Jännitehyppäyksiä

Jännitehyppäyksiä, known in English as voltage transients or voltage surges, are short-duration, high-amplitude voltage fluctuations that occur in electrical systems. These events can be significantly higher than the normal operating voltage and can last from microseconds to milliseconds. They are a common phenomenon and can originate from both internal and external sources.

Internal sources of jännitehyppäyksiä include the switching of heavy inductive loads, such as motors or transformers, within the same electrical network. The sudden interruption of current flow in these inductive components can induce a voltage spike. Other internal causes can be the operation of power electronic devices like variable frequency drives.

External sources are primarily lightning strikes, which can induce massive voltage surges in power lines. The electromagnetic field generated by a lightning strike can couple onto nearby conductors, causing a significant voltage increase. Other external causes include faults on the power grid and switching operations by the utility provider.

The impact of jännitehyppäyksiä on electrical and electronic equipment can be severe. They can degrade insulation, damage sensitive components, and lead to equipment failure. This can result in costly downtime and repairs. Protective measures, such as surge protective devices (SPDs), are commonly employed to mitigate the effects of jännitehyppäyksiä by diverting the excess voltage safely to ground. Understanding the causes and effects of these transient events is crucial for maintaining the reliability and longevity of electrical systems.