GE PTG440SAMR, Technician Service Manual

Page: 49 / 85

Page 49
XI. SPECIAL EDITION ON MAINTENANCE OF ENVIRONMENTAL PROTECTION
REFRIGERATOR
iii. Operational Sequence
a. Vacuum pump starts to
operate (to be stopped until
finishing the vacuum
extraction till to Point 13).
b. Open VB valve first and then
open LB, HB valves.
LB
VB
HB
1 2
3
L H
Open the valves by 1-2-3 sequence
c. Vacuum extraction (5 minutes)
d. After extracting vacuum for 5
minutes, close HB, VB valves
and leave LB valve open.
HB
L H
VB
e. Open CB valve and let 50g of
freon enter the freezing system
from LB side, the low pressure
gauge be kept at 3-4 kgf/cm 2
of pressure at this time.
f. Close both CB and LB valves.
g. Loosen the nut of connection
point A to discharge the air.
Confirm the balance of high,
low pressures.
Valve Regulation
L H
CB
LB
L H
CB
LB
L H
A