STEP 1
TOUCH PROBES TO GET MAXIMUM
METER READING.
STEP 2
ROTATE THE ARMATURE AND
COMPARE READINGS.
STEP 1
STEP 2
ROTATE ARMATURE AND REPEAT
TEST.
3.
Hold a hacksaw blade or other similar strip of steel (not aluminum or stainless steel) lengthwise against the armature lamination's and slowly rotate
the armature under the blade. A shorted winding will create a magnetic field and the metal strip will be attracted to the slot where the shorted
winding is located. When this happens, the blade will vibrate and cause a growling noise.
4.
You may also test for a shorting winding by using the meter circuit. The red test probes should be touched to adjacent commutator segments, or
to every other segment depending on armature design. The probes should be moved around the armature until the maximum reading is achieved.
The test probes should be held in this position while the armature is rotated for testing. The meter reading will be the same for all good windings.
If there are shorts between turns in a winding you will get a low reading. A winding shortened to ground will read zero. An open (broken) winding
will read zero.
TO TEST FOR WINDINGS SHORTED TO GROUND:
1.
Place armature in jaws.
2.
Turn power on.
3.
Press one black probe to the shaft of the armature, press the other probe to each segment of the commutator. If the lights comes on, that
indicates there is a short to ground. If the light does not come on, that indicates the insulation is good. If the light is dim or intermittent, it may
mean there is dirt or metal chips bridging between electrical points and ground. Clean armature with stiff bristle brush and repeat tests.
4.
If the light comes on indicating a short to ground, the grounded winding can be located with the meter circuit as follows:
a)
Place the Hi-Lo switch on Hi.
b)
Place one red probe against the shaft and the other against one segment of the commutator. Rotate commutator as shown and repeat test.
Repeat for all segments. When you touch the commutator of the winding that is grounded, there will be a low or no reading. The segments
of the commutator on either side of the grounding winding will show a higher reading.
ASSOCIATED EQUIPMENT CORPORATION
5010 BROWN AVENUE
ST. LOUIS, MISSOURI 63115
(
314) 385-5178
W1570
Rev. 09/97 027-0257
