| 摘要 |
PURPOSE:To check up a fault on the winding side rapidly and without fail by providing a transformer for an auxiliary meter on the third winding of a transformer for meters, by obtaining thereby a three-phase star voltage having the same phase with the three-phase star voltage of a secondary winding, and by conducting the comparison of voltages by means of a balance relay. CONSTITUTION:When the voltage of a three-phase main circuit falls due to a fault, etc., voltages on the secondary winding W2 side of a transformer GPT for meters and on the third winding W3 side thereof fall together, and therefore, a balance relay BRy does not operate. When any disconnction or short-circuiting occurs in a fuse F on the winding W2 side of the transformer GPT or on the winding W3 side thereof, a contact of the relay BRy corresponding to the side whereon such a fault occurs operates. Accordingly, the contact action of the relay BRy performs locking operations of protection relays Ry1 and Ry2, switching operations of AVR for a generator from automatic operation to manual, and an alarming operation for informing the abnormality in the circuit of the transformer GPT. |
