82
• Resistance of each leg to leg on three phase compressor or each leg to neutral on single
phase compressors.
• Check of continuity from each leg to ground.
• Review of all system alarms including the relative timing of the alarms and modes of operation.
It is important to note that other components or lines may have been damaged if the compressor
has failed. At times the internal damage to a compressor creates extreme levels of vibration before
complete failure. Refrigerant lines and connections may be damaged before the compressor stops.
Inspect tubing and components of the system before completing the compressor replacement.
Compressor Replacement
• Refrigeration oil must be tested for acid and particulate during any compressor
replacement. For the initial testing, the compressor sump should be used to sample the
oil. Oil can be recovered through the Schrader port on the low point compressor shell or
through the suction line connection after the compressor has been removed.
• Use Virginia KMP, New-Calgon Phase III, Sporlan Test-All, or equivalent oil test where oil
is sampled into a container. Vapor sampling methods may not show particulate and should
not be used.
• Read the oil test kit manufacturer’s instructions to determine if there is acid present in the
oil. Determine if there are other contaminants by viewing the samples for darkness,
cloudiness, or particulate.
The following procedures must be used depending on the results of the test above:
Any Compressor Service
• A new filter dryer must be installed when the system has been opened. See Section 5.6
for component replacement. If there is no acid or particulates indicated, the new
compressor can be installed and run. Proceed to Testing and Final Diagnosis.
Acid Indicated
• Install a suction line filter shell and charcoal activated core such as Sporlan or Emerson
HH core type or equivalent. The acid levels will be monitored and several core changes
may be required. Install ball valves on either side of the suction filter to facilitate these
changes. Note that larger Desert Aire systems will have suction filter shells installed from
the factory. The shell can be used with charcoal activated cores. Note that a “safety
screen” may be required with some manufacturer’s cores to prevent small pieces of the
core from dislodging and finding their way to the compressor. Follow filter shell and core
manufacturer’s instructions.
• Review compressor and suction line for area where future oil samples can be taken from
the system. If an access fitting exists on the compressor shell below the oil level, no further
action is needed. If this is not available, an access fitting can be located at the bottom of a
trap in the suction line. Braze in a fitting as required to be able to remove an oil sample.
• Ensure there are access fittings directly upstream and downstream of the suction filter.
There is typically one fitting installed on the suction filter. There may be a bulkhead fitting
attached to the compressor suction side.
Desert Aire - SP Manual
Summary of Contents for SelectAire Plus SP Series
Page 2: ...2 ...
Page 12: ...12 Desert Aire SP Manual ...
Page 76: ...76 Figure 41 Filter Drier Assembly Desert Aire SP Manual ...
Page 101: ...101 Desert Aire SP Manual ...
Page 102: ...102 Desert Aire SP Manual ...
Page 103: ...103 Desert Aire SP Manual ...
Page 104: ...104 Desert Aire SP Manual ...
Page 105: ...105 Desert Aire SP Manual ...
Page 106: ...106 Desert Aire SP Manual ...
Page 109: ...109 Desert Aire SP Manual ...
