Gas Charge - Mitsubishi Electric MXZ-2B20NA Installation Manual

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 t5 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(-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 1-3., 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 to 5 turns
*Close
Hexagonal wrench
Service port cap
(Torque 13.7 to
17.7 N.m, 140to
180 kgf.cm, 10 to
13 ff.lb)
Stop valve cap
(Torque 19.6 to
29.4 N.m, 200 to
300 kgf.cm, 15 to
22 ft.tb)
Stop valve Stop valve
for GAS for LIQUID
0.101MPa Compound pressure
[-760 mmHg gauge (for R410A)
(-30 in.Hg)]
Pressure gauge
R410A)
e manifold
valve (for R410A)
igh
Low e hose
(for R410A)
Vacuum pump
(for R410A)
Precautions when usingJ
the control valve
When attachinq the control valve to
the service_ valve core may de-
form or loosen if excess pressure is
applied. This may cause qas 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.
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(140°F)] during cold season. But never use
naked fire or steam.
Indoor
unit
Refrigerant gas i
cytinder
operating valve
(for R410A) _
Union
Stop valve
------------[_D_ Liquid pipe
] Union
Union
Stop valve with
service port
--______ Gas pipe
Union
_"'-._ Ga uge manifold
valve (for R410A)
(__ _ Charge hose (for R410A)
Refrigerant gas cylinder
for R410A with siphon
_'-- Refrigerant (liquid)
LC:/___ _ Electronic scale for
refrigerant charging
Outdoor
unit
7