Water Utilising Systems; Loss Of Charge Protection; Oil Level Checking And Top-Up - Danfoss VRJ Application Manuallines

Application Guidelines

Water utilising systems

Loss of charge protection

Oil level checking and
top-up
System design recommendations
Apart from residual moisture in the system
after commissioning, water could also enter the
refrigeration circuit during operation. Water in
the system shall always be avoided. Not only
because it can shortly lead to electrical failure,
sludge in sump and corrosion but in particular
because it can cause serious safety risks.
Common causes for water leaks are corrosion and
freezing.
Corrosion: Materials in the system shall be
compliant with water and protected against
corrosion.
VRJ scroll compressors together with the variable
speed drive include a loss of charge protection
function. This protection is ensured if pressure
In installations with good oil return and line
runs up to 50 ft, no additional oil is required. If
installation lines exceed 50 ft, additional oil may
be needed. 1 or 2% of the total system refrigerant
charge (in weight) can be used to roughly de ne
the required oil top-up quantity.
Freezing: When water freezes into ice its volume
expands which can damage heat exchanger
walls and cause leaks. During o periods water
inside heat exchangers could start freezing when
ambient temperature is lower than 32°F. During
on periods ice banking could occur when the
circuit is running continuously at too low load.
Both situations should be avoided by connecting
a pressure and thermostat switch in the safety
line.
and temperature sensors are connected to the
drive.
Always use oil from new cans.
Top-up the oil while the compressor is idle. Use
any accessible connector on the compressor
suction line and a suitable pump.
AB141686422149en-US0401
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