Duct Work - Mitsubishi Electric SEZ-KC25VA Manuel D'installation

7. Refrigerant piping work
Refrigerant pipe insulation
• After connecting refrigerant piping, insulate the joints (flared joints) with thermal
insulation tubing as shown below.
[Fig. 7-9] (P.3)
A Thermal insulation tubing 1
B Caution:
Pull out the thermal insulation on the refrigerant piping at the site, insert the flare nut to flare
the end, and replace the insulation in its original position.
Take care to ensure that condensation does not form on exposed copper piping.
C Liquid end of refrigerant piping
E Site refrigerant piping
G Marked "GAS"
I Flared insulation (supplied) 1
K Thermal insulation
M Flare nut
O Ensure that there is no gap here
Q Outside
S Remove tape
T Thermal insulation tubing (small) (supplied) 2
U Tie (large) (supplied) 4
V Ensure that there is no gap here. Place join upwards.
1.Remove and discard the rubber bung which is inserted in the end of the unit piping.
2.Flare the end of the site refrigerant piping.
3.Pull out the thermal insulation on the site refrigerant piping and replace the insula-
tion in its original position.
Cautions On Refrigerant Piping
s s s s s Be sure to use non-oxidative brazing for brazing to ensure that no foreign
matter or moisture enter into the pipe.
s s s s s Be sure to apply refrigerating machine oil over the flare connection seating
surface and tighten the connection using a double spanner.
s s s s s Provide a metal brace to support the refrigerant pipe so that no load is
imparted to the indoor unit end pipe. This metal brace should be provided
50 cm away from the indoor unit's flare connection.
7.4. Purging procedures leak test
PURGING PROCEDURES
Connect the refrigerant pipes (both the liquid and gas pipes) between the indoor
and the outdoor units.
Remove the service port cap of the stop valve on the side of the outdoor unit gas pipe.
(The stop valve will not work in its initial state fresh out of the factory (totally closed
with cap on).)
Connect the gage manifold valve and the vacuum pump to the service port of the
stop valve on the gas pipe side of the outdoor unit.
Run the vacuum pump. (Vacuumize for more than 15 minutes.)
Check the vacuum with the gage manifold valve, then close the gage manifold valve,
and stop the vacuum pump.
Leave it as is for one or two minutes. Make sure the pointer of the gage manifold
valve remains in the same position. Confirm that the pressure gage show -0.101MPa
(-760 mmHg).

8. Duct work

• When connecting ducts, insert a canvas duct between the main body and the duct.
• Use non-combustible duct components.
Caution:
The noise from the intake will increase dramatically if intake A A A A A is fitted
•
directly beneath the main body. Intake A A A A A should therefore be installed as
far away from the main body as possible.
Particular care is required when using it with bottom inlet specifications.
• Install sufficient thermal insulation to prevent condensation forming on
outlet duct flanges and outlet ducts.
• To connect the air conditioner main body and the duct for potential equali-
zation.
10
D Gas end of refrigerant piping
F Main body
H Marked "OUTSIDE"
J Marked "INSIDE"
L Pull
N Return to original position
P Plate on main body
R Inside
Stop valve
*Close
Stop valve
*Open
Hexagonal wrench
Service port
*4 to 5 turns
Remove the gage manifold valve quickly from the service port of the stop valve.
After refrigerant pipes are connected and evacuated, fully open all stop valves on
gas and liquid pipe sides.
Operating without fully opening lowers the performance and causes trouble.
Pipe length :
7 m maximum
No gas charge is needed.
Tighten the cap to the service port to obtain the initial status.
Retighten the cap
7.5. Drain piping work
1.Ensure that the drain piping is downward (pitch of more than 1/100) to the outdoor
(discharge) side. Do not provide any trap or irregularity on the way. (1)
2.Ensure that any cross-wise drain piping is less than 20 m (excluding the difference
of elevation). If the drain piping is long, provide metal braces to prevent it from
waving. Never provide any air vent pipe. Otherwise drain may be ejected.
3.Use a hard vinyl chloride pipe VP-25 (with an external diameter of 32 mm) for drain
piping.
4.Ensure that collected pipes are 10 cm lower than the unit body's drain port as
shown in 2.
5.Do not provide any odor trap at the drain discharge port.
6.Put the end of the drain piping in a position where no odor is generated.
7.Do not put the end of the drain piping in any drain where ionic gases are gener-
ated.
[Fig. 7-10] (P.3)
A Downward slope 1/100 or more
B Connection dia. R1 external thread
C Indoor unit
D Collective piping
E Maximize this length to approx. 10 cm
• Keep the distance between the inlet grille and the fan over 850 mm.
If it is less than 850 mm, install a safety guard not to touch the fan.
[Fig. 8-1] (P.3)
A Air inlet
B Air outlet
C Access door
D Ceiling surface
E Canvas duct
F Connect common reference potential wire between duct-work to air conditioner.
G Air filter
H Inlet grille
Compound pressure
-0.101MPa
gauge (for R410A)
(-760 mmHg)
Pressure gauge
(for R410A)
Gauge manifold
valve (for R410A)
Handle High
Handle
Low
Charge hose
Stop
(for R410A)
valve
(or the vacuum
Vacuum
pump
pump with the
Window
function to
Adapter for
prevent the back
Charge hose
preventing
flow)
(for R410A)
the back flow
Pipe length exceeding 7 m
Charge the prescribed
amount of gas.
Leak test