Carrier 19XL - Manual (Page 216)

Check Pressure Transducers
Once a year, the pressure transducers should be checked against a pressure gage reading.
Check all three transducers: oil pressure, condenser pressure, cooler pressure.
Note the evaporator and condenser pressure readings on the Status01 table on the LID.
Attach an accurate set of refrigeration gages to the cooler and condenser Schrader fittings.
Compare the two readings. If there is a difference in readings, the transducer can be calibrated,
as described in the Troubleshooting Guide section.
Optional Pumpout System Maintenance
For compressor maintenance details, refer to the 06D, 07D Installation, Start-Up, and
Service Instructions.
CAUTION CAUTION
!
Loose power connections can cause voltage spikes, overheating, malfunction-
ing, or failures.