Although rare, a lightning strike on a home can cause damage to the structure and its contents. This includes electrical short circuits, damage to electronic devices, and even fires. Therefore, every home should ideally have a lightning rod. If you’re planning to install one, it’s essential to first understand how it works, its types, and the installation process.

How Lightning Rods Work

The lightning rods referred to here are more accurately called lightning catchers or conductors, used for residential purposes. Here's how they work, as explained in IPA Fisika SMP dan MTs untuk Kelas IX by Mikrajuddin Abdullah:

When clouds with an electrical charge (e.g., negative) are near the lightning rod, the metal rod will undergo induction and become positively charged. If the cloud produces a lightning strike aimed at the rod, the cloud's negative charges will transfer to the rod. These charges are then conducted through a metal cable into the ground. Simultaneously, the positive charges in the rod will move back toward the cloud.

According to Machmud Effendy, a lecturer at Universitas Muhammadiyah Malang, there is a distinction between a lightning catcher and a lightning rod. A lightning catcher channels lightning into the ground with minimal voltage, while lightning rods, commonly used in factories, use high-voltage electricity to prevent lightning from reaching the building.

Types of Lightning Rods

According to the e-skripsi website of Universitas Semarang (USM), there are three types of lightning rods:

1. Conventional Lightning Rods

   These are basic lightning rods that act as a shield by redirecting lightning to the ground. They are passive and only activate when struck by lightning. They rely on their height relative to surrounding objects and their sharp tips.

2. Electrostatic Lightning Rods

   These are an advanced version of conventional rods. While the principle is similar, electrostatic rods utilize ions generated by two electrodes at the tip of the rod. Under the influence of the electric field between the cloud and the ground, the electrodes generate a potential difference. The voltage between the electrodes can create sparks that ionize surrounding air molecules, forming an upward streamer. This upward streamer forms more quickly and at a higher point than with conventional rods, enhancing protection effectiveness.

3. Dissipation Array System (Lightning Preventor)

   Technically, this is the proper type of lightning rod. It works by reducing the charge buildup on the building it protects. The lower the potential difference between the building and the lightning, the less likely the cloud will discharge its energy.

How to Install a Lightning Rod

As detailed in the Lightning Rod Installation Module by Fajar Danur Isnantyo on the Universitas Sebelas Maret (UNS) Spada site, here are the steps for installing a simple lightning rod:

1. Create Grounding

   Grounding is the final point where electricity is discharged into a neutral medium, typically the ground. Ideal soil has high salt content, moisture, or acidity.

2. Install Lightning Conductors

   Lightning must be conducted from above to the ground via a conductor. Materials like copper, aluminum, or galvanized metal are typically used, with a resistance of no more than 5 ohms. Grounding depth varies by region, but 6 meters is generally effective, with some installations going as deep as 20 meters.

3. Install the Cables

   The length of the conductor affects material resistance—the shorter the span, the lower the resistance. Avoid 90-degree bends in the cable to prevent erratic lightning discharge. Opt for curved or circular bends. The minimum cable thickness is 50 mm, but thicker cables are better. Conductor shapes can vary, such as twisted wires or solid rods.

4. Attach the Finial Tip

   The method of connecting to the finial tip may vary depending on the manufacturer. However, the conductor cable must be securely and electrically connected to the finial tip.