S260-20-8
11
Figure 21.
Components of head mechanism assembly.
Figure 20.
Removing straight pin with allen wrench.
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Figure 22.
Correct position of shaft retainers
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GREASING RECOMMENDATIONS
When a Type NR or NRV switch is removed from service,
check these points in the actuator for sufficient lubrication:
• Spring anchor boss
• Actuator drive lever spring anchor
• Mechanism shaft through cam center
• Pinion gear on motor shaft and mechanism gears
Apply “MOBILGREASE 28” or a similar low-temperature
grease to these areas. Well-lubricated mechanisms will reduce
subsequent wear and preserve smooth actuator operation.
NOTE: Grease need only be applied to these points when the switch
is removed from service. Do not remove switch from service for sole
purpose of applying lubrication to the actuator mechanism.
Head Mechanism
The head mechanism requires no periodic maintenance.
observe the following procedure when disassembling the head
mechanism:
1. Remove the contact structure as described in “Shop Repair
Procedures—Complete Contact Box Assembly” section.
2. Remove the bushings as described in “Shop Repair Proce-
dures—Bushings” section.
NOTE: This step is not mandatory, but is suggested to simplify
working on the head mechanism if a service rack is not available.
3. Perform Steps 1 and 2 in “Actuator Assembly” section to
free the actuator mechanism from the operating shaft.
4. With a hammer and punch, drive out the roll pin that
secures the reset lever to the operating shaft (Figure 21).
5. Remove the sleet hood cover and slip the operating handle
spring from the reset lever. Slide out the operating shaft.
6. Install new parts as required. Be sure roll pin that fixes
reset lever to operating shaft is driven in until 3/16-inch of
pin projects as shown in Figure 21.
7. To replace the latch lever assembly:
A. Remove screws that secure the shaft retainers to the
head casting.
B. Lift out the latch lever assembly.
C. When reassembling, slip the latch lever torsion spring
and latch lever onto the latch lever shaft.
D. Screw the two shaft retainers to the head casting to
secure the latch lever shaft.
E. Hook the torsion spring on the latch lever assembly. Be
sure the two shaft retainers are positioned as in Figure
22, and that the latch lever is retarded when moved
away from the head casting.
8. Install the contact structure and bushings to complete
assembly.
