It is important to ground the lightning arrester separately from the system grounding. This is because the lightning arrester is designed to carry large, transient currents, such as those caused by lightning strikes, whereas the system grounding is designed to carry smaller, steady-state currents. If the lightning arrester and the system grounding were connected, the high currents from the lightning strike could potentially damage the grounding system and compromise its ability to protect the electrical equipment.
Instead, the lightning arrester should be connected to a separate grounding electrode, such as a ground rod or grounding plate, which is specifically designed to handle the high currents from the lightning strike. This ensures that the lightning arrester can effectively divert the lightning current to ground, while protecting the system grounding from damage.
It is also important to ensure that the grounding electrode for the lightning arrester is properly installed and maintained. This includes ensuring that it is properly bonded to the electrical system and that it has a low resistance to ground, so that it can effectively dissipate the high currents from the lightning strike.