Mechanical And Electrical Problems - Jet JWBS-15 Operating Instructions And Parts Manual

12.2 Mechanical and electrical problems

Table 5
Symptom
Machine will not
start/restart or
repeatedly trips circuit
breaker or blows
fuses.
Band Saw does not
attain full speed.
* WARNING: Some corrections may require a qualified electrician.
Probable Cause
No incoming power.
Cord damaged.
Band Saw frequently trips.
Building circuit breaker trips or fuse
blows.
Overload automatic reset has not reset.
Switch or motor failure (how to
distinguish).
Motor overheated.
Motor failure.
Miswiring of unit.
Switch failure.
Extension cord too light or too long.
Low current.
Correction *
Verify machine connections.
Replace cord.
One cause of overloading trips which are
not electrical in nature is too heavy a cut.
The solution is to reduce feed pressure
into the blade. If this does not resolve the
issue, check for loose electrical lead.
Verify that band saw is on a circuit of
correct size. If circuit size is correct,
there is probably a loose electrical lead.
Check amp setting on motor starter.
When the 3HP and 5HP Band Saw
overloads on the circuit break built into
the motor starter, it takes time for the
machine to cool down before restart.
Allow machine to adequately cool before
attempting restart. If problem persists,
check amp setting on the motor starter
inside the electrical box.
If you have access to a voltmeter, you
can separate a starter failure from a
motor failure by first, verifying incoming
voltage at 115 +/-10% (or 230+/-10%)
and second, checking the voltage
between starter and motor at 115 +/-10%
(or 230+/-10%). If incoming voltage is
incorrect, you have a power supply
problem. If voltage between starter and
motor is incorrect, you have a starter
problem. If voltage between starter and
motor is correct, you have a motor
problem.
Clean motor of dust or debris to allow
proper air circulation. Allow motor to cool
down before restarting.
If electric motor is suspect, you have two
options: Have a qualified electrician test
the motor for function or remove the
motor and take it to a qualified electric
motor repair shop for testing.
Double check to confirm all electrical
connections are correct. Refer to wiring
diagram to make needed corrections.
If the start/stop switch is suspect, you
have two options: Have a qualified
electrician test the switch for function, or
purchase a new start/stop switch and
establish if that was the problem on
change-out.
Replace with adequate size and length
cord.
Contact a qualified electrician.
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