To calibrate oil pressur e differential on op en-drive machines, ref er to Oil Pressure Dif ferential
Calibration at the end of t his s ec t ion.
Calibration can b e checked by com paring the pressu re readings fro m the transducer against
an accurate refriger at ion gage. These readi ngs ar e all viewed or calibrat ed from the Status01
table on the LID. The tran s duc e r can be checked and cali brated at 2 pressure po int s. These
calibration point s are 0 ps ig (0 kPa) and between 240 an d 260 psig (1655 to 1793 kP a) . To
calibrate these tran s duc e rs:
1. Shut down the compressor.
2. Disconnect the tran s duc e r in question from it s Sch r ade r fitting.
Note: If the cooler or condense r ve s s els ar e at 0 psig (0 kPa) or are open t o at mospheric pres-
sure, the transducers can be calibrated for zero without removing the transducer from
the vessel.
3. Access the Status01 table, and view the particular transducer reading; it should read 0 psi
(0 kPa). If the reading is not 0 p si (0 kPa), but within ± 5 psi (35 kPa), the value may be
zeroed by pressing th e SELECT softkey whil e the highlight bar is located on the transduc er,
and then by pressing the ENTER. The value will no w go t o zero.
If the transducer val ue is not within the calibr a tion range, the trans du cer will return to the
original readin g. If the L ID pressure va lue is within t he allowed ra nge (noted ab ove), check
the voltage ratio of the t ransducer. To obtain the voltage ratio, divid e the voltage (dc) inp ut