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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
