Mitsubishi Electric MXZ-3D54VA Installation Manual page 6

4. PURGING PROCEDURES, LEAK TEST, AND TEST RUN
4-1. PURGING PROCEDURES AND LEAK TEST
) Remove service port cap of stop valve on the side of the outdoor unit
gas pipe. (The stop valves are fully closed and covered in caps in
their initial state.)
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 5 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 the pointer of gauge
manifold valve remains in the same position. Confirm that pressure
gauge shows -0.0 MPa [Gauge] (-760 mmHg).
6) Remove gauge manifold valve quickly from service port of stop valve.
7) Fully open all stop valves on the gas pipe and the liquid pipe. Operat-
ing without fully opening lowers the performance and this causes
trouble.
8) Refer to -2., 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
affect performance of the air conditioner.
9) Tighten cap of service port to obtain the initial status.
0) L eak test
4-2. GAS CHARGE
Perform gas charge to unit.
) 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 condi-
tioner for cooling.
Note:
In case of adding refrigerant, comply with the quantity specified for the refrigerat-
ing cycle.
CAUTION:
When charging the refrigerant system with additional refrigerant, be sure to use
liquid refrigerant. Adding gas refrigerant may change the composition of the
refrigerant in the system and affect normal operation of the air conditioner. Also,
charge the liquid refrigerant 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.
4-3. REMOVING THE MAINTENANCE PANEL
The setting of Dip Switch on the outdoor control P.C. board can be
changed without removing the front panel.
Follow the procedures below to remove the maintenance panel and set
the Dip Switch.
1) Remove screw(s) which fix the maintenance panel.
2) Remove the maintenance panel, and perform necessary settings.
3) Install the maintenance panel.
Note:
Make sure to fix the maintenance panel securely. Incomplete installation
could cause malfunction.
En-5
Stop valve cap
*4 to 5 turns
(Torque 9.6 to
29.4 N•m, 200
*Close
to 300 kgf•cm)
*Open
Hexagonal wrench
Service port cap
(Torque 3.7 to
7.7 N•m, 40 to
80 kgf•cm)
Stop valve
for GAS
Precautions when using
the control valve
Body
Close
A
Open
Control
Service port
valve
Charge hose
(for R40A)
Union
Union
Union
Union
Refrigerant gas
cylinder
operating valve
(for R40A)
Maintenance panel
Compound pressure
–0.0MPa
gauge (for R40A)
(–760 mmHg)
Pressure gauge
(for R40A)
Gauge manifold
valve (for R40A)
Handle High
Handle
Low
Charge hose
(for R40A)
Stop valve
Vacuum pump
for LIQUID
(for R40A)
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
Indoor Outdoor
unit
unit
Stop valve with
Gas
service port
pipe
* D unit is for
4D7VA only.
Gauge manifold
valve (for R40A)
Charge hose
(for R40A)
Refrigerant gas cylinder for R40A with siphon
Refrigerant (liquid)
Electronic scale for refrigerant charging