GINRI Voltage Monitoring Relay DC Over/Under Voltage Relay DVRD

External overvoltage is also called lightning overvoltage and atmospheric overvoltage. Caused by the discharge of thunderclouds in the atmosphere to the ground. It is divided into two types: lightning overvoltage and inductive lightning overvoltage. The lightning overvoltage has a duration of about tens of microseconds and has a pulse characteristic, so it is often called a lightning shock wave. The direct lightning overvoltage is the overvoltage that occurs when lightning flashes directly hit the conductive part of the electrical equipment. A lightning strike hits a live conductor, such as an overhead transmission line conductor, called a direct lightning strike. A lightning strike in a conductor that is normally grounded, such as a transmission line tower, causes its potential to rise and then discharges the live conductor. Direct lightning strike voltage amplitude can reach millions of volts, which will damage the insulation of electrical installations and cause short-circuit ground faults. Inductive lightning overvoltage is the overvoltage induced on the electrical equipment (including secondary equipment, communication equipment) that is not directly struck by lightning due to the sharp change of the space electromagnetic field during the lightning strike. Therefore, overhead transmission lines need to be equipped with lightning protection lines and grounding devices for protection. The lightning protection capability of the transmission line is usually indicated by the line lightning resistance level and the lightning strike rate.

Features:

• Compact modular size
• DC circuit monitoring of over-and undervoltage
• Adjustable over-and undervoltage threshold
• Adjustable trip delay time
• Powered by the measuring circuit
• 2C/O contacts
• 2 LEDs for status indication

Protective Functions

• DC overvoltage
• DC undervoltage

Applications

• DC cabinet
• Battery
• Electric control system