Shunt Trip A Ttachment; Shunt Trip Attachment - Construction Details - Westinghouse DB-50 Instructions Manual

E nergize relay operating coil.
close the breaker manually.
release arm should operate the relay trip
assembly and the relay trip assembly
should open the relay contacts just before
the breaker latches. This position can best
be determined by watching the pawl in the
breaker operating mechanism, which should
snap in place just after the relay contacts
open. If this operation sequence is not
correct , the relay release arm should be
bent to suit. Make sure that the relay re­
lease arm does not rub on either side of the
relay trip assembly lever aperture . When
the breaker is latched, de-energizing and
then energizing the relay operating coil
should not cause the relay contacts to move
toward the closed position. Trip breaker.
Reconnect closing coil leads to the con­
trol circuit wiring. Check electric closing
of breaker.
Fig.
Slowly
The relay
0
1 6

- Shunt Trip Attachment - Construction Details

SHUNT TRIP A TTACHMENT

The shunt trip mounts on top of the platform
immediately to the right of the operating
mechanism. (See Fig . 1 6 .)
It is non-adjustable and is intended for
intermittent duty only. The shunt trip cir­
cuit must always be opened by an auxiliary
switch contact. Tripping currents are
tabulated in Table No. 2 , Page 7 .
Inspection
With the breaker in the open position,
manually push the moving core against the
stationary core and rotate the breaker
handle to the closed position. The breaker
should be trip free.
The trip lever of the shunt trip should
have from 1 / 32 to 1 / 8-inch clearance to
the trip bar.
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