Protection device for thermal overload protection of electrical operating equipment i.e. oil-filled transformer, has adjusting unit, where signal for disconnecting equipment is produced based on load current, period and dual-body pattern

摘要

The device has an adjusting unit for switching thermal overload protection of an electrical equipment. A signal for disconnecting an electrical equipment is produced based on a load current, a time period and a thermal dual-body pattern of the equipment for the thermal overload protection. The dual-body pattern includes thermal capacitors (Cth1, Cth2) and thermal resistors (Rth1, Rth2) forming respective time constants. A graphical display unit displays a destruction characteristic curve of the equipment and a tripping characteristic curve for the overload protection based on the pattern. Independent claims are also included for the following: (1) a method for protecting an electrical operating equipment (2) a method for adjusting a protection device.