Motor Diagnostics (LTS 15 and LTS 17)
313036H
25
Motor Diagnostics (LTS 15 and LTS 17)
If Motor Diagnostics reveal a damaged motor or if motor brushes are shorter than 1/4 in. (6.4 mm) replace the motor
using Motor Kit, page 28.
Setup
1.
Unplug power cord and Relieve Pressure, page 11.
2.
Remove enclosure and disconnect two black motor
leads to control board (see Wiring Diagram, page
49).
3.
Remove motor fan cover by gently prying up on
retention tabs on sides of motor. Motor shaft should
spin easily when turning fan. If motor shaft does not
turn easily, there is a problem with pump, gears, or
motor (see Troubleshooting, page 13).
4.
Inspect motor windings for evidence of overheating.
If windings appear burnt and motor smells, replace
motor.
5.
Use Ohmmeter to measure resistance across two
black motor leads. Resistance of motor should fall
within range of 1.5 to 4.5 ohms. If motor falls outside
resistance range or is open circuit, replace motor.
6.
Use Ohmmeter to measure resistance of motor
leads to motor laminations. If resistance is not open
circuit, replace motor.
7.
Inspect length of both brushes by looking at brush
torsion spring. If spring is not bottomed out in slot for
brush spring, brush length is acceptable. If brushes
are worn out, replace motor.
Motor Diagnostics (ProLTS 17 and ProLTS 19)
Check for electrical continuity in motor armature, windings and brush as follows:
If Motor Diagnostics reveal a damaged motor or if motor brushes are shorter than 1/4 in. (6.4 mm) or if the motor
shaft cannot turn, replace the motor using Motor Kit, page 28.
Setup
1.
Relieve Pressure, page 11.
2.
Unplug electric cord.
3.
Remove enclosure and disconnect motor leads from
control card.
4.
Remove fan brace.
5.
Remove four screws and front cover.
6.
Remove yoke and guide rods.
7.
Remove gear.
Armature Short Circuit Spin Test
Quickly turn motor fan by hand. There should not be
electrical shorts and fan should coast two or three
revolutions before stopping. If fan does not spin freely,
armature is shorted. Replace motor using Motor Kit,
page 28.
Armature, Brushes and Motor Wiring Open Circuit
Test (Continuity)
1.
Connect red and black motor leads together with
test lead.
2.
Turn motor fan by hand, about two revolutions per
second.
3.
If there is an uneven resistance or no resistance,
replace motor using Motor Kit, page 28.
Summary of Contents for 24N808
Page 41: ...Notes 313036H 7 Notes ...
