Troubleshooting Two Vacuum Problems, 2003 Fall Technical Conference

In both cases presented, problems associated with condensers and vacuum systems are examined. These cases were chosen to illustrate how two completely separate problems can exhibit quite similar symptoms and how a formalized approach can assist in obtaining an accurate diagnosis. Accurate troubleshooting requires good data, careful analysis and attention to detail. As illustrated by these two cases, the differences in symptoms of problems may be quite subtle, and knowing what data to collect can be as important as the interpretation of the data.

Because troubleshooting evaporator problems can be so esoteric, a formal logic tree was developed - a “troubleshooting chart”. For those of us who frequently are involved in troubleshooting evaporator problems, this organized approach has become instinctive. However, we have found that the discipline of a troubleshooting chart is quite useful to operating personnel by reducing some of the blind alleys that many times bedevil a troubleshooting situation.

Accurate troubleshooting requires accurate data. It is usually necessary to obtain vapor temperatures by converting vapor pressures into saturation temperatures. For this reason, the pressure readings are required to be as accurate as possible. The calculated temperatures are usually back checked with a hand held infrared temperature gun. Mill instrumentation is unusually inadequate for accuracy of data required. Therefore, it has been found expedient to provide our own portable instrumentation. Pressure data is usually collected with a Fluke Model 245 portable pressure transducer that plugs directly into a common volt-Ohm multimeter. We have found it advisable to back-check calculated temperatures with an infrared temperature gun. We use a Raytech RayngerST model.