Which method is valid for connecting grounding electrode conductors?

The method of connecting grounding electrode conductors using listed pressure connectors is valid because these connectors are specifically designed to create a reliable and secure electrical connection. Listed pressure connectors are tested and approved by recognized testing laboratories, ensuring they meet safety standards for electrical installations. They provide consistent performance, maintaining the integrity of the grounding system, which is critically important for safety in electrical systems.

In contrast, plastic connectors do not provide the necessary electrical conductivity required for grounding applications. Loose connections can lead to increased resistance, which can result in unsafe conditions, as grounding systems need to ensure a low-resistance path to prevent electric shock hazards. Lastly, relying solely on manual tying for connections does not provide the durable and secure method needed in grounding systems, potentially compromising the effectiveness of the grounding arrangement over time.