Mitsubishi Electric PLFY-WP VBM-E Installation Manual page 6

Connecting ater pipes
A B
Water pipework is screw
C
connections
D D D
Fig
A To outdoor unit
B End connection (brazing)
C HBC controller
D Indoor unit
E Twinning pipe ( eld supply)
F Up to three units for 1 branch hole; total capacity: below
(but in same mode, cooling heating)
Note:
Connection o ultiple indoor units
Total capacity of connectable indoor units: Less than
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
downstream.
Please group units that operate on 1 branch.
D
B
A
C
Fig
E
D D D
F
*1
-
ith one connection (or oint pipe)
A Indoor unit
E
B Water pipe: From HBC unit
C Water pipe: To HBC unit
D Strainer (4 mesh or more)
( eld supply)
E Shut off valve
E ( eld supply)
-
9. HBC water pipe connection sizes
Connection size
Unit model
Water
inlet
PLF -WP32 BM
Rc 3 4
PLF -WP4 BM
screw
PLF -WP5 BM
1 . Please refer to the [Fig. 4-4] when connecting the water supply.
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.
Water treat ent and ualit 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 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.
Removing of foreign ob ects or impurities within the pipes.
During installation, make sure that foreign ob ects, 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 .
2 Water quality standard
Items
pH (25 C) [77 F]
Electric conductivity
(mS m) (25 C) [77 F]
( s cm) (25 C) [77 F]
Chloride ion (mg Cl- ) 5 or less 5 or less
Sulfate ion (mg SO4
Acid consumption (pH4. )
(mg CaCO
Total hardness (mg CaCO
Calcium hardness (mg CaCO
Ionic silica (mg SiO
Iron (mg Fe ) 1. or less .3 or less
Copper (mg Cu ) 1. or less .1 or less
Sul de ion (mg S
Ammonium ion (mg NH4
Residual chlorine (mg Cl ) .25 or less .3 or less
Free carbon dioxide (mg CO
Ryzner stability inde
Reference : Guideline of Water Quality for Refrigeration and Air Conditioning
Equipment. ( RA GL 2E-1994)
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
the heat exchanger is being replaced), rst conduct a water quality analysis and
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, ad ust water quality before replacing the
unit.
Pipe size
Water Water Water
volume ( )
outlet out return
Inner Inner
Rc 3 4
diameter diameter
screw
2 mm 2 mm
Low to mid-range
temperature water Tendency
system
Recirculating
water Make-up
Corrosive
[2 T 6 C] water
[6 T 14 F]
7. . 7. .
3 or less 3 or less
[3 or [3 or
less] less]
- ) 5 or less 5 or less
2
5 or less 5 or less
)
3
) 7 or less 7 or less
3
) 5 or less 5 or less
3
) 3 or less 3 or less
2
- ) not to be not to be
2
detected detected
) .3 or less .1 or less
) .4 or less 4. or less
2
6. 7. –
Water
1.5
1.5
1.5
Scale-
forming