CB Watch 3 User Manual v6.3 - May 2019 Page 18 of 100
HMI: Settings/Opening and Settings/Closing
Figure 17 – Initial setting of number of operations
An alarm can be set against both the number of opening and closing operations if they
exceed a set threshold. This can be used for maintenance purposes.
HMI: Settings/Opening and Settings/Closing
Figure 18 – Setting operation counter alarms
52a/52b 52a/52b contacts status
The 52a/52b auxiliary contacts are proximity switches that are there to reflect a direct
image of the circuit breaker position and indicate the status of the circuit breaker:
• 52a aux. contact: is ON when circuit-breaker is CLOSED, and vice-versa
• 52b aux. contact: is OFF when circuit breaker is CLOSED, and vice-versa
HMI: Measurements/Sensors
Figure 19 – Auxiliary contact status
In an IPO CB, if the 52a or 52b contacts do not show the same value for all 3 poles for
longer than the “pole discrepancy timeout” set, then a “Pole discrepancy” alarm is raised.
This alarm can serve as a reminder of a temporary phase imbalance in an IPO CB and
that the situation should not be maintained for a long time.
HMI: Settings/Operations Monitoring
Figure 20 – Pole discrepancy timeout threshold
In both a ganged and an IPO CB, if for any one pole, the 52a and 52b contacts have the
same value for longer than the “pole discrepancy timeout” set, then a “Pole discrepancy”
alarm is also raised. It can alert to the fact that there is a problem with the 52a and 52b
contacts for one pole and that the position of the CB for that pole might be incorrect.
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