Replacement Of Motor Cutoff Switch (Device Ls1) And Spring Charged Switch (Ls2); Replacement Of Trip Latch Reset Check Switch (Device Ls3) - Siemens SDV-4A Instruction Manual

Overhaul
Replacement of Motor Cutoff Switch (Device LS1) and
Spring Charged Switch (LS2) - The motor cutoff switch
(LS1) and spring charged switch (LS2) form a common as-
sembly of two switches on one mounting bracket. Should
either switch require replacement, it is recommended that
both be replaced as a single assembly. The motor cutoff
switch (LS1) is the "outboard" device with respect to the
mounting bracket. Removal of the two mounting screws
shown in Figure 33 allows both switches to be brought out
for convenient removal of the interconnecting wiring.
Next, mark all wires to both switches. Remove the wires.
Then replace the switches, rewire, and reassemble the
switches to their mounting bracket. Be sure to use the same
flat washer, lock washer and nut configuration in reassem-
bly as was present in the as-shipped condition.
Figure 32. Replacement of Anti-Pump Relay or Auxiliary Switch.

Replacement of Trip Latch Reset Check Switch (Device LS3)

- The trip latch reset check switch (LS3) is mounted on the
trip shaft actuator stop plate, as shown in Figure 35. To
replace this switch, the trip shaft actuator must be removed
by backing out two 10-32 hex socket screws, and then re-
moving 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 subas-
sembly. 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 trip of the switch plunger to be
set 0.06-0.09" ahead of the stop bracket tab, as illustrated
in Figure 34. 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.
Figure 33. Motor Cutoff Switch (LS1) and Spring Charged
Switch (LS2).
2092-98
Figure 34. Trip Latch Reset Switch (LS3).
2102-98
2101-98
33