Home » English riddles » Switchgear » Switchgear Riddle No.9 – Medium Voltage Busbar Temperature Rise » Reply To: Switchgear Riddle No.9 – Medium Voltage Busbar Temperature Rise Reply To: Switchgear Riddle No.9 – Medium Voltage Busbar Temperature Rise 2021-08-03 at 11:08 am #1945 Hamid For enclosed switchgear it is seen that the oxidation of aluminium or copper starts at about 85-90