The term ‘dirty electricity’ generally refers to the electrical pollution that is picked up on the mains power supply. This pollution is the result of all the power devices, appliances, instruments and electrical equipment feeding off the same power grid and sharing many of the same electrical pathways. This pollution can originate from an appliance being used in the next room or the power equipment down the road. If you are connected to the grid, then your power supply is probably contaminated or affected in some way. Essentially, any EMF frequency can contribute to dirty electricity but it is usually reserved for the lower frequency power appliances, switching power supplies, pulsing equipment etc. (That is, mainly in the region from say anything above 50/60 Hz up to a few hundred kHz).
The mains power supply coming into your house is an alternating source, one that reverses its polarity 50 times a second (60 times in the US/Canada). If one were to look at this signal on an oscilloscope it would appear as a sine wave, an undulating curve going up and down 50 times a second. It should be a smooth curve with no bumps or anomalies which would otherwise translate as a sudden rate of change of energy delivery. Anything that deviates from this smooth sine wave alternating power source is considered a form of contamination or electrical pollution. In reality, the ‘purity’ of the mains power of the average household is less than ideal due to a combination of factors; primarily the type of equipment being powered, proximity of appliances and wiring, and the fact that return and ground lines, while, in general, are more than adequate, are less than ideal for practical reasons such as cost and size.
The purpose of a ground and a return conduit is to ensure the free flow of electrons through a circuit to ground. However, if, for example, an electrical appliance uses energy in a pulsed/intermittent manner (e.g., switching power supplies, refrigerators, fluorescent lighting etc.), there will be a repeated surge and relaxation in the flow of electrons to meet energy demands. Given that electrical wiring has a certain finite resistance (due to limited conductive properties and size dimensions), there is limit to the amount of electrons that can be sunk per unit time. This can result in a delay in the discharge of energy into the earth, in the case of grounding, with the result that the ground line voltage level will be shifted temporarily from true ground. (Ideally, electrical wiring used for grounding should have zero resistance so there is no opposition to the flow of electrons and hence no fluctuation in the ground voltage level).
Dirty electricity can also occur through inductive pickup. If we have a nearby oscillating current, one that is the product of pulsing technology or from the sharp transient spikes of an electric motor, or diesel generator, for example, an oscillating magnetic field is created which in turn can induce electrical currents within its range. This is another way in which certain electrical equipment and appliances can contaminate the power supply – through their mutual proximity and field induction of nearby cabling – cabling which can act as a receiving and transmitting antenna. The many different appliances feeding off the regional power grid will have their own unique set of frequencies, harmonics and power cycles whose residual signals pool together as ‘dirty electricity’ in the local electrical power supply.
There are different ways to tackle the problem of ‘dirty electricity’ and this can depend on the particular situation at hand. Sometimes it can require the removal or replacement of a defective or worn out appliance that is contributing more than its fair share of ‘noise’. More popular ways to stem the problem of ‘dirty electricity’ is to use special filters that plug into the mains socket. These filters screen out frequencies higher than the mains frequency of 50 or 60 Hz. Another method employs a ‘demand switch’ that senses when no more electricity is being used in the home and then physically disconnects the house from the power grid. (It is a relay switch can be installed in the electrical breaker box). This can ensure there is no electrical pollution during certain times of the day, or really at nighttime. Alternatively it should be possible to shut off, say, most of the house or selected sections such as the sleeping quarters if it is desirable to have power on 24/7 to supply appliances such refrigerators or necessary medical equipment etc.
Ideally a mains power filter should remove any frequencies higher than 50 Hz (or 60 Hz) and extend upwards to cover the very high frequency RF range of the electromagnetic spectrum. Commercially available filters such as the Graham-Stetzer (GS) Filter cover the 4kHz – 100 kHz range and the Alpha Filter 3B from Bajog Electronics ranges from about 10 kHz out to 30 Mhz. (These are plug-in filters that don’t require an electrician to install).
Energy is related to frequency and the higher the frequency the higher the energy. Fifty kHz (50,000 Hz) has 1000 times more energy than at 50 Hz. Frequencies above about 1.7 kHz begin to penetrate the body more easily too. So there are reasons why it is considered a validate trade-off in filter design to concentrate on frequencies not just say from 100 Hz and up, but rather starting from around 4 kHz.
Dirty electricity can damage electrical equipment and prevent sensitive instruments from working properly as well as cause biological effects.
Since most electronic equipment is located at a low voltage level of its associated power distribution system, it is frequently exposed to the effects of voltage notching. Voltage notching frequently introduces frequencies, both harmonic and non-harmonic, that are much higher than normally exhibited in 5kV and higher voltage systems. These frequencies can be in the radio frequency (RF) range, and as such, can introduce harmful effects associated with spurious RF. – IEEE 519-1992 pg. 39.
The development of spurious RF spikes in the power transmission lines is a serious problem even without having to include the environmental and health costs. Dirty electricity costs billions of dollars in damage to equipment every year just in the US alone.