Purging Procedures, Leak Test, And Test Run - Mitsubishi Electric MXZ-3A54VA Installationsanleitung

3-2. PIPE CONNECTION
• Fasten flare nut with a torque wrench as specified in the table.
• When fastened too tight, flare nut may brake after a long period and
cause refrigerant leakage.
Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit in the same
manner applied for indoor unit.
• For tightening, use a torque wrench or spanner and use the same
tightening torque applied for indoor unit.
3-3. INSULATION AND TAPING
1) Cover piping joints with pipe cover.
2) For outdoor unit side, surely insulate every piping including valves.
3) Using piping tape (E), apply taping starting from the entry of outdoor
unit.
• Stop the end of piping tape (E) with tape (with adhesive agent at-
tached).
• When piping have to be arranged through above ceiling, closet or
where the temperature and humidity are high, wind additional com-
mercially sold insulation to prevent condensation.

4. PURGING PROCEDURES, LEAK TEST, AND TEST RUN

4-1. PURGING PROCEDURES AND LEAK TEST
1) Remove service port cap of 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.)
2) Connect gauge manifold valve and vacuum pump to service port of
stop valve on the gas pipe side of the outdoor unit.
3) Run the vacuum pump. (Vacuumize for more than 15 minutes.)
4) Check the vacuum with gauge manifold valve, then close gauge
manifold valve, and stop the vacuum pump.
5) Leave as it is for one or two minutes. Make sure pointer gauge mani-
fold valve remains in the same position. Confirm that pressure gauge
shows –0.101 MPa [Gauge] (–760 mmHg).
6) Remove gauge manifold valve quickly from service port of stop
valve.
7) After refrigerant pipes are connected and evacuated, fully open all
stop valves on both sides of gas pipe and liquid pipe. Operating with-
out fully opening lowers the performance and this causes trouble.
8) Refer to 1-4., and charge the prescribed amount of refrigerant if
needed. Be sure to charge slowly with liquid refrigerant. Otherwise,
composition of the refrigerant in the system may be changed and af-
fect performance of the air conditioner.
9) Tighten cap of service port to obtain the initial status.
10) Leak test
4-2. GAS CHARGE
Perform gas charge to unit.
1 Connect gas cylinder to the service port of stop valve.
2 Perform air purge of the pipe (or hose) coming from refrigerant gas
cylinder.
3 Replenish specified amount of the refrigerant, while operating the air
conditioner for cooling.
Note:
In case of adding refrigerant, comply with the quantity specified for the
refrigerating cycle.
CAUTION:
When charging the refrigerant system with additional refrigerant, be sure
to use liquid refrigerant. Adding gas refrigerant may change the composi-
tion of the refrigerant in the system and affect normal operation of the air
conditioner. Also, charge the system slowly, otherwise the compressor
will be locked.
To maintain the high pressure of the gas cylinder, warm the gas cylinder
with warm water (under 40°C) during cold season. But never use naked
fire or steam.
6
*4 to 5 turns
Stop valve cap
(Torque 19.6 to
29.4 N•m, 200
*Close
to 300 kgf•cm)
*Open
Hexagonal wrench
Service port cap
(Torque 13.7 to
17.7 N•m, 140 to
180 kgf•cm)
Stop valve
for GAS
Precautions when using
the control valve
Body
Close
A
Open
Control
Service port
valve
Charge hose
(for R410A)
Union
Union
Indoor
unit
Union
Union
Refrigerant gas
cylinder
operating valve
(for R410A)
Gauge manifold
valve (for R410A)
Charge hose (for R410A)
Refrigerant gas cylinder
for R410A with siphon
Refrigerant (liquid)
Electronic scale for
refrigerant charging
Compound pressure
–0.101MPa
gauge (for R410A)
(–760 mmHg)
Pressure gauge
(for R410A)
Gauge manifold
valve (for R410A)
Handle High
Handle
Low
Charge hose
(for R410A)
Stop valve
Vacuum pump
for LIQUID
(for R410A)
When attaching the control valve to
the service port, valve core may de-
form 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.
Stop valve
Liquid pipe
Outdoor
unit
Stop valve with
service port
Gas pipe