One of the core issues affecting the performance and reliability of industrial control systems is electrical noise. It can cause field device misreads; devices to fail, reset, or enter a fault state; equipment damage; or signal retransmission that inflicts communication delays. The topic of mitigating performance issues caused by electrical noise is wide ranging, but we’ll look at three topics here: the types of Electrical Noise, the types of problems caused, and a multilayered approach to EMI noise mitigation.
Types of Electrical Noise
Electrical noise is a very real threat to reliable manufacturing operations. Several types of electrical noise can occur:
- Low-frequency 50 to 60 Hz interference
- High-frequency noise from 100KHz to 30MHz
- Radiated frequency interference (RFI) (100 MHz and higher)
- Electrostatic discharge (ESD)
Types of problems resulting from electrical noise include:
- Erratic operation of sensing systems where measurements might be disrupted or have false variability
- Unstable production measurements, such as miscounts or corruption of output sensors
- Controller lockups or memory corruption, as with programmable controller system lockups
- Component failure over time, such as when input circuits or protective devices are hit too many times with spikes
- Communication failures with transmit and receive causing dropouts, retries and missed packets
A Multilayered Approach to EMI Noise Mitigation
A key factor in mitigating noise is to follow a multilayered electrical noise prevention and mitigation strategy that optimizes control panel space use. These layers should include proper enclosure selection, grounding and bonding, separation, shielding and filtering practices to provide optimal protection.
As a case in point, did you know when space gets tight in a control panel proper shielding can provide the equivalent of 6 inches of air space? The video below demonstrates the effectiveness of shielding in reducing EMI noise.
Demonstrating EMI Noise Reduction
Want to learn more? We invite you to visit Panduit’s solution for noise mitigation. We also invite you to learn more about Control Panel Optimization, a collaborative white paper series from Panduit and Pentair Hoffman, including the third in our series, Noise Mitigation for Control Panels.
To reduce the effects of EMI, it is critical to integrate noise mitigation solutions into your design process. Panduit will work with you to assess your needs and apply design best practices for noise mitigation providing you greater system reliability and enabling you to build a smarter Unified Business Foundation.