TROUBLE-SHOOTING TABLE--MOTOR
The following table lists some of the most common
troubles caused by low voltage, their causes and
suggested remedies:
NOTE: Motors used on wood-working tools
are particularly susceptible to the accumu-
lation of sawdustand woodchips and should
be blown out or "'vacuumed" frequently to
prevent interference with normal motor
ventilation.
TROUBLE
Motor fails to develop
full power. (Power output
of motor decreases rapidly
with decrease in voltage
at motor terminals.) For
example: a reduction of
10% in voltage causesa
reduction of 19% in
maximum power output of
whichthe motor iscapable,
while a reduction of 20%
in voltage causes a
reduction of 36% in maxi-
mum power output.
Motor starts slowly or 1.
fails to come up to full
speed. 2.
Motor overheats. 1.
2.
Starting relay in motor 1.
will not operate.
2.
3.
Motor stalls (resulting in 1.
blown fuses or tripped 2.
circuit breakers).
3.
Frequent opening of 1.
l_u_ or e;reu;t br_ak_r_:. 2.
3.
PROBABLE CAUSE
1. Power line overloaded with
lights, appliances and other
motors.
2. Undersize wires or circuit too
long.
g. General overloading of power
company's facilities. (In many
sections of thecountry, demand
for electrical power exceeds
the capacity of existing
generating and distribution
systems.)
Low Voltage- will not trip
relay.
Starting relay not operating.
Motor overloaded.
Improper cooling. (Air
circulation restricted through
motor clueto sawdust, etc.)
Burned relay contacts (due to
extended hold-ln periods
caused by low line voltage,
etc.).
Open relay coil.
Looseor broken connections
in motor terminal box.
Starting relay not operating.
Voltage too low to permit
motor to reach operating
speed.
Fusesor circuit breakers do
not have sufficient capacity.
Motor overloaded.
Fuses or circuit breakers do
not have sufficient capacity.
Starting relay not operating
(motor does not reach normal
speed).
REMEDY
1. Reduce line load.
2. Increase wire sizes, or reduce length of wiring.
3. Request a voltage check from the power company.
1. Correct low voltage condition.
2. Have relay replaced.
1. Correct overload condition.
2. Clean out sawdust to provide normal air circulation
through motor.
1. Have relay replaced.
2. Have relay replaced.
3. Have wiring checked and repaired.
1. Have relay replaced.
2. Request voltage check from power company.
3. Replace fuses or circuit breakers with proper
capacity units.
1. Reduce motor load.
_.. Replace _uses or circuit breakers.
3. Have relay replaced.
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