Vacuum Interrupters; Contact Erosion; Figure 18 Lubrication Of Operator - Siemens 5-FSV-350 Installation Operation & Maintenance

Interrupter/Operator
Maintenance
Figure 18
Lubrication of Operator

Vacuum Interrupters

The l ife expectancy of vac u u m i nterrupters is a f u nction of the
n u m ber of interruptions and mag n i tude of c u rrent i nterru pted
Life I nterruptions x C u r rent
=
They m u st al so be replaced before 3 0 , 000* mechanical oper­
ations o r when the contacts have been eroded beyond allowed
l i mits. Vac u u m t u b e replacement proced u res are d etailed i n
the following maintenance i nstructions.
The c u rves in f i g u re 19 are offered as a guide to life expectancy.
*Perform l u brication at 3 , 000 operations and overhaul at 1 0 ,000
operations for type 5-FSV-350 and 1 5-FSV-1 000 c i rcuit breakers

Contact Erosion

Contact erosion is checked by visually observing an "erosion
mark" on the exposed movable contact stem of the i nterru pter,
see F ig u re 20. Note the mark is a white dot.
This mark may be seen above the lower primary connection ,
and j u st above the termi nal clamp which fastens the flexible
Rated Max. Volts, kV
Rated Short-Circuit Current, kA 29 41
Rated Continuous Current, A
1 200
2000
3000
Applicable C u rve a F u nction of Breaker Rating
connector to the movab l e stem of the vac u u m t u be.
The MSV and FSV breaker constructions wi l l req u i re a me­
chanics m i r ro r and fl ash l i g ht to view the erosion mark.
The criteria of acceptance i s that as long as the white erosion
mark o r any part of it can be seen with the breaker c l osed ,
contact wear is with i n p e r m i s s i b l e l i m its .
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