GE TBG440ANDR, Technician Service Manual

Page: 34 / 141

Page 34
VIII. MAINTENANCE OF ENVIRONMENTAL PROTECTION REFRIGERATOR
8.3.2 Reactions for HRC-134a
i. Upon welding the tube, blow with
nitrogen to avoid the capillary tube
clogging by the oxidized membrane.
ii. Aiming at the improvement of
vacuum degree for the vacuum
pump of pressure gauge, install
additional valves for the equipment
using bolt to keep non-condense air
from getting in.
iii. shorten the service time as indicated
in the figure.
Operate by the tubing type as shown
on the right side figure:
1 st time vacuum extracting (5 min.)
↓
Fill the freon in (50 gr)
↓
2 nd time vacuum extracting (20 min.)
↓
Fill the freon in (req’d amount)
iv. The tool cannot be used together
with the existing CFC-12. So the tool
must be re-ordered to avoid incorrect
use. Eact connectng part will be
changed from 1/4 inch to 3/8 inch.
Note :
• The tool used for HFC-134a
System must be exclusive,
such as the fast coupling,
vacuum pump, guide tube of
pressure gauge, valve, etc.
Use alcohol to clean the new
parts and the use of oil is
prohibited.
• Compressor
The dryer must be specially
used for HFC-134a and the
process from unpacking to
welding and vacuum
extracting must be completed
within 15 minutes.
• Cautions in case of freon
leakage of the freezing
system:
a. In case of freon leakage,
the entire set of
compressor and dryer
must be replaced.
b. The lower pressure side
and the higher pressure
side at the freon leakage
must be completed
exchanged.