Abstrak
Lightning is a natural phenomenon that occurs in the atmosphere. Lightning is a surge of charge in the form of an electrical discharge from a charged cloud. The discharge that occurs can hit an object such as the earth's surface. The existence of tall buildings on the earth's surface is the closest object that can be struck by lightning The effects of lightning strikes are very dangerous for humans and can cause damage to buildings. To prevent the danger of lightning strikes, a lightning rod is installed. Lightning protection consists of two types, namely internal lightning and external lightning protection. The research discussed external lightning protection. External lightning protection consists of Air Termination, Down Conductor and Earth Termination (Grounding). Based on the results of field measurements, the grounding calculation result was 2.112. The analysis using the protection angle method resulted in an angle formed of 45 with a base radius of 38,75 meters. Furthermore, employing the rolling sphere method produced a spherical radius of 60 meters and a lightning current of 234.89 kA.