
44
5.
CHARGING
5.1.
Triple Evacuation and Dehydration Procedure
Data Aire highly recommends a triple evacuation to be carried out on all Data Aire units to ensure
the highest quality moisture removal. Moisture prevents the proper operation of both the
compressor and the refrigeration system. Non-condensable and moisture reduces service life
and increases condensation pressure, which causes abnormally high discharge temperatures
that can degrade the lubricating properties of the oil. The risk of acid formation is also increased
by non-condensable and moisture and this condition can also lead to copper plating. These
phenomena may cause both mechanical and electrical compressor failure. The typical method
for avoiding such problems is to triple evacuate the system.
It is of the utmost importance that proper system evacuation and leak detection procedures be
employed. Good evacuation includes frequent vacuum pump oil changes and large diameter,
short hose connections to both high and low sides of the system (all refrigerant lines, suction
line, discharge line and liquid line) preferably using copper tubing, vacuum rated or braided
hose.
All valves in the system, solenoid valves, electronic expansion valves, ball valves and service
valves (if the compressor is equipped), need to remain open during the vacuum procedures and
the system must be purged with nitrogen. We recommend using a solenoid magnet tool to hold
the liquid line solenoid valve(s) open during this procedure.
A deep vacuum gauge capable of registering pressure in microns must be attached to the system
on the liquid line service port before the EEV or TXV and should be at the farthest point in the
system for most accurate vacuum readings. A shut-off valve (suggest a Schrader valve core
removal tool) between the system and vacuum pump should be provided to allow the system
pressure to be checked after evacuation.
NOTE:
Do not turn OFF vacuum pump when connected to an evacuated
system before closing shut-off valve.
5.1.1. Tools Needed
•
Refrigerant manifold gauge set -
NOTE:
This manifold gauge set
should not be used
for the vacuum procedure
•
Vacuum rated hoses
•
Nitrogen bottle
•
Micron gauge
•
Schrader valve core removal tool
•
Two-Stage Vacuum Pump(s)