Hitachi FSG Series, Technical Catalogue

Page: 309 / 424

REFRIGERANT PIPING AND REFRIGERANT CHARGE
13
/33
§
Do not remove sealing caps for the pipes until the pipes
are installed and connected.
Install the dryer lower than the main liquid line and within the
angle shown below.
§
Cover the dryer and liquid valve with the factory-supplied
thermal insulator. Perform thermal insulation work by
using factory-supplied tape to avoid any clearance.
Do not remove sealing caps before connecting.
§
Procedures for Installation
1. Check to ensure that the liquid stop valve in the
outdoor unit is completely stopped.
2. Insert the flare nut of the dryer in the liquid line and
expand the liquid pipe for the dryer.
3. Fix the optional dryer and liquid valve by using the flare
nuts.
4. Check to ensure that no leakage occurs by applying an
airtight test pressure of 3.3 MPa.
5. Open the optional liquid valve fully.
6. Perform vacuum pumping for 1 to 2 hours down to.
7. Charge additional and specified refrigerant.
8. Open the spindle of the liquid stop valve in the outdoor
unit.
9. Perform a trial operation in order to collect moisture
into the dryer.
?
NOTE :
The collecting time depends on the level of the
moisture. It is recommended that total operation
hour be 45 hours.
10. If the sight-glass indicates green, collecting moisture
work is completed. However, the color is yellow,
proceed with the following processes.
11. Completely close the optional valve and the liquid
stop valve.
12. Remove the dryer. Pay a special attention to the
connections, since liquid refrigerant is discharged.
13. Mount a new dryer and perform vacuum pumping
from the check joint at the liquid stop valve in the
outdoor unit.
14. If the vacuum degree lower than –756 mmHg is
available, stop the vacuum pumping work. If not,
continue the vacuum pumping work.
Main Liquid Line
Within this angle
Sight-glass
Liquid Stop Valve
Incorrect
Dryer
Flare-Nut
Liquid Valve
Flare-Nut
Brazing
(only D-P30V)
Dryer
Seal the ends