MAINTENANCE
Page
23
ELECTRICAL SERVICE LIFE
The electrical service life of the vacuum
interrupter is defined by the electrode wear and
the number of open/close operations
(mechanical life).
To determine the electrode wear, measure
dimension A between the lever and washer in
the closed (ON) state, as shown in Figure 13.
This dimension is called the “wipe”. If the
1.0mm contact wear gauge cannot be inserted,
then the end of the service life has been
reached.
The drive unit and the closing coils also have
an electrical service life of 200,000 operations.
As a result, these parts should be replaced
around 200,000 operations.
MECHANICAL SERVICE LIFE
The normally energized type has a mechanical
service life of 1 million operations and the latch
type 200,000 operations. The mechanical
service life of the vacuum interrupters is
200,000 operations.
For the components in Table 4, replacement or
detailed inspection and cleaning are
recommended after the indicated number of
operations.
Figure 13 - Wipe Measurement
SERVICE LIFE – CAPACITOR SWITCHING
Switching of capacitor loads produces severe
conditions for contactors, such as high
frequency inrush current and phase-to-phase
recovery voltage more than twice the normal
voltage.
The criterion for the maximum number of
capacitor current switching operations is shown
in the graph below. The vacuum interrupter
should be replaced when the number of
switching operations in the graph is reached.
Table 4 - Recommended Part Replacement
Intervals
Part Name
Number of Operations
for Replacement
Vacuum Interrupter
200,000
Auxiliary Switch
200,000
Moveable Core
Detailed inspection and
cleaning every 200,000
operations.
Stationary Core
Detailed inspection and
cleaning every 200,000
operations.
Closing/Trip Coil
200,000
Flexible Conductor
200,000
Figure 14 - Capacitor Switching Life
A
1
10
10
100
1000
Switching Current (A)
Switching Life (ten thousand)
20 40 60 200 400 600
8
6
4
2
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: [email protected]
