Mitsubishi Electric City Multi PUMY-P250YBM Installation Manual page 18

4. Installing the refrigerant piping
2.
1.
4.
Fig. 4-12
4.5.2. Piping connection and valve operation (Fig. 4-13)
Service port
Used for removing gas from pinch
connection pipe, evacuating refrigerant
inside on-site piping, etc.
(10 to 14 N·m tightening torque)
en
Operating valve Operating valve
Completely closed when shipped from the Completely closed when shipped from the
factory. factory.
Leave completely closed during piping con- Leave completely closed during piping con-
nection and evacuation, and make complete- nection and evacuation, and make complete-
ly open after work is completed. ly open after work is completed.
<When opening> <When opening>
● Turn the operating valve counterclockwise.
● Turn the operating valve counterclockwise.
● Turn until the operating valve stops. ● Turn until the operating valve stops.
<When closing> <When closing>
● Turn the operating valve clockwise. ● Turn the operating valve clockwise.
● Turn until the operating valve stops. ● Turn until the operating valve stops.
Model number Pipe diameter
PUMY-P250YBM ø9.52 *1
ø12.7
PUMY-P300YBM
*1 Use the pipe ø12.7 when the piping
length is over 90 m.
ø12.7 when connecting the indoor
unit for PEFY-P200 or P250.
● Refer to the table to the under for the cap and operating valve
section tightening torque. As a guideline when not using a
torque wrench, tighten until the tightening torque suddenly
increases.
When widening the piping on-site, be sure to satisfy the mini-
mum pipe coupling depth in the table below.
Pipe diameter (mm)
More than 5, less than 8
More than 8, less than 12
More than 12, less than 16
More than 16, less than 25
More than 25, less than 35
More than 35, less than 45
Caution:
• Wrap the body of the operation valve with a wet towel before performing brazing work. If the body of the operation valve reaches a temperature of 120°C or
higher, the device may be damaged.
• During brazing work, be careful not to apply the fl ame to the surrounding wiring or sheet metal. If they come into contact with the fl ame, they may be burned
or fail due to the heat.
• Perform non-oxidizing brazing through nitrogen substitution. Oxidization on the inside of the refrigerant piping may cause deterioration of refrigerant oil or
compressor malfunction.
• After evacuation and refrigerant fi lling is completed, completely open the valve. If the unit is operated with the valve closed, the high pressure side or low
pressure side of the refrigerant circuit will become improperly pressurized, which may damage the compressor.
• Determine the amount of additional refrigerant charge (refer to "4.3. Additional refrigerant charge"), and charge refrigerant additionally through the service
port after completing piping connection work.
Warning:
• When installing the unit, securely connect the refrigerant pipes before starting the compressor.
• When opening or closing the valve below freezing temperatures, refrigerant may spurt out from the gap between the valve stem and the valve body, resulting
in injuries.
17
4.5. Installing the refrigerant piping (main pipe) (Fig. 4-12)
4.5.1. Removing pinch connection pipes
1.
• Perform piping connection and valve operation according to the procedure.
• Pinch connection pipes are attached to the on-site piping end of the liquid side and gas side operation valves when shipped
from the factory in order to prevent gas leakage. When connecting the refrigerant piping to the outdoor unit, remove the pinch
connection pipe of the operation valve according to the following procedure.
Procedure
2.
1. Check that the operation valves are completely closed (turned clockwise).
2. Attach a charging hose to the service port of the liquid side and gas side operation valves, and remove the gas inside the
pinch connection pipes.
3. After removing the gas from inside the pinch connection pipes, cut the pinch connection pipes at the position shown in the
3.
fi gure, and remove the refrigerant oil inside.
4. After the work is completed, heat the brazing section and remove the pinch connection pipes.
<Liquid side>
Brazing type
Cap
Remove the cap, and operate the operating
valve. After the work is completed, re-
attach the cap and sheet packing. (20 to attach the cap and sheet packing. (20 to
24.5 N·m tightening torque) 24.5 N·m tightening torque)
Service port Service port Service port
Used for removing gas from pinch connection Used for removing gas from pinch connection Used for removing gas from pinch connection
pipe, evacuating refrigerant inside on-site piping, pipe, evacuating refrigerant inside on-site piping, pipe, evacuating refrigerant inside on-site piping,
etc. (14 to 18 N·m tightening torque) etc. (14 to 18 N·m tightening torque) etc. (14 to 18 N·m tightening torque)
On-site piping
Perform non-oxidizing brazing.
Model number
PUMY-P250YBM
PUMY-P300YBM
A ø12.7 joint pipe is included with
the P300 model.
Minimum coupling depth (mm)
6
7
1. Remove the cap.
8
2. Remove the stopper.
10
3. Fully open the valve.
12
4. Attach the removed stopper.
14
5. Tighten the cap.
<Gas side>
Brazing type
Pipe diameter
ø22.2
ø25.4
Fig. 4-13
Follow the procedure below to open or close the valve
(after refrigerant leak test, purging work, and refrigerant charge).
Fully closed (factory default)
Valve shaft
Note:
Be sure to attach the stopper. Failure to do so may lead to
unintentional rotation of the valve shaft, that is to say, the valve
opened in the above procedure may be closed, causing the fl ow
of refrigerant interrupted.
Stopper pin
Valve stem does not turn more than 90°.
Operating valve Operating valve Operating valve
Completely closed when shipped from the factory. Completely closed when shipped from the factory. Completely closed when shipped from the factory.
Leave completely closed during piping connection Leave completely closed during piping connection Leave completely closed during piping connection
and evacuation, and make completely open after and evacuation, and make completely open after and evacuation, and make completely open after
work is completed. work is completed. work is completed.
<When opening> <When opening> <When opening>
● T urn the operating valve counterclockwise with a ● T urn the operating valve counterclockwise with a ● T urn the operating valve counterclockwise with a
wrench. wrench. wrench.
● Turn until the operating valve stops. ● Turn until the operating valve stops. ● Turn until the operating valve stops.
<When closing> <When closing>
<When closing>
● Turn the operating valve clockwise with a wrench. ● Turn the operating valve clockwise with a wrench. ● Turn the operating valve clockwise with a wrench.
● Turn until the operating valve stops. ● Turn until the operating valve stops. ● Turn until the operating valve stops.
* Adjust the orientation of the pipe to match
each knockout port hole.
A ø25.4 joint pipe is included with
the P300 model.
* Use depending on the direction the piping
will pass through.
Ball valve
Fully open
Valve shaft
Valve shaft
Stopper
Cap