Data Aire gForce Ultra, Installation, Operation & Maintenance Manual

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gForce Ultra IOM
67
Additional Oil
When charging is complete, add the correct amount of oil to each circuit. In installations with good oil
return and line runs up to 50 ft (15 m), no additional oil is required. If installation lines exceed 50 ft (15
m), additional oil needs to be added. Add 1 or 2% of the total system refrigerant charge (in weight) can
be used to roughly define the required oil top-up quantity.
Top-up the oil while the compressor is idle. Use any accessible connector on the compressor suction
line and a suitable pump. ALWAYS use clean original Danfoss POE oil 160SZ or equivalent from new
cans.
After charging, verifying subcooling and oil level. Close the valve on the refrigerant manifold gauge set
and close the service valve on the refrigerant tank and disconnect the refrigerant manifold gauge set.
Commissioning a Running Compressor
The system must be monitored after initial startup for a minimum of 60 minutes to ensure proper operating
characteristics, such as:
•
Check the current draw of compressor is within acceptable values.
•
Check the suction and discharge pressures are within acceptable levels.
•
Check for proper EEV operation and desired superheat readings.
•
Check the superheat to reduce risk of slugging.
•
Observe the oil level in compressor sump at startup and during operation to confirm that the
oil level remains visible and indicating proper oil return.
✓
Excess foaming in oil sight glass indicates refrigerant on the sump.
•
Monitor the oil sight glass for 1 hour after system equilibrium to ensure proper oil return to
the compressor. This oil check must be done over the full speed range of the compressor to
guarantee:
✓
A good oil return at low speed with minimum gas velocity.
✓
A good oil management at high speed with maximum oil carry over.
✓ Low foaming in sight glass and compressor sump temperature 10⁰ F above
saturation temperature to show there is no refrigerant migration taking place.
•
Acceptable cycling rates of compressors, including duration or run times.
•
Check all piping for abnormal vibration or noise. Movements in excess of 1.5 mm require
corrective measures such as piping braces or brackets.
•
When needed, add refrigerant.
•
Do not overcharge the system.
•
Record type and amount of refrigerant charge as well as operating conditions as a reference
for future inspections.
•
Short cycling protection is provided in the VFD)
. It is factory preset “Enabled” with default
parameters. The minimum run time is set to ensure long enough running time at start up in
order to create enough refrigerant flow velocity in the system to recover the oil to the
compressor sump.