Thiele 00900383, Manual

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78
R
eliant
3700 M
anual
c. Check integrity of both ends of drive wiring harness between the CPU board
connector J8 and the 13-terminal connector to the drive board.
d. Using a digital multimeter or an oscilloscope, measure the amplitude of the
pulse train and verify that it is at least 2.3VDC.
e. If pulse test results are good, replace the stepper motor drive board. If the
pulse tests results are negative, the pulse output on connector J8 of the CPU
board is bad, and the control assembly must be replaced.
1. Slow Blink: (about once per second) indicates a SHORT in motor, motor cable, or
drive power component.
a. Check integrity of motor wires and/or cable. None of the wires should be ex-
posed, and should have their full insulation so they may not short to each other
or any other part of the machine.
b. If wires look OK, go to section titled “Testing stepper motor drive board output
pins.”
c. If stepper motor drive board test results are positive, replace the motor. For
further information, see the section titled “Testing motors.”
2. Fast Blink: (multiple times per second) indicates an OPEN in motor, motor cable, or
drive component.
a. Check integrity of motor wires and/or cable. None of the wires should measure
open, or be disconnected or loose from their terminals.
b. If wires check OK, go to section titled “Testing stepper motor drive board output
pins”.
c. If stepper motor drive board test results are positive, replace the motor. For
further information, see the section titled “Testing motors.”
3. On Steady: indicates a ground fault (wire shorted to zero volts).
a. Remove ground fault.
1. Remove 13-terminal plug-in motor wire coupler from the drive board.
2. Test motor phase pins.
a. Set the multimeter to Diode Test.
b. Place the RED meter lead on one of the leads between the large black sense
resistors located at the center of the drive board located above jumper JP2.
c. Touch the BLACK meter lead to each phase terminal (pins 1, 2, 12, and 13).
This should give readings between 0.450V and 0.550V. If any readings are sig-
nificantly greater than or less than 0.450V to 0.55V, then the unit is faulty and
must be replaced.
3. Test motor common pins:
a. Touch the BLACK meter lead to the positive lead of the large blue capacitor on
the left side of the board, which is located below the red fault indicator LED.
b. Touch the RED meter lead to pins 3 and 11. These pins should give readings
between 0.450V and 0.550V. If any readings are significantly greater than or
less than 0.450V to 0.55V, then the unit is faulty and must be replaced.
Problem Solution
Motor does not run, is noisy,
makes a “growling” sound,
or runs in reverse (contin-
ued)
Drive board red LED illumi-
nated
The stepper motor drive board
has been designed to pro-
tect itself if motor problems
occur. If a problem with the
motor wires or motor is found
and corrected, the board will
still drive a good motor after
correction is made. However,
the board cannot protect itself
from transient voltage spikes
and/or power sags or brown-
outs. It is highly recommended
that in plants where power
problems are evident or in
question, a high quality surge
suppressor or line conditioner
should be employed for added
protection.
Testing stepper motor drive
board output pins
A digital multimeter is required
for these tests.
Measuring zero volts drop
across one of these pins may
be evidenced by blowing fuses
on power-up. See section
titled “Fuses blow on power
up.”