Current flows in every current path to earth in direct proportion to the resistance of each current path. (Ohms Law).  In the sketch above, there are three parallel current paths to earth whose total resistance to earth is calculated as follows:

  1             1         1            1                                                       1          = 9.902 Ohms

R tot =    20 + 1020 +   20     = 0.05 + 0.00098 + 0.05 = 0.10098

A source creating a voltage of as little 1000 Volts on the Network above, could produce a current flow to earth as follows:      I = V/R = 1000v/9.902 Ohms = 100.98 Amps.                                                                                                   

Possible current flow in tower A and tower C                          I = V/R =   1000/20 = 50 Amp                                     Possible current flow through workers on Tower B               I = V/R =1000/1020 = 0.98Amps


Current flow in the human body of 0.98Amps for 30millisecs is life threatening.            Current flow in the human body of 0.98Amps for 1 second is fatal.

 (Dalziel C F, PD IEC TR 60479-2011, IEEE Spectrum STD. 80)


This safety procedure which we currently use in Ireland on a daily basis, cannot protect the workers on tower B, from death and injury.

  Anybody who can scientifically prove that dangerous current cannot flow through the workers on tower B, earn themselves or their or their nominated charity €10,000.

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