is designed for residential, commercial, and light-industrial environments and complies with EU regulations: Low Voltage Directive 2006/95/EC and Electromagnetic Compatibility Directive 2004/108/EC.
