
MA-037 - CB Watch 3 Operating Manual
v7.0 - May 2020
Page 43 of 118
Threshold values
Maximum number of operations
Related to a requirement for a maintenance or inspection operation.
Pole discrepancy
It is set by default to 1s but can be customised. This means an alarm is generated if one pole
remains in a different state for more than 1 second.
Opening/Closing Reaction time (t1), per pole
Opening/Closing Operation time (t2), per pole
Opening/Closing Travel time (t2-t1), per pole
The nominal values of t1 and t2 are usually available from the CB Operating Manual or from
the Factory Acceptance Test of the CB or from the latest test results.
The minimum values are the important ones
Opening/Closing Reaction time discordance
Opening/Closing Operation time discordance
Opening/Closing Travel time discordance
Data is usually available from the CB Operating Manual. A typical discordance threshold
value would be <3-5ms, but it depends on the CB type and state.
Opening contact separation speed, per pole
Data is usually available from the Operating Manual or FAT. Typical values would be
between 2 and 5m/s, but it depends on the CB type. Note that the result is heavily
influenced by the distances set in the previous section above.
Open/Closed position issue
No thresholds are required as it only compares information from 52a/b sensors and travel
sensors and an alarm is raised if they do not concur
Opening/Closing overtravel
Data is usually available from the CB Operating Manual. Typical values would be between 5
and 10mm, but it depends on the CB type. It is set by default to 8mm.