Installation issues with compressor displacement probes
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I would like to ask the teachers: regarding the compressor, what is the relationship between the shaft’s play and the calculations related to the displacement probe when installing it? Thank you
What is the calculation relationship between the shaft runout and the displacement probe? Generally, it works like this: for example, if the displacement is 20 units, then the shaft is pushed to 10 units, and after that the probe can be installed
20 units correspond to 0.2 millimeters. The BENTLY probe generates 7.87 V per millimeter; by measuring the output voltage of the preamplifier at both the nearest and farthest positions of the shaft, and dividing the difference between these two voltages by 7.87, the resulting value gives the gap size. If this value matches the mechanical play, it indicates that the probe is installed correctly. Then, by measuring the preamplifier’s output voltage when the shaft is in the middle position, if the value is 9.75 V, it means the displacement probe is properly installed.
Generally, the displacement probe is installed in the middle position; therefore, for a 20-channel serial configuration, the fitter must first reach channel 10 before installing the probe, with the installation voltage kept around 10V. If the fitter is unable to adjust it to the middle position, we can still proceed with the installation; for example, if the fitter can only adjust it to a closer position, the voltage can be adjusted accordingly. For instance, 7.87×0.1=0.787V, and 10–0.787=9.213V. Thus, the installation voltage should be set around 9.213V. If it can only be powered at the remote end, then the voltage will be 10 + 0.787 = 10.787 V; therefore, the installation voltage should be kept around 10.787 V.
Support for upstairs; the axis remains centered during displaced installation.