Installation, Operation and Maintenance Manual
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flare nuts on both field and factory furnished components. After completion of leak testing, release test pressure
and pull a vacuum on the system.
NOTICE
Tightening of fittings and valves is the responsibility of the installing
contractor.
NOTICE
With any fluid connection there is risk of leakage. Water leakage could
result in property damage to mission critical equipment. A water drain
connection is required. Units with optional steam generator humidifiers will
require an external potable water supply. Water leakage can result from
improper installation and/or practices.
Evacuation
Moisture prevents the proper operation of both the compressor and the refrigeration system. Air and moisture
reduce 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 air and moisture,
and it this condition can also lead to copper plating. All these phenomena may cause both mechanical and electrical
compressor failure. The typical method for avoiding such problems is to evacuate the system.
It is of the utmost importance that proper system evacuation and leak detection procedures be employed. Good
evacuation processes include frequent vacuum pump oil changes and large diameter, short hose connections to
both high and low sides of the system preferably using copper tubing or braided hose. All valves in the system, both
liquid line solenoid valve and Rotolock type service valves (if the compressor is equipped with them), need to remain
open during the vacuum process and the system must be purged of nitrogen. We recommend using a solenoid
magnet tool to hold the liquid line solenoid valve open. A deep vacuum gauge capable of registering pressure in
microns should be attached to the system for pressure readings. A shut-off valve between the gauge connection
and vacuum pump should be provided to allow the system pressure to be checked after evacuation. Do not turn off
vacuum pump when connected to an evacuated system before closing shut-off valve.
Triple evacuate the refrigerant lines, condenser coil and evaporator coil to 500 microns or lower (a micron gauge
and 2-stage vacuum pump are required).
3.10.1
Evacuation Procedures
Note:
Perform these procedures without contaminating the system with non-condensables
1.
Evacuate system down to 4000 microns from both service valves. Then close the manifold gauges, shut off the
vacuum pump and introduce dry nitrogen up to 5psi to the system without contaminating it. Then release the
nitrogen and restart the vacuum pump.
2.
Evacuate system down to 1500 microns from both service valves. Then close the manifold gauges, shut off the
vacuum pump and introduce dry nitrogen up to 5psi to the system without contaminating it. Then release the
nitrogen and restart the vacuum pump.
3.
Evacuate system down to 500 microns or below from both service valves.
4.
Turn off the vacuum pump and conduct a rise test waiting at least 30 minutes to make sure the micron gauge
reading does not go back above 500 microns. If it does, restart the vacuum pump and evacuate until the system