Flare Connection, Pipe Connection; Test Run; Auto Restart Function - Mitsubishi Electric MFZ-KT25VG Installationsanleitung

3. FLARE CONNECTION, PIPE CONNECTION

3-1. FLARING WORK
1) Cut the copper pipe correctly with pipe cutter. (Fig. 1, 2)
2) Completely remove all burrs from the cut cross section of pipe. (Fig. 3)
• Put the end of the copper pipe to downward direction as you remove burrs in order
to avoid to let burrs drop in the piping.
3) Remove flare nuts attached to indoor and outdoor units, then put them on pipe having
completed burr removal. (Not possible to put them on after flaring work.)
4) Flaring work (Fig. 4, 5). Firmly hold copper pipe in the dimension shown in the table.
Select A mm from the table according to the tool you use.
5) Check
• Compare the flared work with Fig. 6.
• If flare is noted to be defective, cut off the flared section and do flaring work again.
Clutch
Pipe diameter Nut
type tool
(mm) (mm)
for R32,
R410A
ø6.35 (1/4") 17
ø9.52 (3/8") 22
0 to 0.5
ø12.7 (1/2") 26
ø15.88 (5/8") 29
3-2. PIPE CONNECTION
• Fasten flare nut with a torque wrench as specified in the table.
• When fastened too tight, flare nut may break after a long period and cause refrigerant
leakage.
• Be sure to wrap insulation around the piping. Direct contact with the bare piping may
result in burns or frostbite.
Indoor unit connection
Connect both liquid and gas pipings to indoor unit.
• Apply a thin coat of refrigeration oil (K) on the flared ends of the pipes. Do not apply
refrigeration oil on screw threads. Excessive tightening torque will result in damage
on the screw.
• For connection, first align the center, then tighten the first 3 to 4 turns of flare nut, by
hand.
• Use tightening torque table above as a guideline for indoor unit side union joint section,
and tighten using two wrenches. Excessive tightening damages the flare section.
Reusable mechanical connectors and flared joints are not allowed indoors.
When connecting the refrigerant piping by brazing, rather than using flare con-
nections, complete all brazing prior to connecting indoor unit to outdoor unit.

4. TEST RUN

4-1. TEST RUN
Make sure the following is done.
• Panel is installed correctly.
• Indoor and outdoor units are installed correctly, and power is supplied.
1) Press the E.O. SW once for COOL, and twice for HEAT operation. Test run will be performed for 30 minutes. If the left lamp of the opera-
tion indicator blinks every 0.5 seconds, inspect the indoor/outdoor unit connecting wire (A) for mis-wiring. After the test run, emergency
mode (set temperature 24ºC) will start.
2) To stop operation, press the E.O. SW several times until all LED lamps turn off. Refer to operating instructions for details.
Checking the remote (infrared) signal reception
Press the ON/OFF button on the remote controller (12) and check that an electronic sound is heard from the indoor unit. Press the ON/
OFF button again to turn the air conditioner off.
• Once the compressor stops, the restart preventive device operates so the compressor will not operate for 3 minutes to protect the air
conditioner.

4-2. AUTO RESTART FUNCTION

This product is equipped with an auto restart function. When the power supply is stopped during operation, such as during blackouts, the function automatically
starts operation in the previous setting once the power supply is resumed. (Refer to the operating instructions for details.)
Caution:
• After test run or remote signal reception check, turn off the unit with the E.O. SW or the remote controller before turning off the power supply. Not doing so will
cause the unit to start operation automatically when power supply is resumed.
To the user
• After installing the unit, make sure to explain the user about auto restart function.
• If auto restart function is unnecessary, it can be deactivated. Consult the service representative to deactivate the function. Refer to the service manual for details.
4-3. EXPLANATION TO THE USER
• Using the OPERATING INSTRUCTIONS, explain to the user how to use the air conditioner (how to use the remote controller, how to remove the air filters, how to
remove or put the remote controller in the remote controller holder, how to clean, precautions for operation, etc.)
• Recommend the user to read the OPERATING INSTRUCTIONS carefully.
A (mm) Tightening torque
Clutch Wing nut
type tool type tool N•m
for R22 for R22
13.7 to 17.7
1.5 to 2.0
34.3 to 41.2
1.0 to 1.5
2.0 to 2.5 49.0 to 56.4
- 73.5 to 78.4
WARNING
Copper pipe
Burr
kgf•cm
140 to 180
Die
350 to 420
Flare nut
500 to 575
Fig. 5
750 to 800
When installing the unit, securely
connect the refrigerant pipes be-
fore starting the compressor.
No good
Good
Copper
pipe
Tilted Uneven Burred
Fig. 1
Fig. 2
Flaring tool
Spare reamer
Pipe cutter
Fig. 3
Clutch type
Fig. 4
Smooth all
Inside is shining
around without any
scratches.
Copper
pipe
Even length
all around
Fig. 6
WARNING
Emergency operation
switch (E.O. SW)
Wing nut type
EN
EN-8