What must happen to grounding electrodes that differ in type at a building?

Grounding electrodes of different types at a building must be bonded together to ensure a continuous and effective grounding system. This requirement is based on the need for safety and functionality in electrical systems. When grounding electrodes, such as a ground rod, a concrete-encased electrode, or a metal water pipe, are connected, it allows for a low-resistance path to ground that can help safeguard the electrical system and any connected equipment.

Bonding these electrodes ensures that they are at the same electrical potential, which is crucial for preventing shock hazards and ensuring that electrical faults can be effectively cleared by protective devices. If the grounding electrodes remain separate or are not properly bonded, it can lead to differences in voltage, potentially creating hazardous conditions during electrical faults or lightning strikes. This adherence to bonding requirements helps maintain system integrity and safety.