Which of the following is NOT a permitted method for connecting grounding and bonding equipment?

The method of connecting grounding and bonding equipment that is not permitted is solder-only connections. This is because soldered joints can degrade over time due to thermal cycling, corrosion, or mechanical stress, which may compromise the integrity of the electrical connection. Grounding and bonding connections must provide a reliable and low-resistance path to ground, and methods that offer greater mechanical strength and longevity are required.

In contrast, listed pressure connectors, terminal bars, and the exothermic welding process are all approved methods for making connections in grounding and bonding applications. Listed pressure connectors are specifically designed to create secure electrical connections under mechanical load. Terminal bars provide a solid and stable mounting point for multiple conductors, ensuring effective grounding. The exothermic welding process creates a permanent molecular bond that is highly reliable and offers superior conductivity. These methods help ensure compliance with safety standards and maintain the effectiveness of grounding and bonding systems.