ON-LOAD TAP CHANGER ATTACHED STATIONARY INDUCTION APPARATUS

ON-LOAD TAP CHANGER ATTACKED STATIONARY INDUCTION APPARATUS An on-load tap changer attached stationary induction apparatus, including a tank, an electromagnetic induction device which is put, together with a liquid insulating material having a flash point higher than 250oC, in the tank, and an on-load tap changer for adjusting the voltage of the electromagnetic induction device, wherein the on-load tap changer has a changeover switch section and a tap selector section, and the following medium is filled as an insulating medium at least for the tap selector section: a silicone liquid to which one or more polyol esters having a flash point higher than 250oC and represented by the following formulae (1), (2), (3) and/or (4) are added: (R1-CH2)2C(CH2-O(CO)-R2)2 (1) R1-CH2-C(CH2-O(CO)-R2)3 (2) C(CH2-O(CO)-R2)4 (3) (R2-(CO)O-CH2)3C-CH2-O-CH2-C(CH2-O(CO)-R2)3 (4) wherein R1 represents hydrogen or an alkyl group having 1 to 3 carbon atoms, and R2 represents one or more alkyl groups having 5 to 12 carbon atoms. (Fig. 1)