Maintenance Data; Servicing - Mitsubishi Heavy Industries SRK25GZ-L1 Handbook

FDT ( N ) -H
8.6

MAINTENANCE DATA

8.6.1 Servicing

(1) Evacuation
The evacuation is a procedure to purge impurities, such as noncondensable gas, air, moisture from the refrigerant equipment by
using a vacuum pump. Since the refrigerant R22 and R407C is very insoluble in water, even a small amount of moisture left in the
refrigerant equipment will freeze, causing what is called ice clogging.
Evacuation procedure
Make sure that the both service valves of gas and liquid line are fully opened.
(a) Check to ensure that there is no internal pres-
sure in the unit. If there is an internal pres-
sure, it should be relived through the service
port.
(b) Connect the charging hose of the gauge mani-
fold to the service port of the gas piping.
Close high pressure valve 2 of gange mani-
fold.
(c) Connect the charging hose A to a vecuum
pump.
Repeat evacuation in the following sequence.
Start the vacuum pump.
Compond pressure gauge indicates -0.1 MPa (-76 cmHg)
Operate the vacuum pump for more than 10 minutes after -0.1MPa
(-76 cmHg) Hg is indicated.
Close low pressure valves 1 of gauge manifold.
Stop the vacuum pump.
Notes (1) Do not use the refrigerant pressure to expel air.
(2) Do not use the compressor for evacuation.
(3) Do not operate the compressor in a vacuum condition.
348
h
h
h
h
Outdoor unit
Flare connection
Service hoses
Charging hose
A
Vacuum
pump
Notes (1) Refer to the exterior-view drawing for the position
of the service valve.
(2) When connecting of the service valve, flare con-
nection for both the indoor and outdoor unit.
Indoor unit
Liquid line
Gas line
service port
Lo Hi
1 2
Gauge
manifold
3
Refrigerant
cylinder