Caution For Piping Connection / Valve Operation - Mitsubishi Electric CITY MULTI PUHY-P-YEM-A Serie Installationshandbuch

Value of α
Total capacity of connecting indoor units
to Model 80
Models 81 to 160
Models 161 to 330
Models 331 to 480
Models 481 or more
9.2. Caution for piping connection / valve
operation
[PUHY-P400/500YEM-A]
• Conduct piping connection and valve operation accurately.
• The gas side connecting pipe is assembled in factory before shipment.
1 For brazing to the connecting pipe with flange, remove the connecting pipe
with flange from the ball valve, and braze it outside of the unit.
2 During the time when removing the connecting pipe with flange, remove
the seal attached on the rear side of this sheet and paste it onto the flange
surface of the ball valve to prevent the entry of dust into the valve.
3 The refrigerant circuit is closed with a round, close-packed packing at the
shipment to prevent gas leak between flanges. As no operation can be
done under this state, be sure to replace the packing with the hollow pack-
ing attached at the piping connection.
4 At the mounting of the hollow packing, wipe off dust attached on the flange
sheet surface and the packing. Coat refrigerating machine oil (R407C: Ester
oil, ether oil or alkylbenzene [small amount]) onto both surfaces of the
packing.
[Fig. 9.2.1] (P.4)
A Close-packed packing
• After evacuation and refrigerant charge, ensure that the handle is fully open. If
operating with the valve closed, abnormal pressure will be imparted to the
high- or low-pressure side of the refrigerant circuit, giving damage to the com-
pressor, four-way valve, etc.
• Determine the amount of additional refrigerant charge by using the formula,
and charge refrigerant additionally through the service port after completing
piping connection work.
• After completing work, tighten the service port and cap securely not to gener-
ate gas leak.
[Fig. 9.2.2] (P.4)
<A> [Ball valve (liquid side)]
<B> [Ball valve (gas side)]
<C> (This figure shows the valve in the fully open state.)
A Valve stem
[Fully closed at the factory, when connecting the piping, when evacuating,
and when charging additional refrigerant. Open fully after the operations
above are completed.]
B Stopper pin [Prevents the valve stem from turning 90° or more.]
C Packing (accessory)
D Connecting pipe (accessory)
[Use packing and securely install this pipe to the valve flange so that gas
leakage will not occur. (Tightening torque: 43 N·m (430 kg-cm)) Coat both
surfaces of the packing with refrigerating machine oil. (R407C: Ester oil,
ether oil or alkylbenzene [small amount])]
E Open (Operate slowly)
F Cap, copper packing
[Remove the cap and operate the valve stem. Always reinstall the cap after
operation is completed. (Valve stem cap tightening torque: 25 N·m
(250 kg-cm) or more)]
G Service port
[Use this port to evacuate the refrigerant piping and add an additional charge
at the site.
Open and close the port using a double-ended wrench.
Always reinstall the cap after operation is completed. (Service port cap
tightening torque: 14 N·m (140 kg-cm) or more)]
H Flare nut
[Tightening torque: 80 N·m (800 kg-cm)
Loosen and tighten this nut using a double-ended wrench.
Coat the flare contact surface with refrigerating machine oil (R407C: Ester
oil, ether oil or alkylbenzene [small amount])]
I ø15.88
J ø34.93
K Field piping
[Braze to the connecting pipe. (When brazing, use unoxidized brazing.)]
α
1.0 kg
1.5 kg
2.0 kg
2.5 kg
3.0 kg
B Hollow packing
[PUHY-P600/650/700/750YSEM-A]
<For variable capacity unit>
• Conduct piping connection and valve operation accurately.
• After performing the following distributor (gas) connection, remove the con-
necting pipe included with the gas ball valve of the variable capacity unit, and
mount the distributor (gas) (accessory).
1 When brazing the distributor (gas), braze it outside of the unit before mount-
ing on the variable capacity unit.
2 During the time when removing the connecting pipe with flange, remove
the seal attached on the rear side of this sheet and paste it onto the flange
surface of the ball valve to prevent the entry of dust into the valve.
3 The refrigerant circuit is closed with a round, close-packed packing at ship-
ment to prevent gas leak between flanges. As no operation can be done
under this state, be sure to replace the packing with the hollow packing
attached at the piping connection.
4 At the mounting of the hollow packing, wipe off dust attached on the flange
sheet surface and the packing. Coat refrigerating machine oil (R407C: Ester
oil, ether oil or alkylbenzene [small amount])] onto both surfaces of the
packing.
[Fig. 9.2.3] (P.5)
<A> [When shipped from the manufacturer]
<B> [After installation]
A Close-packed packing
• After evacuation and refrigerant charge, ensure that the handle is fully open. If
operating with the valve closed, abnormal pressure will be imparted to the
high- or low-pressure side of the refrigerant circuit, or a shortage of oil in the
compressor may occur due to lack of oil flow between units, giving damage to
the compressor, four-way valve, etc.
• For evacuating, be sure to provide an oil balance pipe between the variable
capacity and constant capacity units.
• Determine the amount of additional refrigerant charge by using the formula,
and charge refrigerant additionally through the service port after completing
piping connection work.
• After completing work, shut the service port and cap tightly so that gas leaking
does not occur.
Connect ball valve piping in the order of (oil balance) → (liquid side) → (gas
•
side).
[Fig. 9.2.4] (P.5)
<A> [Ball valve (liquid side)]
<B> [Ball valve (gas side)]
<C> [Ball valve (oil balance side)]
<D> (This figure shows the valve in the fully open state.)
A Valve stem
[Fully closed at the factory, when connecting the piping, when evacuating, and
when charging additional refrigerant. Open fully after the operations above are
completed.]
B Stopper pin [Prevents the valve stem from turning 90° or more.]
C Packing (accessory)
D Distributor (Gas) (accessory)
[Mount packing (accessory) securely to the valve flange so that gas does not
leak. (Screw tightening torque: 43 N·m (430 kg·cm).) Apply a coat of refrigerat-
ing machine oil (R407C: Ester oil, ether oil or alkylbenzene [small amount]) to
both surfaces of the packing.]
E Open (Operate slowly)
F Cap, copper packing
[Remove the cap and operate the valve stem. Always reinstall the cap after
operation is completed. (Valve stem cap tightening torque: 25 N·m (250 kg·cm)
or more)]
G Service port
[Use this port to evacuate the refrigerant piping and add an additional charge
at the site.
Open and close the port using a double-ended wrench.
Always reinstall the cap after operation is completed. (Service port cap tight-
ening torque: 14 N·m (140 kg·cm) or more)]
H Flare nut
[Tightening torque: 80 N·m (800 kg·cm) ··· liquid, 55 N·m (550 kg·cm) ··· oil
blance
Loosen and tighten this nut using a double-ended wrench.
Coat the flare contact surface with refrigerating machine oil (R407C: Ester oil,
ether oil or alkylbenzene [small amount])]
I ø34.93 (PUHY-P600YSEM-A)
ø41.28 (PUHY-P650/700/750YSEM-A)
J Field piping
[Braze to the connecting pipe. (When brazing, use unoxidized brazing.)]
K ø15.88
L To distributor (liquid)
B Hollow packing
15