7 Devices Sensitive to Overvoltages

Overvoltage and lightning strikes are among the most dangerous phenomena for installations. According to insurance companies, the leading cause of electrical damage is lightning strikes or internal overvoltage. Some devices are more vulnerable to these surges and often fail as a result. Therefore, these devices must be protected preferentially and in a staged manner. Let’s examine these devices:

1-CCTV and Cameras

CCTV and camera systems are among the most frequently damaged devices in the field due to surges. Given their widespread usage, these systems should be protected first. CCTV cameras should be protected by placing B+C class surge protection devices at the main energy panel, followed by D class devices at the last junction box near the cameras. Protection products suitable for CAT or BNC inputs should be selected and connected in series for staged protection.

2-Automation and PLC Systems

Low voltage and current devices are always more sensitive to overvoltage. These systems usually operate between 12-14 V, and the selected protection devices should have the lowest possible Up rating. Weak current SPD (surge protective devices) should be selected based on the system’s continuous voltage. The secondary selection criterion is AC or DC type, as the sinusoidal characteristic of the voltage directly affects the choice of protection device.

3-LED Systems and Drivers

Switching events, harmonics, and lightning strikes in the city grid can damage LED systems. LED drivers are particularly sensitive and must be protected. Watch the video below for an example of LED system protection:

4-Servers

Data centers are also sensitive to overvoltage. They typically operate 24/7, so protection must be applied according to IEC 61643 and IEC 62305 standards. Main and sub-panels should be protected with non-lifespan B+C class SPDs, and UPS systems must also be protected.

5-Telecom Lines

Telecom lines are widespread and exposed to overvoltage. SPD devices should be installed at the facility entry. Yılkomer recommends using D class gas and spark gap SPDs in 10-pair or single Krone types. The grounding line for Krone-type SPDs must be connected and integrated with the equipotential system.

6-Rectifiers

Rectifier cards fail in nanoseconds during overvoltage. Both AC and DC sides must be protected. B+C class SPDs for AC and type 2+3 SPDs for DC should be used for full protection.

7-Inverters

Inverters, key components in solar plants, are exposed to both lightning and internal surges. Only using C class SPDs provides insufficient protection. Both DC and AC SPD protection is mandatory. B+C class (Type 2) SPDs must be used to protect against lightning and grid surges.