Joyce LA155P (120 VAC) - Manual (Page 5)

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9. Next, extend the jack to the upper limit position. This will need to be done electrically or with a
screwdriver through the electric motor. Do NOT rotate the translating tube (33). (Make sure
the two clevis ends are oriented properly.) The extended position is the maximum distance
between the two clevis eyes. Do not exceed the designed travel limits of the unit. Refer to
the Travel Limit Chart in Section 4-4.
10. Remove the limit switch gasket, cover (62, 63), and retainer nut (59). Use care not to disturb
the position of the lower cam nut (56).
11. Now adjust the upper limit switch nut cam (56). It is located nearest the translating tube (33)
and controls the extended position. This switch has a blue lead on it. Rotate this limit switch
nut cam until the switch is activated. You will see the switch lever depress and hear it “click”
when it is activated.
12. Insert the retainer nut (59) into the marked slot (for the lower setting) and the slot closest to the
position you have set (for the upper setting). Using a marking pen, mark the slot on the limit
switch nut cam for the upper limit setting.
13. If the unit has a potentiometer, do not rotate the worm. Make sure the threads on the
potentiometer pinion fully engage the potentiometer worm (57) before assembling the gasket
and cover.
14. Replace the limit switch gasket and cover (62, 63), using screws (47).
15. The travel limits are now set to their initial settings. Activate the motor to check for proper
adjustment. Sometimes after installing this actuator in your application, a fine adjustment is
required on the limit switches. To achieve the fine adjustment, follow the procedure outlined
below.
1-8 Limit Switch Adjustment – Fine Adjustment Procedure
1. Remove the limit switch gasket and cover (62, 63) and retainer nut (59). You will see the limit
switch nut cams that you marked for position. Each notch on the limit switch nut cam is equal
to approximately .050 inch of screw travel. By rotating the limit switch nut cams you can fine-
tune the limit settings.
Viewing the Limit switch cavity with the lifting screw and gearbox on your right the
following adjustments can be made:
2. To retract the translating tube (33) more, that is to shorten the distance between the clevis
eyes, rotate the right-hand limit switch nut cam away from the switch lever. This activates the
switch with the red leads. Note: It is critical that you are not setting the limit beyond the
minimum travel of the actuator. Refer to the Travel Limit Chart in Section 4-4.
3. To extend the lower limit, that is to increase the distance between the clevis eyes, rotate the
right-hand limit switch nut cam toward the switch lever. This activates the switch with the red
leads.
4. To shorten the maximum travel so the travel is slightly less at the extended position, rotate the
left-hand limit switch nut cam toward the switch with the blue leads.
5. To extend the upper limit so the travel is slightly greater, rotate the left-hand limit switch nut
cam away from the switch. This activates the switch with the blue leads. Note: It is critical
that you are not setting the limit beyond the maximum travel of the actuator. Refer to the
Travel Limit Chart in Section 4-4.
6. When the fine adjustment is complete, insert the retainer nut (59) into the closest slot and mark
with a marking pen. Note: The retainer nut may now be inserted in notches other than those
you previously marked.
7. NOTE: When a potentiometer is included, it will be mounted to the retainer nut (59). Make sure
the threads on the potentiometer pinion (60B) fully engage the potentiometer worm (57) before
assembling the gasket and cover.
8. Replace the limit switch gasket and cover (62, 63) using the correct fasteners.
9. Activate the actuator electrically to test the limit switch stops. The adjustment procedure can be
repeated as needed.