On the display
The panel prints SYS X YYYYYYYY SENSOR FAILURE: ZZZZZZZZZZZZ. SYS X is the system number. YYYYYYYY shows either FAULT or LOCKOUT. ZZZZZZZZZZZZ names the failed sensor: SUCT PRESS, OIL PRESS, DSCH PRESS, LEVEL SENSOR, or MOTOR TEMP X.
What it means
The manual calls this the Sensor Failure Cutout Fault, one of the unit's system safeties. A critical sensor — a transducer, the level sensor, or a motor winding temp sensor — is not functioning properly or reading out of range. The check runs at start-up and prevents the system from running if one of the sensors has failed; on a running system, it faults and shuts the system down if a safety threshold is exceeded or a sensor reads out of range, high or low.
Why it appears
- A critical sensor — a transducer, the level sensor, or a motor winding temp sensor — has failed.
- The sensor is reading out of range, high or low, against its start-inhibit threshold.
What to check
- Read the ZZZZZZZZZZZZ field on the display to identify the failed sensor: SUCT PRESS, OIL PRESS, DSCH PRESS, LEVEL SENSOR, or MOTOR TEMP X.
- Compare that sensor's reading with the start-inhibit range the manual lists for it (see the thresholds below) — a reading outside that range is the out-of-range condition this fault responds to.
- If the failed sensor is a motor temperature sensor, note that the Unit Setup Mode allows a specific motor temperature sensor to be ignored if it fails.
Setpoints and thresholds
Start-inhibit sensor thresholds from the fault table:
- Suction transducer: 0.3-4.7 VDC
- Oil transducer: 0.3-4.7 VDC
- Discharge transducer: 0.3-4.7 VDC
- Level sensor: 3.0-21.0 mA
- Motor temp sensor: 0-240°F
- Lockout: after 3 faults in 90 minutes
Reset and restart
With FAULT in the YYYYYYYY field, the system restarts when the fault clears — the fault table gives auto-restart after the 120 second anti-recycle timer. After 3 faults the display changes to LOCKOUT: a lockout will not restart until the operator clears the fault using the keypad
.
Questions engineers ask
What does SYS X SENSOR FAILURE mean on a YORK YCAV?
It is the Sensor Failure Cutout Fault: a critical sensor — a transducer, the level sensor, or a motor winding temp sensor — is not functioning properly or reading out of range. It prevents the system from running at start-up and shuts a running system down.
Which sensor has failed on a YCAV SENSOR FAILURE fault?
The ZZZZZZZZZZZZ field on the display names it: SUCT PRESS, OIL PRESS, DSCH PRESS, LEVEL SENSOR, or MOTOR TEMP X. Check that sensor's signal against the start-inhibit range listed on this page.
How do I clear a YORK YCAV sensor failure lockout?
After 3 faults the YYYYYYYY field shows LOCKOUT, and a lockout will not restart until the operator clears the fault using the keypad. A plain FAULT restarts on its own once the fault clears, after the 120 second anti-recycle timer.
What are the sensor ranges for the YCAV SENSOR FAILURE fault?
Suction, oil and discharge transducers: 0.3-4.7 VDC each; level sensor: 3.0-21.0 mA; motor temp sensor: 0-240°F. A reading outside its range is treated as out of range.
Messages next to this one
The same message on other models
Source
Written from the manufacturer's manuals for the YORK YCAV; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YCAV messages: fault codes · YORK YCAV documentation · YORK manuals