faulty, check the supp ly v olt age. It should be 5 vdc ± .5 v. If the s up ply voltage is corre c t, th e
transducer shou ld be recalibrat ed or replaced.
Calibration can b e checked by compa ring the pressu re readings from t he transducer again st
an accurate refriger at ion gage. These readings ar e all viewed or calibrat ed f rom the Status01
table on the LID. The tran s duc e r can be checked and cali br at ed at 2 pressure points. These
calibration point s are 0 ps ig (0 kPa) and between 240 an d 260 psig (1655 to 1793 kPa). To
calibrate these tran s duc e rs:
1. Shut down the compressor.
2. Disconnect the tran s duc e r in question from its 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 to 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), t he value may be
zeroed by pressing th e SELECT softkey whil e the highlight bar is locat ed on the transducer,
and then by pressing the ENTER. The value will now go t o zero.
IMPORTANT: Wheneve r the oil pressure or the coo ler pressure transdu cer is cali-
brated, the other sensor should be calibrated to prevent problems with oil differential
pressure readings.