GE Industrial Solutions PowerVac with ML-18 or ML-18H Mechanism - Manual (Page 12)

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8.5.1—Close Coil Plunger Gap
The close coil plunger gap and correct setting is shown in
Figure 9. The operation check and adjustment procedure for
the coil plunger will start with the close spring discharged,
and verification that the plunger moves freely over its full
stroke inside the coil. To check the closing coil plunger gap
the breaker should be open and the closing spring charged
and gagged. The measurement is made by first depressing
the close plunger button until resistance is felt, this accounts
for the free travel of the armature. The gap “T” measurement
is best made using a ‘go/no-go’ gauge. Refer to figure 9 for
gauge details. With the armature depressed until resistance is
felt the ‘go’ gauge must fit between the coil housing and the
surface of the black PVC cap covering the steel plunger base.
With the armature in the same position the ‘no-go’ gauge
must not fit between the coil housing and the plunger base.
The adjusting nut shown in Figure 9 is used to change this
measurement.
ML-18 Breakers with type designation
-0, -1 & -2 T= 0.25” to 0.30”
ML-18 Breakers with type designation
-3. T= 0.35” to 0.40”
ML-18H Breakers with type designation
-0. T= 0.35” to 0.40”
Figure 9 Close coil plunger gap
8.5.2—Trip Coil Plunger Gap
The trip coils #1 and #2 plunger gap and correct setting is
shown in Figure 10. The operation check and adjustment
procedure for the coil plunger will start with the breaker in the
open position and the closing spring in the charged condition
and verification that the plunger moves freely over its full
stroke inside the coil. This verification is also required for the
second trip coil when supplied. To check the trip coil plunger
gap the breaker must be closed with the closing spring
discharged. The measurement is made by first depressing
the trip plunger button until resistance is felt, this accounts for
the free travel of the armature. The gap ‘T’ measurement is
best made using a ‘go/no-go’ gauge with the ‘go’ end having
a thickness of .200 inches and the ‘no-go’ end with a
thickness of .251 inches. With the armature depress until
resistance is felt the “go” gauge must fit between the coil
housing and the surface of the red PVC cap covering the steel
plunger base. With the armature in the same position the “no-
go” gauge must not fit between the coil housing and the
plunger base. The adjusting nut shown in Figure 10 is used to
change this measurement. The same procedure is used for
measurement and adjustment of trip coil #2.
Plunger Gap T =. 250+.000/-.050
Figure 10 Trip coil plunger gap
8.6—Control Switch Adjustment
Adjustment of various control switches is done as follows.
8.6.1 LCS and SM/LS Switch Adjustment
The breaker is to be in the open position with the opening and
closing spring discharged. This results in the control switch
plungers being in the depressed position. The switches to be
checked are shown in Figure 11. On the LCS and the SM/LS
&CHG switch, the plunger rod is to be flush or slightly
recessed (1/32”) within the rear of switch body. This is a
visual check.
8.6.2 CL/MS Switch Adjustment
The adjustment of the CL/MS on ML-18 models with type-3
designations and ML-18H models with Type-0 designation is
set at the factory and no adjustment is required. Replacement
of the CL/MS switch or removal of the angle mounting
bracket will require re-adjustment of this switch for correct
operation of breaker’s track interlock and close latch. The
adjustment will insure that the switch contacts will not close
before the close latch is in its re-set position. To achieve this
condition shims are required between the CL/MS switch
housing and the plunger spacer. Insert shims until the CL/MS
contacts do not close when the close latch is in the reset
position. Then remove .005inch shim to allow the switch
contacts to close just as the close latch reaches the re-set
position. This will provide the proper timing between the
CL/MS switch and the close latch.
The adjustment of the CL/MS on ML-18 models with type –0,
-1 and -2 designations is set at the factory. Should adjustment