Water Treatment And Quality Control - Mitsubishi Electric City Multi CMB-WM108V-AA Manuel D'installation

• Installation of pipes in a high-temperature high-humidity environment, such as
the top floor of a building, may require the use of insulation materials thicker than
the ones specified in the chart above.
• When certain specifications presented by the client must be met, ensure that
they also meet the specifications on the chart above.
4. Expansion vessel
• Install an expansion vessel to accommodate expanded water.
• Please install expansion vessel at same height level of HBC.
Expansion vessel selection criteria:
• The water containment volume of the HBC and the indoor unit.
Unit model
HBC Controller
PEFY-WP20VMA
PEFY-WP25VMA
PEFY-WP32VMA
PEFY-WP40VMA
PEFY-WP50VMA
* For other indoor units, refer to the installation manual for
each.
• The maximum water temperature is 60°C.
• The minimum water temperature is 5°C.
• The circuit protection valve set pressure is 370-490kPa.
• The circulation pump head pressure is 0.24MPa.
• The design pressure of the expansion vessel is the charged water pressure
(the reading of the pressure gauge).
• Tank volume of expansion vessel is as follows:
Tank volume = ε × G/(1 - (Psupply + 0.1)/0.29) × 1.2
ε = The expansion coefficient of water
(= 0.0171)
* Please choose ε for using antifreeze solution on the type and temperature range
used.
ε = Max density/Min density - 1
G [L] = (HBC [L] + Indoor unit [L] + Pipe [L]) × 1.1
Psupply: Water supply pressure [MPa]
5. Leakproof the water pipework, valves and drain pipework. Leakproof all the way
to, and include pipe ends so that condensation cannot enter the insulated pipe-
work.
6. Apply caulking around the ends of the insulation to prevent condensation getting
between the pipework and insulation.
7. Add a drain valve so that the unit and pipework can be drained.
8. Ensure there are no gaps in the pipework insulation. Insulate the pipework right
up to the unit.
9. Ensure that the gradient of the drain pan pipework is such that discharge can
only blow out.
10. HBC water pipe connection sizes and pipe sizes.
[Fig. 5.2.2] (P.5)
Connection size
Indoor unit
Water inlet
PEFY-W·VMA O.D. 22.0 mm O.D. 22.0 mm
* For other indoor units, refer to the indoor unit installation manual.
* The pipe diameter depends on the capacity of indoor units.
Refer to the indoor unit installation manual for details.
A To outdoor unit
B End connection (brazing)
C Main-HBC controller
D Sub-HBC controller
E Indoor unit
F Twinning pipe (field supply)
G Up to three units for 1 branch hole; total capacity: below 80 (but in same mode, cool-
ing/heating)
H Shutoff valve (field supply)
I Pressure control valve (field supply)
J Auto air vent valve (Highest point on the water pipe for each branch) (field supply)
K Water pipework
Note:
*1. Connection of multiple indoor units with one connection (or joint pipe)
• Total capacity of connectable indoor units: Less than 80
• Number of connectable indoor units: Maximum 3 Sets
• Selection of water piping
Select the size according to the total capacity of indoor units to be installed down-
stream.
• Please group units that operate on 1 branch.
• 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.
14
(Unit: L)
Water volume
10
0.7
1
1.8
Pipe size
Water outlet Water out Water return
I.D. 20 mm I.D. 20 mm
11. Please refer to the [Fig. 5.2.3] when connecting the water supply.
[Fig. 5.2.3] (P.5)
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] < 0.01 + 0.01 x A < 0.16 [MPa] for the supply pressure
range to be used.
(A: Head pressure (m) between the HBC and the highest indoor unit)
If the supply pressure is greater than 0.16 MPa, use a pressure reducing valve to
keep the pressure within the range.
If the head pressure is unknown, set it to 0.16 MPa.
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 unit in an environment which may drop below 0°C,
please add antifreeze solution (Propylene Glycol only) to the circulating
water according to the local regulations.

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