AC Electric And Magnetic Fields

AC Electric Fields

AC Electric Fields (E-Fields) are created by the presence and movement of alternating current (AC) electricity. These fields are invisible forces that surround electrical systems and are primarily influenced by voltage levels — meaning, the greater the voltage, the more intense the electric field becomes. AC Electric Fields are commonly produced by energized electrical wiring, whether in residential, commercial, or industrial environments. These fields typically extend about 6 to 8 feet outward from their source, though in certain situations, they may travel even farther depending on environmental factors and electrical infrastructure.

Importantly, an electric field can still exist around a powered device or circuit even when the device is turned off, as long as it remains plugged in and connected to a live voltage source. This is because the field is generated by voltage, not current, so it doesn't require active electricity flow (current) to be present. As a result, these fields can create continuous, low-level emissions that persist as long as the circuit remains energized.

AC Electric Fields are naturally attracted to conductive materials such as the ground, as well as the human body, which can act as a conductor due to its water and mineral content. These fields fall into the category of low-frequency electromagnetic radiation, generally spanning a frequency range from 5 Hz up to 400,000 Hz (400 kHz). To detect and measure the strength of these fields, specialized instruments known as AC Electric Field metersare used, and their readings are typically expressed in volts per meter (V/m).

Examples Of AC Electric Field Sources:

AC Magnetic Fields

Modern living spaces are filled with numerous electronic devices and electrical appliances, ranging from everyday household items like refrigerators and televisions to computers, lamps, and kitchen equipment. When any of this equipment is turned on or actively operating, it initiates the flow of electrical current through the internal circuitry and connected wiring systems. This movement of electrical current is what gives rise to AC Magnetic Fields, also referred to as B-Fields.

The strength or intensity of an AC Magnetic Field is directly correlated with the amount of current being consumed by the device. In other words, the more electricity a device uses, the stronger the magnetic field it generates. For instance, a high-powered appliance like an electric stove or air conditioning unit will typically produce a much more intense magnetic field than a low-consumption device such as a phone charger.

These magnetic fields usually remain localized, often extending only about 2 to 3 feet from the source. However, under certain circumstances—particularly when dealing with large-scale electrical systems such as high voltage power lines—the reach of these fields can extend significantly farther, even spreading out over several hundred feet depending on the infrastructure and environmental conditions.

AC Magnetic Fields are categorized as a type of low-frequency electromagnetic radiation, operating within a frequency range of approximately 5 Hz to 400,000 Hz (400 kHz). They can be accurately detected and measured using specialized instruments such as a tesla meter, which records in nanoTesla (nT), or a gauss meter, which typically measures in milliGauss (mG).

It’s important to note that while many people refer to EMF (Electromagnetic Fields) in a general sense, they are often specifically describing AC Magnetic Fields when expressing concerns about exposure. However, this usage can be misleading, as EMF is a broader term that encompasses both electric and magnetic fields, as well as a wide range of frequencies. Therefore, referring to only magnetic fields as "EMF" is technically inaccurate.

Examples Of AC Magnetic Field Sources:

Electrical Panels
Overhead Power Lines
Appliances (typically the motor)
Wiring errors in wall wiring
Power transformers