User Guide

Application guidelines
49AB237986441643en-US0701
The system must be monitored after initial start-
up for a minimum of 60 minutes to ensure proper
operating characteristics such as:
• Proper metering device operation and desired
super heat readings,
• Suction and discharge pressure are within
acceptable levels,
• Correct oil level in compressor sump indicating
proper oil return,
• Low foaming in sight glass and compressor
sump temperature 18°F above saturation
temperature to show that there is no refrigerant
migration taking place,
• Acceptable cycling rate of compressors,
including duration of run times,
• Current draw of individual compressors within
acceptable values (max. operating current),
• No abnormal vibrations and noise.
Commissioning
Oil level checking and
top-up
In installations with good oil return and line
runs up to 66 ft, no additional oil is required. If
installation lines exceed 66 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 but in any case
the oil charge has to be adjusted based on the oil
level in the compressor sight glass.
When the compressor is running under stabilized
conditions the oil level must be visible in the
sight glass.
The presence of foam lling in the sight glass
indicates large concentration of refrigerant in the
oil and / or presence of liquid returning to the
compressor.
The oil level can also be checked a few minutes
after the compressor stops.
When the compressor is o, the level in the
sight glass can be inuenced by the presence of
refrigerant in the oil.
Always use original Danfoss oil from new cans.
Compressor series Oil
SM Mineral oil 160P
SY P.O.E. 320 SZ
SZ P.O.E. 160 SZ
Top-up the oil while the compressor is idle. Use
the schrader connector or any other accessible
connector on the compressor suction line and
a suitable pump. See News bulletin “Lubricants
lling in instructions for Danfoss Commercial
Compressors”.
Installation