Juraisin Lightning Protection Systems

For Safety and Peace of Mind

Our system consists of a main copper ground plate, with a minimum of 121 discharge electrodes and attached needles, auxiliary grounding electrodes and ground resistance reducing agent. 

Juraisin Grounding System

The Juraisin Lightning Protection Grounding System consists of a discharge electrode and ground construction system that effectively and instantly discharges the lightning current to the ground. 

 

Standard Construction Methods

 

Presently, in generally operated ground construction in Japan, Lightning Protection Equipment and Electrical Installation are constructed in the same exact manner.  In standard construction methods, a copper plate (900 x 900 x 1,5t) is buried in the ground.  In cases when the desired value of resistance is not obtained, an auxiliary ground rod is installed in the ground to a set point.

 

Drawback of Standard Construction Methods

 

At our company, we believe this construction method is proper in the cases of electric installation, communications related equipment and such.  If an item such as a copper ground plate has a large ground area, it can correspond to electric leakage and the like of 50 and 60 cycles of commercial business electric current, in fixed cycles of small electric currents with small amounts of electric leakage.  However, in reality, it has been shown that this construction method could not correspond to the lightning strike currents in the past.  As a result, a large surge (unusual advance voltage) occurred and presumably caused accidents. 

 

In The Measure and Damage of Lightning by Shinza Uenosono, in the section “Discharge in the Earth of the Grounding System,” Takemitsu Higuchi (Provider of Photo) of Kansai Electric Power Company, describes, “The higher the other object’s insulation resistance, an even higher voltage is created by lightning in order to release a specified electric current.  In such cases, the lightning current becomes stronger.  In order to oppose the strength of lightning, the object needs an insulated strength corresponding to the thundercloud’s electric potential of 100 million volts.  However, that is impossible.  On the other hand, when lightning is absorbed by something that gently grounds it, the voltage that exists there is low and the energy generated small.”

 

Lightning stroke current flows at the speed of microseconds; thus a ground electrode with only four corners such as a copper ground plate type of discharge electrode, cannot instantly discharge the electricity in the ground.  Because of this, an electromagnetic wave and such can occur inside the building.  The current flowing to many equipment, as well as large fire accidents, creates significant damages.

 

Corrosion of Commonly Used Copper-plated Iron Rods

 

The generally used auxiliary ground rod, referred to as a “copper rod,” is not actually copper but an iron rod with copper plating.  Scientific literature describes that when iron is coated with copper plating, corrosion takes place until the iron disappears.  We can also witness this phenomenon in the results of field tests conducted by the Railroad Technical Laboratory.  These tests found that after 15 to 25 years, when copper-plated steel rods were unearthed, the steel had disappeared and was found in the form of a copper pipe with a great deal of pitting corrosion.

 

Economy and Efficiency of the Juraisin Grounding System

 

For our products, in cases of ground electrodes other than copper, we administer melted zinc plating (JIS55).  Operations show these electrodes can function semi permanently.  Our company’s Juraisin Grounding System consists of a ground electrode with a minimum of 121 discharge electrodes and attached needles (in the past, standard ground construction consisted of generally 4 electrodes) with corners and needles.  Our system includes ground resistance reducing agent and regardless of the change in the state of the soil, creates a chemical multiplier effect.  A more stable value of resistance is retained for the long term.

 

Due to this construction method, the number of auxiliary ground bars and such used can be reduced.  Thus, compared with past construction methods, our system is more economical.  Around the area of the Juraisin Grounding System, a wide scope of ground contact area becomes ionized during streamer discharge in the ground thanks to our grounding resistance reducing agent and the chemical multiplier effect.  At the time of lightning strike, the ground contact area is increased and the ground resistance value decreases substantially.  (The Electric Installation Academic Society: Guidebook for Lightning Protection Equipment for Buildings and the Like describes the reduction formula.)

 

The electric charge of the ground that has been inducted by the thundercloud, as well as the discharge of streamers in the ground of the enlarged ground contact area, centers on the Juraisin Lightning Protection System and Grounding System.  As a result, the ability to effectively create a conducting path and receive the electric discharge increases significantly. 

 

Creating Better Grounding Systems Fit for Each Location

 

As described above, our company believes in the importance of ground construction for creating the safest facility possible.  When it comes to lightning protection equipment, we plan, design and operate ground construction suitable for each lightning protection grounding system with our Juraisin Grounding System. 

Contact Us:

Tel:  81 (28) 224-4475

Fax:  81 (28) 222-6902

Email:  info@juraisin.com

Main Copper Ground Plate with Electrodes

Ground Electrodes with Discharging Needles (Type V)

Auxiliary Ground Electrode with Discharging Electrodes

Juraisin Grounding System Construction Example