Chapter 6: Troubleshooting 27 of 37
Chapter 6: Troubleshooting
6-1 Introduction
The utmost in safety precautions should be observed at all times when working on or around
the machine and the electrical components. All normal trouble-shooting must be
accomplished with the power off, line fuses removed, and with the machine tagged as out of
service.
The use of good quality test equipment cannot be over-emphasized when troubleshooting is
indicated. Use a good ammeter that can measure at least twice the AC and DC current that
can be encountered for the machine. Be sure that the voltmeter has at least minimum
impedance of 5,000 OHMS-per-volt on AC and 20,000 OHMS-per-volt on DC scales.
Popular combination meters, VOM and VTVM can be selected to provide the necessary
functions.
Before making haphazard substitutions and repairs when defective electrical components are
malfunctioning, we recommend that you check the associated circuitry and assemblies for
other defective devices. It is common to replace the obviously damaged component without
actually locating the real cause of the trouble. Such hasty substitutions will only destroy the
new component. Refer to wiring diagrams and schematics.
Locating mechanical problems, should they occur, is relatively straightforward. When
necessary, refer to the parts catalog section.
6-2 Electrical Faults
Starter overloads or cuts out
Check motor requirements and
adjust accordingly
Safety switches inoperative
Check and adjust as needed
Motor starts but will not take
load
Check belt tension and adjust as
necessary
Incorrectly connected motor
Check terminal connection with
manufacturer’s connection
diagram and adjust as necessary
Defective starter winding
Check current in each phase
with ammeter, if there is a
marked difference in current in
one phase, contact motor
manufacturer
disconnected from load but not
when connected
Check and replace if necessary
according to manufacturer’s
literature
