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Entellisys Low-Voltage Switchgear
Section 12. EntelliGuard Preventative Maintenance
Entellisys tracks the data needed to manage
preventative maintenance items. Circuit breaker
transition counters, life calculations, run hours of
operation, and last-operation date stamping all aid
in maintaining and servicing the Entellisys system.
In addition, transition counters can trigger alarms
after a certain number of transitions have occurred.
The Entellisys system provides up-to-the-minute
status for every circuit breaker in your Entellisys
installation. There is no need to run around with a
clipboard, recording the operations counter reading
on each of your circuit breakers. The Entellisys
system not only tracks the number of operations
of each circuit breaker, but also estimates actual
current breaking life and mechanical life. Entellisys
shows you what you need to know, whenever you
want to know it.
Viewing and Understanding the Preventative
Maintenance Data
Figure 12.1 shows the Maintenance Data display
that is obtained by selecting a circuit breaker from
the one-line drawing. Each of these entries is
described in the following.
Total Operations
Entellisys counts the number of closed-to-open
transitions, regardless of load, of each EntelliGuard
circuit breaker.
Total No-Load Operations
Entellisys counts the number of closed-to-open
Figure 12.1
Breaker Maintenance Data Display
transitions that occur with no load (less than 1% of
rated current) for each EntelliGuard circuit breaker.
Total Load Operations
Entellisys counts the number of closed-to-open
transitions that occur with load (1% or more of
rated current) for each EntelliGuard circuit breaker.
Total Fault Operations
Entellisys counts the number of closed-to-open
transitions that occur due to a fault on each
EntelliGuard circuit breaker. These are trips issued by
a protection feature, such as short-time, long-time,
and instantaneous overcurrent.
Percent Load Life
Entellisys tracks the percentage of the total load life
of the EntelliGuard circuit breaker that has been used.
When an EntelliGuard circuit breaker transitions from
closed to open, the percentage of load life used is
updated with the equation below, which includes
the frame size and the current flowing through the
breaker at the time of transition. The constant K
depends on the circuit breaker's frame size, as listed
in Table 12.1.
% of Load Life =
Σ(
(Ι
rms
If the current flowing through the circuit breaker
at the time of transition exceeds the maximum
current threshold (see Table 12.2), 45% of the
breaker's life is added to the total load life used.
Table 12.1
Frame-Size Constant Used in Calculating Percentage of Load Life
Κ
Frame Size, A
frame
800
2800
1600
1200
2000
1000
3200
600
4000
500
5000
400
Table 12.2
Maximum Current Threshold
Frame Size, A
Max current threshold
800
15
1600
15
2000
15
3200
13
4000
9
5000
7
2
/
)
Ι
)
/ Κ
frame
frame
59
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