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Instruction Booklet
IB 33-790-1J
Effective November 2010
Instructions for Low Voltage Power
Circuit Breakers Types DS and DSL
EaToN CorPoraTIoN www.eaton.com
Manually operated breakers may also be furnished with
this feature if they are equipped with optional electrical
spring release devices.
5.1.8.4 Closed Breaker Interlock
Figure 31 shows how operation of the spring release
latch is prevented when the breaker already is in the
closed position. The Close Bar is connected to the spring
release latch by a link and bell crank. The link is pivoted
on the lower end of the close bar cam by a pin as shown.
As the Close Bar is pushed, the pin and latch link will
move to the right, along with the lower end of the cam.
The lower end of the link is facing a knife edge pivot on
the vertical arm of the bell crank. The upper end of the
link is facing the Open-Close Indicator Pin. This pin is at
the left end of its slot in the mechanism side frame with
the breaker open and at the right end with the breaker
closed. As the Close Bar is pushed, the link therefore has
two possible end pivots. If the breaker is open the upper
end of the link will swing to the right until it touches the
indicator pin. The lower end of the link will then swing to
the right and push the vertical arm of the bell crank to the
right. The horizontal arm of the bell crank moves down-
ward and presses directly on the spring release latch,
allowing the breaker to close.
If the breaker already is closed and the Close Bar is
pushed, the upper end of the spring release latch link will
swing free to the right because the indicator pin is not
there to stop it. Consequently, no force is applied to the
vertical arm of the bell crank, and nothing else happens.
5.1.8.5 Padlocking Provision
Figure 32 shows the essential parts of the padlock inter-
lock. The breaker is padlocked in the trip-free condition in
which the breaker cannot be closed and the breaker can-
not be moved with the levering device. This figure shows
the relation of parts for padlocking in the trip-free, shutter
up condition. There are three major parts involved, which
are interleaved and assembled on the left hand side of
the levering device assembly:
1. The Shutter;
2. The Trip Plate; and
3. The Padlock Interlock Lever.
The Padlock Interlock lever is located between the Trip
Plate and the Padlock Plate, and is pivoted on a fixed
center toward the rear of the breaker. The front part of
this lever has a sloping slot into which a projection from
the trip plate extends. Horizontal movement of the trip
plate by cam action of the projection against the walls of
the slot, causes the front of the interlock lever to move up
or down. The interlock lever is pushed upward by a
spring. This lever also has a short pin extending outward
normally into a curved notch in the bottom edge of the
padlock plate.
Fig. 32 Padlock Device - Locked Trip Free and Shutter
Raised.
To padlock the breaker, with shutter closed, push the trip
plate in. Pull the padlock plate forward. This exposes the
padlock slot in the padlock plate. Insert the padlock and
lock.
Movement of the trip plate pushes the front end of the
padlock interlock lever down, moving its pin downward
and out of the notch in the padlock plate. Forward move-
ment of the padlock plate and backward movement of the
trip plate places the pin in the padlock interlock lever
behind the notch in the padlock plate. With the padlock
plate held forward, the padlock interlock lever cannot
move. The projection from the trip plate is consequently
held in the slot in the padlock interlock lever, so the
breaker remains locked in the trip-free condition until the
padlock is removed and the members are returned to
their normal positions by their return springs. While so
locked, the shutter is prevented from downward travel by
a horizontal projection striking a bent-over tab on the
padlock plate.
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