ABB SACE Tmax XT7 Operation And Maintenance Manual page 114

Maintenance Certain information about the status of the CB is available in the Measurements-Maintenance menu.
Operation counters The CB operations (total manual operations and TRIPs) are recorded by the Trip unit in the presence of
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Contact Wear
Contact wear provides an estimation of the state of wear of the main contacts of the circuit-breaker. The
value is given in percentage form and is 0% if there is no wear and 100% if the contacts are completely worn
It is calculated automatically by the Trip unit whenever a trip is caused by a protection or, in the presence of
auxiliary power supply, whenever the circuit-breaker is opened in the manual mode.
NOTES:
• the percentage is no longer increased once 100% has been reached
• 80% wear is signaled by a prealarm, while 100% is signaled by an alarm
IMPORTANT: 100% wear does not impose any functional limit on the Trip unit; however,
the state of the circuit-breaker must be checked as soon as possible
Maintenance
The Maintenance function allows the user to be alerted by a Warning that:
one year has elapsed since maintenance was last performed
contact wear has increased by over 10% with respect to the last maintenance value
Two areas are available in the Trip unit menu:
• Activation area (Settings - Maintenance menu): allows the Maintenance function to be activated
• Measurement and reset area (Measurements - Maintenance menu): only appears if the Maintenance
function is activated; provides information about maintenance (contact wear and dates) and the command
for confirming that maintenance has been performed (confirming records the actual date and contact wear
values, and resets the alarm signal).
The reference date is that of the internal clock and the time elapsed is calculated with the trip unit both on
and off (so long as the internal battery functions).
NOTE: manual modification of the date may cause variations to the elapsed time calculation,
thus to the next maintenance date
NOTE: the maintenance signal due to increased contact wear is given for values exceeding
20%
auxiliary power supply and are available in the About-Circuit breaker menu.
The following counters are also available when communication with the Trip unit is activated:
• number of mechanical operations
• number of trips due to protection trips (TRIP)
• number of trips due to failed protection trips (TRIP)
• number of trip tests performed
ABB | SACE Tmax XT
Ekip Touch - Measurements | 1 - Standard Measurements