Note - Mitsubishi Electric CITY MULTI PLFY-WP10VFM Installationshandbuch

4. Connecting water pipes
A B
Water pipework is screw
C
connections
D D D
A To outdoor unit
B End connection (brazing)
C HBC controller
D Indoor unit
E
F

Note:

*1. Connection of multiple indoor units with one connection (or joint pipe)
Select the size according to the total capacity of indoor units to be installed
downstream.
D
B
A
C
Fig. 4-4
E
D D D
F
*1
A Indoor unit
E
B Water pipe: From HBC unit
C Water pipe: To HBC unit
D
E Shut off valve
E
9. HBC water pipe connection sizes
Connection size
Unit model
Water
inlet
PLFY-WP15VFM
screw
PLFY-WP25VFM
PLFY-WP32VFM
11. Install a shut off valve and strainer in a place that is easy to operate and makes
maintenance work easy.
12. Apply insulation to the indoor unit pipework, strainer, shut off valve, and pressure
reducing valve.
13. Please do not use a corrosion inhibitor in the water system.
To preserve water quality, use the closed type of water circuit. When the circulating
water quality is poor, the water heat exchanger can develop scales, 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.
During installation, make sure that foreign objects, such as welding fragments,
sealant particles, or rust, do not enter the pipes.
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
2 Water quality standard
Items
Electric conductivity
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
(mg S
Ammonium ion
Residual chlorine
Free carbon dioxide (mg CO
Ryzner stability inde
Reference : Guideline of Water Quality for Refrigeration and Air Conditioning
3 Consult with a specialist about water quality control methods and calculations
before using anti-corrosive solutions.
4 When replacing a previously installed air conditioning device (even when only
check for possible corrosion.
Corrosion can occur in cold-water systems even if there has been no prior signs
of corrosion.
If the water quality level has dropped, adjust water quality before replacing the
unit.
Pipe size
Water Water Water
outlet out return
Inner Inner
diameter diameter
screw
Low to mid-range
temperature water Tendency
system
Recirculating
water Make-up
Corrosive
water
less] less]
2
3
3
3
2
not to be not to be
2
detected detected
2
–
Water
volume
Scale-
forming
7