What should be done to all external ground rods or earth connections?
Waterproof them with silicone caulk or electrical tape
Keep them as far apart as possible
Bond them together with heavy wire or conductive strap✓Bonne réponse
Tune them for resonance on the lowest frequency of operation
Explication
Separate ground rods that are not bonded together can sit at very different potentials during a lightning surge or a fault, and the difference will find a path through equipment or a person. Bonding them with heavy wire or strap keeps the whole grounding system at one potential.