Fluke Resource Center

Why use a CAT III rated meter in solar PV installations?

Globally, solar installations (also known as photovoltaic or PV installations) are continuing to multiply rapidly, driven by compelling economics for utility-scale solar generation and efforts to decarbonize the grid. As solar distribution systems and loads become larger and more complex, the possibilities of transient overvoltages increase — and the implications for safety become more important than ever.

When you’re taking measurements on solar installations, these transients are invisible and largely unavoidable hazards, which means that your protection depends on the safety margins already built into your tools. That’s where the Measurement Category Rating comes in: it’s designed to tell the user which types of electrical installations the measurement device may safely make measurements in.

A voltage rating alone, however, won’t tell you how well a handheld tool was designed to survive high transient impulses — its category rating also needs to fit the environment you’re working on.