Troubleshooting Ab-12/14 Abrasive Saws; Machine Fault And Operating Problems - Jet AB-12 Operating Instructions And Parts Manual

11.0 Troubleshooting AB-12/14 Abrasive Saws

11.1 Machine fault and operating problems

Symptom
Motor will not turn
Motor will not start:
fuses or circuit breakers
blow
Motor overheats
Motor stalls, resulting in
blown fuses or tripped
circuit
Machine slows when
operating
Loud, repetitive noise
coming from machine
*Warning: Some corrections may require a qualified electrician.
Possible Cause
Low voltage.
Open circuit in motor or loose
connection.
Emergency Stop engaged
Electrical power supply
Trigger switch not activating
Transformer
Magnetic Contactor
Thermal relay
Motor
Short circuit in line cord or plug.
Short circuit in motor or loose
connections.
Incorrect fuses or circuit breakers
in power line.
Motor overloaded.
Air circulation through motor
restricted.
Motor overloaded.
Short circuit in motor or loose
connections.
Low voltage.
Incorrect fuses or circuit breakers
in power line.
Applying too much pressure.
Belt loose.
Floor uneven.
Pulley setscrews or keys are
missing or loose.
Motor fan is hitting the cover.
V-belt is defective.
Table 3
Correction*
Check power line for proper voltage.
Inspect all lead connections on motor for loose or
open connections.
Rotate Emergency Stop button to disengage.
Check: the phases; the cables; the plug; the socket.
Also check that the motor connections are in place.
Check that socket/plug connection from handle to
motor is inserted correctly; check micro-switch in
trigger.
Check that the voltages are present both on the
input and output. Otherwise replace.
Check that the phases in it are present both on the
input and output, that it is not jammed, that it closes
when powered and that it is not causing short
circuits. Change if any of these problems are found.
Make sure it is closed, i.e. check that the phases
are present in input and output, that it is not causing
short circuits and responds when the reset coil is
closed. If it has tripped to protect the motor, check
the amperage setting, re-set, and check the motor.
Change if necessary.
Check that it has not burned out, that it turns freely
and that there is no moisture in the connection
terminal board box. The winding can be rewound or
replaced by experienced motor repair personnel.
Inspect cord or plug for damaged insulation and
shorted wires.
Inspect all connections on motor for loose or
shorted terminals or worn insulation.
Install correct fuses or circuit breakers.
Reduce load on motor.
Clean motor fan with compressed air to restore
normal air circulation.
Reduce load on motor.
Inspect connections on motor for loose or shorted
terminals or worn insulation.
Correct the low voltage conditions.
Install correct fuses or circuit breakers.
Feed blade into workpiece more slowly.
Tighten belt.
Shim beneath stand to make level.
Inspect keys and setscrews. Replace or tighten if
necessary.
Tighten fan or shim cover.
Replace V-belt.
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