What Problems Does TVSS Correct?
Lightning can generate extremely large surge currents and surge voltage. At the point of discharge of a lightning stroke, 600 million volts and 300-500 thousand amps can be generated. A direct lightning stroke is not necessary to cause severe damage. Through magnetic induction a lightning discharge two miles from exposed overhead electrical lines can produce a 20 kV surge.
The Utility Distribution System interconnects many different types of loads. Many of these loads are very difficult for the utility to control. Feeder and capacitor switching combined with momentary short circuits and contact reclosures have become a nuisance for sensitive electronics.
A frequent power disturbance seen in many building wiring systems today is the transient voltage associated with inductive loads. These disturbances are a result of turning heavy electrical equipment on and off in the vicinity of a sensitive device. Such heavy electrical loads could be in the same facility as the affected device or in another facility close by. The transient voltages generated by these switching operations, from the utility to a customer, depends on the current supply and current draw of the load. Example: a vacuum cleaner generates a surge voltage as it changes state. So does a 200 hp motor; however, the motor generates greater transient voltage due to greater available source current and load current demand.
Electrical Line Noise:
Electrical Line Noise (ELN) generally implies any voltage of less than two times the nominal peak voltage of the system. ELN is defined as any form of electromagnetic energy present in a circuit, other than the desired signal and it's harmonic components.