Instruction Book
Effective: May 2016
Page 33
IB131017EN
For more information visit:
www.Eaton.com
The current transfer system consists of a unique flexible
connector attached to the movable stem of the vacuum
interrupter. The flexible connector consists of a large
number of flexible leaf conductors that are pressure welded
on both ends. One end of the flexible connector is
attached to the movable vacuum interrupter stem and
Figure 5-3 Fixed 50 VCP-TRL Interrupter Assembly
(600/800A, 16kA shown)
Figure 5-4 Drawout 150 VCP-TL Interrupter
Assemblies (1200A, 25kA shown)
the other end to the circuit breaker's lower conductor. As
the vacuum interrupter stem moves and the flexible
connector flexes, current is safely and efficiently
transferred between the stem and lower conductor.
5-2.1 CONTACT EROSION INDICATOR
The purpose of the contact erosion indicator is to
monitor any erosion of the vacuum interrupter
contacts. Contact erosion is, however, very minimal
over time with EATON vacuum interrupters. A contact
erosion indicator mark is located on the moving stem
of the interrupter (Figure
6-1
). The erosion mark can
be observed from the rear of the circuit breaker, and
should be done with the circuit breaker closed. If the
erosion mark is no longer visible with the circuit
breaker closed, the entire vacuum interrupter
assembly must be replaced.
5-2.2 CONTACT WIPE AND STROKE
Contact wipe is the indication of (1) the force holding
the vacuum interrupter contacts closed and (2) the
energy available to hammer the contacts open with
sufficient speed for interruption.
Stroke is the gap between fixed and moving contacts
of a vacuum interrupter with the breaker open.
The circuit breaker mechanism provides a fixed
amount of motion to the drive insulators. The first
portion of the motion is used to close the contacts (i.e.
stroke) and the remainder is used to further compress
the preloaded contact spring. This additional
compression is called wipe.
Wipe and stroke are thus related to each other. As
the stroke increases due to the erosion of contacts, the
wipe decreases. A great deal of effort has been spent
in the design of all EATON vacuum circuit breakers,
in order to eliminate the need for field adjustments of
wipe or stroke. Refer to paragraph 6-7 for details on
visually inspecting contact wipe.
CAUTION
THERE IS NO PROVISION FOR IN SERVICE
ADJUSTMENTS OF CONTACT WIPE AND
STROKE. ALL SUCH ADJUSTMENTS ARE
FACTORY SET AND SHOULD NOT BE
ATTEMPTED IN THE FIELD.
