Replacement Of Ls3 - Up To Mid-1991; Replacement Of Spring Dump Switch; Replacement Of Damper Assembly - Siemens SGIM-3268H Manual

Overhaul
The trip latch reset check switch (LS3) is mounted on the
trip shaft actuator stop plate, as shown in Figure 43a. To
replace this switch, the trip shaft actuator must be removed
by backing out two #10-32 hex socket screws, and then
removing two 3/8" nuts which secure the trip shaft actuator
stop plate to the mechanism.
Wires to the switch must be marked and removed. The stop
plate and switch may then be removed as a subassembly.
The switch is a bushing type, for panel mounting, and
threads into the stop bracket. After adjustment, it is secured
by a jam nut and locking nut.
Adjustment requires the tip of the switch plunger to be set
0.06-0.09" ahead of the stop bracket tab, as illustrated in
Figure 43a. Secure the switch, position the stop bracket
assembly, and reattach the wires. Install the 3/8" nuts to
secure the trip shaft actuator stop plate to the mechanism.
Remount the trip shaft actuator.
Confirm that the switch is vertically aligned to ensure that it
will not be struck by the closing hatchet or the trip shaft
actuator.

Replacement of LS3 - Up to Mid-1991

The following paragraphs describe replacement of the trip
latch reset switch for the mechanism used up to approxi-
mately mid-1991.
This mechanism can be identified by observing the close
latch above the spring charging motor on the left side of
the circuit breaker. Refer to Figure 18. The close hatchet 22
has a latch face which bears directly on the close shaft 72.
If the close hatchet includes a bearing which contacts a
hardened latch installed on the close shaft, refer to the
preceding section for replacement of the trip latch reset
switch for your mechanism.
The trip latch reset check switch is mounted to the left (when
facing the front of the breaker) vertical mechanism side sheet
as shown in Figure 43b. The switch is held in place by two
screws. When replacement of the trip latch reset check switch
is required, both screws need to be removed.
Next, mark both wires to the switch, and remove them.
Then replace the switch, rewire and reassemble the switch
to the left hand mechanism side sheet. Be sure to use the
same washer and nut configuration as was present in the
as-shipped condition.
34
Courtesy of NationalSwitchgear.com
Figure 43b: Trip Latch Reset Switch (LS3) (From 1989 to
mid-1991).
Replacement of Damper Assembly (for circuit breakers
with all vacuum interrupters except type VS-15050)
Damper replacement will require the removal of a pin
which ties the damper mounting yoke to the circuit
breaker frame. Refer to Figure 45a.
The damper is attached to the mounting yoke with a lock
washer and 5/8-18 jam nut. For added security, the jam
nut is treated with a thread locking adhesive (Loctite 271
with Loctite type T primer), and then torqued to a value
of 17-20 ft-lbs.
Check all associated parts, damper body and telescoping
tube, for wear. Replace as necessary.
The telescoping tube and internal striker block employ
slugs in variable thicknesses and quantity to control
moveable contact motion. If the telescoping tube is
replaced, the tube must be replaced with the correct tube
to assure that the correct type and number of slugs are
present.