Mitsubishi Electric CITY MULTI CMB-WP108NU-AA Manual De Instalación página 11

Note:
*1. To connect multiple indoor units to a port
• Maximum total capacity of connected indoor units: WL30
• Maximum number of connectable indoor units: 3 units
• Branch joints are field-supplied.
• All the indoor units that are connected to the same port must be in the same
group and perform the Thermo-ON/OFF operation simultaneously.
• The room temperatures of all the indoor units in the group need to be monitored
via the connected remote controller.
• Selection of water piping
Select the size according to the total capacity of indoor units to be installed down-
stream.
• Do not connect multiple indoor units to the same port when operating each of
them in different modes (cooling, heating, stop, and thermo-OFF). The indoor
units connected to the same port must be set to operate in the same mode. Set
them to the same group to make them run/stop in the same mode all together.
Alternatively, enable the thermo setting on the remote controller, or set the
common thermostat (optional) to run/stop the units in the same mode based on
the representative temperature.
• When multiple indoor units are connected to a single port, install a pressure
control valve in the pipe to equalize the pressure of all indoor units.
*2. Connecting WL36 or 48 indoor units to an HBC controller
• When connecting WL36 or 48 indoor units to an HBC controller, connect each
unit to two sets of two ports on the HBC controller, using two junction pipes (Y-
joints).
• Connect an increaser (20A-to-32A) to the merged side of each junction pipe.
• When the junction pipes are connected to 16 HBC controller ports, the branched
sides of the junction pipes cannot be connected to the ports "4 and 5" "8 and 9" or
"12 and 13" at the same time. (See Fig. A.)
• When the junction pipes are connected to 8 HBC controller ports, the branched
sides of the junction pipes cannot be connected to the ports "4 and 5" at the same
time. (See Fig. B.)
• When a WL36 or a 48 model indoor unit is connected to an HBC controller, the
pipes that connect the unit to the same set of HBC controller ports cannot be
branched out to connect additional units.
*3. Maximum capacity of indoor units connectable to an HBC controller for
obtaining the rated performance
• An HBC controller has two pumps. Each pump can accommodate the capacity
equivalent to WL67 indoor units.
• When connecting the pipe to 16 HBC controller ports, make sure that the total
capacity of the indoor units connected to ports "1 through 4 and 9 through 12" or
"5 through 8 and 13 through 16" will not exceed WL67 and will be equal as much
as possible. (See Fig. A.)
When connecting the pipe to 8 HBC controller ports, make sure that the total
capacity of the indoor units connected to ports "1 through 4" or "5 through 8" will
not exceed WL67 and will be equal as much as possible. (See Fig. B.)
If the total capacity exceeds WL67, the performance will be degraded.
11. Please refer to the [Fig. 5.2.4] when connecting the water supply.
[Fig. 5.2.4]
A
B C D E
A HBC controller
B Water pipe
C Pressure gauge (field supply)
D Check valve (field supply)
E Shutoff valve (field supply)
F Pressure reducing valve (field supply)
G Strainer (field supply)
12. Use formula 0.1 MPa [15 psi] < 0.01 + 0.01 x A < 0.16 MPa [23 psi] for the supply
pressure range to be used.
(A: Head pressure (m) between the HBC controller and the highest indoor unit)
If the supply pressure is greater than 0.16 MPa [23 psi], use a pressure reducing
valve to keep the pressure within the range.
If the head pressure is unknown, set it to 0.16 MPa [23 psi].
13. Before performing a pressure test on the pipes in the water circuit, be sure to
install a shutoff valve on the inlet/outlet water pipes of the indoor units. Also,
install a strainer on the field-installed water pipes for easy operation and mainte-
nance.
14. Apply insulation to the indoor unit pipework, strainer, shutoff valve, and pressure
reducing valve.
15. Please do not use a corrosion inhibitor in the water system.
16. When installing the HBC controller in an environment which may drop
below 0°C [32°F], please add antifreeze solution (Propylene Glycol only) to
the circulating water according to the local regulations.
F G
5.3. Water treatment and quality control
To preserve water quality, use the closed type of water circuit. When the circulating
water quality is poor, the water heat exchanger can develop scale, leading to a
reduction in heat-exchange power and possible corrosion. Pay careful attention to
water processing and water quality control when installing the water circulation
system.
• Removing of foreign objects or impurities within the pipes.
During installation, make sure that foreign objects, such as welding fragments,
sealant particles, or rust, do not enter the pipes.
• Water Quality Processing
1 Depending on the quality of the cold-temperature water used in the
airconditioner, the copper piping of the heat exchanger may corrode.
Regular water quality processing is recommended.
If a water supply tank is installed, keep air contact to a minimum, and keep
the level of dissolved oxygen in the water no higher than 1mg/ℓ.
2Water quality standard
Items
pH (25°C) [77°F]
Electric conductivity (mS/m) (25°C) [77°F]
(µ s/cm) (25°C) [77°F]
Chloride ion
Sulfate ion (mg SO4
Acid consumption (pH4.8)
(mg CaCO
Total hardness (mg CaCO
Calcium hardness (mg CaCO
Ionic silica (mg SiO
Iron
Copper
Sulfide ion
Ammonium ion (mg NH
Residual chlorine
Free carbon dioxide (mg CO
Ryzner stability index
Reference : Guideline of Water Quality for Refrigeration and Air Conditioning
Equipment. (JRA GL02E-1994)
3 Consult with a specialist about water quality control methods and calculations
before using anti-corrosive solutions.
Low to mid-range
Tendency
temperature water system
Recirculating
water Make-up
Corrosive
[20<T<60°C] water
[68<T<140°F]
7.0 ~ 8.0 7.0 ~ 8.0
30 or less 30 or less
[300 or less] [300 or less]
(mg Cl-/ℓ) 50 or less 50 or less
/ℓ) 50 or less 50 or less
2-
50 or less 50 or less
/ℓ)
3
/ℓ) 70 or less 70 or less
3
/ℓ) 50 or less 50 or less
3
/ℓ) 30 or less 30 or less
2
(mg Fe/ℓ) 1.0 or less 0.3 or less
(mg Cu/ℓ) 1.0 or less 0.1 or less
not to be not to be
(mg S /ℓ)
2-
detected detected
/ℓ) 0.3 or less 0.1 or less
+
4
(mg Cl/ℓ) 0.25 or less 0.3 or less
/ℓ) 0.4 or less 4.0 or less
2
6.0 ~ 7.0 –
Scale-
forming
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