Figure 21 - Pole Discrepancy Alarm; Figure 22 - Setting Operation Counter Alarms - GE CB Watch 3 User Manual

HMI: Measurements/Alarms
Previous operation
The type of operation that was just performed is indicated as "previous operation type".
This can be Open (O), Closed (C) or a combination operation (CO, OC, OCO).
During each operation, data acquisition is performed from all the sensors for a period
defined in the settings under « Acquisition duration »: 0.3s (300ms) is the default.
HMI: Settings/Operations monitoring
When a current flowing to the coil is detected, the system then samples every 0.4ms for
the acquisition duration, we get a total number of sample of 300 / 0.4 = 750. By analysing
the data from the 52a and 52b contact during this sampling period, we determine the
type of operation that has occurred using the following rules:
If the system sees a Closing operation first, it will check for another Opening operation
during the sampling time
If it does not see one, then it declares a simple Closing operation "C"
If it does see one, then it declares a Closing-Opening operations "CO"
If the system sees an "Opening" operation first, it will check for another Closing operation
during the sampling time
If it does not see one, then it declares a simple Opening operation "O"
If it does see one, then it continues to see if there might be a third operation
during the sampling period
If it does not see one, then it declares an Opening-Closing operation "OC"
If it does see one, then it declares an Opening-Closing-Opening operation
"OCO"
52a/52b contacts switching time
All timing starts from the detection of the open or close command (rising edge of the
current detected on the open or close coil circuit). The auxiliary contact switching time is
measured for each operation:
CB Watch 3 User Manual
Figure 21 – Pole discrepancy alarm
Figure 22 – Setting operation counter alarms
v6.3 - May 2019 Page 19 of 100