Which two factors are important to know when hanging grounds?

• A. Conductor color and insulation type
• B. Weather conditions during installation
• C. Fault current, clearing time
• D. Voltage level and frequency

Answer: (C)

When hanging grounds, you’re sizing the grounding path to carry the fault current for the duration it takes the protection system to clear the fault. The two key factors are the maximum fault current that could flow and the clearing time of the protective device. The higher the fault current, the larger the grounding conductor and hardware must be to avoid overheating. The longer the fault lasts (slower clearing time), the more energy is let through the ground, which also drives the required ampacity and ratings of the grounding components. These two factors together determine whether the grounding path will remain safe and functional under fault conditions. Other considerations like weather during installation or conductor color don’t define the essential capability for hanging grounds.