Refrigerant Piping Installation; Caution - Mitsubishi Electric CITY MULTI PQHY-P200YHM-A Manuel D'installation

9. Refrigerant piping installation

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: fl are connection for the indoor units,
Gas (low-pressure for PQRY-P·Y(S)HM-A) pipes and Liquid (high-pressure for
PQRY-P·Y(S)HM-A) pipes for heat source, brazed connection. Note that the
branched sections are brazed.
Warning:
Always use extreme care to prevent the refrigerant gas from leaking while
using fi re or fl ame. If the refrigerant gas comes in to contact with a fl ame
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.

Caution:

•
Do not vent R410A into the atmosphere.
• R410A is a Fluorinated Greenhouse gas, covered by the Kyoto Protocol
with a Global Warming Potential (GWP) = 1975.
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 inner and outer 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 Commercially available 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 indoor and heat source branching and merging section, be sure to use
the following twinning pipe sets and merge pipe sets (sold separately).
Indoor twinning pipe Indoor junction pipe
kit model PQRY- kit model PQRY-
P·Y(S)HM-A ONLY P·Y(S)HM-A ONLY
Line branch
Lower stream unit Total indoor model
P100 ~ P250
model
Less than 80 in total
CMY-Y102S-G2 CMY-R160-J
Copper pipe size and radial thickness for R410A CITY MULTI.
Size (mm) Size (inch) Radial thickness (mm)
ø6.35 ø1/4
ø9.52 ø3/8
ø12.7 ø1/2
ø15.88 ø5/8
*ø19.05 ø3/4
*ø19.05 ø3/4
ø22.2 ø7/8
ø25.4 ø1
ø28.58 ø1-1/8
ø31.75 ø1-1/4
ø34.93 ø1-3/8
ø41.28 ø1-5/8
* Both pipe types can be used for pipe size ø19.05 (3/4 inch) for R410A air
conditioner.
20
Heat source twinning
kit model PQRY-
P·Y(S)HM-A ONLY
Total heat source
model
P400 ~ P600
CMY-Q100VBK
Pipe type
0.8 Type-O
0.8 Type-O
0.8 Type-O
1.0 Type-O
1.2 Type-O
1.0 Type-1/2H or H
1.0 Type-1/2H or H
1.0 Type-1/2H or H
1.0 Type-1/2H or H
1.1 Type-1/2H or H
1.2 Type-1/2H or H
1.4 Type-1/2H or H
6 Use a fi tting if a specifi ed refrigerant pipe has a different diameter from that
of a branching pipe.
7 Always observe the restrictions on the refrigerant piping (such as rated
length, height difference, and piping diameter) to prevent equipment failure
or a decline in heating/cooling performance.
Indoor twinning pipe set model PQHY-P·Y(S)HM-A ONLY
Line branch
Lower stream unit
Lower stream unit
model
model
More than 201
Less than 200 in
and less than 400
total
in total
CMY-Y102S-G2 CMY-Y102L-G2
Indoor twinning pipe set model PQHY-P·Y(S)HM-A ONLY
Header branch
4 branching 8 branching
CMY-Y104-G CMY-Y108-G
Heat source twinning kit model PQHY-P·Y(S)HM-A ONLY
Total heat source model Total heat source model
P400 ~ P600
CMY-Y100VBK2
8 Branching cannot be made after header branching (corresponding parts are
marked with X in the diagram below). *PQHY-P·Y(S)HM-A ONLY.
To the heat source unit
To the heat source
unit
9 Either a lack or an excess of refrigerant causes the unit to make an
emergency stop. Charge the system with an appropriate amount of
refrigerant. When servicing, always check the notes concerning pipe
length and amount of additional refrigerant at both locations, the refrigerant
volume calculation table on the back of the service panel and the additional
refrigerant section on the labels for the combined number of indoor units
(Refer to item 9.2. for detailed information on refrigerant piping system).
0 Be sure to charge the system using liquid refrigerant.
a Never use refrigerant to perform an air purge. Always evacuate using a
vacuum pump.
b Always insulate the piping properly. Insuffi cient insulation will result in a
decline in heating/cooling performance, water drops from condensation and
other such problems (Refer to item 10.4 for thermal insulation of refrigerant
piping).
c When connecting the refrigerant piping, make sure the valve of the heat
source unit is completely closed (the factory setting) and do not operate it
until the refrigerant piping for the heat source, indoor units and BC controller
has been connected, a refrigerant leakage test has been performed and the
evacuation process has been completed.
d Braze only with non-oxide brazing material for piping. Failure to do so
may damage the compressor. Be sure to perform the non-oxidation
brazing with a nitrogen purge.
Do not use any commercially available anti-oxidizing agent since it may
cause pipe corrosion and degrading of the refrigerant oil.
Please contact Mitsubishi Electric for more details.
(Refer to item 10.2. for details of the piping connection and valve operation)
e Never perform heat source unit piping connection work when it is
raining.
Lower stream unit
Lower stream unit
model
model
More than 401
More than 651 in
and less than 650
total
in total
CMY-Y202-G2 CMY-Y302-G2
10 branching
CMY-Y1010-G
P650 ~ P900
CMY-Y300VBK2
CAP