FEATURES

■ Easy diagnosis by simply clamping to a ground wire.
■ Supports measurement of Total leakage current, Resistive component from leakage current, and third harmonics.
■ Compact, lightweight design with built-in battery. (3kg)
■ Portable design ideal for on-site testing.
■ Safe diagnosis without getting close to high-voltage sections.
■ Quick and efficient operation.

Generally, surge arresters (also known as lightning arresters) are installed as protection devices in a power transmission and distribution facility. The Zinc Oxide elements embedded in gapless arresters have the capability to instantly direct surge currents caused by lightning strikes to the ground. Therse surge currents can reach several kA, and the heat generated by them is immense. As the internal elements deteriorate due to this heat, the arrester may no longer perform its protective function properly, increasing the risk of electrical facility failure or accidents. By regularly inspecting the arresters and detecting degradation early, the appropriate timing for maintenance or replacement can be determined, helping to protect electrical facility.

Surge arresters contain elements through which a small leakage current constantly flows. This leakage current consists of a resistive current in phase with the charging voltage, and a capacitive current that is 90° out of phase with the charging current. As the insulation resistance of the surge arrester decreases due to heat generated by surge currents from lightning strikes, the resistive current (IR) in the leakage current increases. DAC-LAS-3A can measure the total leakage current and resistive current (IR) of the arrester by simply clamping the arrester’s grounding line with a CT. Typically, measuring resistive current requires measuring the system voltage, which involves approaching high-voltage areas and presents safety risks. DAC-LAS-3A does not need to approach high-voltage areas, enabling safe diagnostics.
Furthermore, by switching modes, DAC-LAS-3A can also evaluate the third harmonic current (I3), providing a comprehensive assessment of the surge arrester’s condition.

• DAC-LAS-3A（PDF : 901KB）