Refrigerant Piping Installation; Caution - Mitsubishi Electric CITY MULTI Series Installation Manual

6 Connect the signal cables (TB8-1 and 2) for pump operation ON signal.
7 Make function settings according to the system.
Switch 810
No.
Operation • When No. 810 for Dip switch SW4 is set to OFF
(default)
0 V: fully open, 10 V: closed (for motor valve)
• When No. 810 for Dip switch SW4 is set to ON
0 V: closed, 10 V: fully open (for motor valve)
Switch 901
No.
Operation • When No. 901 for Dip switch SW4 is set to OFF
(default)
Motor valve is open while all heat source units (OC/OS)
are in the thermo-off state.
• When No. 901 for Dip switch SW4 is set to ON
Motor valve is closed while all heat source units (OC/
OS) are in the thermo-off state.
Switch 917
No.
Operation • When No. 917 for Dip switch SW4 is set to OFF
(default)
The relay is closed while the compressor is in operation.
• When No. 917 for Dip switch SW4 is set to ON
The relay is closed when cooling or heating operation
signal is received from the controller.
Switch
No. 1 2 3
810 0 1 0
901 1 0 1
917 1 0 1
*Take the following steps for function setting.
1. Set Dip switch SW6-10 to ON.
2. Set Dip switch SW4.
3. Press SWP1 for two seconds or longer to change the settings.
*Use the following setting combination of Dip switches.
• No. 901 for Dip switch SW4 is OFF, and No. 917 for Dip switch SW4 is ON.
• No. 901 for Dip switch SW4 is ON, and No. 917 for Dip switch SW4 is OFF.

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: flare connection for the indoor
units, Gas (low-pressure for PQRY-P series) pipes and Liquid (high-pressure
for PQRY-P series) 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.
26
SW4 0: OFF, 1: ON
4 5 6 7 8 9
1 0 1 0 0 1
0 0 0 0 1 1
0 1 0 0 1 1
8 Check for proper operation of water flow rate control system including the
heat source unit.
1. Power on the pump, motor valve, and unit.
2. Operate the indoor unit (cooling or heating mode) from the remote
controller.
3. Check that "2000 error" (pump interlock error) is not occurring.
9 Check that the flow rate of water supplied to the heat source unit is within the
allowable range.
• Ensure that circulating water temperature is within the allowable range.
• Ensure that there is no clogging of the strainer.
• When several heat-source units are operated by one pump, ensure that
the flow rate of water supplied to each heat source unit is within the
allowable range regardless of the ON/OFF status of the heat source units
in the system.
[Fig. 8.5.1] (P.4)
System diagram for the use of water flow rate control.
Heat source unit
A
Tuning valve
C
*
Flow switch
E
Power cable
G
Pump interlock
I
Opening command
K
*1 These items are not supplied.
*2 Do not connect the power cables to TB9-1 and 2 to supply power to the motor
valve. Doing so may cause damage to the Input/Output board.
10
1
1
1

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 series ONLY
Line branch
Down-stream unit model
Less than 80 in total
CMY-Y102SS-G2
Heat source twinning kit model PQRY-P series ONLY
Total heat source model
P400 ~ P600
CMY-Q100CBK2
*
1
Motor valve
B
* *
1 Shutoff valve 1
D
1 Water pipe
F
Signal cable
H
Operation ON signal
J
Power supply for motor valve
L
(24 VAC or 24 VDC)
Indoor junction pipe kit model
PQRY-P series ONLY
Total indoor model
P100~P250
CMY-R160C-J
Total heat source model
P700 ~ P900
CMY-Q200CBK
*
2