Reassembly; Installation; Electric Motor; Troubleshooting - Upright X Series Service & Parts Manual

Section
4.12
3. Check the bearing surfaces inside of the head cap,
inside of the cylinder barrel and the rod for signs of
scoring or excessive wear.
4. Replace all seals and o-rings.

REASSEMBLY

1. Lubricate and install new o-rings, seals and wipers
on the head cap and piston.
NOTE: Multipurpose lubricant should be used.
2. Install the headcap on the cylinder rod from the
piston end.
3. Apply Locktite #262 to the threads on the piston
and screw the piston on the rod.
4. Lubricate the piston and install the piston and rod
assembly in the barrel tube.
6. Thread the head cap into the barrel tube and hand
tighten, then turn ¼ turn further.
7. Install the Down Valve and fittings.

INSTALLATION

1. Attach a suitable hoisting device and sling to the
cylinder. Carefully position cylinder in the Elevating
Assembly and install the upper Pivot Pin.
2. On X20 machines make sure the Locking Pin fully
engages the pivot and pin and install the retaining
ring.
On X26N machines install a new roll pin.
3. Carefully lift the cylinder and align the lower mount
and install the Pivot Pin. Make sure Locking Pin is
properly installed then install the retaining ring.
4. Connect the Emergency Lowering Valve Cable and
Down Valve wires.
5. Unplug hydraulic hoses and attach to the cylinder.
6. Replace hydraulic fluid removed from Lift Cylinder.
7. Test with weight at rated platform load to check
system operation. Check for leaks and level of fluid.

4.13 Electric Motor

(Figure 4-18)

TROUBLESHOOTING

1. Read the nameplate to become familiar with the
motor, especially the rated voltage.
2. Try to turn the shaft by hand. Keep motor leads
separated while doing this. If the shaft turns freely
go to step 3. If the shaft won't turn, proceed to step
2A.
4-16
Maintenance
2A. The shaft could be tight for a number of reasons,
this check is to determine if the tightness is of a
temporary nature only. Obtain power to produce
the nameplate voltage. Do Not Make A Permanent
Connection. First touch the motor leads quickly to
the power supply just long enough to observe if the
shaft runs. If it does turn, then hold the motor leads
on the power supply for a longer time. If the motor
sounds normal, go to step 3. If the motor sounds
noisy, it should be taken apart as described in the
disassembly section.
3. If the motor turned freely, connect an ammeter in
the circuit as shown in Figure 4-18A. With rated
voltage applied and the shaft running free, the
ammeter should read less than 20% of the name-
plate full load current. If the motor meets the above
conditions then it can be assumed the original
problem is external to the motor.

DISASSEMBLY

1. Remove thru bolts.
2. Remove pulley end cover.
3. Pull the armature out of the assembly in one swift
motion.
4. Remove commutator end cover.
NOTE: Do not place the stator ring in any mechanical
holding device during the disassembly or assembly
operation. Permanent distortion or other damage will
result.

INSPECTION

Once the motor has been disassembled, go through the
following check list steps to determine where the
problem lies.
1. Bearings should spin smoothly and easily and have
ample lubrication and be free of corrosion.
2. Armature should be checked for grounds and
shorted turns. Refinish commutator surface if pitted
or excessively worn.
3. Brushes should be checked for wear and to ensure
that they are free in the brush holders.
X-Series Work Platform