YORK YVAA — sensor failure fault

The panel shows sensor failure fault — the only wording the manual uses for this message. It has been observed on chillers in high ambient climate locations while the chiller was in standby mode, and it prevented the system(s) from startup. Work on this equipment should only be done by properly trained personnel who are qualified to work on this type of equipment.

This message is the suction pressure transducer range check. An output voltage value below 0.3 V and above 4.7 V results in a sensor failure fault on the impacted system on the chiller, which inhibits the operation of that system. In the documented cases the voltage output of the impacted digital transducers was unregulated and could reach up to 4.9 V, so a transducer that was not actually broken drove the reading above the 4.7 V limit and kept the system from running.

• The voltage output of the impacted suction pressure transducers (P/N: 025-29583-002) was unregulated and could reach up to 4.9 V — above the 4.7 V fault threshold.
• The impacted transducers are digital type, identified by the 2D matrix barcode stamped on the side of the transducer and a new 10-digit serial number on the product label.
• These transducers were released to production in January 2021; transducers prior to this date are not impacted by this issue.
• Transducers manufactured between January 2021 and week 10 of 2022 (date code: 102) have unclamped output voltage.
• The fault was reported on chillers in high ambient climate locations, with the chiller in standby mode.

1. Confirm the transducer is the digital type: it carries a 2D data matrix code on the sensor and a new 10-digit serial number on the product label.
2. Verify the manufacturing date from the transducer serial number: the last 3 digits depict the code for week and year of manufacturing (the example in the manual, 122, means week 12 of 2022).
3. If the transducer was manufactured between January 2021 and week 10 of 2022 (date code: 102), it has unclamped output voltage and needs to be replaced.
4. Replace it with the improved suction pressure transducer whose maximum output voltage is clamped at 4.7 V.

• Fault trip window: suction pressure transducer output voltage below 0.3 V and above 4.7 V.
• Unclamped transducers can drive their output up to 4.9 V under high ambient conditions.
• The improved replacement clamps the maximum output voltage at 4.7 V, preventing the fault during these high ambient conditions.
• Affected build window: January 2021 through week 10 of 2022 (date code: 102); the clamped design was implemented on YVAA and YVFA chillers beginning week 10 of 2022.
• Date code: the last 3 digits of the serial number give the week and year of manufacturing (example: 122 = week 12 of 2022).

The manual gives no reset or clearing routine for this fault. The documented correction is hardware: verify the date code and, for a transducer built between January 2021 and week 10 of 2022 (date code: 102), replace the transducer with a new part - an improved version of the suction pressure transducer that clamps the maximum output voltage at 4.7 V. With the clamped transducer fitted, the sensor failure fault is prevented from occurring during these high ambient conditions.