Protection of power distribution transformers - has transformer hot spot temp sensor controlling circuit breaker

摘要

The circuit breaker and control system is for the protection of low and medium level voltage power distribution transformers and is normally installed on the distribution line posts or at ground level. The design is intended to provide protection against overloading levels below those due to short circuit overload conditions. Initial overload sensing is by environmental temperature compensated heat detectors situated close to expected hot spots in the transformer unit, these operating a pilot relay prior to switching out of the main contact breaker. Load levels exceeding three times the expected load to a complete short circuit load will operate the breaker circuit.