Lightning Current Distribution

According to the standards IEC 61024 and 61312, during a lightning strike in a building having an external lightning protection, the lightning current reaches the earth termination. A part of lightning current goes to earth and remaining part gets coupled into the building through conductive media like Steel reinforcement in Concrete, Earth Conductor Metal Parts connected to earth etc.
The 100% of lightning energy breaks down as follows according to IEC 61312.
50% of the lightning current will flow through the ground.
50% of the lightning current will flow over the connected metal parts of the building. (gets coupled into the building.)

Lightning Current Distribution

According to the standards IEC 61024 and 61312, during a lightning strike in a building having an external lightning protection, the lightning current reaches the earth termination. A part of lightning current goes to earth and remaining part gets coupled into the building through conductive media like Steel reinforcement in Concrete, Earth Conductor Metal Parts connected to earth etc.
The 100% of lightning energy breaks down as follows according to IEC 61312.
50% of the lightning current will flow through the ground.
50% of the lightning current will flow over the connected metal parts of the building. (gets coupled into the building.)