Johnson Controls Frick PowerPac, Установка, эксплуатация и обслуживание

Страница: 13 / 24

FRICK
®
POWERPAC ™
INSTALLATION
170.600-IOM (JUN 11)
Page 13
PURGING THE SYSTEM
Purging of air or other noncondensable gases is required
in order to keep high performance of the system and avoid
corrosion of the equipment which could endanger the safety
of persons and equipment.
When purging a refrigeration system, make sure to observe
the following:
• Refrigerants must not be released into the atmosphere
except CO
2
, which can be released slowly into the atmo-
sphere.
• When purging an R-717 system, use an approved air purg-
er. The purged air must pass through an open container of
water for any remaining R-717 to be absorbed. The water
mixture must be sent to an authorized incineration plant.
• Halocarbon refrigerants (CFC, HCFC and HFC) cannot be
absorbed by water. An approved air purger must be fitted
to the system. This must be checked regularly by use of a
leak detector. All precautionary measures practicable must
be taken to prevent and minimize leakage of refrigerant
from refrigeration and air conditioning systems to the
atmosphere.
NOTE: The occurrence of air is usually an indication of
poor maintenance or lack of thoroughness at installation.
If the chiller contains air, it tends to gather on the high
pressure side of the system.
NOTE: R-717 systems should be purged on a regular basis
to avoid atmospheric air and other noncondensable gases.
AUTOMATIC OIL RETURN SYSTEM
The small amount of oil leaving the compressor unit with
the discharge gas is eventually collected at the bottom of
the evaporator if the refrigerant is ammonia. A reservoir is
mounted in this location. This oil is automatically returned
to the compressor. Oils used with halocarbons are skimmed
from the surge drum, then returned to the compressor.
The float switch controls solenoid valves M1 and M2 (shown
in Figure 10). With a rising oil level, the built-in reed switch
will activate the solenoid valves. The oil is conveyed to the
compressor suction line by means of the hot gas ejector E1.
With a falling oil level, the solenoid valves will close.
Figure 10