Typically, which type of connectors are used on substation ground grids (below grade)?

The use of exothermic welded (Cadweld) connectors in substation ground grids is paramount due to their ability to create a permanent, low-resistance bond between conductors and grounding systems. These connectors utilize a chemical reaction that produces extreme heat, allowing metals to fuse together, thereby ensuring an electrically efficient connection that can withstand the harsh environmental conditions often found in substations. This type of connection is highly reliable and resistant to corrosion, which is essential when dealing with ground grids that are typically buried and can be subject to moisture and other deteriorating factors over time.

In contrast, while the other types of connectors might have applications in various electrical systems, they do not offer the same level of durability and performance in grounding applications. All-purpose aluminum connectors, for instance, may not provide the necessary longevity or reliability for substation grounding. Split-bolt and two-bolt bronze connectors, while useful in some installations, do not create the same permanent bond that exothermic welding provides. Therefore, exothermic welded connectors are the preferred choice for ensuring long-term safety and effectiveness in substation ground grids.