NABCEP PV Associate (PVA) Practice Exam 2025 - Free PV Associate Exam Practice Questions and Study Guide

The primary distinction of a non-isolated inverter is its characteristic of not featuring electrical isolation from the mains power. This means that there is no current-carrying conductor that operates at the same voltage as ground. In contrast, isolated inverters utilize a transformer to provide voltage separation between the output and the input side, which enhances safety and reduces the risk of electric shock or damage from ground faults.

Non-isolated inverters generally connect directly to the input and output without isolation, making them simpler and often more compact. This direct connection allows for a more straightforward design and can contribute to overall system efficiency, although it may introduce risks associated with grounding and leakage currents.

The other options do not accurately define the key feature of a non-isolated inverter. For instance, non-isolated inverters can indeed be efficient and, while they can convert DC to AC, it is not true that this is their sole capability. Additionally, the reliance on transformers is typical of isolated inverters, not non-isolated ones, which underscore the critical safety feature associated with electrical isolation.