Home » English riddles » Substation » Substation Riddle No.5 – Earth mat design » Reply To: Substation Riddle No.5 – Earth mat design Reply To: Substation Riddle No.5 – Earth mat design 2021-08-03 at 11:08 am #3179 Hamid You must know the following information and refer to IEEE 80 or their familiar softwares.