32
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
5.1.7.4 The CONNECT Position
This is the position in which both primary and secondary
disconnecting contacts on the breaker are engaged with
their stationary counterparts in the compartment.
It is the farthest position from the front of the compart-
ment into which the breaker can be levered, as (1) shown
by the drawout position indicator, and (2) when the
mechanical stop is felt as a sudden increase in load on
the levering crank handle.
Note: When levering in from the TEST position, an
increase in load on the crank handle will be felt as
the main disconnecting contacts are engaged. As
cranking is continued, the load will decrease some
and then suddenly increase as the final connected
position stop is reached.
In this position all of the conditions listed for TEST posi-
tion also exist, except
IN THIS POSITION, DO NOT ATTEMPT TO ELECTRI-
CALLY CHECK THE AMPTECTOR TRIP DEVICE WITH
THE TEST KIT OR BY ANOTHER METHOD BECAUSE
BREAKER WILL BE TRIPPED AND CAUSE DISRUP-
TION OF SERVICE.
The trip plate on the hinged compartment door will be
operative, and can be used to trip the breaker when this
door is closed.
In addition to the above interlocks, the interference inter-
lock described in Section 5.1.6.1 prevents a breaker of
the wrong frame size from being placed in a compart-
ment.
5.1.8 Detailed Explanation of Mechanical Interlock
System
That part of the interlock system which prevents closing
of the breaker while being driven in either direction by the
levering device, or while it is standing in any intermediate
position between “TEST” and “CONNECT” or “DISCON-
NECT”, is shown in Figure 28a and b. Figure 28a shows
the shutter and trip plate for normal operation, such as in
DISCONNECT, TEST, or CONNECT positions. The
breaker can be closed and tripped open by all available
devices in the latter two positions except the trip plate on
the hinged compartment door.
In Figure 28a, the shutter prevents pushing the levering
device crank handle onto the worm shaft. If the shutter
alone is pushed downward, it will rotate slightly about its
pivot pin and its lower projection (see Figure 28a) strikes
the hook on the trip plate, and the worm shaft will not be
cleared. So it is necessary to push the trip plate in, which
moves the hook back out of the way of the shutter lower
projection. This permits the shutter to be pushed down-
ward to clear the worm shaft for the levering device crank
handle, as shown in Figure 28b.
Note that pushing the trip plate in also pushes the trip
shaft pin so as to rotate the trip shaft counterclockwise,
thus tripping the breaker open. If closing is attempted
with the linkage as in Figure 28b, a trip free operation will
be made.
Movement of the shutter also is controlled by the interlock
cam, mounted on the levering device shaft to the left of
the worm gear. The interlock cam has a fixed relation to
the levering device arms. Figure 29a, b, c, and d show
the relation between the shutter, interlock cam and lever-
ing device arms for the four basic positions of the drawout
unit in the compartment.
Figure 29a shows the CONNECT position. The cam is in
a position to allow free travel of the shutter interlock pin.
Therefore the shutter can be pushed downward, but only
after pushing in the trip plate as in Figure 28. This trips
the breaker and therefore prevents levering out with the
breaker closed.
Figure 29b shows the TEST position. Note that between
CONNECT and TEST positions the cam will rotate so as
to block the shutter interlock pin. This prevents the shut-
ter returning to its closed position and releasing the trip
plate if the levering device crank handle is removed.
Thus, if a closing operation is tried during this part of the
travel, a trip-free operation occurs and the breaker con-
tacts do not close. Note that this is true for either direction
of breaker travel so that no load is made or broken at the
disconnecting contacts.
When the breaker gets to the TEST position, a slot in the
interlock cam allows free movement of the shutter inter-
lock pin, and the shutter returns to closed position when
the crank is removed. The levering device arms are
almost vertically downward.
Figure 29c shows the DISCONNECT position. Here also
the cam rotates so as to block the shutter interlock pin
while the breaker is between positions thus holding the
shutter open. When the exact position, as shown on the
indicator, is reached, the shutter will close when the
crank is removed. The levering arms will be approxi-
mately 40° below the horizontal.
