Upright SL20 Series, Руководство по обслуживанию и запасным частям

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Page 3-24
Maintenance - 3.21 - Electric Motor
SL20
3.21 E
LECTRIC
M
OTOR
T
ROUBLESHOOTING
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 a.
a. The shaft could be tight for a number of reasons. This check is to determine if the tight-
ness 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 whether the shaft runs. If it does turn, then
hold the motor leads on the power supply for a longer time. If the motor sounds nor-
mal, 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 3-24A. With
rated voltage applied and the shaft running free, the ammeter should read less than 20% of
the nameplate full load current. If the motor meets the above conditions then it can be
assumed the original problem is external to the motor.
Figure 3-25: Electric Motor Service
D
ISASSEMBLY
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. Per-
manent distortion or other damage will
result.
DC
Power
Supply
V
A
Voltage Meter
Ammeter
Brushes and
springs in their
final position Brushes raised with
the springs in locked
position on the side
of the brush
A
B
C
Keep fingers
clear of this
space.
DC
Motor