Understanding Voltage Surge

LighningStorm

What are Electrical Surges

  • Also called Transient, Spike or Impulses
  • It is a random, high‐ energy, short duration electrical disturbance.
  • It has a very fast rise time (1–10 microseconds). Surges, by definition, are subcycle events and should not be confused with longer duration events such as swells or temporary overvoltages.

figure14_electical_surge
voltages

Sources of Electrical Surge

  • There are several causes of electrical surges that can originate outside the home.
  • Approximately 80% of recorded surges are due to internal switching transients caused by turning on/off large electrical loads such as motors , transformers, welding machines or electrical machinery within the plant or at a nearby factories.
Induced Lightning

Externally generated surges due to induced lightning

What Does Electrical Surge Damages?

  • As electronic components become smaller and more powerful, they become more sensitive.
  • Most of the equipment in a manufacturing firms consist of Electronic circuitry made smaller into a chip called Microprocessor.
  • The tremendous rapid increase in the use of sensitive electronic equipment sensitive by virtue of circuit density (microchips having literally thousands of transistors on a single chip)—is now incorporated into almost every new electrical device
  • Distortion on the power or signal lines may disrupt the sensitive signal sequence.
  • Microprocessors can be “upset,” “degraded” or “damaged” by surge events. Depending on the magnitude of the surge.

Results of a major survey conducted by Dranetz on the effects of surges on different microprocessor equipment.

How to deal with this damaging surges?

  • Surge Protection Device SPD is now the standard technology for increasing the reliability and uptime of microchips or microprocessors.
  • The design goal is to divert as much of the transient disturbance away from the load as possible. This is accomplished by shunting the energy to ground through a low- impedance path using SPD’s.

SURGE PROTECTION DEVICE

SURGE PROTECTION DEVICE


SPD Installation

SPD Installation


Two Stage Surge Suppression

Two Stage Surge Suppression


AC Power Waveform Before And After Supression..

AC Power Waveform Before And After Supression..