A surge is an electrical phenomenon in which the system voltage briefly exceeds the normal operating voltage. This condition can cause serious damage to electrical equipment, systems and components, especially if proper protection is lacking.
Types of surges
Temporary Overvoltage (TOV): These surges can last for a longer period of time (seconds or minutes). They can cause:
- Network imbalances.
- Grounding problems.
Transient overvoltage: Short-duration (micro- or millisecond range) but high-amplitude overvoltages. They can cause:
- Lightning strike.
- Electrical connections (operation of switches, circuit breakers).
- Electromagnetic interference (EMI).
Causes of overvoltage
Lightning strike: The voltage transient generated by lightning can cause surges of up to tens of thousands of volts.
Nearby impacts can also have a significant impact on the power grid.
Switching operations: Sudden voltage fluctuations that occur during the switching of electrical switches, circuit breakers, motors and transformers.
Electromagnetic interference (EMI): High-frequency interference, such as that caused by the operation of radio transmitters or high-power industrial machines.
Network problems: Sudden load reduction, such as disconnecting large consumers, which can cause voltage fluctuations.
Effects of surges
Damage to electrical equipment: Surge voltage can burn out circuits and components such as resistors, capacitors, and transistors. Sensitive electronic devices such as computers, routers, and televisions are especially at risk.
Network systems disruption: Surge voltage can cause failures in the electrical network, including damage to transformers and tripping of fuses.
Fire hazard: High voltage can generate heat, which can cause a short circuit and fire.
Surge protection
Surge Protection Device (SPD): These devices are built into the electrical system to absorb surges and protect connected equipment.
- Lightning protection SPD: High performance against surges, such as lightning strikes.
- Transformer SPD: Against transient overvoltages, e.g. during switching operations.
Grounding: A properly constructed grounding system conducts excess energy into the ground, thereby protecting electrical equipment.
Uninterruptible power supplies (UPS): The UPS not only protects against power outages, but also against minor voltage fluctuations, ensuring a continuous power supply.
Cable shielding: Shielding electrical cables reduces the effects of electromagnetic interference, which can cause surges.
Regular maintenance: Regular inspection and maintenance of the electrical network and equipment can prevent voltage fluctuations.
Summary
Surge is one of the most dangerous problems in electrical systems, which can cause serious damage to sensitive equipment. The use of appropriate protection, such as surge arresters, grounding systems and uninterruptible power supplies, is key to avoiding such problems. Preventing surges not only increases the lifespan of equipment, but also results in significant cost savings in the long run.