METHOD FOR MODERNIZING TERMINAL BOX WITH LEADING-IN INSULATORS IN ASYNCHRONOUS INDUCTIVE MOTORS OF MEDIUM VOLTAGE AND POWERS OF 7.2 MW

摘要

The invention relates to a device with leading-in insulators which equips a terminal box of a three-phase asynchronous motor with rotor in shortcircuit, of medium voltage and high powers, by means whereof the supply cables are connected. According to the invention, the device consists of a terminal box (), having at the lower side two semi-plates () joined with a rubber seal () through some screws (), and after joining the semi-plates () there result three circular openings () wherein there are mounted some leading-in insulators (); the connection between a bolt () for passing the insulator () and a terminal () of the motor () is carried out by an upper copper flange () insulated with an insulating PVC layer (); at the other end of the bolt () of the insulator () there is fastened a connecting flange () made of copper, for connecting some aluminium supplying cables () which supply the motor (), these cables () are taken out of the terminal box (), at the environment temperature, in an end box () wherein the insulation of the cables () is no longer influenced by the high temperature and the electric field from inside the terminal box (); the terminal box () is provided on the upper side with a switch limiter () for the operative and maintenance personnel safety, and the switch out or the switch in blocking of a main switch () of the motor () are controlled upon opening a cover ().