Purging Procedures, Leak Test, And Test Run - Mitsubishi Electric MSZ-GE24NA Installation Manual

3-3. PIPE CONNECTION
• Fasten flare nut with a torque wrench as specified in the table above.
• When fastened too tight, flare nut may eventually break 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 piping to indoor unit.
• Apply a thin coat of refrigeration oil (J) on the flared ends of the pipes. Do not apply re-
frigeration oil on screw threads. Excessive tightening torque will result in damage on the
screw.
• To connect, first align the center, then tighten the first 3 to 4 turns of flare nut.
• Use tightening torque table in (3-2.) as a guideline for indoor unit side joints, and tighten
using two wrenches. Excessive tightening damages the flare section.
Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit following the same procedure
detailed in Indoor unit connection.
• For tightening, use a torque wrench or spanner.
When installing the unit, securely connect the refrigerant pipes before starting the
compressor.
3-4. INSULATION AND TAPING
1) Cover piping joints with pipe cover.
2) For outdoor unit side, insulate the piping, including valves.
3) Apply piping tape (G) starting from the connection on the outdoor unit.
• When piping has to be installed through a ceiling, closet or where the temperature and
humidity are high, use additional field-supplied insulation to prevent condensation.

4. PURGING PROCEDURES, LEAK TEST, AND TEST RUN

4-1. PURGING PROCEDURES AND LEAK TEST
1) Remove service port caps from stop valves on both sides of refrigerant lines. (The stop
valves are fully closed when shipped.) Leave closed.
2) Connect gauge manifold to ports of stop valves.
3) Evacuate the system to 4000 microns from both service valves. System manifold gaug-
es must not be used to measure vacuum. A micron gauge must be used at all times.
Break the vacuum with Nitrogen(N2) into the discharge service valve to 0 PSIG.
4) Evacuate the system to 1500 microns. Break the vacuum with Nitrogen(N2) into the dis-
charge service valve to 0 PSIG.
5) Evacuate the system to 500 microns.
6) Close gauge manifold valves, stop the pump, and conduct a 30 minute rise test.
7) System should hold 500 microns for a minimum of 1 hour.
8) Fully open all stop valves on both sides of gas pipe and liquid pipe. Operating without
fully opening lowers the performance and this causes trouble.
9) Refer to 1-3 and charge the prescribed amount of additional refrigerant if needed. Be
sure to charge slowly with liquid refrigerant. Otherwise composition of the refrigerant in
the system may be changed and affect performance of the air conditioner.
10) Remove gauge manifolds and replace service port caps and tighten.
11) Leak test
4-2. TEST RUN
1) Insert power supply plug into the power outlet and/or turn on
the breaker.
2) Press the E.O. SW once. Test run will be performed for 30
minutes. If the upper operation indicator light blinks every
0.5 seconds, inspect the indoor/outdoor unit connecting wire
(A). After the test run, emergency COOL mode (75°F [24°C]
COOL) will start.
3) To stop operation, press the E.O. SW several times until all
LED lamps turn off. Refer to operating instructions for de-
tails.
Checking the remote (infrared) signal reception
Press the ON/OFF button on the remote controller and listen for an audible indicator 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.
4-3. AUTO RESTART FUNCTION
This product is equipped with an auto restart function. When the power supply is cut off
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.)
WARNING
Emergency
operation switch
(E.O. SW)
Stop valve cap
*4 to 5 turns
(Torque 15 to
22 ft-lb, 19.6 to
*Close
29.4 N•m, 200
*Open
to 300 kgf▪cm)
Stop valve for LIQUID
Hexagonal wrench
Service port cap
(Torque 10 to 13 ft
-Ib, 13.7 to 17.7 N•m,
140 to 180 kgf•cm)
Precautions when using the control valve When attaching the control valve
Service port
A
Control valve
Open
Close Charge hose
Body
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. If this procedure is
not performed, the unit will automatically begin operation when power supply is
resumed.
To the user
• After installing the unit, explain to 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.
4-4. EXPLANATION TO THE USER
• Using the OPERATING INSTRUCTIONS, explain to the user how to use the air
conditioner (the remote controller, removing the air filters, placing or removing the re-
mote controller from the remote controller holder, cleaning methods, precautions for
operation, etc.)
• Recommend that the user read the OPERATING INSTRUCTIONS carefully.
Compound pressure gauge
–14.7 psi [Gauge]
(for R410A)
(–0.101 Mpa)
Pressure gauge
(for R410A)
Gauge manifold
valve (for R410A)
Handle
Handle High
Low
Charge hose
Stop valve for
(for R410A)
GAS
Adapter for prevent-
ing the back flow
Vacuum pump (or the vacuum
pump with the function to
prevent the back flow)
to the service port, valve core may
deform or loosen if excess pressure
is applied. This may cause gas leak.
When attaching the control valve to
the service port, make sure that the
valve core is in closed position, and
then tighten part A. Do not tighten
part A or turn the body when valve
core is in open position.