Because of observed noise on the synchro at jack station 11 during recent shutdown lid up/down operations, the synchro at this station was replaced on Jan. 31, 2024. The procedure in Document-234859 was followed.

Prior to starting the replacement, the following counter values and synchro measurements on the station in question and adjacent stations were noted:
The master synchro count value was measured at: 0000
Station 10: Counter: 99392.5, synchro voltage: 5.89 VAC
Station 11: Counter: 0073, synchro voltage: 0.787 VAC (anomaly)
Station 12: Counter: 0068, synchro voltage: 5.98 VAC
 

During the replacement, the master synchro was jogged such that adjacent stations 10 and 12 read a synchro value of approximately 0 volts (as per the nulling procedure). The following observations were made:
The master synchro count value was measured at: 0072
Station 10: synchro voltage: 0.047 VAC
Station 11: synchro voltage prior to swap: 5.70 VAC (anomaly)
Station 12: synchro voltage: 0.282 VAC

After the replacement, before jogging the master synchro back to its starting value of 0000, the following measurements were made:
Station 10: synchro voltage: 0.038 VAC
Station 11: synchro voltage after swap: 0.12 VAC (now correct)
Station 12: synchro voltage: 0.278 VAC

When jogging the master synchro after the swap was completed, it was confirmed that stations 10, 11, and 12 all responded as expected, and their values were synchronized with respect to each other, indicating a successful replacement. The master synchro was jogged back to its original counter value of 0000. The system is now considered operational.