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MOVEABLE
ARCING
CONTACT
MOVEABLE
ARCING
CONTACT
NEW CONTACTS
END OF CONTACT LIFE STAGE
Contact erosion is a function of many variables such as tap voltage load current and
power factor reactor design and tapped winding design. MEPS employs both equalizer
and conventional windings which will produce the typical erosion patterns above.
INTERMEDIATE STAGE
STATIONARY
CONTACT
STATIONARY
CONTACT
EROSION
EROSION
NEW CONTACTS
ARCING
INSERT
ARCING
INSERT
EROSION HAS PROGRESSED TO A POINT WHERE
BURNING CAN OCCUR ON COPPER
CONVENTIONAL
WINDING PATTERN
EQUALIZER
WINDING PATTERN
MINIMUM OF ORIGINAL
CONTACT SURFACE REMAINS
Figure 16. Contact life stages.
Contact erosion patterns
Copper
Copper
11
QD5 QUIK-DRIVE TAP-CHANGER INSTALLATION AND MAINTENANCE INSTRUCTIONS
MN225012EN March 2016