Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filedfiledCritical
Publication of BE743810ApublicationCriticalpatent/BE743810A/xx
H01H83/00—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current
H01H83/02—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by earth fault currents
H—ELECTRICITY
H01—ELECTRIC ELEMENTS
H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
H01F38/00—Adaptations of transformers or inductances for specific applications or functions
H01F38/20—Instruments transformers
H01F38/38—Instruments transformers for polyphase AC