Electrical noise is one of the most misdiagnosed and misunderstood electrical system issues. An electronic device or unit owner may often contact call centers or question Google about unexplained noise. This article outlines all there is to know and how best to address the issue.

What is electrical noise?

This generic name can refer to various electrical system issues. In simple terms, electrical noise is any unexpected and random voltage variation. These variations can be potentially disruptive or damaging to the electrical circuits.

All electrical systems have noise as a natural phenomenon. The most crucial aspect of understanding electrical noise is decoding each sound. Recognizing when it’s alarming and reducing it are essential to prevent electrical failures.

Noise coupling mechanisms

There are four essential noise coupling mechanisms:

• Capacitive coupling: A voltage-based effect of electrostatic noise like lightning discharge.

• Inductive coupling: A magnetic-coupled noise that’s current-based.

• Conducted noise: A noise coupled by a galvanic connection like circuits with shared conductors.

• RFI or radio frequency interference: This is where wire lengths act like they transmit and receive antennas.

Noise sensitivity

Noise sensitivity refers to a controller’s ability to differentiate between electrical noise and standard system signals. High-power controllers often have lower noise sensitivity. Controllers using electronic logic, on the other hand, have higher noise sensitivity.

What causes electrical noise?

Different issues can cause electrical noise in a household. Switches, relay contacts, welding machinery, neon lights, semiconductors, and other components can produce electrical noise.

Homeowners usually have a hard time predicting electrical noise issues. Erratic systems can be one of the symptoms. Other symptoms include fluctuating digital indicators, control instability, or blanked digital indicators.

Below is an overview of the most common causes of electrical noise in appliances.

High voltage start-up and switch

When motors, drives, and other high-voltage units operate, some voltage gets discharged to the ground every time they start and stop. Some of that voltage results in noise. In this case, metal oxide varistors can help prevent noise failure.

Temperature

Circuit temperature increase causes free electrons to move rapidly. This action causes voltage variations and occasionally leads to thermal runoffs. Keep the electronics cool to avoid temperature-related issues.

Insulation issues

The insulation barrier of the cable shielding keeps the voltage flowing freely. Voltage variations occur more frequently when the insulation barrier gets broken or damaged. As a result, the system generates more noise.

Wiring

Communication cables are susceptible to electrical noise effects. Power cables can get bundled with signal cables, which can cause noise issues. For this reason, it’s best to run the signal cables away from power cables. If possible, consider fiber optic cables for their lower EMF interference.

Get the electrical noise inspected ASAP

Electrical noise from an application, cable, or other parts of the electrical system can be a sign of concern. Eliminate the risk of significant damage by contacting local electric services for inspection. The sooner the issue is addressed, the less damage there will be to the system.

If you need a highly-reviewed, licensed electrician in the Phoenix Valley area, call Efficient Electric at 623-900-1461. We would love to hear from you!