Posted on
Your servo suffers from intermittent failure, feedback loss, runs choppy, or trips out on some sort of encoder error. Could electrical noise be the culprit?
Servo Electrical Noise Reduction
Cable Selection
- Use cable with correct number of wires.
- Use twisted pairs for each circuit.
- Use shielded cabling.
Cable Installation
- Keep cables short. Remove excess.
- Ground cable to motor or drive.
- Do not ground cable to both motor and drive.
- Separate high voltage and comm cables.
Effects of Servo Noise
- Noise disrupts feedback signals.
- High noise creates motor malfunction.
- Reducing noise saves on repairs.
Reducing Electrical Noise in Your Servo Motor:
Electrical noise is present in every electrical system. It can disrupt the feedback signals (especially with resolvers) on the motor and cause the drive to misread information and not perform as instructed. Noise is a little thought, high impact problem that is relatively easy to minimize.
Cable Selection Is Crucial
Try to buy cable with the correct number of wires. Use twisted pairs for the send and return of each circuit if possible. Keep your cables as short as possible, and do not just coil up the extra cable and leave it in a cabinet.
Always Use Shielded Cabling
Just having a shield inside the cable is not enough; it needs to be properly grounded at either the motor or the drive but not both. Shielded cabling can actually make your problem worse if you do not have a solid ground.
Keep Feedback Cables from Looping around or Running Closely Parallel to High Voltage Cables
Maximizing distance between communication and high voltage cabling will minimize the impact of noise on your system.
In Summary
Servo motors, drives and encoders are often misdiagnosed as bad when they are really just being affected by noise. Minimizing noise will save you downtime and unnecessary repair costs.
