Mitsubishi Electric MXZ-3A30NA Installation Manual page 8

4-1. PURGING PROCEDURES AND LEAK TEST
4) 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 mani-
fold 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 (~30 in. Hg).
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.
4 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 (140°F)] during cold season. But never use
naked fire or steam.
"Open 22 ftelb)
Hexagonal! wrench
70. 101MPa Compound pressure
[-760 mmHg
4 to 5 turns Stop vaive cap (-30in. Hg)] gauge (for R410A)
(Torque 19.6 to 29.4 Nem,
Pressure gauge
*Close 200 to 300 kgfcm, 15 to
6 (for R410A)
Gauge manifold
valve (for R410A)
Stop valve
for GAS
/
Service port cap Pea
(Torque 13.7 to
17.7 Nem, 140 to
180 kgfcm, 10 to
13 ft*lb) Vacuum pump
top valve (for R410A)
for LIQUID
Precautions when using When attaching the control valve to
the service port. valve core may de-
the control valve
form or loosen if excess pressure is
applied. This may cause gas leak.
Control
val ven
Pe & Service port When attaching the control valve to
cna the service port, make sure that the
valve core is in closed position, and
then tighten part A. Do not tighten
Charge hose Part A or tum the body when vaive
Body (forR410A) core is in open position.
REA EN
Stop valve
Liquid pipe
Outdoor unit
(MXZ-4A36NA)
Stop valve with
service port
Gas pipe
Refrigerant gas
cylinder
operating valve
(for R410) \
~+— Refrigerant gas cylinder
for R410A with siphon
Refrigerant (liquid)
LJ ~— Electronic scale for
refrigerant charging