Airtight Test, Evacuation, And Refrigerant Charging - Mitsubishi Electric PUHY-P-YSGM-A Anwendung

flare nut size (mm)
outer diameter
ø6.35
ø9.52
ø12.7
B
ø15.88
ø19.05
[Fig. 10.2.2] (P.4)
<A> [Ball valve (gas side/In the case of Sub unit)]
<B> [Ball valve (liquid side)]
<C> [Ball valve (gas side/In the case of Main unit)]
<D> This figure shows the valve in the fully open state.
<E> [Stop valve for oil balance]
<F> To Sub unit
<G>To Main unit
<H> To Indoor unit
<I> To liquid distributor (accessory)
<J> Oil balance (Between outdoor units)
<K> To *A
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)
[Manufacturer: Nichiasu corporation]
[Type: T/#1991-NF]
D Distributor (Gas) (Accessory)
[Use packing and securely install this pipe to the valve flange so that gas leakage
will not occur. (Tightening torque: 40 N·m) Coat both surfaces of the packing with
refrigerating machine oil. (Ester oil, ether oil or alkylbenzene [small amount]) Dis-
tributor (Gas) may be attached on the main unit side.]
E Connecting pipe (Accessory)
[Use packing and securely install this pipe to the valve flange so that gas leakage
will not occur. (Tightening torque:40 N·m) Coat both surfaces of the packing with
refrigerating machine oil. (Ester oil, ether oil or alkylbenzene [small amount])]
F Cap, copper packing
[Remove the cap and operate the valve stem. Always reinstall the cap after op-
eration is completed. (Valve stem cap tightening torque: 23 ~ 27 N·m)]
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: 12 ~ 15 N·m)]
H Flare nut
[Tightening torque: Refer to the following table.
Loosen and tighten this nut using a double-ended wrench.
Coat the flare contact surface with refrigerating machine oil (Ester oil, ether oil or
alkylbenzene [small amount])]
I Operating portion
[Fully closed at the factory, when connecting the piping, when evacuating, and
when charging additional refrigerant. Open fully after the operations above are
completed. To open: Turn the shaft counter clockwise with an allen wrench until it
stops. To close: Turn the shaft clockwise until it stops.]
J Cap
[After completing work, tighten the cap of the shaft securely not to generate gas
leak. (The tightening torque is 25 N·m)]
K Service port (Oil balance)
[After connecting oil balance pipe, make vacuous using the service port. (The
tightening torque is 12 ~ 15 N·m)]
L Field piping
[Braze to the connecting pipe. (When brazing, use unoxidized brazing.)]
M Open (Operate slowly)
N ø28.58
P ø15.88
Appropriate tightening torque by torque wrench:
Copper pipe external dia. (mm)
ø6.35
ø9.52
ø12.7
ø15.88
ø19.05
Tightening angle standard:
Pipe diameter (mm) Tightening angle (°)
ø6.35, ø9.52 60 to 90
ø12.7, ø15.88 30 to 60
ø19.05 20 to 35
dimension B
size in inches
R410A
1/4" 17.0
3/8" 22.0
1/2" 26.0
5/8" 29.0
3/4" 36.0
O ø41.28
Q ø9.52
Tightening torque (N·m)
14 to 18
35 to 42
50 to 57.5
75 to 80
100 to 140
[Fig. 10.2.3] (P.4)
Note:
If a torque wrench is not available, use the following method as a standard:
When you tighten the flare nut with a wrench, you will reach a point where
the tightening torque will abruptly increase. Turn the flare nut beyond this
point by the angle shown in the table above.
<Piping connection example>
• Connect pipes between the Main unit and the Sub unit according to [Fig. 10.2.4].
• When connecting pipes to the ball valve, perform the work on the gas side first.
• The gas distributor can be attached to the Main unit side.
[Fig. 10.2.4] (P.5)
<A> Main unit
<B> Sub unit
<C> Control box
<D> To indoor unit
<E> Gradient of the distributor must be within 15° from the ground.
A Connecting pipe (flange type) (accessory)
B Front panel knockout hole
C Connecting pipe (gas) [not supplied]
D Connecting pipe (liquid) [not supplied]
E Connecting pipe (oil balance) [not supplied]
F Gas distributor (accessory)
G Connecting pipe (accessory)
H 90° elbow (ø28.58) [not supplied]
I Liquid distributor (accessory)
(1) Front piping
(2) Bottom piping
Note:
In the case of bottom piping or bottom wiring, do not block the holes on the
base with the foundation or base frame. Moreover, for bottom piping, build a
foundation with a minimum height of 100 mm to allow the piping to run un-
der the unit bottom.
Caution:
• Always remove the connecting pipe from the ball valve and braze it out-
side the unit.
- Brazing the connecting pipe while it is installed will heat the ball valve and
cause trouble or gas leakage. The piping, etc. inside the unit may also be
burned.
• Use ester oil, ether oil or alkylbenzene (small amount) as the refrigerat-
ing machine oil to coat flares and flange connections.
- The refrigerating machine oil will degrade if it is mixed with a large amount of
mineral oil.
• Keep the ball valve closed until refrigerant charging to the pipes to be
added on site has been completed. Opening the valve before charging
the refrigerant may result in unit damage.
• Do not use a leak detection additive.
• Faulty connection of the balance oil pipe may damage the compressor.
10.3. Airtight test, evacuation, and refrigerant
charging
1 Airtight test
Perform with the ball valve of the outdoor unit closed, and pressurize the con-
nection piping and the indoor unit from the service port provided on the ball
valve of the outdoor unit. (Always pressurize from both gas pipe and liquid pipe
service ports.)
[Fig. 10.3.1] (P.5)
A Nitrogen gas B To indoor unit
D Lo knob E Hi knob
G Liquid pipe H Gas pipe
J Service port
Observe the following restrictions when conducting an air tightness test to prevent
negative effects on the refrigerating machine oil. Also, with nonazeotropic refriger-
ant (R410A), gas leakage causes the composition to change and affects perform-
ance. Therefore, perform the airtightness test cautiously.
C System analyzer
F Ball valve
I Outdoor unit
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