Purging Procedures Leak Test; Confirming Drain Discharge; Drain Piping Work - Mitsubishi Electric Mr.SLIM PEAD-A09AA7 Manuel D'installation

6. Refrigerant piping work
Cautions On Refrigerant Piping
 Be sure to use non-oxidative brazing for brazing to ensure that no foreign
matter or moisture enter into the pipe.
 Be sure to apply refrigerating machine oil over the flare connection seating
surface and tighten the connection using a double spanner.
 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 [19-11/16 in] away from the indoor unit's flare connection.

6.4. 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
-0.101 MPa (-760 mmHg).
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 [23 ft] maximum
No gas charge is needed.
Tighten the cap to the service port to obtain the initial status.
Retighten the cap

6.5. Drain piping work

• 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.
• Ensure that any cross-wise drain piping is less than 20 m [65 ft] (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.
• Use a hard vinyl chloride pipe VP-25 (with an external diameter of 32 mm [1-1/4 in])
for drain piping.
• Ensure that collected pipes are 10 cm [3-15/16 in] lower than the unit body's drain
port.
• Do not provide any odor trap at the drain discharge port.
• Put the end of the drain piping in a position where no odor is generated.
12
Compound pressure gauge
-0.101MPa
(for R410A)
(-760 mmHg)
Pressure gauge
(for R410A)
Gauge manifold valve
(for R410A)
Handle
Low
Handle High
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 [23 ft]
Charge the prescribed
amount of gas.
Leak test
• Do not put the end of the drain piping in any drain where ionic gases are generated.
[Fig. 6-5-1] (P.4)
Correct piping
Wrong piping
A Insulation (9 mm [3/8 in] or more)
B Downward slope (1/100 or more)
C Support metal
K Air bleeder
L Raised
M Odor trap
Grouped piping
D O. D. ø32 mm [1-1/4 in] PVC TUBE
E Make it as large as possible. About 10 cm [3-15/16 in].
F Indoor unit
G Make the piping size large for grouped piping.
H Downward slope (1/100 or more)
I O. D. ø38 mm [1-1/2 in] PVC TUBE for grouped piping. (9 mm [3/8 in] or more insulation)
J Up to 700 mm [27-9/16 in]
N Drain hose (accessory)
O Horizontal or slightly upgradient
1. Insert the drain hose (accessory) into the drain port (insertion margin: 25mm
[1 in]).
(The drain hose must not be bent more than 45° to prevent the hose from
breaking or clogging.)
(Attach the hose with glue, and fix it with the band (small, accessory).)
2. Attach the drain pipe (O.D. ø32 mm [1-1/4 in] PVC TUBE PV-25, field supply).
(Attach the pipe with glue, and fix it with the band (small, accessory).)
3. Perform insulation work on the drain pipe (O.D. ø32 mm [1-1/4 in] PVC TUBE PV-
25) and on the socket (including elbow).
4. Check the drainage. (Refer to [Fig. 6-6-1])
5. Attach the insulating material (accessory), and fix it with the band (large,
accessory) to insulate the drain port.
[Fig. 6-5-2] (P.4)
A Indoor unit
B Tie band (accessory)
C Visible part
D Insertion margin
E Drain hose (accessory)
F Drain pipe (O.D. ø32 mm [1-1/4 in] PVC TUBE, field supply)
G Insulating material (field supply)
H Tie band (accessory)
I To be gap free. The joint section of the insulation material meet must be at the top.

6.6. Confirming drain discharge

 Make sure that the drain-up mechanism operates normally for discharge
and that there is no water leakage from the connections.
• Be sure to confirm the above in a period of heating operation.
• Be sure to confirm the above before ceiling work is done in the case of a new
construction.
1. Remove the water supply port cover on the same side as the indoor unit piping.
2. Fill water into the feed water pump using a feed water tank. In filling, be sure to put
the end of the pump or tank in a drain pan. (If the insertion is incomplete, water
may flow over the machine.)
3. Perform the test run in cooling mode, or connect the connector to the ON side of
SWE on the Indoor controller board. (The drain pump and the fan are forced to
operate without any remote controller operation.) Make sure using a transparent
hose that drain is discharged.
SWE SWE
connector
OFF ON OFF
<OFF> <ON>
4. After confirmation, cancel the test run mode, and turn off the main power. If the
connector is connected to the ON side of SWE, disconnect it and connect it to the
OFF side, and attach the water supply port cover into its original position. (Tighten
the screws of the water supply port cover to the torque of 2.0 ±0.2 N·m.)
SWE SWE
connector
OFF ON OFF
<ON> <OFF>
[Fig. 6-6-1] (P.5)
A Insert pump's end 2 to 4 cm [13/16 to 1-5/8 in].
B Remove the water supply port.
C About 2500 cc
D Water
E Filling port
F Screw
ON
ON