Drain Piping Work - Mitsubishi Electric Mr.Slim PEAD-A24 Installation Manual

6. Refrigerant piping work
Refrigerant pipe insulation
• After connecting refrigerant piping, insulate the joints (flared joints) with thermal
insulation tubing as shown below.
[Fig. 6-9] (P.3)
A Pipe cover (small) (accessory)
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 Pipe cover (large) (accessory)
I Pull
K Return to original position
M Plate on main body
O 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
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 -0.101MPa
(-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.
16
D Gas end of refrigerant piping
F Main body
H Thermal insulation (field supply)
J Flare nut
L Ensure that there is no gap here
N Band (accessory)
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
Vacuum (or the 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.
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 pre-
vent 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.
• Do not put the end of the drain piping in any drain where ionic gases are generated.
[Fig. 6-10] (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 550 mm [21-11/16 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 break-
ing 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. 6-12])
5.Attach the insulating material (accessory), and fix it with the band (large, acces-
sory) to insulate the drain port.
[Fig. 6-11] (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.
Leak test