Special Drive Situations; Special Motor Considerations; Analog Signal Wires - Baldor ID15J1F50-ER Installation And Operating Manual

Special Drive Situations

For severe noise situations, it may be necessary to reduce transient voltages
in the wires to the motor by adding load reactors. Load reactors are installed
between the control and motor.
Reactors are typically 1% to 3% impedance and are designed for the
frequencies encountered in PWM drives. For maximum benefit, the reactors
should be mounted in the drive enclosure with short leads between the control
and the reactors.

Special Motor Considerations

Motor frames must also be grounded. As with control enclosures, motors
should be grounded directly to plant ground with as short a ground wire as
possible. Capacitive coupling within the motor windings produces transient
voltages between the motor frame and ground. The severity of these voltages
increases with the length of the ground wire. Installations with the motor and
control mounted on a common frame, and with heavy ground wires less than
10 ft. long, rarely have a problem caused by these motor-generated transient
voltages.

Analog Signal Wires

Analog signals generally originate from speed and torque controls, plus DC
tachometers and process controllers. Reliability is often improved by the
following noise reduction techniques:
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•
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5-10 Troubleshooting
Use twisted-pair shielded wires with the shield grounded at the drive end
only.
Route analog signal wires away from power or control wires (all other
wiring types).
Cross power and control wires at right angles (90°) to minimize inductive
noise coupling.
MN715J