Which method is an acceptable connection for grounding conductors?

When considering grounding conductors, it is essential to ensure that the connections are reliable and meet safety standards. Both endothermic welding and the use of clamps, when properly listed, are recognized methods for establishing solid electrical connections for grounding conductors.

Endothermic welding is a method that involves a chemical reaction to produce heat, allowing the conductors to fuse together at a molecular level. This welding process creates a bond that has very low resistance, which is critical in grounding applications to ensure efficient fault current paths.

Using clamps for grounding connections can also be acceptable, provided they are listed for that specific purpose. Listed clamps are tested and verified to meet safety and performance standards, ensuring that they will function effectively without introducing significant resistance or mechanical failure.

Therefore, the correct answer identifies both endothermic welds and clamps as acceptable methods of connecting grounding conductors, highlighting the importance of using specified and rigorous methods to ensure system reliability and safety.