24
GB
9. Refrigerant piping installation
9.1. Caution
This unit uses refrigerant R410A. Follow the local regulations on materials and
pipe thickness when selecting pipes. (Refer to the table below.)
1
Use the following materials for refrigeration piping.
•
Material: Use copper alloy seamless pipes made of phosphorus
deoxidized copper. Ensure the inside and outside surfaces of
the pipes are clean and free from hazardous sulfur, oxide, dusts,
shaving particles, oils, and moisture (contamination).
•
Size: Refer to item 9.2. for detailed information on refrigerant piping
system.
2
Field-supplied piping often contains dust and other materials. Always blow it
clean with a dry inert gas.
3
Use care to prevent dust, water or other contaminants from entering the
piping during installation.
4
Reduce the number of bending portions as much as possible, and make
bending radii as big as possible.
5
For branching and connecting pipes for indoor and heat source units, use
the following twinning and connecting pipe sets (sold separately).
Indoor twinning pipe kit model
PQRY-P·Y(S)LM-A ONLY
Indoor junction pipe kit model
PQRY-P·Y(S)LM-A ONLY
Line branch
Total indoor model
P100~P250
Down-stream unit model
Less than 80 in total
CMY-Y102SS-G2
CMY-R160C-J
Heat source twinning kit model PQRY-P·Y(S)LM-A ONLY
Total heat source model
P400 ~ P600
Total heat source model
P700 ~ P900
CMY-Q100CBK2
CMY-Q200CBK
The pipe is connected via a terminal-branch type connection in which refrigerant
piping from the heat source unit is branched at the terminal and is connected to
each of the indoor units.
The method of pipe connection is as follows: flare connection for the indoor units,
Gas (low-pressure for PQRY-P·Y(S)LM-A) pipes and Liquid (high-pressure for
PQRY-P·Y(S)LM-A) pipes for heat source, brazed connection. Note that the
branched sections are brazed.
Warning:
Do not use refrigerant other than the type indicated in the manuals
provided with the unit and on the nameplate.
- Doing so may cause the unit or pipes to burst, or result in explosion or fire
during use, during repair, or at the time of disposal of the unit.
- It may also be in violation of applicable laws.
- MITSUBISHI ELECTRIC CORPORATION cannot be held responsible
for malfunctions or accidents resulting from the use of the wrong type of
refrigerant.
Always use extreme care to prevent the refrigerant gas from leaking while
using fire or flame. If the refrigerant gas comes in to contact with a flame
from any source, such as a gas stove, it breaks down and generates
a poisonous gas which can cause gas poisoning. Never weld in an
unventilated room. Always conduct an inspection for gas leakage after
installation of the refrigerant piping has been completed.
2
Water quality standard
Items
Low to mid-range
temperature water system
Tendency
Recirculating
water
[20<T<60°C]
[68<T<140°F]
Make-up
water
Corrosive Scale-
forming
Standard
items
pH (25°C) [77°F]
7.0 ~ 8.0
7.0 ~ 8.0
Electric conductivity (mS/m) (25°C) [77°F]
(μ s/cm) (25°C) [77°F]
30 or less
[300 or less]
30 or less
[300 or less]
Chloride ion
(mg Cl-/ℓ)
50 or less
50 or less
Sulfate ion
(mg SO4
2-
/ℓ)
50 or less
50 or less
Acid consumption (pH4.8)
(mg CaCO
3
/ℓ)
50 or less
50 or less
Total hardness (mg CaCO
3
/ℓ)
70 or less
70 or less
Calcium hardness (mg CaCO
3
/ℓ)
50 or less
50 or less
Ionic silica
(mg SiO
2
/ℓ)
30 or less
30 or less
Refer-
ence
items
Iron
(mg Fe/ℓ)
1.0 or less
0.3 or less
Copper
(mg Cu/ℓ)
1.0 or less
0.1 or less
Sulfide ion
(mg S
2-
/ℓ)
not to be
detected
not to be
detected
Ammonium ion
(mg NH
4+
/ℓ)
0.3 or less
0.1 or less
Residual chlorine
(mg Cl/ℓ)
0.25 or less 0.3 or less
Free carbon dioxide (mg CO
2
/ℓ)
0.4 or less
4.0 or less
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.
4
When replacing a previously installed air conditioning device (even when
only the heat exchanger is being replaced), first 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, adjust water quality before
replacing the unit.
8.4. Pump interlock
The heat source unit may become damaged if it is operated with no water
circulating through the pipes.
Interlock unit operation and the water-circuit pump. Use the terminal
blocks for interlocking (TB8-1, 2, 3, 4) that can be found on the unit.
In the case of a pump interlock circuit signal connection to the TB8-3, 4, remove
the short-circuit wire. Also, use pressure valve 63PW with a minimum current of
5mA or less to prevent miss detection due to poor connection.
Pump interlock cords of parts of appliances for heat source use shall not be
lighter than polychloroprene sheathed flexible cord (design 245 IEC 57).
[Fig. 8.4.1] (P.4)
A
Pump interlock circuit connection (field-supplied)
[Fig. 8.4.2] (P.4)
This circuit is for interlocking of the heat source unit operation and the water-
circuit pump.
A
Heat source unit
B
Control panel (field-supplied)
C
To next heat source unit
X
: Relay
FS
: Flow switch
52P : Magnetic contactor for water circuit pump
MP
: Water circuit pump
MCB : Circuit breaker
* Remove the short circuit wire between 3 and 4 when wiring to TB8.
* Use an insulated ring terminal to connect the wiring to TB8.
Terminal
No.
TB8-1, 2
Output
Relay contacts output
Rated voltage: 220 ~ 240V
Rated load: 1A
Operation
•
When setting No.917 for Dip switch 4 (Dip switch 6-10 is
ON) is OFF.
The relay closes during compressor operation.
SW4 0: OFF, 1: ON
1 2 3 4 5 6 7 8 9 10
1 0 1 0 1 0 0 1 1 1
•
When setting No.917 for Dip switch 4 (Dip switch 6-10
is ON) is ON.
The relay closes during reception of cooling or the heat-
ing operation signal from the controller.
(Note: It outputs even if the thermostat is OFF (when the
compressor is not operating).)
Summary of Contents for CITY MULTI PQHY-P YLM-A Series
Page 378: ......
